Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: red_noir on January 27, 2010, 03:46:18 pm
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Well I finally took some pics ! its a brand new maccsteam 3.5 inch horizontal boiler with 2 inch gas tank. I also got the steam dome adapter.
I'm waiting on my Gram TVR1A to arrive as well as some other bits and pieces !! I'm really exited about this project being my first real attempt at steam ! I'll continue to give updates as parts make there way to me !
Red
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Gratulation with your new boiler and hobby,,looks great...,,,,,,,i know you will get real many good hours with it...thats fore sure...and not easy to get out of your mind again,,,,,,,,,,
Regards Bernhard
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Nice- I have owned some Maccsteam boilers in the past--they are great!! We look forward to your projects updates :-))
It looks as if brass pipe was the way to go..nice bending job!!- I just ordered some handle benders also -I only bought the 1/8 so far - after Derek's input I may need to get the 3/32 also
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dubro makes 1/8 and 5/32 benders ! Brass bends much better than copper at 90 degrees. plus its a stronger material.
Thanks for the comments :}, I'm waiting on a gas regulator some steam pipe flanges a lubricator and some other little things as well as a tvr1a. I'll continue to update my progress here.
I'm really liking the plain brass and copper look so far I'm thinking I'm gonna keep it this way !
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I have that same boiler in my steam launch powering a Graham TVR1A, . Question, did you get the turret from Maccsteam?
andy
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yep got it from maccsteam ! Mike Abbott is a great guy to deal with ! I went to check the mail a few min ago and notice I received my Gram Tvr1a !! :-))
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Ok took a break from my other work for two hours and started on the TVR1A, I'm really impressed with this engine so far ! all the pieces fit together really well !
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Red....great looking & great quality components with the Macsteam setup........... O0 ....as you read more into the subject you will find that it is imperative for you to remove the gas tank from the hull prior to refilling .......
The next part following on from this is you must consider the gas tube run from the tank to the boiler burner must be of sufficient long throw sets/spacing to physically remove the gas tank without stressing the gas tube bends ......the real point for me is that I remove the gas tank from the fixed tube work
Having fallen into this [unknown to me] trap >>:-( ....... I had a number of knurled "thumb & forefinger" nuts manufactured to allow the quick disconnection of the gas tank from the boiler burner line ...the special fitting cones also included nitrile soft sealing o-rings as opposed to the angular brass faced steam sealing sealing cones
You have mentioned that a gas regulator on order.......irrespective of the nationality of origin.........have a look at the data sheet & I am sure it will depict the same soft sealing....which is I suspect is a part of the EU gas regulations for LP applications......PER./ZXJX something ....keep us posted .......Derek
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hi.........Did you get the Hex bolt to it...??.....look a lot better than normal screws
Regards Bernhard
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Nice to see another one built. How's the performance of the Maccsteam boiler? I've never seen one for real.
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....as you read more into the subject you will find that it is imperative for you to remove the gas tank from the hull prior to refilling .......
Unless you incorporate an arrangement whereby you fill the tank through fitted pipework and vent outside the hull as I do.
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Dave...I stand corrected :embarrassed:....please look at ....Mayhem....Build Masterclasses...Ben Ain Build by Bunkerbarge..... extract as below...clearly an alternate to removal of the gas tank for filling.......Derek
"The other significant modification was the filling arrangement for the on board gas tank. I have always had a particular dislike for the ‘Ronson’ type filling valves, be they fitted to a cigarette lighter or a model gas tank. When you think about it all you are doing is inverting the purchased gas canister to allow liquid to flow then using the fitting on the canister you are opening the Ronson valve to allow the liquid to flow into the on board tank. The problem is if liquid is to flow into the tank then the displaced gas must be allowed to escape somehow. Because this does not happen the liquid is constantly spitting and blowing out as gas is trying to escape through the open valve at the same time as the liquid is flowing in. I have already modified the filling arrangement for the tank by filling through a clear hose into another valve and it quickly became obvious that the liquid would not flow very easily as the displaced gas could not escape.
To resolve this the Ronson valve was removed, at which point I noticed with surprise that the valve was not fitted with a dip tube, and the boss was drilled and tapped to accept a 5/16th x 32 tpi standard 90 degree globe valve to which a dip tube had been fitted. The idea of this valve is three fold, firstly it allows gas to escape at a controlled rate while liquid is flowing into the tank, secondly when liquid is seen spitting out of the valve you then know that the tank is full of liquid and finally the dip tube guarantees a liquid level and hence a gas space in the tank, thereby ensuring that the tank is never completely full of liquid and hence liable to being hydraulically locked.
I tried out the new valve with my camping gas canister, filling through the valve that had been used in the past with the new valve very slightly cracked open. I was surprised at just how much more quickly the liquid was seen to flow through the clear hose so obviously allowing the liquid to displace the gas worked well. After a few minutes liquid was seen spitting from the valve so at that point I knew that liquid was at the level of the dip tube so I stopped filling. Simple, effective, considerably safer and a lot quicker than using the Ronson valve so I was very pleased with the modification. The valve will be plumbed into an overboard pipe to ensure that a build up of gas inside the hull does not occur, making the arrangement considerably safer than the original".
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With all due respect to Bunkerbarge, I would be VERY careful about discharging gas, especially if you are close to people smoking or other steam boat users.
