The Forestry Forum

General Forestry => Sawmills and Milling => Topic started by: wardbrook on June 27, 2018, 05:04:53 AM

Title: Belsaw M20
Post by: wardbrook on June 27, 2018, 05:04:53 AM
I have a lead on a Belsaw M20 for what I think is a pretty good deal. Most everything I can find in searching the internet is about the M14, which seems to be the much more common entry level mill. The mill for sale has a 40" inserted tooth blade and 3 dogs as well as 60' of carriage. It is fully disassembled but appears to be complete. 

I have been gathering parts slowly and had planned to build a portable bandsaw mill. All of my research up till this point has been on that style of mill. This deal seems like it may be too good to pass up plus I am a sucker for old technology and a fun project.

So I have been reading what I can on these mills. My tractor is an old Ferguson to-35 basically the same tractor as a ford 8n. I believe it would be under-powered for this application. I do however have an older (1983) Mercedes turbo diesel sitting in my lawn that runs great but is rusted beyond what is worth fixing. I haven't been able to part with it because I thought the powertrain could be used for something someday. This seems like it could be just that project. If memory serves me correctly the motor makes somewhere in the realm of 120hp and 170 ft/lbs of torque around 2400rpm. I have seen several mentions of automotive drivetrain running "backwards" to these mills. Is there a reason I could not run it through the transmission and use reverse gear? I am assuming as these are made for a PTO, that my goal shaft speed is about 540 rpm? I see basically two options. Run the mill through the rear end (Mercedes stock rear end or a larger truck rear end if the stock one is not up to the task?) and braking/pinning the non used side of the differential, or run the drive direct off the driveshaft output at the transmission and eliminate the rear end, either way pulleys could be used to achieve any desired speed at a desired engine rpm. What am I overlooking here, it cant be that simple? 

I was planning to build a 32" bandmill. Most of the logs I would be milling are more in the 14"-22" range but I figured I would kick myself everytime a log came by that was a little too big for my mill. With the 40" blade circular I would assume that actual cutting width is about 18" but after squaring up a log you could easily get by with say 20" logs. Can you cut larger logs by spinning them 180 degrees and making two cuts or is lining back up non practical.? 

He says the mill comes with a "mechanical governor" can someone enlighten me as to what this is? Most all tractors I know of have their own engine governor, is this piece governing speed of something other than the engine rpm? What am I missing here.

What else should I know, what should I look out for. Am I crazy to buy this thing should I just build the bandsaw mill? 

Thanks for any help its appreciated. 
Title: Re: Belsaw M20
Post by: Don P on June 27, 2018, 06:15:57 AM
Sounds like a cool project. I have an M14 presently on a To35 and 46" blade which is underpowered at that size, so I've ground back every other tooth. I know of an M16 but don't know the M20. That is 60' of track, you must have more than the stock 10' M14 carriage, even with the 10' carriage on 14' logs chatter of the unsupported ends is a problem.

The Mercedes in reverse with a drive reduction in the 4:1 range should work. You can find the larger blade, I'm limited to a 17" cut with the 46" blade, max practical log around 28" although I've whittled away at up to about 32" so you are going to be in the 14" range above the carriage. My tractor governor maintains, or tries to maintain speed, not sure what his mechanical is doing, he might have used it with a non governed engine.
Title: Re: Belsaw M20
Post by: DMcCoy on June 27, 2018, 08:11:39 AM
I have a M14 which I extended to include 3 dogs and 12' of carriage without the extensions.  As Don mentioned chatter becomes an issue with unsupported ends.  Belsaws are light mills, ok for light logs.  I have cut some 24" x 16' 4" stuff with mine but it is very difficult.  Mine has a 42" saw which cut 16 1/4" max.  It wastes a lot of good lumber in sawdust, especially when cutting thin boards.  I built my own bandsaw and that is all I use anymore.
Title: Re: Belsaw M20
Post by: TKehl on June 27, 2018, 09:54:32 AM
Can you cut larger logs by spinning them 180 degrees and making two cuts or is lining back up non practical.? 

