PTO powered bandmill

[crazyal]

There has been a couple if threads in the past about building a mill. If you search you should be able to find them. I know at least one of them had a link to a website devoted to them. I would love to see pictures as this evolves.

 

[tuolumne]

Well, it's been a while. Now the bandmill is reality and tomorrow I intend to start sawing lumber. The saw head design is based on parts available from Linn Lumber. I modified the saw-head carriage design to recieve PTO power and remain stationary. The carriage travels on the rails and is driven by the tractor hydraulics. I would welcome any questions regarding the mill...I have asked many on this forum in the past, and recognize the value of coming back to post real projects. What's left is to finish painting!

Early shot of saw head progress. Band wheels are 21" diameter on 1-7/16" shafts. The yoke at the far end moves with the hydraulic ram to tension the blade.

Overall view - no guards

PTO attachment/gearbox/drive pulleys

Hydraulic controls, rear view - old propane tank will be for blade lubrication. Two extra valves are available for a hydraulic log turner, or hydraulic raise and lower.

Carriage drive wheel and gearing. One side of the carriage is long to enable the wheel to drive a 16' log all the way through the blade.

Log dog.

Guard on one side.

 

[beenthere]

Anxious here to learn more about the launch of the new mill. You've done a lot of work getting it to this stage, and we'll look forward to some pics or vids. :cool2:

 

[MJPetersen]

Great Job!!:thumbsup: I too am anxious to see it in action.

Mike

 

[scrout]

Looks great.
I built a linn 190. My only concern is the beefiness of your carriage. My cross bunks are 2x2x1/4 sq and my carriage wheels only have to support about 400 lbs of sawhead, not a 1500 or 2000 lb log. And if you are flipping a 16 ft 10x10 wet fir cant, it is really heavy and slams down pretty hard. Looks like it will cut like crazy with the grunt of that PTO setup. I have an 18 horse briggs and can bog it pretty easy. We want lots of video too!!

 

[irvingj]

Vermont, eh? Nice job!!:thumbsup:

 

[Army grunt]

Keep us posted. we need pics.
Army Grunt

 

[tuolumne]

Looks great.
I built a linn 190. My only concern is the beefiness of your carriage. My cross bunks are 2x2x1/4 sq and my carriage wheels only have to support about 400 lbs of sawhead, not a 1500 or 2000 lb log. And if you are flipping a 16 ft 10x10 wet fir cant, it is really heavy and slams down pretty hard. Looks like it will cut like crazy with the grunt of that PTO setup. I have an 18 horse briggs and can bog it pretty easy. We want lots of video too!!

The castors are rated at 2000 lb. each, so they should be OK. Today I milled a 24" diameter x 10' maple log. That has to weigh around 2000 lbs as my loader could just lift it. I was suprised that I was able to flip the log with a peavy after a few cuts; I do not yet have a boat winch that I intend to use on a mast to flip the really big ones.

Overall, I was very pleased with the cutting performance. The hinge that I have mounted the gearbox on is not robust enough, and there is a bit of slop. This sets up a harmonic that limits my cutting speed to about 10' per minute or things start vibrating. I'll need to rework that mount somehow.

This picture shows a 10" log on the mill (trial run).



Here is the 24" sugar maple log in progress.



The PTO never slows at all. I feel that I'll be able to cut much faster when I get rid of the vibration. I am running at about 2200 rpms which gives me around 5600 ft/min. blade speed. Sorry, but I have no video capability.

 

[boxygen]

I must say I was skeptical of the idea when the thread started, but you made it happen! :thumbsup: Very nice job. I would get to the patent office quickly, I would think you could sell a bundle of these if you could make them in a cost effective way. Please keep us in the loop as you fine tune the machine

 

[irvingj]

Really nice. Wish I had the capability to fabricate as you have done!

PS-- could you post some more pics of your chicken house? That looks neat, too!

 

[piller]

That's really impressive! Looking forward to more info/pictures. How does the log carriage feed and blade up/down work?

 

[tuolumne]

That's really impressive! Looking forward to more info/pictures. How does the log carriage feed and blade up/down work?

The carriage feed is run by a hydraulic motor which turns the little rubber tire shown in one of the pictures. This drives against the underside of the log carriage rail on one side. This system is working way better than I had hoped. The saw-head carriage up/down is by a hand crank on the top of the support post. A chain runs from one side to the other; these turn the acme rods on each side which haul the carriage up and down with a captured nut. I thought this would be easy; in truth, I am quite tired of cranking already. At 5 turns to the inch I am getting a workout. The advantage over a hydraulic motor (besides cost) is the consistency. 6 turns with the saw kerf gives me 1-1/16" lumber every time without scales. If I add a hydraulic motor, I'll add a scale as well.

 

[Army grunt]

Really great. It would be good if you would share what you have done on a sight i go to often . I found it when I started building my saw mill.
Home Built Bandsaw Bandmill - Build your own Bandsaw Sawmill - Home
Also I found that when you cut turn the cant so the cut is going into clean wood not the bark, this will add to blade life
My mill pictures by falcon6667 - Photobucket
Army Grunt

 

[Reg]

Congrats, looks good.
I admit to having some misgivings (-:
If I had got onto this thread before you actually built it I would have "opined" that starting and stopping heavy logs would be a MAJOR problem, e.g. would rock the rig around.
Pleased to see I was wrong - when I'm wrong I learn (-:

The other thing about PTO powered stuff that needs to be tractor fed - is the need for at least two tractors, e.g. one to carry logs to it & boards from it and one to run it.
FINE if you have a few tractors and can spare one for the PTO task.
Sometimes a li'l 20 or 25 HP gas engine is the economic way to go.