Convention has it that most steam boaters either run using disposable commercial gas canisters, or they remove the gas tank for filling. Removing the tank ensures that no gas is left at the bottom of the boat, just waiting to make it's presence felt the second you light up. I have seen this happen twice, both times with open launches, and both times frightening the owners and bystanders. I have also seen the charred evidence of several other similar incidents. Removing the gas tank also ensures that you can choose a safe spot to fill, reducing any possibility of accidental ignition of the overflow gas, by smokers or running steam boats.
Clevedon Steam sell a little kit, with a thumb wheel and O ring that fit on the copper feed pipe from the gas tank and which is designed to make the task of removing and replacing the tank just a little easier.
Everyone is very aware of the dangers of pressure vessels when messing with steam models. I consider errant propane / butane gas to be a much more likely cause of an accident than a boiler or gas tank exploding.
Neil
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I was reminded only recently how dangerous it is , I was filling my small gas lighter the type you use to light the gas and your boilers with I use it for heat shrink, it only takes a few seconds to fill, but for some reason I did it over the bench, I normally stand in the middle of my work room to do it , but i did walk to the other end of my room and put the ronson tube back in the metal cabnet, before returning to the bench to continue , I lit the lighter and went to shrink a wire when the bench lit up and removed all the hair on my hands etc and a singed smell everywhere, it had been a few min from filling and the bench is flat so I hate to think how much can be in the bottom of a boat if you where to fill it there as it would probably stay there for some time being heaver than air.
I will never fill a tank in a boat, ill stick to the tried and tested way.
peter
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Hmm, there should be a pr*t warning etched into the gas wands Peter. Loath to admitt it but a few weeks ago I decided to refill ours and used the liquid fill technique, fill canister down onto the receiver. You stop when you have a discharge of gas. Which I did. What I didn't take into account was that the Hob unit (Was in the kitchen) was lit and despite dropping the can, wand and trying to beat my "Flaming" hands out, there was enough free gas to have gone up my loose fitting sleeves.
Soooooo, I'll take your singed hands and add arms, chest, beard and one eyebrow, wife though the resultant picture was QUITE hilarious.
Was THREE feet away from the hob with my back to it and NEVER anticipated a flash over from that distance.
BE WARNED.. :embarrassed:
Regards Ian.
As an edit Red Noir, at EVERY stage of the build of your new engine, make sure that the bits rotate and move smoothly to each other. It's no good f you find a tight spot and decide "I'll fix it later". Trying to chase binds is a looooooooooong process.
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well I should be back at it again tonight, with the tvr1a. The top end is almost complete and now I'm concentrating on mating the two half's together ! updates to be posted soon !
As for the concern about the fuel tank, to sum it all up the major concern is that " Butane is flamable take caution when refilling and do it in a well ventilated area away from and open sources of ignition !!"
check and check !!!
cheers
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With all due respect to Bunkerbarge, I would be VERY careful about discharging gas, especially if you are close to people smoking or other steam boat users.
Convention has it that most steam boaters either run using disposable commercial gas canisters, or they remove the gas tank for filling. Removing the tank ensures that no gas is left at the bottom of the boat, just waiting to make it's presence felt the second you light up. I have seen this happen twice, both times with open launches, and both times frightening the owners and bystanders. I have also seen the charred evidence of several other similar incidents. Removing the gas tank also ensures that you can choose a safe spot to fill, reducing any possibility of accidental ignition of the overflow gas, by smokers or running steam boats.
Clevedon Steam sell a little kit, with a thumb wheel and O ring that fit on the copper feed pipe from the gas tank and which is designed to make the task of removing and replacing the tank just a little easier.
Everyone is very aware of the dangers of pressure vessels when messing with steam models. I consider errant propane / butane gas to be a much more likely cause of an accident than a boiler or gas tank exploding.
Neil
I actually discharge considerably less gas than you do when trying to fill with the ronson type of filling valve. No matter what method you choose it is obviously of the utmost importance to apply common sense and an appreciation of all the safety aspects of the procedure.
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Nice to see another one built. How's the performance of the Maccsteam boiler? I've never seen one for real.
My Maccsteam boiler is great, I get good run times in the house, but when I went to our local lake it was only just above freezing, it takes considerably longer to build up steam, roll on the summer. I will make a pad of insulating material to cover the exposed end of the boiler (opposite end to the burner) just to conserve a bit more heat. The advantage of cold weather is that if you keep you refill cylinder warm, in the car, or up your jacket, the gas tank takes a bit more gas. But overall I am pleased with my boiler, it will not keep up with a sustained full speed run, but how often do you do that any way, the pleasure is running the engine at a speed slow enough that you can see it all working. 3.5 inch boiler Graham TVR1A engine.
I did ask Mike Abbot at Maccsteam if he thought that a super heater would work, but he doesn't think it is worth the trouble on this size of boiler, because the size of the superheater coil would be too small.
Andy
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Thanks! I did build 2 superheaters on small boilers and they both worked well. I maybe a coil out of tube and put it down the chimney, cutting 2 appropriate slots at the bottom of the chimney. It's not hard to do and I think it helps the engine runs smoother because of less condensation.
Do you know how many Galloway (water) tubes the 3,5 Maccsteam boiler has?
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Graham says don't superheat with the TVR1 - soggy steam aids lubrication, he says in the instruction booklet. However there is a slight difference between heavy superheating and just drying the steam out a bit, which probably won't hurt. Only hand turning my engine so far as I'm waiting for the hex head bolt kit before fitting steam chest and cylinder covers. My only reservation with the engine is that the cylinders have to be screwed tight to the base before the crosshead guides are fitted, so you can't fit them both loosely and tighten them gradually while turning things over. The only place wear is showing up (dirty oil) is in the crosshead guides!
