Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Steam => Topic started by: xrad on February 18, 2021, 10:49:22 pm
-
Hello All, Been a while since last post. Built many model projects and wrote many C++ model codes in the last few years. But now, I am am working on a new 1/24 scale Brooklyn tug based on original blueprints from Camden NJ USA shipyard(my home county!). It will have either a mildura or Stewart marine twin and a home made scott boiler....should be a cool project. I built one of the 1/32 scale dumas tugs in live steam a few years ago and it is tied with my lightship models as a favorite subject. Here is a pic of hull plans. 52.5" stem to stern length, 12.5 width (may have to adjust a bit for seaworthiness)
-
This looks like an interesting project. I have no experience of steam models but I'm happy to tag along and see how it develops.
Regards,
Ray.
-
I remember your 1:32 scale version from 2014/5/6 very well O0
https://www.modelboatmayhem.co.uk/forum/index.php/topic,48955.msg502623.html#msg502623
So will look forward to this steam build
Derek
-
Welcome back xrad - about time too {-) I'll be watching this one mate :-))
-
Oooohh-- I wanna see them planks go on. i had no idea how to plank a tug, so I made it up, and used this unorthodox method, using all straight 1/8 x 1/4 cedar sticks --no steaming, no tapering. The keel was installed after the hull was made, and curvy part next to the keel was made with epoxy filler WEST 410.
It will be fun to watch you do it--probably the "right way"; the lines are similar to St Andrew
-Carl
-
I was a particular fan of “Moran” tugs in the States during my travels.
Jerry C.
-
Hi everyone! Thx for replies! I don't know if there is a 'right way,' whatever works is always fine. yes, I have missed boat building...forgot how much fun it is! So the hull frames and stringers in rough orientation. Hull will be glassed so not too concerned about minor details at this point....I added 3/4" of freeboard to make here a bit more seaworthy...
-
rough wood planking..looks don't matter here. Then a wipe of bondo fiberglass resin over the planks, which makes a better coating for the 5 oz cloth. Then lay on the glass. Then coat with more resin. When resin dry, a light sanding. Then thick coat of woodland scenics modelling putty(it's like spreading cool whip..and it's the cheapest of the light model pastes..). woodlands putty is light and very easy to sand. great for building up the hull where needed. great for filling gaps.
after dried and faired, then the real hull build begins...Not sure if I will make a split mold or just glass inside-out a one off....
-
I'd like to see how you make the mold.
-
I decided to make a one-off. Short answer: But if you were to make a mold, you would need to make a perfect hull 'plug' with any detail like rub rails built in. then put a 'seem' divider down the middle (a doubled thin piece of ply or similar bolted together- not glued). then wax and lay up a gelcoat, then strong glass mat. Do one side at a time thereby making two halves. Pop these halves off, polish inside and wax. Then re-bolt halves together. Now you have a female mold master from which you can make the model.
this is helpful:
https://www.nordictugs.com/nordic-tug-factory-tour/
-
Pretty sure that filler from Woodland Scenics might be the same as deluxe materials and a few others. You might find it way cheaper to use DIY stuff from Screwfix or BnQ for exactly the same product. Pollyfilla make no discernable different product if I remember. I guess the equivalent for you would be Home Depot. I know I've found the same stuff here anyway and also in Castorama in France for 1/10'th the price for the same thing for bricolage (though France naturally more expensive).
-
So what will you do to make a one-off? I guess the hull you are making will still be a plug, and that you will glass over it in several layers/directions, then maybe vacuum bag? I guess you cannot pull a vacuum with the hull still on bulkheads. So you lay glass and then more resin then have a sanding and fairing party to get it smooth?I hope you will share the process. Sounds a lot easier than making a mold, then vacuum bagging a hull on the mold. I'd like to see the glass thickness as you make the lay-up. I've never done this.
-Carl
-
Thx for replies and tips! yes, the light filler is a bit pricey, but i only needed 3.5 jars at 11$ each. Yes, one off hull. plenty of sanding and fairing to do. I use bondo to smooth the hull after a few layers of 5-6oz cloth. It's supposed to represent a metal hull so a few imperfections (aka 'dents') actually add to the realism. I will post pics as build progresses...but mixed up in several other builds as well which delay this whole process....
