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LT230 PTO DIY kit possibly on its way


Soren Frimodt

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The one on the yard crane had two band brakes. One was brake, the other clutch. When you moved the lever you started engauging the drive just as the brake came off. It needed adjusting every so often.

So you fit a disk brake on the drum side (brake) and one on the other side of the diff (clutch). Once the PTO is in, the disk spins freely in the clutch-brake while the drum brake is held with a spring. Move a lever to overcome the spring, releasing the drum-brake and stopping the clutch-disk-brake, which forces the drive out through the sun gears. Proper Old School :)

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Yeah its a very simple technique and we have discussed it up and down in and out.. BUT the problem is that you will be relying on the differential gears (sun gears) to work at high speeds for a long time, and how well do they cope doing that when you spin your wheels without a locker? Not very well, it often ends in tears.. Plus there's the thing about doubling the speed when you use the differential. But using a locker when you pull with the winch, and then unlock it, and brake via the diff, on an axle on the opposite side of the drum, would work. But a very expensive solution.

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I hear the argument against the sun gears, and its fair. So I put forward the use of a standard landy clutch plate;

Weld the diff up so its just a 90 degree 3.5:1 gearbox. Fit the input flange with a metal disk 3" larger than the standard clutch pressure plate of your choice. Fit the outer rim of the disk with a brake caliper (winch brake). Drill the disk to take standard clutch parts with release bearing, and link it to the caliper. (quite a linkage task I know). This gives good leverage on the caliper due to diameter and because its before the gear reduction,.

Using a hydraulic caliper may make the linkage simpler, as the master cylinder can be connected directly to the clutch fork rod. That makes the brake self adjusting, which solves the problem of wear with mechanical linkages which need constant adjustment.

If 3" on top of the clutch diameter is way too big, maybe a car clutch plate would do? Or, maybe the brake would have to be on its own because of diameter, in which case, bolt the disk to the diff pinion, then a short shaft to clear the caliper and then fit a flywheel?

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Today has been a productive day. Although I spent most of it mounting my Eberspächer to the 90", I was still able to give the odd helping hand now and then on the winch project. For instance I got the noble job of turning the pinion with a crank, whilst he spooled the 52 meters of 12mm wire on the drum :D

The drum is a snug fit over the turned down hub, and has some remainings of a driveflange turned down and welded to the inside. This in turn has another driveflange, with the halfshaft on the ouside. Meaning that the halfshaft goes through the flange welded to the drum, so that the drum mount is sandwiched between the hub and driveflange ones bolted up. Hard to describe but hope you get it.

Anyways here's a pic:

post-9137-0-36618800-1318695436_thumb.jpg

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Because of the relatively low friction in this setup, do to the tall gearing, pulling it by hand will be no problem. And if you unlock the drum directly you could end up with wire allover the place because there would be nothing to stop the drum from turning, and therefore the wire would expand. Not a problem with rope, but we're not confident on that for this type of winch.

But anyhow, our plan is to spool out the cable rather than freespool it out. Some sort of rollers and an extensive wire guide system will allow us to spool out the wire using the engine power. But thats all in a later stage of the build.

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  • 3 weeks later...

Progress is somewhat slow at the time, our machinist is going away on a 4 week course, and my brother is pretty hung up on work..

But yesterday he did spend some time on the winch though and it is getting there.. all mounting is done, and a tray surrounding the bottom half of the drum is made, and it's a bit wider that the drum so that you can slide the drum off the hub and it'll rest in the tray.

post-9137-0-85847900-1321197695_thumb.jpg

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Hi Søren.

I'm very very interested in this project for my next build.

I have one concern though. Do you have anything limiting the pulling force? Weak parts were mentioned before, but I'd like to be certain not to decapitate my co-driver. I know there are plenty of threes in the forest, but I've trained him for a while now. ;)

I might have missed it somewhere in the thread, but what kind of drive shaft have you used in the winch? Custom made?

You guys do an impressive job. Are you building for Danish challenge comps or are you planning to go elsewhere? (Plans are forming for the Swedish challenge cup 2012 ;))

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Hi Calle-fas, I'm glad you find this interesting, but I fear you might have misunderstood this a bit. We are not offering a winch setup, we are merely offering the PTO DIY kit because we thought this was an easy and cheap alternative to what else is out there. I have only chosen to post the progress of the winch because there seemed to be a interest.

So everything regarding a winch is something you will have to do yourself, but of course you are welcome to copy this :)

Regarding your technical questions I have some answers for you: The steelwire will run inside an aluminium tube, so it shouldn't be that dangerous ;) Driveshaft is a special edition 10 spline "Weld-Self" version ;)

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Hi Calle-fas, I'm glad you find this interesting, but I fear you might have misunderstood this a bit. We are not offering a winch setup, we are merely offering the PTO DIY kit because we thought this was an easy and cheap alternative to what else is out there. I have only chosen to post the progress of the winch because there seemed to be a interest.

So everything regarding a winch is something you will have to do yourself, but of course you are welcome to copy this :)

Regarding your technical questions I have some answers for you: The steelwire will run inside an aluminium tube, so it shouldn't be that dangerous ;) Driveshaft is a special edition 10 spline "Weld-Self" version ;)

I don't think there's been any misunderstanding. It was my intention to copy the winch myself. :D

Regarding the wire I'm more worried outside the car than inside. On my hydro winch i have a pressure relief valve that sets the maximum pulling power. Using 12mm I find it very unlikely that you will snap the wire, but I'd rather have a safety device that goes first. Maybe something like fused freewheeling hubs or a shear pin.

Just to make sure I understand correctly. You've shortened the shaft yourselves?

/Calle

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I don't think there's been any misunderstanding. It was my intention to copy the winch myself. :D

Clearly there has been, on my account :D

Hmm, I see where you are going, but achieving the right dimension for that "weak spot" would be very difficult do to shockloads etc.. I would however prefer some sort of "slip" arrangement, that you wouldn't have to fiddle with to get going again. But again quite complicated and time consuming to get right.

And yes, we have shortened it and welded it to an old series flange, we are using two old series flanges in this setup as one is welded to the drum and sandwiched by the one welded to the shaft

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Clearly there has been, on my account :D

Hmm, I see where you are going, but achieving the right dimension for that "weak spot" would be very difficult do to shockloads etc.. I would however prefer some sort of "slip" arrangement, that you wouldn't have to fiddle with to get going again. But again quite complicated and time consuming to get right.

Very true. Not a job you want to do in the middle of a bog or ford. And knowing the sand/gravel slopes that seem to be quite common in Danish challenge you don't want the winch going into free spool when the "fuse" goes.

And yes, we have shortened it and welded it to an old series flange, we are using two old series flanges in this setup as one is welded to the drum and sandwiched by the one welded to the shaft

Ah now I understand (maybe). :D

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There are plenty of agri PTO safety clutches out there in the 1000rpm as well as 540rpm shafts. Some are friction plate type, but others are sprung-plugers. So re-setting isn't a problem :)

I'd even wondered about one to protect my rear axel! But it needs a CV at both ends.

Nice machining. I like the smooth inner radious. And some smart broaching in such a short distance!

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