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I know Graham says not to superheat. But my superheaters aren't very large, so they don't raise the steam temperature too much. Steam drier is a good description. After some experiments I have settled on using a u-shaped superheater, going down and up the flue in the boiler. I have tried one with a coil coils and it heated the steam to the point of metling the solder on my old Wilesco :-)
Bedsides I use always lubricators, so I don't worry about water lubrication.
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Thanks! I did build 2 superheaters on small boilers and they both worked well. I maybe a coil out of tube and put it down the chimney, cutting 2 appropriate slots at the bottom of the chimney. It's not hard to do and I think it helps the engine runs smoother because of less condensation.
Do you know how many Galloway (water) tubes the 3,5 Maccsteam boiler has?
6 according to the website.
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Unless your using a flash steam installation forget the word "Superheat" and substitute Steam drier. You don't get anywhere near "Super" untill the pipes are glowing red on "Our" scales.
Regards Ian.
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UPDATE !!
Ok the engine is done and almost broken in on air !! runs like a clock ! I just got the displacement lubricator today and finished soldering up a brass mount for her !! here are some photos guys !
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Out of interest what is that on top of the funnel for ?
Peter
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exhaust deflectors ! LOL What I thought it looked cool ! <*<
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you normally run the exhaust up the centre of the chimney to accelerate the gases to make the flue more efficient, that may slow it down.
Peter
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hmm good point I guess we will have to see if its an issue ! if so I have a second pipe !
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Too much draft is as bad as not enough, by increasing the air velocity you may also require air dampers/restrictors. It's not solid fuel we're burning.. Without instrumentation I would use trial & error to find the optimum ( no choice really, actually an obvious statement. ) Try without assisted draft & if you're not happy then maybe with..... The burner will tell you when it's not happy...
One mans viewpoint, not carved in stone...
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Mike Abbot at Maccsteam advice is not to have the steam exhaust pipe to short in the flue , it may drag the fire out, I have mine about 1/4 inch below the top of the flue, not had any chance to experiment and shorten it anymore
If any one else has tried shortening it we would like to know the result. Glad you got yours running well, it took me ages to get mine right, now it is really free. I still think it could do with a fettle, there is a slight delay starting in one direction compared to the other, I think maybe one of the eccentrics has moved slightly, but, I am waiting for my hex bolt kit.
Andy
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Mike Abbot at Maccsteam advice is not to have the steam exhaust pipe to short in the flue , it may drag the fire out, I have mine about 1/4 inch below the top of the flue, not had any chance to experiment and shorten it anymore
If any one else has tried shortening it we would like to know the result. Glad you got yours running well, it took me ages to get moine right, now it is really free. I still mthink it could do with a fettle, but I am waiting for my hex bolt kit.
Andy
Cheddar have theres in a similar place just below the top, that is why I was wondering about the flaps as it would be blowing directly on to it.
Peter
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Well I finished most of the plumbing yesterday ! the tvr1a has a few hours of run time on it and all in all Im very pleased !
Im just lookin for a boat to put her in now O0
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Very nice plant and neat piping there. What did you use to make the body of the condenser?
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I used two one inch copper pipe end caps with a section of pipe in between them, the cap is made from old Midwest heritage steam engine fill bushing that I drilled for the stand pipe !
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Hi Red Noir,
What a wonderful job you're making of that plant- i'm with you on thinking the brass and copper looks great 'naked'- you may change your mind when you find out just how difficult it is to keep a hot oily steamplant clean when it's painted, let alone bare metal.
Just wondering what solder you used on your condenser and pipe joints?
Greg
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Just wondering what solder you used on your condenser and pipe joints?
Greg
hey Greg
I used silver solder on all my joints !
Im really enjoying the bare metal look and its simple to keep clean, I'm beginning to enjoy the non shinny look its taking on !
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Beautiful work Red Noir......I love the pipework :kiss:....& I assume those are Winfried Niggle round 4 x bolt flanges :-))
Oh....& yes the components build is also superb O0
Traditional last century marine steam pipework [spool runs] were generally in the vertical or horizontal planes with minimal bend sweeps other that 90 degrees or 180 degrees
However in OZ we are taught to call a spade a spade ....so >>:-( ..
I question the positioning of the Forrest Classics gas regulator .......but not just from a visual :police:
1. Is the diaphragm in the regulator OK for 150 degrees C continuous rating? ...as the pilot appears to be from the steam dome
2. A lower boiler water take off point pressure source could be as low as 105 degrees C
3. A further advantage of using a fluid [water] as the pilot signal over a gas [steam].....is far greater stability of the pressure source without high frequency pressure oscillation's
Still a brilliant job.........Derek O0
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Excellent work.... :-))
Although I do agree with Derek ( on all accounts) that there should be a water (condensate) column isolating the diaphragm. Same reason you use a pigtail/syphon with pressure gauges on steam duty... A simple U-bend/hairpin bend would accommodate without major pipe changes..
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Depending on which source you prefer to believe it seems that Viton rings are good for well over 200 degrees C and the seals in the Forest Classic attenuator are Viton, the diaphragm is metal. At a guess and without the benefit of steam tables to hand I would say the boiler shell should be at something like 120-130 degrees C. Anyone with a set of steam tables feel free to correct that!
Anyway bottom line, I have recently installed a Forest Classics attenuator actually on the boiler shell and after about 2-3 hours of running have had no challenges so far. An option could be to upgrade to silicon seals but I'm hoping I don't need to and it will continue to work reliably.
