Author Topic: Farm Boy  (Read 20944 times)

Offline Dalboy

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Re: Farm Boy
« Reply #120 on: December 30, 2024, 05:36:53 PM »
I’ve been looking at the Farmboy on the forum. I’m about 85 percent done with my Farmboy #8. I am trying to find an o-ring to seal the cylinder head with no luck. I was wondering  what you used for yours.

Dave

Sorry for such a late reply, but with looking after my wife and Christmas I have not been on here. Also I need to update work on the Farm Boy. At this moment I can not help until I go into the workshop which I will do tomorrow. But from memory I managed to find an O ring of the right size but as I mentioned I will check tomorrow and also update what I have done since my last work done.

Offline mikehinz

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Re: Farm Boy
« Reply #121 on: December 31, 2024, 12:32:19 AM »
I’ve been looking at the Farmboy on the forum. I’m about 85 percent done with my Farmboy #8. I am trying to find an o-ring to seal the cylinder head with no luck. I was wondering  what you used for yours.

Dave

Dave, in case you don't hear from anyone else, when I built my Farm Boy (I have a build thread on it here in the forum) for the o-ring for the head, I used the following from McMaster Carr, their pn 9464K79.  Specs as follows:

Material - Viton Fluoroelastomer Rubber

Cross Section Shape - Round
Dash Number - 025
Fractional Width - 1/16
ID 1 3/16  OD 1 5/16 

Actual Width 0.07"
ID 1.176" OD  1.316"

You didn't ask for the info, but for the piston I used a Viton -020 o-ring also from McMaster. 

Also when I machined the piston, I tried various groove depths but in the end I used exactly what Jerry Howell's drawing called for.  That might seem extremely loose but it works great as the friction to the cylinder wall is quite low so you'll get good coasting between hits.

Hope this helps!

Mike
MIke
Wichita, KS, USA

Offline Dalboy

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Re: Farm Boy
« Reply #122 on: December 31, 2024, 11:21:30 AM »
I have just checked, and I am using a 2.4X29.6.NBR nitrile O ring. The same size as the other end, I got mine from a company here in the UK called Simply bearing. You may need to source some from your neck of the woods as I can see you are not in the UK

Offline Dreeves

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Re: Farm Boy
« Reply #123 on: December 31, 2024, 01:21:19 PM »
Thanks for the info on the o rings. I was able to make a paper gasket to get the engine running. I will order the o rings mikehinz posted. I was able to get the correct piston o-ring.

Dave

Offline Dalboy

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Re: Farm Boy
« Reply #124 on: January 20, 2025, 06:44:10 PM »
Just got around to updating where I am with this build.

Managed to get the Fly wheel locking collars completed and could not resist a part dry fit with they in place.


I have been putting off cutting a test tube to complete the oiler for the engine. So I tried to use a glass tube cutter which failed, and it shattered, so a good clean up and vacuum got rid of the broken bits. Next I wrapped the tube in some masking tape (I have about ten tubes as that was the minimum I could get at the time) this was gently gripped in the lathe yet strong enough not to slip, a Dremel was used with a small diamond disk and a short section soon parted ways from the tube. This section was rubbed on some very fine wet and dry paper to get rid of any sharp edges (With the tablets I am on if a cut myself it takes forever to stop)

As most of the parts were already made from brass, the only other part was the control needle, which is from silver steel (tool steel depends on where you are in the world). This needed a point on one end and then cut to length and fixed into the top adjustment piece.

The complete oiler ready for the engine once completed as there are still bits that need making. Without measuring it I would say between 1 1/4″ to 1 1/2″ tall.


Offline Dalboy

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Re: Farm Boy
« Reply #125 on: January 20, 2025, 06:58:50 PM »
After two failed attempts at the governor assembly, I manage to silver solder the two arms on and now happy with the outcome.

Now onto some other small parts and a base for it to sit on so that I can attach the flywheels.

Gov assembly



After making some pins I am able to do a test fit of the governor assembly hopefully this makes a little sense where thing go

Offline Dalboy

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Re: Farm Boy
« Reply #126 on: January 20, 2025, 07:04:59 PM »
More work on the Fuel tank. First a little late I managed to get both stand uprights completed all except the fixing holes. As well as the end cap fixing screws.



Onto today drilled the filler hole and fuel outlet this was threaded 1/4″ x40. Turned some brass for the outlet elbow and did the same method as I did for the carbaretor elbow by milling at 45deg most of the way through heating and bending before silvers soldering.

Fuel tank with outlet fitted (1)Fuel tank with outlet fitted (4)

Twisted the tank upside down to show outlet pipe in position. I need to take apart to clean swarf out of the inside.

A small note I have stripped and cleaned all of the swarf out of the tank and I still need to make a fuel cap for it
« Last Edit: January 20, 2025, 07:08:47 PM by Dalboy »

Offline Dalboy

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Re: Farm Boy
« Reply #127 on: January 20, 2025, 07:07:36 PM »
This now brings me up to date. I have started a side project so that I can continue with the build. I am making a spring winder so that I can make the valve springs. It will also be used for other springs that I need for my other main project which is the Rob Roy loco

Offline Admiral_dk

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Re: Farm Boy
« Reply #128 on: January 21, 2025, 06:35:05 AM »
Great progress and I like the color too  :ThumbsUp:

Per           :cheers:

Offline Dalboy

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Re: Farm Boy
« Reply #129 on: January 24, 2025, 07:48:51 PM »
Great progress and I like the color too  :ThumbsUp:

Per           :cheers:

Thank you have stopped again to make a spring winder so I can make the springs for the tappets

Offline Roger B

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Re: Farm Boy
« Reply #130 on: January 25, 2025, 08:20:56 AM »
Coming along nicely  :praise2:  You must now be on the last 20% that also takes 80% of the time  ::)
Best regards

Roger

Offline Dalboy

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Re: Farm Boy
« Reply #131 on: January 27, 2025, 04:49:55 PM »
Coming along nicely  :praise2:  You must now be on the last 20% that also takes 80% of the time  ::)

Yes agree even when making the wooden models that I also make. This was the last one I made.

Anyway I have made a spring winder so I can make the valve springs as I mentioned earlier. I have added a picture of that.


 

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