Received my copper 'L' pipe (seamless tube) today for boiler. 4" horizontal cross tube design using 1.5" flue with 3/8 cross tubes, all 'L' thickness. These are 1 ft sections which will be cut down as needed. Have to calculate the measurements, but should provide enough volume and steam for the mildura...probably a machined bronze steam 'dome' if i'm lazy, or a copper riveted dome (yet to be decided).... I have used 'L' on my other boiler builds and it is plenty thick for this size boiler...
For cutting some of the copper sheet for boiler ends, I plan to try my plasma cutter...will see how that works out!
-
bondo.....
-
Hi !
That's going to be an interesting project ! :-))
I plan to try my plasma cutter...will see how that works out!
[/size]This will be nice to see and learn.
[/size]Regards.
-
Some more work on the 1/24 tug build. Cutting inexpensive copper water bottle to make water tanks. Replacing long crank with short crank on Mildura Marine twin. Basic setup in hull.
-
I wrote some code for a water level sensor and steam pump valve control unit as well as for a condenser tank pump controller. The boiler water level sensor is a two wire circuit, one contact inside the boiler, and one on outside. It is very sensitive so I may need to add a sensor 'averaging of reads' or 'delay' to the loop. The boiler controller has a USB charger/internal battery and can run by itself. Or you can hook it up to the condenser pump controller and a larger battery. If you want to prime the boiler pump, there is a 5 second auto-run button. Just keep pressing it until pump primed. Then you can adjust the 'fill' run time with the rotary encoder. see the build here, including the C++ code in case you want to make one:
https://forums.adafruit.com/viewtopic.php?t=191380 (https://forums.adafruit.com/viewtopic.php?t=191380)
The condenser tank pump is just a motor speed controller which operates via a push button.
-
Welcome back! What's a couple of years between friends? {-)
Looking like a comprehensive suite of controls you are fitting to the steam plant. The boiler looks lovely, you have done a great job there. It looks like the hull is much as it was 2 years ago but it never pays to rush these things!
Greg
-
You got it :-)) ...welcome back xrad {-) .........regards Derek
-
Thanks Guys! I appreciate your return welcome! :D I missed this forum but I was busy rebuilding a few cars, and creating many electronic projects. Too many hobbies, not enough lives...lol...Thought I would get back to this build finally as I have a few weeks off. Yep, hull unchanged :-)) . But will be soon! More to come.....
-
I machined up a fitting for the boiler sensor. It is brass, stainless, and has some 3/16 Teflon rod. I drilled the rod in reverse on the lathe, using a 2mm drill. 2mm threaded rod through the teflon. The brass fitting is drilled two sizes, a hair under 3/16 for the teflon rod (but not all the way through). then a slightly smaller size so that the pressure does not blow the teflon out. I machined a tiny teflon bushing so the rod does not ground out on the brass fitting (not pictured). The first attempt with the short teflon rod did not work as boiler bubbles coated the short rod enough so that the circuit never showed discontinuity.
the second attempt used a longer teflon rod and worked fine. The sensor detects low water between the two black marks on the sight glass. when the boiler gets to the bottom mark, the senor is always triggering. Now it's just a matter of finding the correct 'fill time' which is adjustable. I don't want to fill too much and lose heat, or too little and then always cycling. Will depend on water pump output also......
-
So I cut the teflon tube in half (from the long tube pic above). This sensor now works perfectly. I have two marks on the sight glass, high and low. The sensor trips at the low mark. I hooked up my double slide valve pump. I timed the water pump valve by hand to the servo motion. You can see the marks on the water bottle. I sloshed around the water in the boiler without false triggering. With the sensor in the center of the boiler and dropping in from the top, it is in the best location to avoid false triggering from wave motion.
I had the timer set originally to 5 sec, but moved this to 6 sec after several runs. the boiler fills each time to the high mark! Nice! Since the amount of 'cold' water is relatively minimal, the boiler maintains pressure and temp fairly well. and the pump is not cycling at all.
If on the water, the boiler begins to overfill due to false triggering, I will write some more code to diminish the false signals or delay another fill cycle.