If it fails I'll let you know but I've already had a chat with the chap who makes the valve and he doesn't see any reason why they shouldn't be mounted on the shell.
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Where would one find Winfried Niggle flanges. A quick search on Google only yielded this forum.
thanks in advance
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Where would one find Winfried Niggle flanges. A quick search on Google only yielded this forum.
thanks in advance
Here:
http://www.modellbau-niggel.de/Flansch-Verbindungen-c20.html
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Hmmm
I never realized that the regulator should be on the wet side. Ive noticed that the regulator doesn't seem to work the way its meant to either.
I added a photo, the green line represents where I could move the sense line to.
also the flanges are really nice addition to this project, the only down side I see to them is the tiny bolts and nuts they use ! I made a socket for them by heating up a piece of pipping and forcing the bolt head into it deforming it and making a wrench !
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Alternatively, as with a pressure gauge supply pipe, just coil it to make a condensate trap.
Greg
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Hmmm
I never realized that the regulator should be on the wet side. Ive noticed that the regulator doesn't seem to work the way its meant to either.
I have two of these attenuators, one mounted directly on the boiler in a boat and the other one via a take off from a branch on the top in a lorry. Both are connected to the steam space not water and both work fine. The one I have fitted to the lorry was actually fitted by the guy who makes the valves so I'm not sure why we are thinking that there is a requirement to connect the boiler side to the water space.
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this is the instructions I got with the valve ! seems self explanatory to me !
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Here:
http://www.modellbau-niggel.de/Flansch-Verbindungen-c20.html
Thanks Calin--that is a great source--I so wish someone on the US would carry / stock offer all the steam goodies that are so plentiful in Europe / other side of the pond
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Interestingly, neither Forrest Classics, Anton nor JMC mention an operational temperature range for the regulator or pilot fluid....when I asked Anton if the diaphragm was Viton....[prior to my purchase of a V71 regulator] the answer came back...NO ...neoprene
Anton also clearly depicts the pilot source as lower boiler water ...so if it leaves the boiler @105 degrees C....it will cool down to say 70 degrees C @ the regulator which is fine for the neoprene ....whereas Forrest Classics implies the pilot source is from a steam dome >>:-
I understand this is a little of track....but it is interesting to see & hear how various manufacturers deal with the same issue ...... O0 ....Derek
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Red Noir says........Ive noticed that the regulator doesn't seem to work the way its meant to either....
I have had one issue with Forrest Classics about a defective gas tank discharge valve
The tank was purchased through a third party. however I dealt with the principal of Bix/Forrest Classics & I found their response excellent...
If you have a question on the functionality...why not post a few questions back to them ....with their response we all may learn :-))......Derek
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Red Noir says........Ive noticed that the regulator doesn't seem to work the way its meant to either....
I have had one issue with Forrest Classics about a defective gas tank discharge valve
The tank was purchased through a third party. however I dealt with the principal of Bix/Forrest Classics & I found their response excellent...
If you have a question on the functionality...why not post a few questions back to them ....with their response we all may learn :-))......Derek
That's precisely why I spoke to the man who makes the valve. He was extreemly helpful but I agree Derek, it's interesting to see how different manufacturers deal with the same issue. I guess at the end of the day there is no right or wrong way but whatever works for you.
I'd be a bit more concerned with the comment that the valve doesn't work the way it's meant to. There are a couple of things to bear in mind though.
Firstly it’s not always obvious just what’s happening with the flame if you can’t see it so the valve may be turned down to the pilot jet but it is still actually putting heat into the boiler, although comparatively little. If the pilot jet is a little too large you may still experience the safety lifting after the model remains stationary for a while. This can be rectified by using a smaller pilot jet however there becomes a risk of the flame going out if the pilot jet is too small for the operating conditions.
Secondly operating temperatures do have an effect on the valve setting so if you set the valve up in a nice warm workshop then take the model out into a very cold ambient temperature, the set point may well not remain the same, or certainly as in the case of the Forest Classics unit which uses a metal diaphragm.
If you could tell us exactly how it is not working we might be able to point you in the right direction.
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I believe the problem was. That I was running the boiler at very low pressures ! my Tvr1a ran so well at 10 psi that I wouldn't let the boiler get up to high enough pressures for the regulator to do its job !
Last night, I allowed it to reach forty psi and set the regulator for that and I could hear the gas go to a lower setting at 40 psi. it seems to be working as advertised but I need to do a few more runs to work out the bugs.
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The one I have mounted directly on the boiler I set to about 35 psi and it seems to be OK at that.
The trouble is with a boiler with a working pressure of 45 psi the safety valve has to be set less than that so mine is set at 40 psi. You then want to set the valve to less than that so I went with 35 psi but of course this all depends on your own boiler and engine configuration.
I'm glad though that you seem to be getting to grips with the valve and learning a bit more about it. I would suggest that you give Forest Classics a call as they are very helpful and always interested in feedback as regards how the valves are performing.
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35 psi seems like a better alternative to 40psi. At 40psi my safety valve starts to act up.
I ordered a PPS whistle today from pm research, I cant wait to get it on this project !
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Just my humble opinion...
