Pto adapter

[George Willer]

I'm talking actual HP felt at the end of the PTO shaft. I guess to satisfy my mind, I'll have to figure a way to do this at one of the shows. I'm the type of person who doesn't listen to what a person says, but what they do. Woods stated the required HP(30-35hp) needed and if the cub still has only 9 or so, why is this thing even working? This is a very good topic and I hope someone can break through my hard head Thanks, Rick

Rick,

You'll have to measure both the torque and RPM to determine horsepower.

Here's a small Prony brake setup to measure torque that would still allow access to the shaft to measure RPM at peak torque. It will require a little scaling up but that shouldn't be difficult. The difficulty I see is finding a way to get rid of the heat generated. The old timers used a hollow brake drum that used centrifically held water for a heat sink.

http://www.geocities.com/koneheadx/measuringshaftpower.html

You'll find a Google search for Prony brake helpful.

[George Willer]

Allen:

LOL!

BTW, I am looking into a way to make a PTO adapter that will reverse the rotation and divide the RPM by 3 in order to work with standard 3-pt options. The main reason I want to do this is that I can get a 3-pt log-splitter for a lot les than one woith an engine(plus, i think it will be fun to try.

Does anyone know how far and in what directions(for instance, x" to the right, and y" down) the pto shaft on a Cub would have to be moved to get it to the correct spot for use with 3-pt implements?

Andy,

I'd never try to discourage trying an interesting project, but you may find the gear set required will cost more than the splitter engine. I have a Prewitt adapter that is a little larger than the Hub City adapter... with MUCH heavier gears. Problem is, it's worth more than a splitter. (or 'ole Scruffy)

[awander]

Yeah, I'm tryin' to find a less-expensive way of doing it than using gears.

Do any of the list members know a good source for standard PTO shafts that can be mounted to a plate with a bearing?

The Cub PTO is 31/32 x 10 splines at 1800 RPM, correct?

And the most common standard PTO is 1-3/8" x 6 spline at 540RPM?

[George Willer]

Andy,

You could use chain and sprockets, but it would take 3 sprockets. A driving sprocket, an idler, and a driven sprocket on the opposite side of the chain. It would be a challenge to do so in a neat package. It WOULD give the advantage of flexibility in the location of the output shaft.

[awander]

George:

That's exactly what I was thinking.

Another idea involves using dual-row chain and single-row sprockets, with a length of the chainwrapped around one sprocket only, and the second, driven sprocket using the "other" row of the chain.

But I need to know the proper offsets before i can go much further.

[George Willer]

George:

That's exactly what I was thinking.

Another idea involves using dual-row chain and single-row sprockets, with a length of the chainwrapped around one sprocket only, and the second, driven sprocket using the "other" row of the chain.

But I need to know the proper offsets before i can go much further.

Andy,

I don't understand how that would reverse the rotation, or isn't that your intention?

I expect the offset you want to know is how much the drive line is offset. 7 1/2 " would put the shaft back to the tractor's center line.

[awander]

George:

What I'm thinking of doing is using 2 sprockets as gears. One of them gets a dual-row chain wrapped once round it, so it becomes, in essence, a "female" sprocket. The other sprocket is driven by the second row of the dual-row chain(the row that does NOT have the teeth from the driving sprocket inside it).

The 2 mesh as if they were gears-one has "female teeth"(the chain) that move along with it, and the other has the male teeth that mesh with the chain.

Think I'm crazy?

[George Willer]

George:

What I'm thinking of doing is using 2 sprockets as gears. One of them gets a dual-row chain wrapped once round it, so it becomes, in essence, a "female" sprocket. The other sprocket is driven by the second row of the dual-row chain(the row that does NOT have the teeth from the driving sprocket inside it).

The 2 mesh as if they were gears-one has "female teeth"(the chain) that move along with it, and the other has the male teeth that mesh with the chain.

Think I'm crazy?

Andy,

OIC now! That sounds like it would work. Now all you need is a 4" and 12" PD sprocket and the double chain (and a few other goodies). Maybe a salvage 1 3/8" PTO shaft could be used?

[awander]

Yeah, maybe. I don't have any of that sort of stuff laying around, so I am going to have to find a supplier that will let me scrounge, or where i can get it inexpensively.

the one thing about the double chain idea that worries me is that sing-ce the driven sprocket will only be engaged on one tooth at a time, it will wear rapidly. The idler sprocket with the driven sprocket on the outside of the chain loop might be better in that respect, if there is room.

Do you know how far above or below the Cub PTO shaft a new shaft would have to be to work withm saym a CAT 0 3-pt. hitch? I plan on moving it to the tractor centerline, but how much does up and down matter in this application?