 

[Eric Nova Scotia]

I am not 100% sure what you want to do. It would be harder to get power from the tractor to a horizontal band head. If you have it vertical, same setup as a circular mill you could place the tractor on the opposite side of the track. Use an old rear end (differential) under the track, drive the pinion with the pto, put a double pulley on the studs on one end of the rear end to drive the bandsaw and use the brake on the other end for a clutch. The brake on the pulley end can be use for a quick stop if needed. I would not plan on changing saw speed for small and large logs. Saws like to run one speed. This is especially important with circular saws. All circular saws are tensioned for a specific speed and if you change that speed, either by trouble or the lack of power the saw with start wobbling and making all kind of fancy and scary cuts. For a bandsaw, around 30 hp is really nice. It will work with less but that is when it takes 5 minutes per cut and the saw has more tendency to go around the knots instead of through them. Remember that regardless how much power you have you still have to keep very sharp blades on the machine.

PS make sure that the differential is not positrac. These things are so handy around a mill. I have seen log decks, firewood trimmers and many other things build with these, and they are cheap and reliable.

Have fun
Eric

Eric

 

[Eric Nova Scotia]

After posting the above reply I then realized I was still on page one and there was 4 more pages going to a finished mill. Sorry that I jumped the gun. The only thing that I question is the pto shaft. If you cut a large log that shaft has to stretch to its limit, with an increase joint angle and large cuts. You might get some vibrations from that and it will be hard on the U joints. Just be sure that the pto shaft does not come apart. Nice work and have fun with it. Maybe you can use my ideal on the differential on your next project, like a slab trimmer.

Eric

 

[tuolumne]

I guess it is time to report back in about how things are running. With a stiffer gearbox mount I can saw fast enough to bog the tractor down without vibration. Someone suggested a need for two tractors....I have a log loading deck that will hold enough logs to saw all day. I just roll them onto the mill with a peavy since it is level to the carriage. It takes about 1 minute to back the tractor up, hook up the hydraulics and connect the PTO, so one tractor is plenty for my operation. So far I've sawn around 5,000 board feet of maple, ash and pine. I've also sawn flats on logs for a log cabin, as well as a number of rectangular timbers. Overall the performance has been good...

Here are two things that I plan to change. One will be the addition of a hydraulic motor to raise and lower the saw head. That crank really tires me out at the end of the day...especially when sawdust gets in the threads! I also plan to add some brushes to clean the threads as they turn and a shield to keep off some of the blown dust. I'll post pictures when that is done.

The second change will be to add some sprockets and use a chain to either end of the carriage running off the hydraulic motor to pull it back and forth. I have found the the tire drive slips too much for good control of the log. If the air pressure is too high it slightly raises the carriage when I get down to the last few boards affecting the cut parallelism; if the pressure is too low it begins to slip and I need to assist the carriage along with my foot. A more positive drive system would be desireable. Some day....it works for now!

The dogs work really well; quick and solid locking. I mean to add some shorter dogs some time; the rings are already in place on the carriage. This will help with the last few boards since the geometry of the long dogs means adding blocking for the last board.

 

[PapaPerk]

This has always been my practice with the wood chipper. With my rototiller, I have turned the PTO on and off while at full RPM. Is this a problem? The rototiller seems to have almost no startup load when it is out of the ground. Like the rototiller, a bandsaw would have a very small startup load compared to a wood chipper. What is the reason behind this practice?

Yes it's a problem. You are slamming the h*ll out of the clutch and drivetrain... hard on the tiller too. Would you rather be slowly pushed or shoved violently? You are shoving the machine violently. Start it off at idle... engage the pto and then bring up to operating speed. :thumbsup:

 

[PapaPerk]

Well, it's been a while. Now the bandmill is reality and tomorrow I intend to start sawing lumber. The saw head design is based on parts available from Linn Lumber. I modified the saw-head carriage design to recieve PTO power and remain stationary. The carriage travels on the rails and is driven by the tractor hydraulics. I would welcome any questions regarding the mill...I have asked many on this forum in the past, and recognize the value of coming back to post real projects. What's left is to finish painting!

Early shot of saw head progress. Band wheels are 21" diameter on 1-7/16" shafts. The yoke at the far end moves with the hydraulic ram to tension the blade.
View attachment 209114
Overall view - no guards
View attachment 209108
PTO attachment/gearbox/drive pulleys
View attachment 209109
Hydraulic controls, rear view - old propane tank will be for blade lubrication. Two extra valves are available for a hydraulic log turner, or hydraulic raise and lower.
View attachment 209110
Carriage drive wheel and gearing. One side of the carriage is long to enable the wheel to drive a 16' log all the way through the blade.
View attachment 209111
Log dog.
View attachment 209112
Guard on one side.
View attachment 209113

Awesome!!! Looks great!

 

[PapaPerk]

This reminds me of the traditional circular saw mill with the moving carriage. You are just using a band saw instead. I really like it. Very nice work... seriously! :thumbsup: