Farm Boy running

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simonbirt

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Just thought I would post a link to this short video of my Farm Boy
I have been building it over the last year of and on and ran it for the first time the other day. I should say I have little experience of internal combustion, all my projects so far have been external combustion.

I would welcome comments and suggestions from all you knowledgable people. It is suggested in the building notes that acetone is a good fuel for this engine. This is what I have used, but it is not great to paint or varnish and as I plan to use both on the engine and base I can see a problem. It also has a tendency to rust steel, the needle valve on the fuel had a surface coating after the first run.

Starting is a bit tricky, the most reliable method I have found is to flood it, close the needle valve and then open the valve once it starts to fire. Needle valve setting is very sensitive an 1/8th of a turn one way or the other makes a big difference.

As I say in the video I suspect that it is running a bit slow, although I like slow running it makes it difficult to get going with the governor engaged.

Finally, I need to make a fuel tank and incorporate a non return valve. Does anybody have a design for one? I am thinking ball and light spring? I have made lots for boilers but they rely on high pressure to keep them closed, I’m assuming that a clack type valve would not work.

An interesting project so far, makes a pleasant change from steam. Now have to paint the engine, have a go at some name plates, make a base and a fuel tank. Then on to the next project, any thoughts?
 

gunna

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Cant help with your questions Simon, but gee it runs nice as it is.
Ian.
 

danallen

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You don't want a spring on your one way valve. Just a small ball about 1/8" sitting vertical and gravity. Looks good.
 

ShopShoe

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That's very nice. I don't think it's too slow. It's hitting and missing very well.

Thank You for posting.

--ShopShoe
 

Engine maker

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Nice work,

I built SN# 003and the double size one SN3003-X2. Denatured alcohol or Coleman Lantern fuel (white gas) both work fine, but with alcohol you have to lube after running so it won't get surface rust. As an added point, with Coleman you can run it in the house with almost no odor.

Easy one way valve is a RC fuel filter ( the aluminum ones, they unscrew) with a small ball bearing dropped inside. Just mount it vertically.

Fuel tank height may be a point to look at, may be a bit low. It can pull the fuel up but not too far. Starting both of mine, needle open about 3/4 turn, finger to choke mixer and give a good flip, remove finger. flip and off they go.

It may be a tad slow. From listening to it your coasting about 10 revolutions between firings. It needs some breaking in and it will get to around 25 - 30. You can look at this Coolspring engine show video


at the 20:15 time and see how long they will coast. My small one does way above 60.

Jim G
 

rklopp

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Congratulations on very nice surface finish and workmanship. It seems to run great in my opinion. As for a check valve in the fuel line, on my Breisch Hired Man I just have a 1/8" ball bearing sitting on a brass seat under gravity. If I had a drawing for the valve, I'd be hard-pressed to find it now. The internal geometry is a bit like a safety valve for a 16mm narrow gauge steam engine without the spring.
 

simonbirt

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You don't want a spring on your one way valve. Just a small ball about 1/8" sitting vertical and gravity. Looks good.
Thanks, I was not spotting the obvious (vertical) I had it my head that I would feed fuel from the side of the tank and therefore have a horizontal valve. Gravity is an often overlooked commodity.
Nice work,

I built SN# 003and the double size one SN3003-X2. Denatured alcohol or Coleman Lantern fuel (white gas) both work fine, but with alcohol you have to lube after running so it won't get surface rust. As an added point, with Coleman you can run it in the house with almost no odor.

Easy one way valve is a RC fuel filter ( the aluminum ones, they unscrew) with a small ball bearing dropped inside. Just mount it vertically.

Fuel tank height may be a point to look at, may be a bit low. It can pull the fuel up but not too far. Starting both of mine, needle open about 3/4 turn, finger to choke mixer and give a good flip, remove finger. flip and off they go.

It may be a tad slow. From listening to it your coasting about 10 revolutions between firings. It needs some breaking in and it will get to around 25 - 30. You can look at this Coolspring engine show video


at the 20:15 time and see how long they will coast. My small one does way above 60.

Jim G
Thanks Jim,

Interesting video, hit and miss engines are something of a rarity here in the UK. For me they are the missing link between steam and the modern internal combustion engine, which makes them interesting to build.