[George Willer]

Andy,

IMHO vertical location of the shaft isn't very important if the drive shaft is done right, but the closer to the implement height the better. Torsional vibration is a factor if:
1. The universal joints aren't properly timed. (With both ends of the center section in the same plane)
2. The drive shaft and the implement shaft aren't parallel. (as when an implement is under power and in a turn)

[400lbsonacubseatspring]

Yikes. This is one topic that leaves me scratching my head over and over. My simple mind just can't absorb all this enginering paperwork. If we had a GIANT CURTAIN with several cubs lined up behind that curtain with only their PTO shafts sticking through, I find it hard to believe that my backhoe cub's pto would measure the same power or HP as a regular cub and not be bumped up because of the gearing. I'm talking actual HP felt at the end of the PTO shaft. I guess to satisfy my mind, I'll have to figure a way to do this at one of the shows. I'm the type of person who doesn't listen to what a person says, but what they do. Woods stated the required HP(30-35hp) needed and if the cub still has only 9 or so, why is this thing even working? This is a very good topic and I hope someone can break through my hard head Thanks, Rick

Rick,

To put this in simplest terms, HP is an expression of work done in a specific amount of time. By gearing down your PTO, you increased its ability to do work, but increased the amount of time it takes to do it. The end HP remains the same.

A good example of this is if Ralph and I were to race up a flight of stairs, he would beat me in terms of time, but in reality, we probably both would generate about the same amount of HP, even though I'm actually doing more work, hauling my 400lbs up the stairs. Ralph, being a pixie, would be doing less work, faster, and I would be doing more work, slowly. We did an experiment with this in highschool physics, and found that a lot of the smallest girls actually generated more horsepower than the football players, because they were able to run up the stairs much faster. But no one would argue that the girls were more "powerful" than the football players, of course. (Even though, by definition, they were.)

Torque is simply an expression of force. Exactly like how much force you put on the handle of a wrench.

I guess the reason the cubs are so versatile at their 10HP rating +/- is that they are set up to do an enormous amount of work, and are very robustly built for the 10 horses they produce, so their transmissions and attachments can gear down that power to do whatever job you need.

The fact that a 10hp tractor can turn over earth is pretty amazing in itself, really. The cub is a football player, not a fast little girl.

[JimCT]

If this is of any help, and maybe a little different way of figuring power available at the PTO, when I connect the belt-driven 3.5KW generator I have on the cub to the house I can cook breakfast on the stove in about 15 minutes. Bacon, eggs, (oatmeal if you want it) and coffee, Can't make toast at the same time though...

[Rick Prentice]

I thought I was going to transfer some pics of a gear reduction setup, but once again, this wonderful computer is letting me down, sorry for now, Rick

[Daniel H.]

I salvaged a gear box off of a Allis-Chamlers power unit from an All-Crop Harvester. It reverses direction, has a standard 1 3/8 PTO output,and has approximately a 3:1 reduction. The power unit was the motor as a "B" Allis tractor, so the gear set should be plenty heavy for the cub. I would think these could be had at a reasonable price from a salvage yard or someone's fencerow. My trouble is figuring how to mount it to the tractor. Here are some pictures for thought.

http://dhutchens.yadtel.net

[400lbsonacubseatspring]

I salvaged a gear box off of a Allis-Chamlers power unit from an All-Crop Harvester. It reverses direction, has a standard 1 3/8 PTO output,and has approximately a 3:1 reduction. The power unit was the motor as a "B" Allis tractor, so the gear set should be plenty heavy for the cub. I would think these could be had at a reasonable price from a salvage yard or someone's fencerow. My trouble is figuring how to mount it to the tractor. Here are some pictures for thought.

http://dhutchens.yadtel.net

Daniel,

I see a "flange" where the longer, thinner splined shaft is. In one of your pics, I see a bolt hole there, through that flange. Is there another, on the opposite side (or maybe even more?)

One of the easiest things that come to mind would be to make a flange adaptor out of a piece of steel pipe, going from the existing flange on your gear reducer, to the pto unit bolts, um...bolting on the way that the flat pulley adaptor did. You could study a flat pulley adaptor for how that mounted, but they were pretty simple bolt-on devices. You could probably scrounge some of the needed parts to mate to the cub pto shaft from one as well.

I'd make the pipe long enough to include a universal joint, so you won't have to be critical as far as welding a perfectly straight shaft, or having your weld break under load. Cut the existing long shaft, add the U-joint and the part that fits the cub pto, and bolt it on up.

Aside from making a pan for the gearbox, it seems it should work pretty well.

What a clever find.