does stalling out hurt your tractor

[wedge40]

It sounds like the shear pin isn't doing its job. Running the PHD at higher RPM might create the extra stress required to snap the shear pin instead of stalling the tractor. I agree the easiest thing would be to get a slip clutch installed.

Wedge

 

[Soundguy]

Your right, it has nothing to do with the original question. Just that he did this while using his post hole digger. and then was told that he should not be doing that at an idle, but to reach 540 pto speed it should be at near full throttle. Now to me it sounded like he was being advised to use his auger at the 540 pto speed which could lead to a disaster. But then I must have just taken that post wrong, I seem to be very safety conscious lately. Maybe he should get himself a slip clutch like you suggest so as not to do any damage to his engine.

I don't see any post suggesting he runn at full tilt.

I do see one post saying to not run at idle, then int he next sentence the poster said what it took to reach full pto speed on THEIR tractor.

I didn't take that as a sugestion to run at full tilt.. but rather to not specifically run at idle.. As other have said.. you can get away with a lil more than idel and be safe.. there are plenty of other mitigating factors as well.. like the slip clutch... though it will have to be set to slip low.. IE.. at lower than the tractors hp rating at whatver slow rpm is being used.. etc..

soundguy

 

[patrick_g]

Idle is too slow to work a small tractor engine. But... if the diggin' is easy it might not be much work. I run anywhere from idle to about 2600 RPM (PTO speed) but reserve the higher speeds for special purposes like tossing dirt shavings farther away from the hole. I don't dig at high RPM. I raise the 3PH control to stop digging progress then rev up and raise the 3PH to toss shavings farther from the hole. I don't actually dig over about 1800RPM and usually slower.

Under about 1700RPM is not good for working the engine. These RPM comments are for a 40 PTO HP Kubota Diesel. Maybe other brands are happy and safe putting out generous levels of torque at slower speeds but I'd confirm that with reference to a manual before I made it a habit.

Pat

 

[meb9796]

Thanks for the responses guys. Sounds like I should've been running it slightly higher than idle. The first hole I did, I had it higher than idle and broke a shear pin in less than 2' of dirt. After that, I ran it at idle and only did 12" or less at a time and rose brought the auger up and then went back down to finish digging. Again, I've done almost 60 3' deep holes with a 12" auger and haven't had a problem. If it stalled, I would just turn the tractor back on, raise the rpm's to 1,500, and then start raising the 3ph and then turn on the pto, and 9 out of 10 times, it would come loose. Only occasionally would it stall out again and I would raise the rmp's a bit more and then try again until it came loose.

I really doubt if I could even dig a hole if I ran it at the 540 pto speed that is normal for FEL and mowing work. That thing jumps around enough when I first hit the ground, that I can only imagine what it would do if I hit the ground at full pto speed

But my question still remains , what should I check on my tractor after all that stalling (about 30-40 times total over the past month).

thanks again for all the responses, I love this forum!!!!!

 

[MtnViewRanch]

I don't see any post suggesting he runn at full tilt.

I do see one post saying to not run at idle, then int he next sentence the poster said what it took to reach full pto speed on THEIR tractor.

I didn't take that as a sugestion to run at full tilt.. but rather to not specifically run at idle.. As other have said.. you can get away with a lil more than idel and be safe.. there are plenty of other mitigating factors as well.. like the slip clutch... though it will have to be set to slip low.. IE.. at lower than the tractors hp rating at whatver slow rpm is being used.. etc..

soundguy

Well, like I said, I must have interpreted the post wrong.

 

[patrick_g]

I really doubt if I could even dig a hole if I ran it at the 540 pto speed that is normal for FEL and mowing work. That thing jumps around enough when I first hit the ground, that I can only imagine what it would do if I hit the ground at full pto speed

Place the auger in contact with the ground before exceeding idle speed to sort of create a de facto axle for the rotating mass. Doing this will help elliminate the wild gyrations that, although entertaining to observers not monetarily connected to the equipment nor related by blood or marriage to the operator, nevertheless could conceivably get out of control and cause a problem.

Pat

 

[have_blue]

Place the auger in contact with the ground before exceeding idle speed to sort of create a de facto axle for the rotating mass. Doing this will help elliminate the wild gyrations that, although entertaining to observers not monetarily connected to the equipment nor related by blood or marriage to the operator, nevertheless could conceivably get out of control and cause a problem.

Pat

I used a 16" auger a while back, and after some experimentation, learned to use it just as you said. I'm glad you qualified that "entertaining" part. My buddy was laughing at me, but I was sitting there bouncing, and having visions of my PTO exploding.

 

[patrick_g]

Bob, Glad nothing too exciting happened.

I have a 9 inch and a 12 inch auger for my PHD but haven't used a 16 inch. If the digging were at all hard I'd be afraid of shearing lots of shear bolts with a 16. My PHD, a SPEECO which seems to be more or less typical in design, uses the same shear bolt attachment irrespective of the diameter of the auger. I have "worn out" and then sheared the bolt a few times. Although a harder bolt is tempting I have managed to stay the course with the soft ones it is supposed to use.

Since the shear bolt's "radius of attachment" is the same for different sized augers, the larger the auger the more torque (circumferential shearing force) involved.

I think the torque requirement goes up, at least, with the area of the end of the drilled out cylinder and it seems there should be an additional load factor related to the area of the cylindrical walls due to friction. While actually boring dirt there is probably a figure for the volume swept out per unit time too but if you aren't super speed drilling that is probably negligible.

Up sizing from 9 inch to 12 inch should increase the torgue by a factor of (12*12) / (9*9) or 144/81 which is 1.777...7
So going from 9 to 12 inch ups the torque about 78%. Going from 9 inch to 16 inch increases torgue to about 3.2 times as much. Going from 12 inch to 16 inch is a 78% increase too.

Since I shear bolts at a manageable but not insignificant rate using the 12 inch auger with no roots or rocks, I think a 16 inch auger would be prone to shearing bolts pretty quickly in my setup. It would be EASY to use a harder bolt but then that would defeat the purpose of having a shear bolt as then the U-joints would be the weak link and shear bolts are way easier to change and cheaper too than U-joints (or PTO parts.)

Pat

 

[Egon]

The chances are there is nothing to check after stalling the tractor. If your battery is not in the best condition too many successive stalls may run it down sufficiently that it will not turn the starter. You'll get that "err err" sound heard in cold country come cold season!

 

[chumly2071]

Stalling the engine is a lot bigger problem for engines with turbochargers. if you stall it and the turbo is spinning at any kind of speed, you have stopped the flow of oil to the bearings. Can lead to a bad day for the wallet. With my diesel turbo engines, I always try to let them idle, even if for only a short time, to let the speed come down on the turbo and the exhaust gas temps come down as well.