-
mock-up of the boiler gas control valve and fresh water tanks:
-
condenser bungs machined up. water tank endplates formed.
-
finished the condenser. The condenser is dual purpose. It preheats the boiler water and condenses the exhaust steam. The boiler preheater fittings are made with 5/16 brass pipe (the thick walled stuff for live steam). 1.5" lengths pressed into 1/2 bronze bungs I machined off 1/2 bronze rod. Then, pipe threaded 5/16 x 32 UNEF. I had to split the die and spread it a little with the grub screw for correct thread diameter. The fittings are then soldered to the end cap. A copper coil is made from inexpensive refrigeration tube (.18-.19" dia..i forget the fraction..probably 3/16th). Then the coil is brazed to the fittings and end cap brazed to the condenser body. All parts brazed with 45 silver solder.
-
more pics:
the condenser has two exhaust inlets (engine and water pump) and two vent outlets to the stack. The preheater coils are placed towards the exhaust inlets. The preheater coils were made on a cardboard tube. The condenser has a brass plug on top to check water level. There is a bottom drain with valve. This will go to an electric self priming pump for emptying......
-
How thick is that boiler barrel?! :o
-
Hi Martin. The condenser barrel wall is .125 thick. I was not sure if I was going to thread the barrel, or use bungs so I went with the thicker wall. Next time, I will use .083 and bungs. Some more progress. Finished the two water tanks. These have walls and end caps of .025 copper...really thin, so you have to be careful working it. There is 1/4" pipe inlet and 1/4x40 vent bungs on top of each tank. I have an electric pump that sits on top of a gallon jug of distilled H20, and it will pump these tanks full via a filling receptacle.
The end caps for the water tanks are brazed to the outside of the tanks to keep the rounded edge look. The key is to place a 3 or 4 spot welds around the endcap opposite the natural solder flow. Then, turn the tank 180 degrees and braze fill all the gaps with the natural flow. Why? because it is easy to keep the end cap in place in reverse at first, so you can check alignment. I'm sure there are jigs and other ways, but this was easy.
once done, check for leaks under some minimal pressure. One tank no leaks, the second, tiny leak at the threads of the lower outlet. so, all good. Next, boiling citric acid bath for 30 min, then a quick polish. Big steam plant parts are done. The piping is easy, but will have to wait unit the base/hull mounts are completed.
-
Brazed up a brass mounting base from 1/2" U channel and some solid bar. Made the mount for the boiler pump and servo, brass and silver steel and regular steel. Stainless 3-48 and 4-40 screws hold the parts to the base. the idea is to have the engine and boiler pump exhausts a bit higher than the condenser tank so that condensate runs down to condenser tank. It is a modular setup so that individual parts or the whole boiler /pump/condenser can be removed. Basically, only two steam pipes extend beyond this relatively contained system, the engine steam IN and exhaust OUT. To also make things a bit easier, the engine and boiler pump hot sides are to starboard, and exhausts to port....
-
Bonjour,
beautiful setup indeed :-))
I see a whistle valve, will you build it or buy it ? The first option is a challenge ok2
-
Thank you rhavrane! As for the whistle, I have a small commercial unit which I will be using. I finished the water tank mounts. Hammered some 1" wide brass strips to appropriate angle and silver soldered them to steel bars. I will make band straps to hold the tanks in place...... Test fitting assembly into hull went well, and the mounts do not touch the hull as expected. I have several inches of bow-stern adjustment of the assembly, which will help with ballasting/stability.
-
made a few band clamps with 2-56 screws and .016 brass strips. Silver soldered on some right angle for the screws. Mounted the hand pump. It is adjustable by about 1/2" so that fitting alignment is made easier by using 1/4 thick brass clamps mounted to a 1" wide brass base..... This is the PMR (PM Research) water pump machined kit. It has stainless backflow preventing balls and pumps really well. I have used this to create over 200PSI of pressure. It is not to scale, but close enough for me....... I plan to plumb this on it's own circuit to the starboard side of boiler, where there will also be a blow down valve.....
