The Home Machinist!

RSG wrote: ↑Sun May 01, 2022 8:43 am

BigDumbDinosaur wrote: ↑Sat Apr 30, 2022 3:15 am

RSG wrote: ↑Fri Apr 29, 2022 5:13 pm LOL@BigDumbDinosaur

Exhibit A:

https://www.youtube.com/watch?v=taU6qu5pXBo

brilliant! Eliminates the need to worry about burnt out light bulbs in the strobes.

Also, the flames let you know the engines are still running.

GlennW wrote: ↑Sat Apr 30, 2022 10:26 amCold air enters the front of the belly scoop, is heated going through the radiator, and expelled through a reduced opening.

The Mustang was the best-known example of the use of the Meredith effect to reduce cooling-system-induced drag. NACA exploited the idea in the 1930s with radial engine cowlings, but with less effect than seen with a liquid cooling system.

Back to connecting rods...

Grinding the parting line to close up the big end bore. (1" micrometer for scale) Then honing the bore back to size to get it round and straight again.

And then you fit a new bearing, bore it to size, and radius the corners.

The fork rods aren't as much fun to do as the blade rods, as you can get away with using a Sunnen cap grinder on the blade rods. The fork rods are way more labor intensive.

They need to have the beam hand lapped to the upper bearing block for 100% contact. Then the parting line on the bearing blocks get hand lapped on the lapping plate until the bore is as round as possible and on size, or slightly under size with the rod assembled. Assemble, check dimensions, disassemble, lap, clean, assemble, check dimensions, over and over again...

Then the ID is honed back to size and round again.

Then it's off to the grinder where it is fixtured to a mandrel so the OD can be ground round again.

Here is the wear pattern that left a ridge in the center that you need to eliminate. After grinding and a light polish with a 3M Trizact belt. Then when you get through all of that, the rods get assembled onto the crankshaft and the centerless ground cotter pins, which are soft and a light interference fit, get installed in the rod bolts/nuts. These are really fun to install or remove.

Super impressive from front to back!
Do you grind those little fellas on the centerless grinder you mentioned earlier?

No, I bought a bunch a long time ago when they were still available.

I have a universal grinder, but not a centerless grinder.

I have never run a centerless grinder but would assume that would be a fiddley little job considering the raw material that is a cotter pin!
About the time a fella thinks he has worked on some pretty intricate stuff along comes something from the 30's that makes you go hmm. I am grateful for the opportunities I have had to work with good tradesmen and engineers. I think it gives a guy a great appreciation for all we have and for those who carried the weight and pressure in the past. I never tire of seeing work like this Glenn. Thanks for the close up of a simpler yet not so simple time!

I'm constantly amazed at these engines.

partime wrote: ↑Fri Oct 21, 2022 5:27 pm I have never run a centerless grinder but would assume that would be a fiddley little job considering the raw material that is a cotter pin!

It's not nearly as difficult as one might expect, although most would find it quite boring. The pin would be ground by plunge, not through feed, for obvious reasons. It's fast and easy, although quite repetitious. Likely one every 10 seconds or so, depending on the skill of the operator.

H

Looking good Glenn!

If there was ever a need for precision this would be it