With all diaphragms there are several conditions at play. The main ones being hysteresis & repeatability... A higher working pressure will often narrow the hysterisis ( linearity) band but repeatability is a condition of uniform temperature &/or material science (stability.) Thermal shock is the main bugaboo for repeatability hence my recommendation for isolating with a condensate trap. Not only a possible problem with material science, just good engineering practice. My credentials ? Control instrumentation design & application, a career over 40 years.. I am considered by many to be a boiler/steam controls expert... :embarrassed:
No matter what the vendor says, isolate with a condensate trap. Tens of 1000's of instrumentation engineers can't all be wrong.... ok2
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Well Mayhem members...we have comment here from benjaml1 .... "I am considered by many to be a boiler/steam controls expert" O0...& is certainly modest at that :o
We have a number of qualified marine engineers [both steam & motor] %)
We have an electronic GURU in computing & control for flash steam %%
So having said all this ;D benjaml1 {-) gets my vote as an appropriately qualified specialist in the area of steam control where we can use full scale rules & relate down to model steam engineeing... :police: {-) O0 :-)) - Derek
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Hi...i have one from Forrest to,,set to 60psi,,,and work ok............and i have one from Anton in France,,,set to 50 psi,,,,the did told me...if the gastank get more pressur than 45 psi..3 bar...i scut use a valve before the regulator....
i have that valve to,,,,,,,,,,,
Regards Bernhard
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Apologies for being a little "cockey", remind me not to post after a few pints down the pub... :embarrassed: :embarrassed:
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Hullo Bernhard..........if my memory serves me correctly.... %% ...you also had two gas regulators from an alternate British manufacturer that were non functional & were returned
You also have a German manufactured duplex [twin] yellow cast body gas regulator that you advised was totally functional :-))
I think your ANTON unit is the same V71 that I have ......but mounted with the adjustment screw vertically down >>:-(
Hullo benjaml1.........don't be embarrassed ....sometimes the best thoughts are after a few pints down the pub... {-) {-)...& your comments on the subject are totally valid ...keep up the good work :-)) ....Derek
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Hi, would Greg, or anyone else for that matter like to expand on the part of this discussion about condensate coils/loops etc? I have never been able to understand how putting a simple "U" siphon in a gauge line stops water that may condense in the line from making its way to the gauge the next time the boiler comes up to pressure. I know that in theory any air/steam on the gauge side of the condemsate should transmit the pressure to the gauge without compressing but I still suspect that the condensate would make its way to the gauge. Also if it does get water to the gauge does it matter? I have one of my boilers (a Cheddar Puffin) with the gauge siphon connected to the steam dome and laying horizontal. It was like that when I got it at least five years ago and it is still working fine. Maybe attenuators/regulators are more sensitive but I still struggle to see how a coil in the pipe leading to them will stop condensate getting to the diaphram. Please enlighten me! Thanks, Ian.
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hi........haaaaa What great memory you have Derek.. ;)..... yes thats true...i did have 3 from that UK place ...and only one iwhas working..2 whas send back..and i get my payment back,,,.and yes i have to from Germany...they work to,,ok to,,,,,,,
Bernhard
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Hi ian,
You have a common misconsception held by many;
I have never been able to understand how putting a simple "U" siphon in a gauge line stops water that may condense in the line from making its way to the gauge the next time the boiler comes up to pressure....Also if it does get water to the gauge does it matter?...Maybe attenuators/regulators are more sensitive but I still struggle to see how a coil in the pipe leading to them will stop condensate getting to the diaphram.
The 'U' bend or a small coil in the pipe provides a solid plug between the steam and the fragile internals of the gauge- you WANT water to be acting on the bourdon coil in the gauge- if it has condensed it is likely not to rise above 40-50degC and stops thermal shocks and repeatability (see post above by an EXPERT ;D) something that will eventually stop the coil working to it's calibration and may show the wrong pressure.
The only reason that you may have got away with it being straight off the dome is that our plants work at such low temperatures that, yes, yours might just be okay, but I wouldn't gaurentee it.
Hope that helps.
Greg
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OK....we are all learning :-)) ...so I pose a question to benjaml1 & gondolier88 ...
Please consider the simple U tube gauge syphon ....why does the condensed steam which is now water displace the trapped pocket of air which was in the tube ...so that the water now acts upon the gauge internal Bordon tube?
It has nothing to do with the Boyle's & Charles combined gas equation :o
It has nothing to do with permeability of gases....... :((
So if this event within science does not take place we would need to bleed all trapped air prior to any gauge or gas regulator diaphragm...... %% :embarrassed: ....Derek
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Hi Derek,
Quite simply, air compresses and the compressed air fills the gauge to a corresponding pressure of the pressure vessel, be whatever that is.
Liquids or gasses acting on the bourdon coil, as long as they are of a constant pressure and of a low temperature in the limits of the gauge will display the correct pressure and protect the gauge from becoming damaged.
This can be seen on a valve chest pressure gauge on a full size engine- if a guage is subject to the full fluctuations of the chest it bounces dangerously and could easily become damged, but put an isolation valve on the supply and shut it to within a gnat's right family vegetable and a smooth and slow average pressure is shown that is safe and easy to read.
Greg
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To add to the most excellent prior postings. The correct installation for a primary measuring device (on saturated steam) is below the pressure tap...This ensures the wet leg is always.....wet. Some of it flashes off on reduction of pressure but is quickly satisfied on resumption. Differential devices ( two or more pressure taps) incorporate "flash pots" to minimise the effect of drifting wet legs...
