Any way to convert this 3/4 crankshaft?

[Gdiddy58]

To a centrifugal clutch with key without replacing the crankshaft? Surely someone has created a threaded collar.

 

[hermans13]

What is the diameter of the thread? What is the diameter of the smooth part of the shaft?
What is the overall length of the shaft and length of the threaded section?
Is there a keyway and does it run the full length of the shaft and through the threaded section?
If there is a keyway, is it 3/16" or 1/4" wide?
Please rotate the crankshaft 180 degrees and take of the keyway for us to see.

 

[mchadsey1]

To a centrifugal clutch with key without replacing the crankshaft? Surely someone has created a threaded collar.

Is the whole shaft threaded with some sort of bushing over the threads ? What did this motor power ?

 

[sparkwizard]

More pictures. Answer all of the questions above.
Your answer is "MAYBE" at this point.
Did it have a gear reduction box bolted to it?

 

[Gdiddy58]

What is the diameter of the thread? What is the diameter of the smooth part of the shaft?
What is the overall length of the shaft and length of the threaded section?
Is there a keyway and does it run the full length of the shaft and through the threaded section?
If there is a keyway, is it 3/16" or 1/4" wide?
Please rotate the crankshaft 180 degrees and take of the keyway for us to see.

Total shaft length all way to the oil seal is 2 5/8.
Length of threaded portion is 9/16
Diameter of shaft is 3/4.
No key way. Was used on a water pump.
Engine has low usage and runs perfect.

 

[Gdiddy58]

Thread diameter is 5/8

What is the diameter of the thread? What is the diameter of the smooth part of the shaft?
What is the overall length of the shaft and length of the threaded section?
Is there a keyway and does it run the full length of the shaft and through the threaded section?
If there is a keyway, is it 3/16" or 1/4" wide?
Please rotate the crankshaft 180 degrees and take of the keyway for us to see.

 

[Gdiddy58]

Only threads are what is visible. No bushing or collar or key way.
Used on a water pump.

Is the whole shaft threaded with some sort of bushing over the threads ? What did this motor power ?

 

[Gdiddy58]

More pictures. Answer all of the questions above.
Your answer is "MAYBE" at this point.
Did it have a gear reduction box bolted to it?

No gear reduction box. Had a water pump that the impeller screwed onto the crankshaft.

 

[Minimichael]

I've seen this too and wondered the same. It looked to me like the smooth shaft is also a bushing, independent of the threaded shaft. Nevertheless, since the smooth part is already 3/4", there's no conversion that would still allow a keyway. I put it on the shelf to wait for a future replacement crank.

 

[hermans13]

If available, you can replace the crankshaft with a conventional PTO end.
The only other thing that I can think of is to have the crankshaft machined down to 5/8" with a 3/16" keyway added.
If anyone else has an idea or experience, please chime in.

 

[cl350rr]

If you don't mind spending some $, take it to a machine shop and ask them to cut a keyway in the shaft. Some machinist trade schools will do it for free.

 

[hermans13]

cl1350rr, That's a good idea, at least the shaft size stays 3/4".

 

[mchadsey1]

cl1350rr, That's a good idea, at least the shaft size stays 3/4".

One drawback as it appears there's no shoulder on the shaft that protrudes past the crank seal keeping a clutch or driver from rubbing the case .

 

[hermans13]

The easiest way would be to replace the crankshaft with one that has the PTO that you need.
You can start looking on line or stop by small engine shops, they may have used engines with a crankshaft that may work.
Good luck to you, please let us know how you make out.

 

[sparkwizard]

Some of us might have the crank you need.
If you have some simple tools, it can be swapped in an easy afternoon.

 

[Gdiddy58]

One drawback as it appears there's no shoulder on the shaft that protrudes past the crank seal keeping a clutch or driver from rubbing the case .

Good point!

 

[Bird Brain]

Outside of a fancy taper lock adapter from keyless to keyed which i could not find, how about something like this angle grinder nut? Its 5/8-11 with 4 symetrical holes already. Could it be bolted to the center hub on a 3/4 shaft centrifugal clutch and use that as a drive dog for it? It would be a spin on clutch with no side to side adjustment however but would solve the other problem mentioned of no shoulder or "step" on the shaft but it would locate it like this positively away from wrecking the seal and bearing if so equipped. Just another idea to play off of. Good luck.

 

[Augiedoggie]

To a centrifugal clutch with key without replacing the crankshaft? Surely someone has created a threaded collar.

Fabricating an adapter bushing is an easy operation for any competent machinist. If you had to hire a machinist at prevailing rates, you would likely find it cost prohibitive. Keyed crankshafts are as common as cow shit in a field. Simple operation to remove your threaded crank and replace it.

 

[sparkwizard]

You could get your clutch installed and adjusted where you want it, then just weld it to the crankshaft. You might get a couple years of use out of it like that.
OR.... get a good cutoff tool and just cut a keyway into the side of your crank.