I certainly would not have the patience to do that.  If it was squared up, maybe…  But if you can square it up on the mill, you wouldn’t need to flip it, right. 
“I wish my sawmill wouldn’t cut so wide.”
                                                No one ever
With that said, how often do expect to run into one too big to handle?  If occasionally, so does everyone else (even with my 4’ slabber).  If every other log, maybe look at something else or invest in a good chainsaw to halve or quarter the logs lengthwise so they will fit. 
Those Mercedes diesels are sure something!  I’d say it ought to run it.  One thing to remember though, tractor HP is rated in continuous output whereas automotive is in peak power.  Still should be a lot more than the MF though.
I’ve also seen an old hillbilly setup where instead of running belts and sheaves, they ran the tire against the blade sheave, chained the car down good, and put it in drive. 
Title: Re: Belsaw M20
Post by: wardbrook on June 27, 2018, 05:04:36 PM

I’ve also seen an old hillbilly setup where instead of running belts and sheaves, they ran the tire against the blade sheave, chained the car down good, and put it in drive.
I was thinking a slightly more refined version of this. I saw a post on this forum of a guy using a Dodge Dakota with the 3.9 "Magnum" with the bed removed and spider gears welded running with a flat pulley on the drive wheel. Funny I just traded a dodge dakota 3.9 this winter for a snow mobile. I could easily do a similar set up with the mercedes. I would probably weld up a permanent frame for it that got it sitting high enough for easy maintenance. I would probably torch off all the front end parts and inner fenders for easy access to any engine repairs. leave a drivers seat and gut the rest of the interior and build in some shelves and tool boxes for saw mill related parts and tools. Dry storage and already built controls plus a covered motor area and 12v output for lights or whatever else I want to run. Hopefully I could fab up whatever governor he has to work with the Mercedes motor as it only has a speed limiter governor currently I'm assuming its a pulley driven mechanical type he has perhaps could be installed in place of ac compressor. Id like to leave the power steering pump might be useful for some lower flow rate hydraulics uses down the line who knows... 
Most of what I intend to cut is pine and hemlock. Other then that I do have a good amount of ash in my woodlot very straight and tall. I have a lot of maple too but I leave the big ones for syrup and the culls are firewood so I can't see milling much or any of that. I don't have a single Oak tree to contend with. The majority of what I think I would mill would be within the capacity of this mill. I do have an Alaskan chainsaw mill with a 32" bar I could half or quarter with in a pinch. 
I think I may bite the bullet and pick this thing up. Thanks Guys
Title: Re: Belsaw M20
Post by: Don P on June 27, 2018, 09:19:56 PM
With the pine and hemlock and the smaller blade go ahead and hook to the Fergie to start with and get your shed built then you can take your time getting the Mercedes ready. Ash can be a grunt power wise, it also helps to mix it up with something like poplar every other log or two to clean up the blade. I thought about hooking a car to mine, I planned on leaving the heater working too, a warm break room.
Title: Re: Belsaw M20
Post by: Flyingpig on June 28, 2018, 08:13:49 AM
My M14 is set up similar to what you have available to you. I run a Datsun L20B on it 120hp 110ft lbs torque. It uses an external v belt driven mechanical governor. This works very well. The engine is mounted in its own skid. We run it in fourth gear. It has a output mandrel running against a tire mounted on the saw mandrel to achieve direction change. I’ve ran the mill like this for about six months every other weekend and the tire has done its job quite well.
Title: Re: Belsaw M20
Post by: moodnacreek on June 28, 2018, 12:57:34 PM

It's good see old car motors rigged up to cut wood. I was starting to think it was a thing of the past. The real trick is to rig up a governor so you don't have to saw with a string.
Title: Re: Belsaw M20
Post by: Flyingpig on June 28, 2018, 06:24:44 PM
Yes you sure know it when the governor isn’t working properly that’s for sure!