Haoleguy
Platinum Member
Is there perceptible sound change when the slip clutch is activated?
Rotary Cutter Slip clutch not slipping at factory specs...
- Thread starter Travis_R
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Farmwithjunk
Super Member
Not from the clutch itself, but it generally takes something abrupt and sorta "violent" to make a properly adjusted slip clutch to slip. In most cases you'll hear THAT. You're more likely to SEE a change in the function of whatever the slip clutch is protecting.
OP
Travis_R
Veteran Member
If I loosten the nuts on the slip clutch another turn, I could probably turn the springs with my fingers...
SPYDERLK
Super Star Member
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- JD2010, Kubota3450,2550, Mahindra 7520 w FEL w Skid Steer QC w/Tilt Tatch, & BH, BX1500
No ... or subtle. And it dedends on how slippage activates. x] If you are mowing thick grass with a bushog and you exceed the clutch setting you wont detect it and it only takes several seconds of slip to overheat it. A clutch set that sensitive is going to get a lot of wear and need frequent adjustment. x] If the clutch is set just a little tighter it will ride thru thick grass, but will slip if you hit an obstacle. The problem here is that once its job of protecting against the potentially catastrophic overload of the impact is done it may not lock back up due the heavy ambient load from the grass. You have to be alert to detect this. x] Instead of either, the clutch should be set tight enuf to hold torque that will bog the engine noticeably as it slips. A quick impact slip is nothing to the clutch - it protects against the catastrophic overload and suffers no detriment. A steady state slip with the engine overpowering it you have to detect quickly. A bogging engine gives a good cue. ... The final consideration that was mentioned earlier is an implement much too light duty for the tractor horsepower. A big engine can break a gearbox if the clutch is set above what the gearbox can tolerate. The gearboxes are tufer than you might think tho.
larry
SPYDERLK
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I thot you indicated it slipped when the spring tension was relaxed.
Are you driving a big implement with a little tractor??larry
IslandTractor
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I disagree. I have the same basic type of mower and slip clutch (Woods 600 medium duty). Once a season I loosen the bolts, mark position with a marker, then engage the PTO. After I see that the clutch has slipped, I retighten a turn and repeat the PTO engagment. When I get no slippage at engagement RPM (1000) then I tighten another turn. No measurements. That is it for the season. Clutch doesn't cause any problems or get hot and I do fairly regularly strike objects that would clearly shatter a shear bolt. I use the mower mostly for clearing brush and back into a lot of material I cannot see well so I hit rocks and stumps regularly. I much prefer spending thirty minutes adjusting the clutch under controlled conditions at a time of my choosing than I did replacing shear bolts in the field.
Chilly807
Elite Member
There's nothing too difficult involved with servicing a slip clutch, other than checking it a couple times a year to be sure it's not seized.
To me, spending an hour or two once a year to disassemble it, inspect and clean it up isn't so bad. I remove mine from the mower every fall after I'm done cutting for the year. It gets stripped down, checked and stored inside for the winter.
I don't like saying this, because I know that some folks will take it the wrong way, but this isn't rocket science. If you own machinery and want to work on it yourself, you should be mechanically inclined and have the tools to do it. The new breed of "weekend farmers", and that includes me, needs to understand that either you can work on this stuff yourself, or pay someone else to do it. Paying someone else to do routine maintenance doesn't make much sense to me.
All I'm using is a wrench, a socket, a ratchet and a set of dial vernier calipers to measure and set the spring length. My day job pretty much ensures I'm competent using all of them. You should have the same load on all of the springs within reason. The calipers are available at Princess Auto, Harbour Freight, etc for under $20 on sale, accuracy is well within what you need for this kind of job. How to use them is pretty much self-explanatory or can be found on the net in 10 minutes.
A shear bolt is about as simple as it gets, and has limitations because of that. They break and have to be replaced, and people complain about that. The shear bolt on my post hole digger only breaks when I'm using it, usually with a cloud of black flies around my head, and just as it's getting too dark to really see well where the hole is to punch the old one out and replace it. Or I used the last one the weekend before and forgot to buy more.
The slip clutch needs maintenance regularly, and people complain about that. I was one of them, and somedays I still am.
I guess at the end of the day I prefer the adjustability of the clutch over the simplicity of the shear bolt, because I can't match the shear bolt perfectly to the tractor.
This goes back to a post I made earlier about which side of the equation we want to protect.
