Winch calculations

[Gordon Gould]

Plumb's got a good point about the ability to disengage the winch quickly. If something binds up solid, and the odds are it will, you have to go to the tractor to kick the PTO out of gear, which is the last place you should be if something breaks. You may find the PTO won't disengage easily if it's under a lot of strain as well.
Sean

I agree with this 100%. Even if nothing breaks the tractor is going to start moving. Very dangerous to say the least.
It is mind boggling the number of weird and unpredictable things that happen when you winch logs.

 

[Snowstorm]

I am fabbing a M6 Braden winch into a psuedo-Farmi for firewood skidding. If I Google Braden winch, there is an excellent 40-page manual. On page 39 is a table which includes max input RPMs and line speed in Ft per minute for many Braden models, but not the M6. I emailed Pasccar, the current manufacturer of Braden, and they sent me an old M6 brochure with some specs, but not all. Soooo, we resort to extrapolation.

With a worm gear reduction of 34:1, I assume 34 revs of the worm = one rev of the gear = one rev of the winch drum. With a 5" winch drum diameter, one rev = 16". At 300 RPM input speed, that is 4800" or 400 ft per minute. I think 100-200 ft/ min is plenty fast enough for a log to be travelling behind a winch, so I would need to cut my input speed in half--easy to do with a jack shaft and a small sprocket. (PTO speed 300 rpm to jack shaft, 12 tooth sprocket #60 chain to 24 tooth sprocket on worm)

Request critique of my assumptions and calculations. Thanks in advance.

If you are making a winch for skidding logs and option would be to consider mounting it on a small trailer in conjunction with an arch. This will lift the butts of the logs up off the ground when skidding without making the tractor tippy. You could also put a transmission in between the PTO and winch to reduce your line speed.
Kevin

 

[Gordon Gould]

Hey SnowStorm I love it

 

[easygo]

Snowstorm,
That thing is a classic. Did you build it? I would be curious if the fairlead actually has a roller or it's just a piece of steel the cable slips over?

 

[VroomVroom]

Hey snowstorm, I thought for certain you were from Newfoundland canada with that set up. Nice job. How did you seal the rear end to prevent water?

 

[Baby Grand]

I like the ratchet for locking the cable. Is that a rear axle making the right angle?

 

[tree grower]

Snowstorm--(appropriate name this winter !!)--That is quite a fabrication, but it is large enough to be a better skidder than a buncher. I anticipate 90% of my movement to the log to be backing off a road, so the 3ph format is preferred. In light of the comments about line tension, disengaging the winch, and safety, the warnings to go hydraulic have probably hit home. Further research has revealed that my 800 pump operates @ 2000 psi and 4-4.8 gpm. The 1700 pump is 2100 psi and 5.3 gpm. Would I be correct to assume that input psi and gpm is fungible--ie 4.5 gpm @2000 psi is the same whether it comes from a 5 HP engine or a 100 HP engine?

On a related matter, 30 or more years ago, you could purchase a clutch for a power plant. I seem to recall them being used on sawmills using a LeRoi power plant. I haven't found one for sale in recent years. The unit I have in mind is a two-piece clutch (disk + pressure plate), more or less 4" in diameter, and activated by a hand lever, one end of which is bolted to a base. Pull the lever toward the engine, and clutch engages, pull toward the powered implement, and it disengages. Am I having fuzzy memories, or do I recall correctly ?? Such a unit would allow use of the PTO, but also feature actual clutch function.

 

[Snowstorm]

Hey snowstorm, I thought for certain you were from Newfoundland canada with that set up. Nice job. How did you seal the rear end to prevent water?

Before I put the the axle with the drum down into the rearend I took a piece of inner tube about 12 x 12, cut a small hole in it, stretched it on over the spline and slid it up to the bottom of the locking gear. Not very fancy, but it kept rain and snow out of the rearend for more than 20 years. It got pulled down inside the rearend before this pic was taken and it had not been removed yet.

Kevin

 

[Snowstorm]

Snowstorm--(appropriate name this winter !!)--That is quite a fabrication, but it is large enough to be a better skidder than a buncher. I anticipate 90% of my movement to the log to be backing off a road, so the 3ph format is preferred. In light of the comments about line tension, disengaging the winch, and safety, the warnings to go hydraulic have probably hit home. Further research has revealed that my 800 pump operates @ 2000 psi and 4-4.8 gpm. The 1700 pump is 2100 psi and 5.3 gpm. Would I be correct to assume that input psi and gpm is fungible--ie 4.5 gpm @2000 psi is the same whether it comes from a 5 HP engine or a 100 HP engine?

On a related matter, 30 or more years ago, you could purchase a clutch for a power plant. I seem to recall them being used on sawmills using a LeRoi power plant. I haven't found one for sale in recent years. The unit I have in mind is a two-piece clutch (disk + pressure plate), more or less 4" in diameter, and activated by a hand lever, one end of which is bolted to a base. Pull the lever toward the engine, and clutch engages, pull toward the powered implement, and it disengages. Am I having fuzzy memories, or do I recall correctly ?? Such a unit would allow use of the PTO, but also feature actual clutch function.

Someone passed the following link to me when I was looking for a clutch to put inline with a PTO driven implement. It looks something like you describe.

Surplus Center - PTO IN/OUT BOX

 

[Snowstorm]

Snowstorm,
That thing is a classic. Did you build it? I would be curious if the fairlead actually has a roller or it's just a piece of steel the cable slips over?

The fairlead is a homemade one - a piece of shaft with a piece of pipe over it. I need to replace it with one with bearings.