Measuring and Straightening a Crankshaft

[great white]

out of round is easy. Take two measurements 90 degrees apart and compare.

I'm having a hard time picturing what you're trying to do, but if it's wear on the snout you can usually turn in down and press a sleeve over it.

A hit and miss is a little out of my wheelhouse though. I'm used to working on modern stuff that typically has far tighter clearances than that "turn of the century" iron.....

 

[Martin W]

Here are a couple pictures. Right now it is mounted in a 4 jaw. I can get the left journal to run perfectly true, but the right one is out .037”. If I get the right one to run true the left journal is out .037”
If I put it between centers both journals are out .070”.
the shaft to the left of the timing gear is where the flywheel goes and the other end is where the clutch sits which needs to be repaired.
Are the Center holes out? Is the crank bent?
This weekend I will put it on some V block and measure and see what that says.
Martin

 

[OTmachine]

Sounds like the centers are off. You could use a false center or a 4 point adjustable center on the tailstock end to adjust the outboard journal true, then recheck runout. Vee - blocks would be easier and a better method.

 

[f350ca]

The centre's could be off, but why? I'd hazard to guess it was built using the centre's and the .07 is wear. The old stuff usually wasn't made of very hard steel, that much wear in this old girls life is quite reasonable.
Does the .07 line up on both journals? If so then it's probably straight and you're seeing wear.

Greg

 

[OTmachine]

So, if there is .035” wear on one side of the journals, the journals would not mic round. Should be checked 1st. If you really want to know how it sits with the world, locate the rod journal clamped down with a toe clamp, ( provided that the rod journal is true), in a vee block on a mill table for reference. Then using a height gage and dial test indicator check and see where each journal is in relation to the other at different clock positions of crankshaft rotation. Or you could also just use the mill spindle as an indicator holder. Hope this makes sense to you.

 

[FOMOGO]

I think I would grind off just the surface of that weld on the counter weight, loosen the bolt, and see if you can't tap it true. Mike

 

[pdentrem]

Test as close to the centers as possible. If the runout is the same then the centers are no good. I had to make new centers on a few rolling mill rolls that were improperly made.

 

[K30]

Not much help with the crank, but here's some history on it. Gramps probably would have been able to fix you right up, or probably would have had a spare crank. I couldn't tell you how many of those engines he fixed up and sold. He was a big part of the beginning of the 'Power of the Past' show. When I was a kid, it was on their farm. All those town mentioned are within a couple miles of me. I still see Ottawa engines on a regular basis.

Ottawa Engine Company

OTTAWA MANUFACTURING COMPANY OF OTTAWA KANSAS The August Reddemann Cross-cut Saw by Brian Wayne Wells As published in the May/June issue of Belt Pulley Magazine “As the old saying goes: “Firewood w…

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