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Thanks benjaml1 & gondolier88..........I had previously asked Anton if I should bleed the condensate line to just under my V71 regulator [to displace the entrapped air].......his partner Christine Betrange ....came back & said "unnecessary"
Even though my communicatiopns to Anton were in French/English ....dedicated responses were just single words ...without explanation >>:-(
I fully understand that if we pressurize the condensate, we pressurize the trapped gas equally.......however any trapped air will behave like a gas accumulator when pressure fluctations occur within the boiler - the result being a lack of the word "stability" that we have spoken about previously
Greg also mentions "if a guage is subject to the full fluctuations of the chest it bounces dangerously and could easily become damged' <:( ...I also understand this.....but :police: it is also the high frequency pressure oscillations or reversals that the gauge mechanics cannot resolve or display [time frequency to pressure varience] that will also cause gauge damage
Hence the importance of the WET leg as noted by benjaml1
Still a good learning curve..........seems to me that we should not just accept that condensate will occur....but in an optimal situation we should attempt to bleed all entrapped air just prior to the gauge or regulator......Derek O0
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Still a good learning curve..........seems to me that we should not just accept that condensate will occur....but in an optimal situation we should attempt to bleed all entrapped air just prior to the gauge or regulator......Derek O0
Unnecessary.... The volume of the wet leg should exceed the mechanical & volumetric displacement of the diapragm/bourdon tube mechanism. In the model world that is minute.
It is almost impossible to saturate a bourdon tube. Although I have done it on full sized gauges by drilling the block connector & installing a vent screw. This was for a remote gauge application where it was necessary to fill the entire sealed system with silicone. However I digress.... Most gauges have built in restrictors (also called snubbers) at the connection to dampen wild action, often they are not enough, hence the use of remote isolation dampers. The prime duty of a wet leg on saturated steam is that of temperature isolation to reduce the operating temperature of the device & reduce thermal shock..
Have I mentioned freezing ? Don't leave said same device in your garden shed (over the winter) without draining. I have seen DP cells rated at 10,000 psi separate... :o
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In my drive to try to get more and more modellers interested in model steam I am often met with a level of uncertainty based on fear of the unknown. I spend a lot of time trying to explain the processes involved and remove some of the mysticysms involved with model steam but when I read through this lot I can see why things are as they are.
While it may make members feel good to be talking almost a foreign language I hope we are always able to relate our levels of expertise to newcomers and provide a welcoming environment where questions are encouraged. Let's not also forget that a very high percentage of model steam boat plants are below the 'Blue Book's' required 3 bar-litre limit and operate at temperatures not very far above around 120-130 degrees C so is temperature shock really an issue on a model boat plant in the middle of a boating lake? If we then consider the significant number of plants of the Mamod and Wilesco type that are not even fitted with pressure gauges and work at about 15 to 30 psi then the whole explanation below seems to be, whilst very interesting, somewhat acedemic.
I think there would be some real value in trying to explain to the other 95% of the membership who haven't got a clue what is being talked about here just what does "saturate a bourdon tube" mean and enlighten every one on some of the other phrases being bandied around.
I'm sure there will be a tirade of indignant posts now extoling the virtues of being able to freely express thier opinions etc..etc.. but I'd really like to see posts such as these offerred as something to learn for everyone rather than just the benefit of a very few. To me there is no point in being an expert if you can't pass your expertise on to others so now that we have defined the experts maybe they could help to remove some of the shrouds of mysticysm surrounding steam systems rather than adding to them.
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Hi,
Perhaps as a moderator BB you would be willing to make one of those permanent threads at the beginning of steam R&D that could be entitled 'Beginner's need to know info on Steam' or some other suitable title that members could add SIMPLE hints and tips- perhaps sending them to a moderator first to help keep it simple, free of repetition and interesting. Along with this could be included a glossary of terms from everything from 'boiler' to 'bourdon tube' and 'safety valve' to 'thermal efficiency' etc?
I agree that steam at it's simplest is a kettle harnessed to a piston- but the guys on here with full size experience know that it is much more than that- and for most, once a certain level of knowlege is reached it becomes enjoyable to research the developement of steam over the ages upto the stupidly high temperatures and pressures and efficiency we see in Nuclear sub's or a powerstation.
Just a suggestion...
Greg
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Wait until they start on about "Superheating" BB {-)
Regards Ian.
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Hi,
Perhaps as a moderator BB you would be willing to make one of those permanent threads at the beginning of steam R&D that could be entitled 'Beginner's need to know info on Steam' or some other suitable title that members could add SIMPLE hints and tips- perhaps sending them to a moderator first to help keep it simple, free of repetition and interesting. Along with this could be included a glossary of terms from everything from 'boiler' to 'bourdon tube' and 'safety valve' to 'thermal efficiency' etc?
I agree that steam at it's simplest is a kettle harnessed to a piston- but the guys on here with full size experience know that it is much more than that- and for most, once a certain level of knowlege is reached it becomes enjoyable to research the developement of steam over the ages upto the stupidly high temperatures and pressures and efficiency we see in Nuclear sub's or a powerstation.
Just a suggestion...
Greg
I think that's a great idea Greg and something I'll have a play around with. I don't think they need to go via a moderator but we would obviously reserve the right to remove anything that wanders off topic.
Thanks for the suggestion.
As for superheating Circlip, we could start a whole thread on it's own for that but perhaps it would be best behind locked doors of a small padded room?!! I'm with you on that one though, let's just call them driers O0
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OK did some piping rework ! and I'm submitting it for approval ! :D
ReD
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I wouldn't worry about approval- I think we'll all be coming to you for approval! :-))
Greg
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I couldn't agree more with the prior post.... May I also respectfully add..... Lovely work... :-))
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hey thanks ! that put a smile on my face :embarrassed:
well to sum it all up i put a dip in the sense piping to the valve. after all the soldering was done it didn't work ! >>:-( no gas ! what the h3LL !!!!
i began doing a pipe by pipe check, all pipes were clear then I realized it was the regulator that was stopping flow and acting like a check valve, after much cursing I realized i had installed the valve the wrong way around the first time and it worked???? Now suddenly it wouldn't.
