Rotary Cutter rotary cutter question

[gav64]

I am looking into a rotary cutter to use a couple of times a year to cut about 2 acres of forest underbrush, plenty of rocks out there.
which is a better choice, slip clutch or shear bolt. I am more worried about the tractor (hst tranny) than the cutter.
Any recomendations for cutters for this application. glenn

 

[Farmwithjunk]

I am looking into a rotary cutter to use a couple of times a year to cut about 2 acres of forest underbrush, plenty of rocks out there.
which is a better choice, slip clutch or shear bolt. I am more worried about the tractor (hst tranny) than the cutter.
Any recomendations for cutters for this application. glenn

The MORE you need the protection, the MORE VALUEABLE a slip clutch becomes. Shear bolts will also drive you bonkers in conditions like you described. You'll be on the ground changing bolts instead of mowing.

Just make sure the slip clutch is adjusted correctly and able to slip when needed.

 

[HD Labs]

I am wondering the same thing myself. If the slip clutch never slips and gets seized up then it does me no good. On the otherhand I don't want to have to change shear bolts every time I hit a rock or stump. How often is enough to adjust slip clutch? Any hints on making sure its adjusted properly? I am looking to buy cutter as well and am hung up between WOods BB60 and Bush Hog Squealer 600. Specs seem to be the same but woods is about $300 more. Like the orange paint and the 5 year gear box warranty though.

 

[MrJimi]

Is there an easy way of checking a slip clutch just prior to mowing, if its stuck it would the same as welded?

Jim

 

[Farmwithjunk]

I am wondering the same thing myself. If the slip clutch never slips and gets seized up then it does me no good. On the otherhand I don't want to have to change shear bolts every time I hit a rock or stump. How often is enough to adjust slip clutch? Any hints on making sure its adjusted properly? I am looking to buy cutter as well and am hung up between WOods BB60 and Bush Hog Squealer 600. Specs seem to be the same but woods is about $300 more. Like the orange paint and the 5 year gear box warranty though.

OK... Here goes. This usually gets about a thousand "No, this is how you do it" replies, but here we go.

Find the 6 or 8 (depending on brand of slip clutch) bolts that hold the clutch sandwiched together. Untighten them 'till springs are out of tension. With mower hooked to the tractor, start PTO. That SHOULD make it slip. If clutch is siezed, shut down everything. Take a big spud bar or something simular and "lock" blade carrier (i.e. stumpjumper) so it can't turn. Apply PTO S.L.O.W.L.Y. and carefully. That will make it slip. Once it's free, remove spud bar (shut down tractor/PTO while removing bar) Let it slip under power for a couple minutes. Shut everything down, and re-tighten slip clutch bolts PER SPECS IN MANUAL. Every brand of clutch and every HP rating has its own specs. (Stack height of spring/bolt/nut) That's it. Install gaurds and start mowing.

I do mine once in the spring and again about halfway through the season. If the mower sits out in the rain, maybe a time or 2 more than that. It takes all of 1/2 hour and you'll never have to stop and search for ANOTHER shear bolt.

 

[Soundguy]

The MORE you need the protection, the MORE VALUEABLE a slip clutch becomes. Shear bolts will also drive you bonkers in conditions like you described. You'll be on the ground changing bolts instead of mowing.

Just make sure the slip clutch is adjusted correctly and able to slip when needed.

FWJ.. I'm thinking that if he only mows 2x per year.. he's gonna spend more time adjusting, slipping/checking his clutch each time he mows.. vs changeing a few gr2 shear pins.

If he mowed often.. it would be a different story altogether..

Soundguy

 

[HD Labs]

I'm a little slow at understanding how the slip clutch actually works. Could someone explain that a little and maybe that would help him to understand the concept as to how it works and why or why not it would be better for his situation.
I on the otherhand probably would use mine at least every 6-8 weeks but wouldn't necessarily use it in the rough stuff to cause it to slip. Could this affect how often it needs to be inspected/serviced?
I only have one area that really has any rocks to speak of and the rest is fairly well maintained.
May rarely try to forge a new path into some sapplings but more often than not just maintenance. What would you get SOundguy? I think I am safe to assume that Farmwithjunk would get slip clutch???