-
Simple mount made for the condenser tank. Some plumbing done. The boiler and site glass blow downs combine into single line into condenser. x2 back flow check valves keep boiler steam where it should be. One manual valve to open boiler, second one on the site glass. Still plenty of room to use the hand pump. Pump fill line also added. Kinda have to do everything in reverse to see where all the lines will go. Cool puzzle.....also had to machine a bunch of adapter fittings which are useful, but time consuming to make....
-
Bonjour,
In France we would call your steam plant "une usine à gaz" ", a "gaz factory" meaning very compmex, but what a beautiful "usine à gaz"" :-))
Is there any equivalent of this idea in English ?
-
I don't know of an english equivalent, but Rube Goldberg excessive plumbing comes to mind. If you have a fixed die, just take a dremel cutoff wheel and split the die with a slight V groove for the set screw. This will give you the extra thread depth (diameter)needed for some of the fittings.....for example, this is a 5/16-32 fixed die thread which has been cut and is perfect fit spread open a bit, but as-is was too loose for the union nut...
Notice the thin shim to keep the die centered....
-
some more plumbing done. I used 1/4" between the water tanks, which reduces slightly for the rest of the run through the pump and into the boiler fill port. 1/4" tube also used for water tank fill lines, with brass caps on top. There is a condensate drain after the steam pump which can be used with electric drain pump or by the steam pump to empty the water tanks. This same valve is also used to help prime the steam pump. I used up a bunch of old fittings and valves which is why so many different parts ;) . I try to use 3.5mm copper tube for most of the other runs, which is pretty inexpensive at 20 ft for 40$. This is generally connected to 3.5mm ferrules and 1/4-40 nuts. Smaller tubing used for gas and a few other places, like the water tank vents. All of the runs are modular and can be removed for repairs, although sections are brazed at some fittings, like 'T' fittings, to decrease use of union nuts.
waiting on some .016x1/4 brass straps so I can finish the tank straps.....
-
Finished the plumbing major components and tested the system. Works very well. I posted a short youtube vid for anyone interested. Thanks to Andrea for supporting me throughout this project :-)) !
https://www.youtube.com/watch?v=8-Eo9tzdVhM (https://www.youtube.com/watch?v=8-Eo9tzdVhM)
-
Bonjour Xrad,
Again, amazing steam plant indeed :-))
I especially like this double donkey pump, could you please remind me where it does come from as I would like one too !
-
Thank you! So I bought this duplex pump from a machinist named Don 8 or 9 years ago. It is a 3/4 scale van brocklin design which works very well. I do not have his full name or address anymore. Minimal pressure need to get her going. This design has been copied by a few machinists and they end up selling them here and there. Also in the pic is a shuttle type pump. It used to work really well, but then something must have worn out. I need to fix it. Pumps measure about 3.5 to 4 inches in height. You can find them for sale on facebook and other sites. for example:
http://www.chaski.org/homemachinist/viewtopic.php?t=106764&sid=709d00c1f31d8cd479b960c6cef853b0 (http://www.chaski.org/homemachinist/viewtopic.php?t=106764&sid=709d00c1f31d8cd479b960c6cef853b0)
https://www.facebook.com/SteamPump (https://www.facebook.com/SteamPump)
The duplex pump was about 400$ and I bought two. One was a little cheaper due to a slight machining error.
I have/had quite a collection of live steam boilers, trains, boats, and engines over the years. I rebuilt every one to working condition except a 3/4 northern. I still have it in pieces.....you can see it in the background of one of the pics. The duplex pump was originally for this large steam engine. Here are a few pics....
-
and some of the pumps...
-
Bonjour Xrad,
Thank you for this information and I envy too your Stuart bi and tri steam machines :-))
For the moment, I'm going to be satisfied with the one made to me by JMC https://youtu.be/hSwG2p45iGY still on sale.
-
that is a very nice pump.
I found the guy who I bought the pump from in case anyone interested:
http://www.chaski.org/homemachinist/viewtopic.php?t=81142 (http://www.chaski.org/homemachinist/viewtopic.php?t=81142)
You would have to join to PM him. Maybe he (steamingdon) still makes them????