Simon
 

JohnBDownunder

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To me (in my minuscule experience), it sounds about right and as has been said by Engine Maker above it will increase in revs after running in.
I think these are a great little engine. Plan to make one some time in the not too distant future if life stops getting in the way. I thought being retired meant lots of free time - HA, not so as family takes precedence and rightly so.

As a lad,(some 70 yrs ago) the local wood man would sometimes come and saw logs into foot blocks in our back yard. He had a Hit n Miss driving the saw and as designed the miss part got shorter with load. No, he had a horse and cart, not a bullock wagon.

Try adding some load to the off-side fly wheel and listen to the firing sequence change. That's the fun part of these I reckon. ;) Off side keeps your fingers away from the governors!
 

ds engines

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Hi great engine just finishing one off myself.What ignition system are you using it looks very nice where can i buy the kit to build the ignition system.
 

timo_gross

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People tend to ask me: "What is it good for?" 🙄
So if you want to impress "the kids", you need to at least be able to charge a smart phone or tablet with it. :)

If you want to impress me, already good enough, as is. 👏
I have no clue how fast it must run, but it looks good to me from an unexperienced spectators point of view.

Greetings Timo
 

Brian Rupnow

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That sir, is a masterpiece. Use Naptha gas as fuel (sometimes called white gas). It is very low odor and runs all of my engines just fine.--and it will not harm your paint.----Brian
 

Iampappabear

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Great looking and running engine Simon, I currently have a Farm Boy in the works which is about 90% complete, only hope it runs as well as yours.... someday. I guess too much to hope you are in southern Ontario where i might get a chance to see it live.

Colin
 

Harglo

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Just thought I would post a link to this short video of my Farm Boy
I have been building it over the last year of and on and ran it for the first time the other day. I should say I have little experience of internal combustion, all my projects so far have been external combustion.

I would welcome comments and suggestions from all you knowledgable people. It is suggested in the building notes that acetone is a good fuel for this engine. This is what I have used, but it is not great to paint or varnish and as I plan to use both on the engine and base I can see a problem. It also has a tendency to rust steel, the needle valve on the fuel had a surface coating after the first run.

Starting is a bit tricky, the most reliable method I have found is to flood it, close the needle valve and then open the valve once it starts to fire. Needle valve setting is very sensitive an 1/8th of a turn one way or the other makes a big difference.

As I say in the video I suspect that it is running a bit slow, although I like slow running it makes it difficult to get going with the governor engaged.

Finally, I need to make a fuel tank and incorporate a non return valve. Does anybody have a design for one? I am thinking ball and light spring? I have made lots for boilers but they rely on high pressure to keep them closed, I’m assuming that a clack type valve would not work.

An interesting project so far, makes a pleasant change from steam. Now have to paint the engine, have a go at some name plates, make a base and a fuel tank. Then on to the next project, any thoughts?
These Farm Boys are by far the most smooths {long} miss cycle for there size. Mine ran so well I made a 20% larger on same nice runner. I use propane.
Harvey
 

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simonbirt

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Hi great engine just finishing one off myself.What ignition system are you using it looks very nice where can i buy the kit to build the ignition system.
The ignition system is home made, based upon information cleaned on this site. I can send you a board and instructions, not hard to assemble. A few have commented on track widths etc and suggested improvements. I have tested one for many hours on a test rig and it is still fine, in fact it is the one running the engine in the video. Besides I have several boards in stock as there was a minimum order.

If you would like one, let me know where you are and I will send one.
 

simonbirt

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These Farm Boys are by far the most smooths {long} miss cycle for there size. Mine ran so well I made a 20% larger on same nice runner. I use propane.
Harvey
Love the woodwork, very pretty.
 

simonbirt

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Great looking and running engine Simon, I currently have a Farm Boy in the works which is about 90% complete, only hope it runs as well as yours.... someday. I guess too much to hope you are in southern Ontario where i might get a chance to see it live.

Colin
Hello Colin,

Sadly not in Ontario or even Canada, UK. I will make a better video when I have it painted and a base made.
 

simonbirt

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That sir, is a masterpiece. Use Naptha gas as fuel (sometimes called white gas). It is very low odor and runs all of my engines just fine.--and it will not harm your paint.----Brian
Thank you Brian, I really appreciate your kind comment. I think I will get some Colman fuel as another drawback of acetone is that it is kind to O rings.
 
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