I also found that the no.5 jet was now clogged ! So i disassembled the valve ( its actually quite simple all the parts are brass and stainless and the seals are butyl rubber o'rings) after all was assembled and the piping sorted out, and the n0.5 jet un-clogged every thing work as advertised ! set to 30psi and the valve regulates gas pressure !!
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before image of the valve ! >>:-(
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A simple mistake, one that I almost made myself.... :embarrassed:
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Red……just thinking & see a few potential issues with the current gas regulator pilot source
1. If you were to open the boiler steam discharge valve @ the lighting of the boiler you would fill the steam line to the lubricator with condensate during boil up
2. You could also have an issue where the condensate displaced the lubricator steam oil at a high rate at the cracking of the engine steam distributor valve
3. If you kept the steam discharge valve closed @ boiler lighting until the boiler relief valve cracked, by opening the steam discharge valve would immediately send the pressure signal to the regulator to go into low flame mode
4. Certainly 1. & 2. are not acceptable, however 3. is not necessarily a sound change in system functionality considering the critical time where you need to clear condensate & ensure stability of the gas regulator flame height & hence pilot signal
5. Cotton string insulation will certainly assist with minimizing condensate from the boiler steam discharge valve………..to the lubricator
Bernhard…….would you like to comment on the advantages of insulation on the discharge side tube from the engine to the separator? ....Derek
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As an observation and NOT a critisism, going with Dereks point No.2 why have a steam through flow of the displacement lubricator?? They still work on a "Leg". Despite having a control valve, I would expect a venturi effect. Many roads to Rome.
Regards Ian.
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Circlip is completly correct- should you find condenstae is a problem regarding displacement of oil issues then you could;
1- put it on a dead leg- just 'T' into the main line and place it 1" or so away from it.
2- As Derek suggests put a steam stop valve on top of the boiler, or as he also suggests,
3- Insulate the line to minimise the problem.
However, that said TVR1's work at such low pressure that the saturated steam would lubricate the cylinders without oil with no detrimental effects anyaway, so you could just choose to ignore all of us and leave your lovely pipework as it is!
Greg
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Guys, give the man a break and look more carefully at his pictures: the steam pipe to the gas regulator is not closed by the steam valve for the engine. They just share a common T-connector.
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You're looking at the wrong pipe Kno3, the one we are seeing is the one connected to the Displacement Lubricator and as far as giving the guy a break, both Greg and I have stated "An Observation"
As it stands, he can run out of lube far quicker than desired.
AGAIN, Many roads to Rome.
Regards Ian.
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Gents....maybe I have to eat 1/2 of my hat.... :embarrassed: ......[please keep the :police: @ bay] {-)
When I review forest .jpg I see the boiler discharge steam isolation valve is outboard of the supply [of the pilot signal] to the gas regulator....& it is an assumption that the needle valve controls only the steam supply to the lubricator
It is lucky we have ten thousand members looking over our shoulders %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %% %%
Sorry Red for any false assumptions :embarrassed:......Derek
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Hmm, Double indemnity to shut off the steam supply to the engine, wonder why??
The Steam dome take off has a globe valve that can turn off the supply to the lubricator/engine and another globe valve to turn the steam supply off at the lubricator.
Refill the Lubricator while the boiler is in steam??? :D
Regards Ian.
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wow ! keeping up with you guys is tiring ! {:-{
There is no mystery in how I set up my pant. The lubricator I used had a shut off, that's all!
I was hoping to modify it, and use it as a crude throttle valve instead of paying 45 pounds for a throttle valve.
I use what I have.
Anyhow ! :-))
I bought the boat this is going in today, some of you might recognize another member has that same boat ! should be fun seeing how mine will differ !
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Nice choice on the boat RED... :-))
I know Bernhard will approve also.. ok2
I have one of those in my sites for future project too!!
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hi..............Great boat.........and the your ide ,with strip it down it real good...i didnt do that ,,,so i have to lack,,,it many times...it whas not easy to do it water tight,,,,,,,,,,,,
Regards Bernhard
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hey thanks Bernhard, Ill strip the paint down for sure and epoxy the hull !
I was just wondering if you could post a pic of the prop shaft to engine setup you have on your boat?
Red
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UPDATE !
Boat arrived today, and after about an hour of tearing a good boat apart this is what I'm left with !
I also came to the realization that my steam plant setup has to be revised so that it fits in the boat. <:(
Ahh well !
RED
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O0 ...Red...it's only a few more lengths of K&S beautiful brass or copper tube & will look great...I also see the whistle is installed...however a few observations
1. you may need to angle the engine down say 5 degrees
2. have you considered the major surgery to provide prop clearance?
3. you may need to revise the scale effect & remove the ore rowlocks & things
If I were building such a vessel I self admittedly would go back & study the many .jpgs posted by Bernhard in his threads on similar looking vessels .....Derek :-))
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Just thinking Red...... %% @ my age......this is a perfect time to complete displacement trials & inclination tests {-)
1. get the bathroom scales out & confrim the dry weight of the hull
2. whist in the bath room 1/2 fill the bath [with water] add the basic hull ....gauge the draft....add the engine+boiler [filled with water]+the condensor+gas tank+4xAA sized batteries+3x servos ...then gauge the draft
3. from here you can reasonably accurately calculate the mass of ballast required to bring the vessel to correct operating draft
4. if luck is on your side O0 ...you could consider a full length of 1.5 mm thick galvanised plate with up turned sides....this would enable all of the components to be installed on the bench top out of the hull & the tube spools created , bent & installed as one complete engine/boiler assembly...all you need to do is loosten 1/2 of the engine to shaft coupling to install/remove :-)) ......