As much as I don't want to damage the cutter gearbox (which I think the cutter manufacturer is trying to protect when they specify either a clutch setting or a shear bolt size), I REALLY don't want to damage the PTO components internal to the tractor. That gets expensive with a capital "E".
We spent a bit of the weekend mowing heavy meadow grass, and the lighter setting on the clutch springs seemed to work well. The clutch housing was cool to the touch, so it's not slipping there. It's set substantially lighter than the factory setting, so the PTO protection is improved as well. I noticed it did move on a sudden start or stop, and that's fine with me.
Impact loads are bad enough, try wrapping a length of 3/8 steel cable around the output shaft.. without either a shear bolt or slip clutch things are going to get exciting very shortly.
Rant over..
Sean
To me, spending an hour or two once a year to disassemble it, inspect and clean it up isn't so bad. I remove mine from the mower every fall after I'm done cutting for the year. It gets stripped down, checked and stored inside for the winter.
I don't like saying this, because I know that some folks will take it the wrong way, but this isn't rocket science. If you own machinery and want to work on it yourself, you should be mechanically inclined and have the tools to do it. The new breed of "weekend farmers", and that includes me, needs to understand that either you can work on this stuff yourself, or pay someone else to do it. Paying someone else to do routine maintenance doesn't make much sense to me.
All I'm using is a wrench, a socket, a ratchet and a set of dial vernier calipers to measure and set the spring length. My day job pretty much ensures I'm competent using all of them. You should have the same load on all of the springs within reason. The calipers are available at Princess Auto, Harbour Freight, etc for under $20 on sale, accuracy is well within what you need for this kind of job. How to use them is pretty much self-explanatory or can be found on the net in 10 minutes.
A shear bolt is about as simple as it gets, and has limitations because of that. They break and have to be replaced, and people complain about that. The shear bolt on my post hole digger only breaks when I'm using it, usually with a cloud of black flies around my head, and just as it's getting too dark to really see well where the hole is to punch the old one out and replace it. Or I used the last one the weekend before and forgot to buy more.
The slip clutch needs maintenance regularly, and people complain about that. I was one of them, and somedays I still am.
I guess at the end of the day I prefer the adjustability of the clutch over the simplicity of the shear bolt, because I can't match the shear bolt perfectly to the tractor.
This goes back to a post I made earlier about which side of the equation we want to protect.
As much as I don't want to damage the cutter gearbox (which I think the cutter manufacturer is trying to protect when they specify either a clutch setting or a shear bolt size), I REALLY don't want to damage the PTO components internal to the tractor. That gets expensive with a capital "E".
We spent a bit of the weekend mowing heavy meadow grass, and the lighter setting on the clutch springs seemed to work well. The clutch housing was cool to the touch, so it's not slipping there. It's set substantially lighter than the factory setting, so the PTO protection is improved as well. I noticed it did move on a sudden start or stop, and that's fine with me.
Impact loads are bad enough, try wrapping a length of 3/8 steel cable around the output shaft.. without either a shear bolt or slip clutch things are going to get exciting very shortly.
Rant over..
Sean
OP
Travis_R
Veteran Member
I haven't tried this method yet...
Farmwithjunk
Super Member
I'm with ya! The only "hassle" would be what would happen if you DIDN'T have a slip clutch and still hit a number of "land mines". The oldest mower I currently own is a 7 year old Bush Hog 286. It's chopped up small trees, been backed into brush piles, struck rocks and stumps, ground up a bicycle frame, and a host of other "slip clutch testers". No way of knowing for certain, but an educated guess is it has seen roughly 600 hours of use, most of that was mowing in conditions that would make most folks shut down the tractor. Just the nature of my business.....
If it had a sheer pin, I'd have spent as much time on the ground replacing shear bolts as I did mowing. With a slip clutch, never so much as a lost second due to hitting "stuff". And in 7 years, that slip clutch has been "serviced" 3 times..... (I've engraved "index marks" with a cold chisel, and can verify the fact that it does slip from time to time)
....Still running the ORIGINAL friction disc in the clutch.....
I've yet to see a slip clutch that was of insufficient quality where it wasn't able to deal with the torture I occasionally put a mower through. They ARE NOT nearly so fragile as some would lead you to believe. These things are designed to take a beating.
OP
Travis_R
Veteran Member
Maybe the 285 is too much cutter for my tractor? I have no idea. All I know is that the tractor dies before the clutch will slip.