-
finished the tank straps with 3-48 stainless bolts and nuts through brazed brass angles. Tested everything. still no leaks. eventually, i'll get to the hull mounts for boiler and engine and drill the hole for the prop shaft. I have to find a good location for the water tank overflow tubes, which will depend on the deck access.....
-
all pipes polished. while everything is off the boiler frame, I am working on a simple pocket with clamping mount to attach frame to hull....
also, i noticed that the burners were not burning with equal flame. I found that one jet was partially blocked, debris or or poorly made? Also, I had incomplete ignition of gas and there was 'rumbling' (not back-burning) inside the boiler at anything more than a pretty low gas setting. This means that the gas was burning somewhere else inside the boiler pipes, and not just past the burner like it should be, due to lack of oxygen/poor gas-O2 ratio. The rumbling sounds like a pulse jet engine in case you have not heard it. The easy test for this is to turn the gas down until the rumbling goes away, OR gently blow into the burner side holes (those nearest the boiler), and if the rumbling goes away, that is your problem.
So, I drilled out both jets with #80 drill (.0135", .3429mm), the smallest size I have. I set the pin drill into the milling machine drill chuck and carefully aligned the jet holes for drilling, and drilling down about .5 thou at a time, was able to accomplish this without issue. This new jet size just about in the middle between a #8 (.25mm) and #16 jet (.4mm). So of course the burners now run a bit 'more' rich. And they ran rich before I drilled them. But the extra jet diameter allows me to add a moderate amount of air via the extra piping you see on the back of the burners. This is shared and somewhat balances the burners, and subjectively, increased burn temp/flow by about 10-20%. Also, the burners work very well on just a little bit of gas too, so when the tank output low, or the gas regulator sets to low, or I set the tank valve to low, the burners work great. No more 'rumbling'!
The way the burners are designed left little room for adding fresh air ports. Location of pipes at the back of each burner burner is not ideal, but it works out well and I do not have to redesign the way the burners mount to the boiler or the main layout on the boiler frame. Plus, they look cool! Also, the 5/16-27 thread allow me to use different size restrictors if needed, or open up both pipes for individual flow. You can hear the air being sucked into the new intake pipe and the chimney exhaust smells much cleaner....
-
Still working on this project.
Just completed the third of three modular units for boiler control:
1) condenser pump controller
2) Automatic boiler fill controller
3) automatic gas valve controller
https://forums.adafruit.com/viewtopic.php?t=206037 (https://forums.adafruit.com/viewtopic.php?t=206037)
link to C++ code
So for this latest build, I need a way to control the gas burner valve. I decided on a servo with 90 degree throw to a valve with 90 off. good match. Why? because, if the boiler has hit the blow off PSI (usually about 50-60psi), then any additional heating would be wasted. So you can now set the 'pressure' with first selection (highlighted by white DOT and RED LED). this is the trigger point. Above this pressure, the BLUE LED comes on and the gas valve is turned down moderately (to the 'servoEnd' position, but not to OFF, obviously. When the pressure is reduced by steam usage, then the servo arm moves back to initial setting 'servoBegin' setting, and burner turns up to full blast again. I 'could' also trigger the burner to full ON if the boiler automatic filler (unit 2) is triggered, in order to heat the newest 'colder' water up to steam ASAP (but not really necessary as it passes through a pre-heater). ...but that is for another day.... Or.....I could put all the electronics/code into one build....also for another day. The current modular system is just that, modular. If I do not want to use a component, I can leave it out. and it's easy to place around the hull for balance. Everything runs off a 7.4 50c lipo. more than enough juice for hours....Automatic Gas Valve Controller code is here. If you are new to arduino/C++ coding, you may enjoy reading through this for tips and tricks. Especially how to run a single rotary encoder for multiple tasks. Also, using some basic float variables converted to integers, and how to take an analog sensor environmental reading and convert it to an adjustable output back into the environment. Enjoy!
-
Hello !
Very interesting work Xrad! Thanks for sharing.
A friend of mine has shining plumbing too , on his steam plants. When I asked him why he was spending so much time and energy to rub those pipes, he answered me :
-"That makes the ladies come and ask how I do so?"
No comments ! %)
-
code tag test