First Farm Boy Parts

[metalmad]

Hi Jgedde
Looking good Mate
I'll be watching this one
Pete

 

[Brian Rupnow]

Coming together very nicely!! Its great to see two or three hit and miss engines going together at the same time on this forum. ---Brian

 

[Billyboy]

I built a Farm Boy a couple years ago. You made a very good move by using SS for the flywheels. Cast iron is very dirty to work with and your flywheels look great. I am very happy with my finished engine. It runs great, easy to start and will run forever.

 

[gabby]

Yup I think I just might tag along on this one too.
The flywheels look great.

 

[Rivergypsy]

Very nice work - the base especially looks very tidy

I'll be following...

 

[jgedde]

Thanks for all the good words! I just finished the crankshaft.

It was a challenge to make. Even though I made it from 1144 StressProof, I had a lot of problems with warping. During turning of the main shafts, I removed it from the center and found it running out... A lot! Like 30+ thou!

On one side, I was able to correct the center and get it turned down to the proper diameter. On the other side, I needed to weld up the center hole and redrill it.

Now that it's all said and done, I have a crank with the proper OD journals with only 0.0004 of TIR end to end. Good enough for me!

John

 

[jgedde]

And here's the connecting rod with wrist pin bushing installed...

John

 

[gabby]

Very nice work there jgedde, but I cant help asking, is the crank journal to wide for the big end or is it simply an optical, it just don't look quite right
Cheers
Graham

 

[jgedde]

Very nice work there jgedde, but I cant help asking, is the crank journal to wide for the big end or is it simply an optical, it just don't look quite right
Cheers
Graham

Thanks for the kind words Graham.

To answer your question: It's a combination of optical illusion and the fact that the big end is indeed narrower than the journal. There's a flanged, split bearing that has yet to be machined that "takes up the slack". In other words, the big end bearing has radial and thrust surfaces with the thrust surfaces on both sides of the rod.

Like this:

John

 

[gus]

Hi John,
You are my inspiration. Your crankshaft is very well made.
Our neighbour builds Power Break Presses for a living. As a young grad,I watched him
machining crankshafts for power press and he made it look so easy. Till today I have cold feet when I think of building steam engines that require single throw crankshafts.All my crankshafts are useless.
Right now just completed another Deep Sea Rod Holder which has passes sea/fishing trial and about to go into building another version for 2014 Deep Sea Fishing Trip with rod lift/swing to retrieve fish.
After this ,Will go into crankshaft machining.

 

[jgedde]

Thanks Gus! What I have learned about crankshaft making is this:

Choice of material is very important. Residual stresses in the metal are your worst enemy. Hot rolled is best. That said, even with the stressproff 1144 I used, the crank still warped during machining; although it wasn't too late to recover when I noticed.

In retrospect, it would have been much better for me to mill or bandsaw away as mush material as possible before drilling the centers and turning the shafts and journals.

I made the main bearings today and line bored the engine block. The crankshaft fit with no binding and turns freely. Whew!

John

 

[Brian Rupnow]

Machining crankshaft from solid give you a true appreciation for the term "Pucker factor". A very nice job on a difficult part.----Brian

 

[gus]

Thanks Gus! What I have learned about crankshaft making is this:

Choice of material is very important. Residual stresses in the metal are your worst enemy. Hot rolled is best. That said, even with the stressproff 1144 I used, the crank still warped during machining; although it wasn't too late to recover when I noticed.

In retrospect, it would have been much better for me to mill or bandsaw away as mush material as possible before drilling the centers and turning the shafts and journals.

I made the main bearings today and line bored the engine block. The crankshaft fit with no binding and turns freely. Whew!

John

Hi John,

Thanks for the tip. Use hot roll M.S.Bar. Will building a horizontal double acting,slide valve steam engine using same crankshaft. As a 12 year old kid,I used a cross cut chisel to chisel out crankpin. How I did it was a sheer puzzle??? Wised I kept it but that was 1957.

The 3rd generation Deep Sea Rod Holder with lift/tilt function is making headway.

 

[jgedde]

Here's the water hopper. I didn't take any pictures of the water hopper machining itself, but here are some shots of the water hopper funnel being turned.

The circular boss sticking out is a separate piece shunk fit into the hopper after the water tank was bored out...

John

 

[jgedde]

Here is the completed water hopper:

John

 

[jgedde]

And a momentus moment: a dry fit up of the frame parts, the cylinder sleeve, piston and connecting rod, water hopper and crankshaft...

John

 

[jgedde]

Next up was to make the split bearing for the big end of the rod. Didn't take any pictures of the actual machining but it went something like this:

Slit a piece of bearing bronze lengthwise down the middle. Then, glue them back together with CA glue. Next was turning them round to the specified OD, turning the groove, drilling and reaming to fit the crankshaft, drilling an oiling hole, and machining clearance slots for the cap screws.

Here they are: the ID will be "cleaned up" after they are installed in the connecting rod.

John

 

[jgedde]

And finally (enough work for today), fitting the bearings to the connecting rod, and the whole schmiel to the crankshaft.

Here is a closeup of the split bearings, the connecting rod installed, and a "Houston, we have a problem"...

Looks like I didn't cut the radius in the back of the frame deep enough. Oh well. A job for tomorrow I guess. At least I don't have to put metal back on!

John

 

[Brian Rupnow]

Looking very good.---Brian