Help!? Any one have any experience with a slip clutch for a pto shaft? I bought a three point wood chipper at auction saturday. Was told a slip clutch would be a good idea for it, so I stopped @ TSC on the way home and bought one.
Now as I look at it I wonder how does it know when to slip? There is no info about horsepower/torque values for when it might slip. If my tractor is 40 hp and the chipper requires 40 hp, does the slip clutch need to be set different then it would if say I had an 80 hp tractor and a larger chipper? Seems to me it should be adjustable???
mh
You are right , the slip clutch sould be rated for HP if it is for standard 540 RPM equipment. If not for standard 540 RPM equipment it should be rated for torque in ft-lbs. The slip clutch should be matched to the equipment it is driving not the power unit. Most farm slip clutches are not adjustable, but I have seen a few that are adjustable.
If your chipper was made professionally and dosen't have a slip clutch, it is probably using a shear pin or shear bolts to do the same thing as a slip clutch. Look on the drive line for these items and I bet you wll be able to save yourself a lot of workremaking a drive line assy. I assume you didn't buy an overrun assy as this is a different item also.
Searching on Google, I found another piece of equipment that uses one and the adjustment is as follows;
(I am not quoting) Run the equipment at as close to maxumum laod as possible for 30 min. shut dow and check the heat of the clutch. it should be slightly warmer than the surrounding metals having absorbed some of the severe shock loads. Loosen the bolts evenly if needed and run again untill the clutch heats up slightly. Too loose and you should hear the clutch slip and see heat related problems such as blistered paint on it.
Amazing what you can find when you "google"!
Thanks fer yer thoughts
mh
On most of the slip clutches on my farm machinery if the slip clutch is heating under normal load, you will be replacing the clutch disks very quickly. Most slip clutches are designed for only very short periods of overload on the driveline.
I don't think you want that slip clutch slipping while operating at recomended loads . It should only slip if a whad or obstruction of sorts happens into the machine.
I think most of them you tighten the bolts to make it slip easier. If it is the right size I think the correct procedure would be to tighten it (take the tension off of the springs) and let it slip just a little if it hasn't been used for a long time. This is to make sure it isn't frozen. Then you loosen the bolts so that the full tension is on the clutch. If it slips much, you will see smoke from the clutch and you can bet it will be hot.
This is a little info I got from my parts dealer, the newer clutches no longer have asbestos in the lining and if they aren't used regualrly or slipped once in a while everything bonds together and you lose the protection. He said you should loosen the tension and slip it every once in a while to make sure it hasn't seized up. A slip clutch saves a lot of time, shear bolts are just a cheap way of protecting your equip. Much better to have the clutch slip while you are out in the field than have to stop and change a shear bolt..
The slip clutchs I have (3 of them) all have a section in the instrukshuns that specify how to setup the springs.
Basically you tighten the bolts down until the spring is compressed to a set dimension. That exerts the correct amount of pressure, based on the thickness of a new, not yet abused clutch.
Let's see if I can post something to show it.
(https://forestryforum.com/gallery/albums/userpics/11799/Slip%20Clutch%20Detail.jpg)
Murf,
That is exactly the kind of info I was looking for. I wonder why instuctions were not included with my clutch? I guess a phone call to TSC is in order to find out where my instructions are.
mh
Moose, check to see if the manufacturer has a website. If it's a big company they may well have all you need as a free download PDF document.
Of course if it was made 'offshore' you may have a problem to "be hardening the tension of the slip-spring with the wrench of proper calibration but being cautious not to exceed the maximum tension permitted by the usage"......... ::)
The easiest way to test the whole thing would be to hook the chipper to a big tractor, rev her up real high and and throw in a big chunk of white oak. ::) If she takes that you don't need a slip clutch. ;) If it brakes you will know the weakest part. :P :D
Yer a big help pigman! With friends like you,.. who needs enemies :D
Here is the part where I admit to being a complete idiot,
The post from dana got me to thinkin' ( some times my brain don't kick in till I've had a good swift kick in the other end) I called the company to ask how best to protect the chipper. I was told only the bigger chipper (than mine) needs the slip clutch, the smaller ones are driven by a set of four belts, the belts take up the shock loads. I took the clutch back.
I hope someone else is able to use the info we have gathered on this thread, I hate to think I wasted everyones time :-[
mh
Ahhhh, the 4 belt slip clutch. When the belts start smoking, kill the power and clean out the machine.