Series 4 PTO shaft, how short can I go?

[MinnesotaEric]

Hello Everyone, I was hoping someone can tell me what the "Absolute" shortest (say end-end including yokes and joints) I can cut down a series 4 PTO shaft with 1-3/8" 6 spline on either end? I'm trying to build a homemade log winch using a vintage Ramsey #200R 8000lb winch that will be mounted fairly close behind the 3 pt arms (design version #1). Thanks in advance. Steve

Please, for the love of God, get some 1/4" stock and recreate that wooden abomination in steel.

As for your questions about driveshaft length, be aware that you can got as short as you need to go, but aware that as you go shorter, the higher the angle of attack will also shorten the length of expected service your U-joints will experience. As for myself looking at your photos, the angle of attack isn't a concern. What concerns me is carpentry over blacksmithing. Please get out your Multimatic and attend to my concern!

Your milage may vary as legally I do not know you, as I am as the morning mist in a rising sunny day and I know you not.

 

[Supercharged86]

This big issues are overlap, which has been well addressed, and u joint angle.

This chart describes how quickly the life of the joint is shortened by increasing the angle the joint operates at.

Increasing the angle also causes the shaft to not operate smoothly inducing vibration.
Unlike the constant velocity joints used on all front wheel drive cars and now many all wheel drive ones as well, the rotational angles of the cardan style joints are not uniform throughout 360 degrees.
Yes if you turn one end of the shaft a full turn the other end will also turn a full turn but in between the full 360 degrees the amount of rotation is not always the same at each end. If you take a socket universal joint and try and turn a nut while the joint is at a strong angle you will feel the lumpy action I am referring to.

This link is to a government web site explaining to farmers the limitations of cardan joints

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/eng9924

Dave M7040

Sorry but I dont know why the link is not a link but you can copy and paste into your browser to read it

Hi Dave, Thank you very much for the information. Right now I have the winch situated so that the input shaft is two inches (I can go higher) above the horizontal center line of the PTO output shaft (figuring the blade bottom will dig into the ground a few inches). Unfortunately the winch input shaft is on the lower right side and therefore the PTO shaft will be slightly off center to the right by perhaps 10*. I'm trying to shift the winch to the left as much as possible to keep the offset minimal. Cheers. Steve

 

[Supercharged86]

Please, for the love of God, get some 1/4" stock and recreate that wooden abomination in steel.

As for your questions about driveshaft length, be aware that you can got as short as you need to go, but aware that as you go shorter, the higher the angle of attack will also shorten the length of expected service your U-joints will experience. As for myself looking at your photos, the angle of attack isn't a concern. What concerns me is carpentry over blacksmithing. Please get out your Multimatic and attend to my concern!

Your milage may vary as legally I do not know you, as I am as the morning mist in a rising sunny day and I know you not.

Hi Eric, LOL! No, this is just my scale model. I figured it was better to build it first out of wood that way I can easily make changes based on unforeseen problems or necessary changes. I didn't want to waste expensive steel materials nor my welder friend's time. Sure, alot of extra work up front but in the end, time well spent. The plan is to use lots of 1/4" plate, 1"x1", 2"x2", 2"x2" angle, 6" U-channel, 1"x1" wire mesh, etc. Thank you though for your concern, Steve