Topic: Xrad's Live Steam Trawler (Read 19302 times)

xrad · « **Reply #25 on:** December 15, 2013, 04:24:33 pm »

repaired a water pump. Bought from a nice guy named Vern who lives in northern plains area. Pump needed some repairs including removing all the expanded gasket goo, and repairing of a valve rod. Ball valve surfaces needed some cleaning.....

It is a steam hog and may be better on my 3/4 Northern rather than the trawler....

http://www.youtube.com/watch?v=HfBsafxi12k&feature=youtu.be

The basic function of a 'shuttle' pump:
There are 2 valves. The position of the 1st vale to encounter 'steam in' is determined by the position of the piston rod. There is a rod inside the piston rod. it is loose and has less travel than the piston rod. It controls the position of the first valve. The first valve position controls steam to the second valve (the shuttle valve). This controls steam to the piston. Top side is prettty direct. The steam also travels inside a hole bored into the cylinder wall to get to the far side of the piston.

Wtaer side of pump pretty straightforward with four ball valves and double acting piston. I estimate the piston to be about 20-25 % less diameter than the steam piston.

The original valve rod was in two pieces. I made the mistake of thinking that I had all the pieces, so the first one I made was too short. I added about 6mm more to the second rod and this was perfect. New one out of brass, old one steel.

Timing is easy, just make sure that 'steam in' valve travel is appropriate to uncover the ports and that the valve rod is long enough so that the piston rod can act unimpinged. The shuttle valve needs no timing, but shuld be (Very) free to move. Pump worked best when I could shake it and hear the 'shuttle' valve sliding back and forth.

xrad · « **Reply #26 on:** December 29, 2013, 04:46:20 pm »

Well.......the Sweden burner was a flop. I got it to burn well but it jumped from the end to the jet and would then cycle with a popping sound. And then I added the smoke stack and it ran like crap....so....time to build my own burner.
It is 1.5 in wide and about 4 inches long. Solid brass base and thick brass tube. Screen mesh just inside of the stainless perforated end. This keeps the flame from jumping to the base port. The base port flares 20 degrees for mixing gas and air in the brass tube before burning. Lights easily hot or cold. uses number 8 jet(and uses no more gas than my smaller 3/4 in burner). 4-40 set screw.
Might have to build a surrounding guard so as not to draw too much cool air into boiler when firing. about 1/4 inch gap around the burner.

see vid:
http://www.youtube.com/watch?v=Z09Bvdtlmu0&feature=youtu.be

xrad · « **Reply #27 on:** December 29, 2013, 07:02:52 pm »

Did a steam test after a few more minor adjustments to burner. Added an air regulator. Smoke stack in place. 10 minutes even to 70PSI blowoff. Able to maintain 55-60 PSI with part open steam valve (maybe 1/15 open). Boiler was about 5/6ths full with cold water (not ice cold). My best boiler build is ~8 minutes to steam so I am VERY happy with the results. A fill water preheater would do well here and may be built into the condenser. Just need to build the burner surround collar so the fit to the boiler is better. The above mentioned 1/4 gap between burner and boiler burner tube was mostly plugged with a bit of aluminum foil.

Basic layout comming together.

BFord Low water detection unit.
6v 100 psi open/close valve (normally closed)
6vbat
hand pump
Electric pump (allegedly can hit over 100 PSI, yet to test..alternate is twin double action steam pump)
Boiler and engine
Side water tanks
gas tank

Not pictured is adjustable voltage regulator w/readout and several 6v relays to run the waterpump, lights, valve, etc...might need a bigger battery
long way to go........

xrad · « **Reply #28 on:** January 02, 2014, 01:52:06 am »

Did some lagging today. Used 3/4 character hickory left over from flooring, ripped down to a 1/4 plank and then ripped to smaller pieces. Honed a curve on the backside but was too lazy to bevel all the edges. Went with a thicker cut for strength and looks. Brass straps.
The wood has a very tight grain and is strong and cheap. A few drops of CA glue to hold position while the bands were applied. Blue mark applied to inside of curve so that I stained the correct side.

stained and oiled...no poly or anything on top...just let a natural aging occur..

I was just looking at micromark's nickle plating kit. I should have plated the cylinder head and valve chests to avoid the rust back when it was all apart. I will have to make an air compressor valve attachment to blow out the engine after running. Anyone else do this?

steam up · « **Reply #29 on:** January 02, 2014, 12:13:48 pm »

Really enjoyed taking a fresh look at this thread during some down time thanks.

xrad · « **Reply #30 on:** January 04, 2014, 02:26:00 pm »

THANKS! Appreciate the comments.

BOILER BURNER UPDATE:
Well, looks like burner number 3 was a bust because after it is placed into the boiler burner tube for over 20 minutes, the stainless screen becomes too hot and 'back burning' occurs. It sounds like an afterburner with a real loud roar. I tried to place the screen/screens in all different positions and burner tube lengths, but it did not prevent the back burning. Why?...because the whole burner heats up too much and the thin screen can not dissipate the heat well enough to prevent ignition of the gas before the tiny pores of the screen. This only happens when the burner is inside the burner tube where the air circulation is directional and minimized.

So..how to fix?.... Addressing the back burning first: The 4th design incorporates a .3 in thick brass slug with 150 #54 holes drilled through. The .3 in length is arbitrary but seems more than thick enough to prevent gas burning through the pores even when hot. This slug was then pressed into the end of the short tube and tested. This burned well but not really hot. Took a while to get the boiler going. So back to the long tube with an axial gas flow design. Beveled base port mixes air/gas well with the longer tube. The collar is for air adjustment with several different air hole sizes tried as well.

Then, when things started looking good, the 'long' burner was placed into the boiler and WOW boiler tube harmonics and a standing wave with the burner jet created the worst loud whistle(like a flute). When the burner was far enough out to stop the whistle, it was too far out of the boiler. The standing wave actually compressed the flame decreasing heat when in too far...so..back to the drawing board.

I decided to press the brass slug back into the long burner tube about 1/2 inch. This significantly decreased the standing wave nearly to nill, but the burner was now running poorly due to lack of oxygen at tip.

Next, I drilled 8 holes ~3/8 around the burner tip to allow air into the flame. WOW!! this was it. Now the 1/4 inch gap around the burner (when inside the boiler tube) really supplies air into the burner tip and the burner roars out the end with a really hot flame. Almost all of the orange glow is gone and the flame base is blue/white in color and dancing well on the brass slug!! The boiler really heats up well now, and with the wood lagging. The flame is hot enough to melt brazing sivler rod if placed in the flame three inches or closer to the slug end. However, it does not seem hot enough to melt the cross tube brazing due to the water drawing heat away. Burner can be turned down to less heat if needed by bottle valve.

Pics show the attempts, and vid the final iteration.

see vid.
http://www.youtube.com/watch?v=JTg72W_h630

All 2-56 screws stainless. 3 set the slug and three set the tube. tube and base brass. Air collar bronze

southsteyne2 · « **Reply #31 on:** January 05, 2014, 05:37:48 am »

Seems to me your problem is no external air holes on the burner body ,check out the firetube burner from clevedon steam as I use this one with no problems
Cheers
John

xrad · « **Reply #32 on:** January 06, 2014, 07:07:10 pm »

THANKS for tips! I have three of Jerry's burners. The outside visible holes are actually outside the inner burner tube in a burner shield of sorts.The only holes in the main tube are for air at the jet support. Mute point as my burner design works great now. I get my number 7 and 8 jets and jet mounts from him. Nice stuff!

My next issue is boiler filling. I have an ebay Microcosm electric boiler pump. Very nice unit. I tested this unit from 6-14.5 volts and even when pumping at its best, it only manages about 100ml in 90 seconds. Much too little a volume for me and it really did not like to pump against 65psi, although rated for it by seller.

next I tried my duplex pump. Works great once I removed a beetle from the water side. don;t know how it got in there....The issue is valve control. I have several servo controllers as in the pic, but nothing really worked well. I was going to try a servo type solenoid with 10mm retraction, but then I still have to rig up another valve into the system.

I also tried a Clippard high pressure pneumatic valve(as recommended and sold by Bill Ford). This did not work at all and as soon as temp and pressure was at working levels, the valve blew through the top. Not enough flow through the valve anyway. So on to something else.

On ebay, I found what I think will solve the problem. A high pressure high temp steam/hot water valve 1/2 NPT. Pricy but should work. Runs off 12v so I can wire a relay through the WLDS to operate the valve. Once this all works, and my stainless 'flask' water tanks arrive, I can do the hull layout better and get to building the engine/boiler support frame.

As a side note: I get my stuffing 'tubes' ,propellers, electronics, and other bits from Nick at Harbor Models. VERY fast email replies and shipping. Always excellent service from him. One of my favorite bit is a servo relay used for lights on another trawler I built.
http://www.harbormodels.com/

peter61_uk · « **Reply #33 on:** January 06, 2014, 11:23:54 pm »

This is proper engineering. I just wish I had the facilities to be doing some myself.............. But I build on the dining table so I think "er indoors" would get all ansty if I plonked a lathe and pillar drill on there

I am very very impressed ............

southsteyne2 · « **Reply #34 on:** January 07, 2014, 12:15:49 am »

Are you fitting the inner tube of the burner into the boiler ? as mine fits snug into the furnace tube on the outside dia of the burner which allows air to mix with the gas.
Cheers
John

derekwarner · « **Reply #35 on:** January 07, 2014, 12:27:36 am »

Xrad.......I also have a Microcosm electric boiler pump

The pump appears to be of good quality.....however the as supplied 12v DC geared motor sounded like a VW engine in a tin can.....

Have substituted a locally purchased 12v geared motor & added a 4.0 mm shaft size plumber block for support

Yet to be installed or commissioned, however the boiler relief valve is 3 Bar [45 PSI] so will be lighter duty..................Derek

xrad · « **Reply #36 on:** January 07, 2014, 03:39:12 pm »

Hi fellas, Thanks for the replies!
Decoy: My Microcosm pump must have been made on a Wednesday because it was fairly quiet and pumped well once oiled with a few drops of steam oil. There is an inner O ring on the piston which I have a feeling won't last too long.

SouthSteyne2: No , it is not snug due to required air flow for 1) to keep the flame oxygenated and hot, and 2) to keep the burner cooler. I tried adding a foil damper between the burner and the burner tube but it did not make a significant difference in boiler heating as the flame was less hot. The increased heat from decreased airflow was minimized by decrease in burner flame temp, and also the gas was not burned as efficiently. The cooling effect of the 'air collar' is minimized by the much greater increase in burner flame temp. I don;t have a temp gauge that can measure this, I only used time to blowoff valve pop for several different designs. 10 min is the best I can get with this burner set-up and room temp H2O. It is a really hot flame but also not very noisy. Kind of a nice balance.

Peter61: As far as 'er indoors' I am the man of the house which means nothing really; as long as I want to make a big mess in my little corner of the basement, all is cool.

xrad · « **Reply #37 on:** January 08, 2014, 02:26:43 pm »

I could have gone to the hobby store and bought a small thrust bearing, but I decided to build a thrust bearing. Bronze case, brass disc on a stainless 3/16 shaft. Half filled with oil. About 2x2 inches. I may decrease the diameter of the internal disc if the friction is too much. It is about 1 inch right now.

The case was made as a mirror image machining process. 3/16 bore first, followed by internal case boring to required diameter and depth of the brass disc. Then the outside of case machined down for bolt spaces. All this as one process on the lathe w/4 jaw chuck. Then split the case with slitting saw on the mill. reversed the halves and screwed together with thin gasket.

The mounts yet to be designed.

This bronze bar was harder in some spots than others, which I did not like as machining was at times not so easy.

xrad · « **Reply #38 on:** January 19, 2014, 09:03:57 pm »

MAde a new thrust bearing. See pic below. 3/16 stainless rod and some real flanged bearings. very smooth. Not thrust bearing per se, but will work with the forces required.

Tested the steam valve with boiler water level detection unit. starts about 45 sec into video. see the flashing LED which tells that relay activated and steam flows starting the duplex pump. Valve rated for 265 degrees(stainless/viton 23$ on ebay). I ran it for about 45 minutes with no issues.

My method of aging props, I use copper plating for all my models...my signature on my builds.. Salt water, 7 volts, copper wire.

video at :
https://www.youtube.com/watch?v=37BZJHCT9wM&feature=youtu.be

xrad · « **Reply #39 on:** January 27, 2014, 04:25:53 pm »

tried another new piston and O ring on my shuttle pump. Still no pressure to speak of. Piston is .0015 less than bore diameter and O ring is proud by at about 1/4 tp 1/3 its diameter. Snug fit water side and the engine side of the pump works great. Just does not make pressure. I put in 4 new stainless balls and checked all the seats. everything looked clean and had a good fit. I might use the engine side to power a hand pump. suction is pretty good but I can put my finger over the outlet and stop the flow with mild pressure. My other pump, I can;t stop the flow with my finger...

