Chainsaw Hydraulic Conversion

NCMau · May 5, 2017

Hi everybody. I am involved in a project in which I need some words of wisdom. I have an old McCulloch mod 660 chainsaw (the type Paul Bunyan used to use). My intention is to remove all the unnecessary gas components and make an hydraulic conversion to be mounted on a tractor loader bucket. This machine is pretty beefy so I think it would make a good candidate for this project.
What I am not sure is how much of hydraulic power I need.
The tractor has a 7.i GPM PTO pump which drives the loader. I was looking at a motor on eBay, Parker MGG20010, which is a high speed/low torque motor. My question is if it has enough torque to do the job.
Keeping mind also that this chainsaw a 3:1 reduction gear for the chain, which it should increase the torque.
I am hoping this motor would work. The reasonable price of $94 is within my budget.
Need to add that the purpose of this saw will be to cut small hanging tree branches, not wood processing work.
Ideas?

muddstopper · May 5, 2017

My thoughts start with a few questions. Why do you want to mount a bar to a stripped chainsaw case then mount on a bucket. . I understand the want to trim branches, just not the use of a chainsaw case that will take more time and labor to modify than just making a bar mount to bolt your little motor to. As for power for small limbs, Those little motors dont make a ton of power, gearing the to slow the chain and make torque probably wont wrk as well as throwing the max oil and running max rpms. the motor is rated at 5000rpms, small chainsaws turn 10,000, to 13000 rpms. Even max rpms of your little motor is going to be half speed of a gas chainsaw. You can get more chains speed by using a larger chain sprocket and on small limbs, I think I would go for the extra speed over the extra torque. Your not going to have a lot of hp either method you choose. One other thing about those size motors is the shaft size, 9/16 dia and 1 3/8 length. If you go with a rim sprocket, its going to be hard to get one that will fit on the shaft. Oiling the chain is also going to be an issue, I assume one reason for trying to use the chainsaw case is to take advantage of the chain oiler.

NCMau · May 6, 2017

muddstopper said:
My thoughts start with a few questions. Why do you want to mount a bar to a stripped chainsaw case then mount on a bucket. . I understand the want to trim branches, just not the use of a chainsaw case that will take more time and labor to modify than just making a bar mount to bolt your little motor to. As for power for small limbs, Those little motors dont make a ton of power, gearing the to slow the chain and make torque probably wont wrk as well as throwing the max oil and running max rpms. the motor is rated at 5000rpms, small chainsaws turn 10,000, to 13000 rpms. Even max rpms of your little motor is going to be half speed of a gas chainsaw. You can get more chains speed by using a larger chain sprocket and on small limbs, I think I would go for the extra speed over the extra torque. Your not going to have a lot of hp either method you choose. One other thing about those size motors is the shaft size, 9/16 dia and 1 3/8 length. If you go with a rim sprocket, its going to be hard to get one that will fit on the shaft. Oiling the chain is also going to be an issue, I assume one reason for trying to use the chainsaw case is to take advantage of the chain oiler.

Yes muddstopper you are right. Thanks for the chime. One of the main reason I wanted to use the chainsaw case is the oiler and also because everything is ready there. All I would have to do beside stripping the saw, is to adapt the motor to the crankshaft. The bulkiness is not a problem because it is mounted. One thing I did not realize that these chainsaws have such a high RPM. With that in mind, I can see that I would be making a hole in the water….. even if I would choose the biggest motor of the series, I would get an increase of HP but the speed remains the same.
So here is option No 2.
I have an Eaton H 101-1704 motor. This motor has a max speed of 1021 RPM and a torque of 497 lb/in which would produce 8 HP, if my math is correct. This motor, of course, would still not be adequate for a chainsaw but I think it would work with a circular saw setup. The speed would still be slow, but I would use a 3:1 pulley setup to increase the speed.
To make this adapter for a 12” circular saw would be no problem, as I have the arbor and the bearings on hand.
I would have preferred the chainsaw option, but I see now that it is not much of viable option.
You think this motor would work for this purpose?

Rustyiron · May 6, 2017

The place to check is Forestry Forum for the guy's building firewood processors. They've found the right motor and a way to oil the bar with hyd. oil. I agree with Mudstopper on putting that old Mac on the shelf for display only!
http://www.forestryforum.com/board/index.php

edit; I skipped over reading your last line about only trimming small branches.

