Easy homebuilt stub shaft

[dieselbikin]

Buy the sprocket from https://www.surpluscenter.com/item.asp? ... powerTrans that has the right OD to drill your bolt circle and the correct ID for your stub shaft. Next buy keyed shaft of correct diameter for sprocket and driven device and cut to length https://www.surpluscenter.com/item.asp? ... powerTrans . Finally, insert keyed shaft into sprocket and weld.

This would be cool to run a supercharger, alternator, or Comet driver from the right side so you wouldn’t have to flip the swing arm. What do you think?

[dieselbikin]

Here is a mockup of my stub shaft idea. I put white dots where the holes would be drilled to bolt it to the flywheel. These are actually parts for my diesel dyno.

[Crazymanneil]

Thats clever. Would have saved me a fortune compared to getting my stub shaft made. Reckon she'll be nice and straight?

N

[pietenpol2002]

I like how you're thinking on this. I too have interest in having an auxiliary PTO. Concerns have been expressed on this board regarding side loads on the flywheel side bearing which was designed for axial loads only.

My idea was to use a Lovejoy type coupler from the flywheel to an outboard bearing via a stub shaft. Doing so would place axial loads only on the flywheel bearing.

Here's how I would think about it. One could attach the Lovejoy coupler directly to a stub shaft much as you've proposed. Below is an example of 1/2 of the coupler mounted to a horizontal Changfa diesel flywheel.

lovejoy flange 1.jpg (10.89 KiB) Viewed 12042 times

The ideal would be to use a flanged lovejoy like the one below. I just don't want to know what it costs.

lovejoy 2.jpg (11.02 KiB) Viewed 12042 times

The other half of the lovejoy would attach to a stub shaft that would then pass through the 2 bearings of a Murray mower deck spindle housing which would be bolted to the flywheel blower housing in place of the pull starter. The 2 bearings of the spindle housing could easily handle the side loads applied by any attachments.

Murray Spindle.jpg (13.1 KiB) Viewed 12048 times

[smokyjoe]

I like the idea of using a hubbed sprocket, real good idea!

For those with a lathe, I found an "easy cheap" stub shaft is the old axle from a car or truck that has a flange piece on the end to attach the hub. The hardest thing is to get the bolt circle centered that bolts to the flywheel or crankshaft (measure twice, drill once or if you're lucky enough use an indexing head on a milling machine to drill the holes on a circle). Usually the axle is bigger in diameter than what is needed, so the flange end can be chucked up on a faceplate on the lathe and that end centered and the runout turned away and trued in the shaft turning process. Usually these are made of chrome-moly or vanadium steel so you'll be hard pressed to break off a shaft! The downside is that you may need carbide tools to turn the bearing race down as this is usually case hardened, but the hard surface seems to be only about a millimeter or so then you're into softer stuff.

I found an old Ford car axle that is a good start for the shaft on my Hatz flywheel which has a relatively large bolt circle for the size flywheel. The axle shaft is about 1-1/4 inches which has to be turned to 3/4 inch, but it cost nothing so I can't complain! And it has a large piece on the end opposite the shaft so it can be turned down to fit into the flywheel center so the whole mess will be concentric and not rely on the bolt holes being exactly perfect to true it up.

[cumorglas]

that's brilliant. i have a pile of dana 35's leftover from jeep projects.. they aren't strong enough for anything on a jeep but perfect for this.