Made two universal joints the old fashion way with two steel pins. allows for some deflection in the shaft alignment. More than I will need.

pump vid:
https://www.youtube.com/watch?v=K2wb7Fm4qYs&feature=youtu.be

peter61_uk · « **Reply #40 on:** January 27, 2014, 08:12:34 pm »

I am absolutely so impressed with the precision work you are doing here ......... Really enjoying this thread.

xrad · « **Reply #41 on:** April 08, 2014, 11:41:40 pm »

Been side tracked with an Alfetta turbo project and my Tich. Not a boat, but thought you would enjoy:
https://www.youtube.com/watch?v=WW0-xH-wxw8
PS: I am using the boat boiler!

xrad · « **Reply #42 on:** April 26, 2014, 02:56:02 pm »

Did some work on my stuart triple: Copper cladding w/patina, condenser straps, condenser mount, straightened drain cocks after punching out some aluminum washers. DEI exhaust wrap insulation under cladding.

Landlocked · « **Reply #43 on:** April 26, 2014, 09:36:29 pm »

Xrad,

Showed my wife your work to compare it with my hack work. She exclaimed that it must be one of those crazy Brit's whose work that I'm always amazed by. Thanks for keeping up our side of the pond's reputation. Becoming a machinist is on my retirement goal list.

Landlocked/Ken

xrad · « **Reply #44 on:** April 29, 2014, 02:16:11 pm »

Hi Ken, thanks for the compliments. But, my skills are not anything to be proud of yet. I forget more than I can remember with the mill and lathe setups.....

Riveting is fun...I made a few tools to accomplish this and will build a control box for my yard boat and post pics soon.
Cheers, X

KBIO · « **Reply #45 on:** April 30, 2014, 06:36:24 pm »

Hello!
Very pleasant to follow up.

Something new for me.
Thanks.
Regards.

xrad · « **Reply #46 on:** May 02, 2014, 04:53:02 pm »

Thanks KBIO

Starting work on a Scott type boiler (not Scotch). It is basically a 3x9 in tube with 12 or so pigtail coils on the bottom(outside the boier). The flame shoots through the pigtails. It is a combination of a flash boiler and a watertube boiler. I have one on another boat and once I rebuilt it, it steamed up very fast and can maintain steam well.

I di a few tests with the copper pigtails and I will post results.

Think of it like a Stuart small boiler on steroids....will post pics soon

ooyah/2 · « **Reply #47 on:** May 02, 2014, 06:45:06 pm »

Quote from: xrad on May 02, 2014, 04:53:02 pm

Thanks KBIO

Starting work on a Scott type boiler (not Scotch). It is basically a 3x9 in tube with 12 or so pigtail coils on the bottom(outside the boier). The flame shoots through the pigtails. It is a combination of a flash boiler and a watertube boiler. I have one on another boat and once I rebuilt it, it steamed up very fast and can maintain steam well.

I di a few tests with the copper pigtails and I will post results.

Think of it like a Stuart small boiler on steroids....will post pics soon

xrad,

The Scott boiler you describe is by a design of A.Rayman a well known straight runner in the past and the Co, author of EXPERIMENTAL FLASH STEAM and still alive today.

Some time ago I posted some pics of this design which was powered by a pressurised paraffin blow lamp.
The engine had an open crank case and at a boiler pressure of 150 p.s.i did 15,000 r.p.m. free running.

It's a super fast steamer but not a Flashsteam boiler, mine would get up to 150 p.s.i. in less than 2 mins with the burner working at 60 p.s.i. and could delivery very high Super heated steam.

Here is the link to the thread.

http://www.modelboatmayhem.co.uk/forum/index.php/topic,24875.0.html

George.

xrad · « **Reply #48 on:** May 05, 2014, 12:19:59 am »

Thanks George. Nice work!

Here is my basic plan, nothing too difficult to make. Also pic of near final build bits on the triple....

The Scott boiler(or my variation) I am thinking of is described on page 190 of Model Power Boats by Hobbs, 1929. This is likely in reference to David Scott's design from about 25 yrs earlier for model boat use.

ooyah/2 · « **Reply #49 on:** May 05, 2014, 11:58:01 pm »

Quote from: xrad on May 05, 2014, 12:19:59 am

Thanks George. Nice work!

Here is my basic plan, nothing too difficult to make. Also pic of near final build bits on the triple....

The Scott boiler(or my variation) I am thinking of is described on page 190 of Model Power Boats by Hobbs, 1929. This is likely in reference to David Scott's design from about 25 yrs earlier for model boat use.

xrad,
Thanks for the pics of your proposed mods to the Scott boiler.
I am always interested in peoples experiments in boiler design so I would be obliged if you could post a larger pic as I can't make out some of your sketch and I don't have the publication that you refer to.
If that's not possible I can P.M. you my mail address and you could send it by e-mail.

What size and type of burner do you propose to use ?
What type of fuel are you going to use?

George.

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Author Topic: Xrad's Live Steam Trawler (Read 19302 times)