I am sure many Mayhem members would be interested in the displacement trial results............ :-X Derek
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Ore locks are all gone, I had planed to remove them anyhow before I snapped the pics ! As for calculating draft, It will have to wait. Unfortunately the Lapstrake construction of the hull on a desk top model, doesn't lend itself well to water tightness !
Multiple coats of finishing epoxy will be applied to water tight the hull !
I have a question in regards to paint, what type do you guys use? and do you spray it with a clear coat of any sort after the final painting is done?
my idea for this model is my own loose rendition of a small wooden fishing vessel, something like a Monterrey clipper.
Tomorrow work begins on working out a way to make the steam plant removable from the boat for easy maintenance. :D
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Hey, that lake looks familiar! And the boats too. The photo must have been taken on one of the rare sunny days too.
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Hi........ here is another one....... http://cgi.ebay.co.uk/Model-Live-Steam-Launch-Fully-Working-/200480484547?cmd=ViewItem&pt=UK_ToysGames_ModelKits_ModelKits_JN&hash=item2ead916cc3
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Stunning work as always... :-))
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Hi......Thanks........Bot it is not mine........it is on Ebay i did see it,,,,,,,,,,,
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Lovely model but I think the price is a bit ambitious
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Bernard ! I do like your boats better, your attention to detail is incredible ! :-))
Well I grabbed the camera and snapped a few pics, sorry for the grainy photos but the battery went dead on my DSLR so I had to use my point and shoot ! none the less this is where I'm at. The hull got some planking done on the aft and fwd decks using coffee stir sticks as decking and applied some stain and a coat of epoxy. As for epoxy the entire boat has had two coats and I'm quite confident its water tight now ! The bathtub test is soon to follow ! I also now have an occupant for my boat !( hes held on temporarily by tape ) The neat thing is his r\h arm is attached to the rudder so when it moves so does his arm giving the illusion he's steering the boat ! :embarrassed: anyways enjoy !
Red
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Nice work! She's starting to take shape now.
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Hi.. :-)).........where the skeleton sit....there i have made a sit..and under there the batteries is,,,,,
Regards Bernhard
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Thanks Guys ! :embarrassed:
Bernard I'm going to house the servos and radio gear in small crates around the inside of the model, something along the lines of what you do with your servos in your boats. I have high torque metal gear micro servos looking for a home at the moment, so the should work fine as-well as a micro receiver.
also here's a pic of the re-work I did to the hull, its not done but you can see the section I removed to house the 5 blade 50mm prop !
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Hi Red Noir,
Just a little point about the cutout you have done- you may find it blocks the prop quite a bit- it might be worth looking into making it taper more onto the prop.
Greg
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Hey Greg !
That's just the initial cut out with reinforcing ply put in. I still need to build the area up with balsa and make it more hydroponically smooth as to not completely blanket the prop and cause cavitation. Im just waiting for the prop to arrive so that I can cut down the stuffing tube and shaf and work out all the details !
Red
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IT FLOATS !!!! :o
Boiler is 3/4 full, I'm really happy that she didn't leak either !A future note for anyone else using this sort of model ! it requires allot of epoxy to seal !!
Anyhow here are some pics from my bathtub voyage !
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:-)) :-)) :-)) lucky you...that it dont leak.....................
look just great in the water...........
Regards Bernhard-..
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Looks superb on the water..... :-))
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Hi,
That looks superb Red! It looks so well proportioned- a real scale model. Try hard to keep it that way mate, it looks like a real steam launch in the bottom photo!
Greg
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Very nice. Does it already have ballast or is it going that deep just because of the steam plant's weight?
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Thanks alot guys ! I'm so happy with the way its turning out. This being my first r/c boat its been quite the learning process.
No ballast, that's with the steam plant ready to be fired up ! radio gear wont weigh much cause Ill be using a micro receiver and servos and a small high mah pack.
Red
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Well done Red.... :-)) It feels good when the first boat is actually in the water!!
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Hi Red....she look great in the water & without ballast........ {-)
Only question is ....I am sure the lubricator must be loose as it is sitting in the horizontal plane........ %% ...Derek
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Only question is ....I am sure the lubricator must be loose as it is sitting in the horizontal plane........ %% ...Derek
I think you may be mistaking that for the pressure regulator ???
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Sorry Red....& yes Benjaml1 ...I have been off line for a week %% ........apologies....just a dumb comment from me ...I believe the people in the white coats along with a few :police: ....are on their way {-) {-) {-) {-) {-) {-) {-) - Derek
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Had me checking though.. Thought I may have missed something myself. :embarrassed:
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OK...OK...seriously ;D ...we have seen a few similar hulls with supurb installations of machinary & accessories & fine detailing by Brehnard......... :-))
Now another varient on the hull by red_noir .......however with a differing installation of machinary O0 & still progressing
With a little fore thought & a few {-) ...I could see this identical size hull format & similar/differing installations of steam machinary be the SPRINGER version of a steam powered open launch O0 %) :-)) ...Derek
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hi Red-noir.......... Eny news with your launch...
Regards Bernhard