Poor man's PTO reverser / reducer thoughts

Tue Feb 24, 2004 11:38 am

I was reading the thread about seeding and remembered thinking about this before.
My approach would be to make a unit that would mount down in the center under the axle and attached to a cross mounted frame between the final drives. There are two places where sizes of pulleys can be varied according to the speed wanted. That can be calulated out and I am not including those calculations in this message. You might want different speeds for different applications. It would consist of a pair of shafts held in a pair of front and rear mounting plates about 8" apart probably using ag ball bearings (common as fleas on most combines) on all 4 points. One shaft would be belt driven by a decent sized "Vee" belt from a pulley on the regular PTO to a pulley on that shaft. (Multiple thinner belts could also be used). That would be the driving shaft. It would have a flat belt pulley between the mounting plates. For this discussion lets say it might be 3" wide x about 4 or 5 inches in diameter. On the other shaft mounted between the plates would be a tire and wheel about like a wheel barrow tire or the like that would friction drive from the flat pulley. Perhaps a flatter faced tire would be better. There would then be a PTO stub shaft mounted on the back end of the same shaft that the tire is mounted on. If you desired one could also be mounted on the front of that shaft but about the only use that pops to mind would be a snow blower and if one were used the friction drive would need to be kept dry.
Such a drive would easily power a seeder and many other implements. I have no idea what the maximum possible output from such a drive would be but as a long time #$%& CUB owner I'll bet it will handle anything a CUB engine could throw at it. :D
Contact pressure could be controlled somewhat by the amount of air in the tire.
There is a company that makes a very heavy 6' or 7'+ bush-hog for large tractors that uses a special friction drive tire not only to power the mower but to turn a 90 degree change of direction with the power without a gearbox.
I sure hope this is making sense to somebody besides me... :D
I just toss this out as another possibility with including too many specifics.
(manufacturing rights reserved) :lol:

Tue Feb 24, 2004 2:27 pm

Farmer, similar thoughts passed through my mind (short trip) the other day. I believe it could be easily done.

Tue Feb 24, 2004 3:37 pm

I'm sure it has been done many times, but the idea of using a tire to make a friction drive reverser was probably rare. This mount for a jackshaft or one like it would be a good place to begin to make such a drive. It made a good converter to drive the shaft driven mower. Note also that it made a useful place to mount the counterbalance spring for the hand lift with reversed function, and an alternate drawbar.

The wide channel iron platform worked well to mount the bearing blocks.


Tue Feb 24, 2004 4:18 pm

Ok guys, it is time for the Keep It Simple for the Newbie principle. What in tarnation is a jack shaft :?:

I know it is probably something simple :oops: and once explained I will probably feel like a jack shaft's third cousin the jackass :oops: :roll: , but I will ask it anyways.

Ever since I saw Ralph's spreader, I have been trying to wrap my head around how to build one for the back of Ellie-Mae. :?: :idea: :roll: I have at least 3 acres that have been backfilled and now is in dire need this spring to be sown, and I ain't doing it by hand.

So, the second part of this is - how does someone mechanically challenged figure out how to built a contraption such as this. The only spreader I have right now is one of those little ground driven speaders you push around a postage stamp lawn :cry:

Tue Feb 24, 2004 4:38 pm

I have an old Allis Chalmers power unit that has a small gear box with a PTO shaft on it to run an All-Crop Combine. I wonder if something like this could be adapted to the cub? Assuming the AC engine turns the same direction as the Cub and about the same speed wouldn't the gear ratio and direction be correct? The kink would be attaching it mechanically to the cub and matching the PTO shaft. It is after the clutch on the donor engine and is about the right size. Any comments?

Tue Feb 24, 2004 4:48 pm

Rudi wrote:Ok guys, it is time for the Keep It Simple for the Newbie principle. What in tarnation is a jack shaft :?:

Rudi, a jackshaft is a short (usually) shaft with a drive pulley on one end and a driven pulley on the other. Drive / driven pulleys are different sizes to either reduce or increase speed. Generally used to reduce speed and increase torque to drive an implement. One of my belly mowers is for a fast hitch cub, it has a chain sprocket on the pto shaft driving a chain sprocket on a jack shaft. The other end of the shaft has a belt pulley whic drives the mower deck pulley.

Wed Feb 25, 2004 3:18 am

Also, as there is a belt [or more] in this power train, the direction can be reversed simply by crossing the belt - it only requires the belt to be long enough to run 'crossed'
That is the old-time compensator for power units and machines that were not standardized in direction of operation.
Did I say it right?
The whole subject is intriguing.
Keep dreaming! :)