Rustyiron · May 6, 2017

I want to build the same type "trimmer" and have been wondering about using a hyd motor & rotary blade. No oiling and a much more reasonable rpm needed along with some built in inertia (the blade itself) and possibly a flywheel of some type. :confused3:

NCMau · May 6, 2017

Rustyiron said:
I want to build the same type "trimmer" and have been wondering about using a hyd motor & rotary blade. No oiling and a much more reasonable rpm needed along with some built in inertia (the blade itself) and possibly a flywheel of some type. :confused3:

Rustyiron, in the next few days after I get some hardware I will be involved with this circular blade project. I hope the motor on hand will do the job. Will post the outcome.

Steave · May 7, 2017

The Parker motor you have would run a circular saw. I have the MGG20020, just slightly larger than the MGG20010, on mine with a 16 5/16"-32 tooth blade. Had to put a flow control to throttle it down to 8 GPM which lets it spin about 4000 RPM which the blade is rated for. The momentum of the blade will let it zip thru a 3-5" limb as soon as it touches it. If the blade happens to be against the limb it won't have the torque to get started though.

The motor came off a hydraulic hand held concrete saw and I used it and the part of the bar that the motor mounted to and welded it to a homemade cobbled up frame to mount on my skid steer. It works pretty good but has a learning curve on how to not break something.

The problem I see with building one from scratch is the 9/16" arbor as already mentioned. I need a new arbor 9/16" to fit a 1" hole in the blade. I'm using the arbor that was on the concrete blade but over time it is getting a little worn, I guess the pressure of pushing sideways on the motor shaft when cutting. Haven't found one of those boogers anywhere yet and will need one by the end of summer. It's getting wobbly.

Haven't been very good at pictures but I'll try to find a few.

Steave · May 7, 2017

Found some pictures just hope they turn out. Also about the arbor, if you have a buddy that does machine work it could be made fairly reasonable. That's probably what I'll have to do since I don't have the machinery for that.

4570Man · May 7, 2017

I've nearly given up on a hydraulic saw for my firewood processor. It's just not feasible for the budget I wanted to spend on this project. I plan on going electric instead. If I was going to do what your trying to do I'd pull the spark plug out of the saw and pull the pull rope off the saw. I'd build an adapter to hook the motor on the crankshaft of the saw. The rpm would be far from optimal but I assume you only intended to cut a few limbs. For my project a circular saw wasn't a viable option due to the blade size needed. If you're only planning on cutting small limbs I'd use a cheap 12" miter saw blade.

NCMau · May 7, 2017

Steave said:
The Parker motor you have would run a circular saw. I have the MGG20020, just slightly larger than the MGG20010, on mine with a 16 5/16"-32 tooth blade. Had to put a flow control to throttle it down to 8 GPM which lets it spin about 4000 RPM which the blade is rated for. The momentum of the blade will let it zip thru a 3-5" limb as soon as it touches it. If the blade happens to be against the limb it won't have the torque to get started though.

The motor came off a hydraulic hand held concrete saw and I used it and the part of the bar that the motor mounted to and welded it to a homemade cobbled up frame to mount on my skid steer. It works pretty good but has a learning curve on how to not break something.

The problem I see with building one from scratch is the 9/16" arbor as already mentioned. I need a new arbor 9/16" to fit a 1" hole in the blade. I'm using the arbor that was on the concrete blade but over time it is getting a little worn, I guess the pressure of pushing sideways on the motor shaft when cutting. Haven't found one of those boogers anywhere yet and will need one by the end of summer. It's getting wobbly.

Haven't been very good at pictures but I'll try to find a few.

I have a feeling that even with my Parker motor and the speed pulley increaser, the blade would not start with the blade against the limb. With a theoretical speed of 3300 RPM, the torque would be decreased to 160 lb/in. I compare the the situation with my 2 HP table saw with develops more torque than my hydraulic motor. The blade would not run with a wood block in the teeth. It will be an operational learning curve and I am looking forward to get on with this project.

Edited: Basically that is what I will be doing. A 2" pipe mounted on the side of the loader. I like your idea of the rope. Does the blade segment have some sort of spring action mounted with the main mast? It is not clear on the pic. If you can not find a suitable arbor, have one machined. It should be a reasonable charge.