PTO shaft help needed

[RIPPER]

I have an old MacKinssic chipper that I am re-gearing. It was made for a 1000RPM pto and I am converting it to a 540 RPM PTO. I had to lower the pulley cross member to make room for a 15in pulley. I have 3 questions:
1. Is there a Max angle that Knuckles should be allowed?
2. How much overlap do I need on the PTO shafts? They are round with 3 ribs.
3. There is no sheer pin, Just a woodruff key on one side and square key on the pulley side. I see TSC has a clutch adapter with a sheer pin. Do I need this or are there other suggestions?
This is going to be used on my 2210.
Thanks in advance.

 

[RoyJackson]

1. Is there a Max angle that Knuckles should be allowed?
15° is the recommended maximum for universal joints.

2. How much overlap do I need on the PTO shafts? They are round with 3 ribs.
My manual recommends 2" minimum overlap at maximum extension. You also don't want the shaft bottoming out at minimum length (if you add the clutch described in (3), you'll want to factor in the clutch length).

3. There is no shear pin, Just a woodruff key on one side and square key on the pulley side. I see TSC has a clutch adapter with a shear pin. Do I need this or are there other suggestions?
That's probably an over running clutch you're describing. That would be a good addition.

 

[rambler]

I had 2" of overlap on a tiller, & it wrecked the shaft, wallowed it out. I'd like 3-4" but some of those short 3pt little bitty tractors don't allow much.

An overrunning coupler is for tractors without live pto, it will not help for a slip clutch at all. The square key on the original shaft is likely the 'shear pin' if no other is found, you can add a slip clutch of course, just get a slip clutch, not an over running clutch - 2 very different things.

--->Paul

 

[NewToy]

Just picked up a KKII tiller and had to adjust the pto shaft length. They were emphatic in the instructions that at least 6" of overlap were required.

John