pto powered bandsaw ?

[Renze]

i have seen plenty of home made bandsaws on YouTube, made with some frame, a rolling saw portal, and 2 old car tires to drive the saw band around... the log stays in place and the bandsaw portal moves through the log.
But they are all low power, gas or electric powered...

Older circular sawmills have a stationary blade, and roll the log on a bed through the sawblade. The big drawback is that it needs double the length of bed.

Does anyone have an idea how to power a moving bandsaw head with a stationary tractor PTO drive ? the idea is to cut costs, so hydraulic is no option...

 

[PILOON]

Don't think what you want to do is possible.

Sure, a PTO generator could drive an electric motor but that would end up costing more than hydraulics.

Forget any kind of flex drive due to power required.

OK, I could see a long PTO shaft doing the job but that would be cumbersome and prone to trouble.(and very dangereous) as the tractor would need to be a fair distance from the sawmill in order for the shaft to slide in and out to reach both ends of the mill.
With a long shaft unsupported in middle it would probably whip about and kill the operator.
Also the carriage would probably fall off the tracks as it relies on the engine weight to keep it 'on track'.

Your best bet is still a gas engine.

Locally sawmills are offered fo about $4000.CDN with 12 hp engine.
While considered underpowered they still do cut wood.

Why not consider a chainsaw mill? basically a saw clamped to a channel that follows a 2 x 4 as a guide.

 

[BHD]

use a 90 degree gear box and set the head up stationary and move the log on a carraige. like in the circular saw units, I would put the vertically instead of hormonally, most used some type of cable system that would power the log carraige system,

 

[Brad_Blazer]

You could use one of these to transmit power but the length is pretty limited.
http://www.nookindustries.com/pdf/NookSpline.pdf
Otherwise drive the tractor alongside the rails to power the saw and move it.

My brother hired a sawyer who had a Woodmiser with a 40hp turbo diesel. It wasn't underpowered. Lots of hydraulics and good control with the operator on a seat that moved with the carriage.

Brad

Edit : It's Wood Mizer. The one I saw was similar to this: YouTube - Wood-mizer Portable Sawmills - LT40 Super Hydraulic

 

[dfkrug]

But they are all low power, gas or electric powered...

One day, I would like to build one with the moving carriage. I have collected
the motor (and spares) I want to use: water cooled, 2-cyl Honda CX500
engine @ about 50hp. Compact, powerful, cheap.

 

[Renze]

You could use one of these to transmit power but the length is pretty limited.
http://www.nookindustries.com/pdf/NookSpline.pdf

I've been thinking in that direction too (instead of using a very, very long PTO shaft as suggested, use just the 6 meter PTO shaft with bearings on both ends, and use a 2 foot sliding outer shaft that moves along with the saw..

Problems i see in that setup, is that the PTO shaft will whip around, and that it wont slide very long: If you dont grease it it wont, and if you do grease it, it will be covered in sawdust and wont slide either

But this nook spline gives a new perspective to that principle: I could use a big 200x200mm square tube as driveshaft, and make a collar around it rolling on several of those polyethylene hand pallet pumplift truck rollers to reduce the axial friction. The rollers have enclosed bearings so wont take up sawdust, and the axle (square tube) can remain bone dry, so it wont catch any sawdust.

Otherwise drive the tractor alongside the rails to power the saw and move it.

Ive been thinking about that too, it would be killing 2 flies in the same slap.. However the tractor will pull the saw portal off the rails... and i'd need to get on and off the tractor in order to load and unload logs, pick up the boards, etcetera...


Maybe i should just be statisfied with the 7.5 Hp (or was it 7.5 Kw ?) 3 phase electrical motor, i bought it 2 years ago for 15 Euro as a backup for our irrigation pump...
In the end it will be cheapest, and the continous torque of a 10 hp electrical motor will outperform a 15 or 20 hp gas engine any day....

Would it really make a difference, is power the limiting factor, or the saw band itself ?

 

[Brad_Blazer]

The more I think about it the more it makes sense to have a dedicated motor that travels with the bandsaw. If you want more power just mount a bigger motor from some junk vehicle. A driven carraige is probably needed to make use of more than 10 - 15 hp.

That electric motor should be plenty. Here is an example of an electric band saw head:
Sawunits

You'll need to have a way for the power cord to traverse. The Wood Mizer video shows a fancy cable carrier.

 

[Paddy]

Renze,

I built a band saw saw mill 25 years ago. Very simple 8 Hp engine on a moving saw, stationary log. Worked good enough to build a 2500 sq-ft timber frame home. I mostly sqared logs to 8" x 8" 10' long. I used cast iron pullys. These were comercial types, 18" dia and with 3 or 4 groove V-belt. I bought a length of belt to make the rubber surface. The pullies were mounted on 1" dia keyed shaft, 16" long. I made one of the shafts, adjustable for tracking.