 

[CDsdad]

I'll probably get corrected, but anyway.

You hit a stump, rock, terrace row, bottom out or whatever with your bushhog. Instead of stalling or binding your tractor pto and transmission when your bushhog stalls, the slip clutch allows the tractor pto to keep turning even when the implement stalls. It is the weak link in the connection between your tractor and bushhog. After you get the implement out of a bind and stress off the slipclutch, the implement will return to normal operating speed if it ain't tore up.

Hope that's what you were looking for. As far as mechanics of the thing, I'd have to draw it to explain it. Maybe somebody else can explain better.

 

[Soundguy]

My 2 large mowers ( 10' and 15' ) both have torque limiters on them ( slip clutch )

I like them just fine. My 5' rotary mower has a shear bolt.. I'm ok with that too. I don't find it a hard chore to line up a shaft and yoke, and then drive a slug out with a punch, and then slide a new bolt in, and put a locknut onit with 2 wrenches. I carry the wrenches a small hammer and the punch in the tractor tool box along with some shear bolts.. It's really no big deal. Also.. once you have mowed an area often enough.. all the rocks are flat!

For what to use? I look at it kind of as a money / repair / repalce issue, and also take into account where it will be mowing.. etc.

For sure.. a properly adjusted slip clutch will give you some good protection with no bolts to change.... however.. that soft grade 2 bolt bops like a baloon when you feed 30 hp thru a driveline. My mower has popped a shear bolt on an ant mound... and I never felt it.. nada.. nothing...

Lots of equipment uses shear bolts.

I fthe fellow is gonna be good about adjusting his clutch prior to each mowing.. then that will be a real safe bet. If he forgets naw and then.. go with shear botls.. all you have to do is forget once with a slip clutch.. and you may have a driveline with -0- protection.

Also.. look at mower and tractor. I don't want the expense of replacing a 10' or a 15' mower.. or the tranny in a 75-95 hp machine.

On the other hand.. a gearbox o5' mower ? that's realitively cheap (grin). i do think shear bolt protection is -fine- for the averagfe user.. and slip clutch is extra insurance. As a test.. if you have a smooth shaft coupled slip clutch, you can always adjust then attach with a soft bolt.. mow.. and then when an issue arises.. see what goes first.. the soft bolt.. or the clutchslipping... That will tell you a bit..

As for how a slip clutch works.. it's just a torque limiter.. has disc;s in it that are held in contact by pressure from the adjustment bolts/springs.. That is.. one sod eof the drive line is not permanently coupled to the other side.. the connection is rigid.. but when your input torque overcomes the tension on the nuts/spings, and the output is in a bind ( rock/stump.. etc ).. then the force overcomes the pressure/friction holding the clutch coupled, and the input slips.. thus letting the tractor pto still spin even if the mower blades are stopped or slowed.. that help any? in this case.. a picture / diagram would be worth 1000 words.. etc.


Soundguy

 

[Farmwithjunk]

FWJ.. I'm thinking that if he only mows 2x per year.. he's gonna spend more time adjusting, slipping/checking his clutch each time he mows.. vs changeing a few gr2 shear pins.

If he mowed often.. it would be a different story altogether..

Soundguy

In the original post, he mentioned cutting 2 times a year.....In a lot with stumps and plenty of rocks. Under conditions like that, I'd hesitate to use a mower that was offered with only a shear bolt. (probably light duty mower). All the good mid duty and heavy duty mowers I know of all come standard with slip clutch.

I'm just not a shear bolt advocate, in any conditions. Also, a great deal would depend on how much a person wanted to spend, I suppose.