Rotary Cutter Agri Supply GR-1 Slip Clutch Adjustment

[LeTempt]

I have a 5' Howse economy rotary cutter and I just purchased a GR-1 slip clutch from Agri Supply for it. It did not come with any adjustment instructions at all. The springs looked like they were basically fully compressed. I emailed customer service and asked them to send me the instructions. I was a little surprised with their response.

All they said was if it is to loose, tighten each bolt 1/4 turn and if it is to tight, then loosen each bolt 1/4 turn.

I would prefer to get a ballpark adjustment and do some minor adjustments before I break something. Any suggestions on spring length adjustments?

Thanks,
Jeff

 

[JRobyn]

Based on this related thread, I'm guessing the maker of the AgriSupply clutch is Grizzly - http://www.tractorbynet.com/forums/ls-tractor-owning-operating/355259-pto-slip-clutch-question.html

Very surprised that ASC gave you such a crappy answer. Maybe Grizzly will do better.

My Bondioli and Pavesi slip clutch (via BushHog) runs the springs at a specified length (I don't recall exactly without some looking), but the coils are CLOSE to touching, but definitely NOT touching.

p.s. ASC seems to be quoting this - http://forddistributing.com/media/d...m/a/maschio_tiller_slip_clutch_adjustment.pdf

p.p.s "Grizzly" brand seems to be an ASC house brand. I can't find a separate website for them anywhere.

 

[LeTempt]

Thank you JRobyn.

After my sub-standard initial reply from Agri Supply I received another email this morning that actually gives me the details I was looking for:

"Good morning Mr. Letempt,
My name is John Morris from Agri Supply and I understand that you would like to have some more precise settings information for the slip clutch you purchased from Agri Supply. I apologize for the informal answer that you rec'd previously. Let me line this out for you:
Spring Settings
Spring Height * *in.-lb * *ft.-lb.
29 mm/1.14" * * 2300 * * 190
28 mm/1.10" * * 3720 * * 310
27 mm/1.06" * * 5040 * * 420
26 mm/1.02" * * 6430 * * 540
You will want to measure just the spring height for this measurement to be accurate. As you tighten the spring this increases the amount of torque it is going to take to allow the disc to slip. Adjust up or down to achieve the proper pressure to allow the clutch to slip.
If I can help you further please feel free to give me a call at 1-800-345-0169 x 207.
Regards,"

 

[Mike9]

I downloaded this from a link to a TBN thread. It gives the adjustment for the horsepower for 20 - 50 HP tractors.

 

[LeTempt]

Thank you Mike9. I did some calculations based on the numbers that John from Agri Supply provided and came up with similar HP numbers based on the spring length.

I came up with 190 ft-lb would equal about 19.5 HP, 310 ft-lb would equal about 31.9 HP, 420 ft-lb would equal about 43.2 HP and 540 ft-lb would equal about 55.5 HP.

Thanks,
Jeff

 

[JRobyn]

Excellent! Really good on ASC! That's much better than the info I got from BushHog on mine. I assumed that since their gearbox was rated for 90Hp, that their slip clutch would transmit WAY more torque than I wanted for my 43Hp tractor. So asked them what spring length adjustment I should use. Their reply - use only our one stated/specified spring length. Made no sense. So I run about 1/16" longer anyway.

Don't make the mistake I once did and leave all the springs way loose. About an hour of the wife bushogging that way completely burned up the rear friction disk!

I use one of these to set my spring lengths - 6" Stainless Steel Pocket Ruler

Cheap and effective. I have one made by General that cost 5 times as much but can tell almost no difference in function.

 

[LeTempt]

JRobyn,

I did back my springs off quite a bit using a chart in my mower manual for the manufacturer's optional slip clutch adjustment. Their unit looked like the one I got from Agri Supply, but apparently they are not the same. I mowed about 1/2 acre and checked it for any heat buildup and it was cool to the touch. I will adjust the springs to the maybe about 26.5 mm (about the 45 HP setting) so I do not damage the 45 HP gearbox. I have a Harbor Freight 6" digital caliper that I got on sale for about $10 a few years ago that made setting the spring length very easy using the interior measurement function.

Thanks,
Jeff

 

[Gem99ultra]

Excellent! Really good on ASC! That's much better than the info I got from BushHog on mine. I assumed that since their gearbox was rated for 90Hp, that their slip clutch would transmit WAY more torque than I wanted for my 43Hp tractor. So asked them what spring length adjustment I should use. Their reply - use only our one stated/specified spring length. Made no sense. So I run about 1/16" longer anyway.

Don't make the mistake I once did and leave all the springs way loose. About an hour of the wife bushogging that way completely burned up the rear friction disk!

I use one of these to set my spring lengths - 6" Stainless Steel Pocket Ruler

Cheap and effective. I have one made by General that cost 5 times as much but can tell almost no difference in function.

I doubt seriously that you will be able to measure within .004 or .006 thousands of an inch with a 6 inch metal ruler. Even with a a digital dial caliper, getting good measurements consistently for all springs is going to be a hit and miss ordeal. I would suggest that you cut yourself a metal template to the precise length that you need, and tighten each spring using that as your block. Even then, you may find that you need to adjust your template based on your tractor. ...just my opinion.

 

[JRobyn]

As one can see from the spring length charts, +/- 1/32" is not really going to make that much difference. And there are 8 springs, so any slight variations are evened out between them all.

 

[DieselBound]

I recently picked up a Bush Hog 286 w/90hp gearbox (I think it's 90hp; seems that some specs for this model show up as more) to run on my Kioti, which is rated at 43hp at the PTO.

According to Bush Hog the springs on the slip clutch should be set to either 28mm or 32mm, depending on the slip clutch being used: either “Bondioli & Pavesi /
Binacchi” or “EG / Comer”

This would suggest that that chart isn't necessarily universal? But on the other hand I'm not sure how a "one size fits all" such as noted in Bush Hog's manual holds for tractors of different PTO ratings.