The Steamboating Forum

Was able to get some more parts completed over the last few months. Cutting a keyway and a little bit of finishing and painting is all that remains for the thrust bearing assembly. I changed from the original design using a single ball bearing and bronze bearing to one using two ball thrust bearings.





Cheers

Ken

A trick that has worked well for me when silver soldering small bits together and with reasonably flat surfaces (not usable for round things in round holes) is to grab my spring loaded automatic center punch and pop three punch marks on one of the mating surfaces. As wide apart as possible. It provides just the right gap for the solder to penetrate and still get full strength. I apply the flux before heating. Water based.

Hello everyone,

I have been working on the crankshaft for the York engine since early November and can finally say that it is completed. It was really a wet noodle of a part and many creative setups were needed, moving the rests many times and never had quite enough room to make a complete cut without re-setting the tools, it really pushed the envelope of my 12x36 lathe. Finish ground using a toolpost grinder and an 8" wheel. The pucker factor was high when cutting the keyways and the square at the end of the shaft. You know the feeling when you realize how much time is in a part and you just can't mess it up on the last features.





Cheers

Ken

Marinesteam:

"The solution is to use a high-temp compatible plastic plain bearing. And these bearings are also less expensive, weigh far less and take up less room than a ball bearing."

Please, if you would, tell us more about these plastic bearings and where they can be sourced. Thank you.

Tim,

Missed your question, sorry for the delay.

The plain bearings that I was referring to were molded for the customer from a proprietary compounded plastic by my previous employer. They were essentially a PEEK plastic with a high carbon fill. A similar product is available from McMaster-Carr in Vespel

http://www.mcmaster.com/#standard-sleev ... s/=12dmwjv

A similar bar stock material is also available http://www.boedeker.com/tecapeek-cf30.htm, but it's not going to be inexpensive

Cheers

Ken

Starting the cylinder block casting. Decked both top & bottom. It's a bit big for my mill but got the job done with no mismatch in the surface. Yeah!

Looks good Ken

-Ron

Working on the bed plate.

Next weeks task is to complete the remaining drilling, deck off the bottom mounting area and to clean up the thrust bearing lug faces.

Ken

It is a bit difficult to see just how you are clamping the base casting to your table but it looks like you are clamping in 4 places. It is always a good idea to pack up the casting in just 3 places. i.e. in a triangle, and then to clamp directly over the top of the three packers, this way you are least likely to spring a twist into the casting as you clamp it down. Also, if you work like this and any stress is relieved withing the casting by machining it, the casting will be able to move to it's most relaxed position and your final cuts will be in the correct place, rather than the casting twisting after you release the clamps.

Cheers

Lionel

Quote: "It is always a good idea to pack up the casting in just 3 places."

Yes, for establishing an initial accurate plane of reference. Or shim the irregular surface with Joblocks or expandable parallels.

Quote: "the casting will be able to move to it's most relaxed position and your final cuts will be in the correct place, rather than the casting twisting after you release the clamps."

Depends on the mass and rigidity of the casting, but once an initial accurate plane is established, it is best to flip the piece to the work surface and hold it firmly at a sufficient number of points to eliminate deflection from cutter/machining forces. Castings are naturally annealed when cooled slowly and typically have very little internal stress, unlike a weldment.

-Ron