I don't remember all the details but, I know the limiting factor on my saw was the blade drifting up and down if I push it too fast. Could have been blade speed?

Patrick T

 

[SkunkWerX]

I would come off of the tractor's PTO with a pully/belt system.

This would accomplish two things:
1. ability to set proper band-blade speed.
2. reduce shock loads, nto worried about the tractor PTO, more the band-blade which might be more subject to fatigue and breakage if driven directly.

You would have to stationary mount the blade power assembly, and use a guiderail or roller assembly carraige to move the wood through the blade.

 

[dfkrug]

I built a band saw saw mill 25 years ago. Very simple 8 Hp engine on a moving saw, stationary log. Worked good enough to build a 2500 sq-ft timber frame home. I mostly sqared logs to 8" x 8" 10' long. I used cast iron pullys. These were comercial types, 18" dia and with 3 or 4 groove V-belt. I bought a length of belt to make the rubber surface. The pullies were mounted on 1" dia keyed shaft, 16" long. I made one of the shafts, adjustable for tracking.

So the rubber belt went over the 18" pulleys to act as blade drive wheels?
Any reason you did not use automotive wheels/tires as seen in some of the
home-built units? Sounds like 18" pulleys woould be hard to come by.

Also, how wide was your bandsaw blade?

 

[Western]

I would come off of the tractor's PTO with a pully/belt system.

This would accomplish two things:
1. ability to set proper band-blade speed.
2. reduce shock loads, nto worried about the tractor PTO, more the band-blade which might be more subject to fatigue and breakage if driven directly.

You would have to stationary mount the blade power assembly, and use a guiderail or roller assembly carraige to move the wood through the blade.

You can see one like this in Branson Missouri at Silver Dollar City. Very effecient. pto drive belt to larger pully, then shaft to blade on fixed rails, rollers the log slides on and you got boards!..and they are using an old steam powered tractor.

 

[Western]

I would come off of the tractor's PTO with a pully/belt system.

This would accomplish two things:
1. ability to set proper band-blade speed.
2. reduce shock loads, nto worried about the tractor PTO, more the band-blade which might be more subject to fatigue and breakage if driven directly.

You would have to stationary mount the blade power assembly, and use a guiderail or roller assembly carraige to move the wood through the blade.

You can see one like this in Branson Missouri at Silver Dollar City. Very effecient. pto drive belt to larger pully, then shaft to blade on fixed rails, rollers the log slides on and you got boards!..and they are using an old steam powered tractor. Last I "saw" it it had a fixed rotory blade,,a biggun too

 

[Paddy]

dfkrug,

Yes, I used the pully as the wheel with the cut to fit belt as the "tire". Most band saws use a very rigid wheel with a thin rubber band of sorts. The auto tire would be very wide. The 18" wide by 3" wide pullys were just ordered out of a catalog of industrial pullys. With luck, I supose you could find them at a major scrap yard. My blade was mostly 1-1/4" wide. Can't recall the tooth count, but very few per inch! Most industrial suply shops weld blades to order and they are cheep. Just the other day I was at Fastenal, Industrial and Construction Supply, and they had a display for band saw blades, cut and welded to your spec.

I was 22 years old when I built it so my welding skills were not so good. But the basic frame was an unsidedown "U". The tract was 4" angle weld on an old axel. I used flat vice thread to make the the adjustable tables at each end. Each turn was 1/8".

Patrick T

 

[Renze]

I think i should decide either way: use the 7.5 hp electrical motor on a short frame and keep the log stationary, or:

Go big time, and use 40 PTO hp and put the log on a roller table, to roll ut under the stationary saw head.

The method based on the rolling collar shaft, or the variant i described with pallet truck rollers on a square shaft, will be much more expensive and require a precision balanced, perfectly straight square tube driveshaft. Too expensive.

To yank a log through a 40 hp powered saw, wont be easy when using car wheels and standard bearings, as band saw guides. in other words, there is an extra investment to beef up and professionalise the saw head, before the 40 hp will come to use.

Somebody said that the weight of the motor kept the saw head in place, and prevented vibrations. Using the 7.5 hp electrical motor as sawhead ballast as well as using rubber car tires, will be the most efficient solution, cost vs. output.

WoodMizer offers a pneumatic saw band tension kit: Using the rubber car tires will achieve the same thing




Does anyone have ideas about how to figure out the sawhead feed ? Will this require another electrical motor, or can the saw head motor, also pulls itself along on a cable, using a dog clutch to engage the steel cable pulley ?
Then i could still use multiple pulleys to achieve several cutting speeds, and tension the steel cable by a spring, to even out the different diameters of the pulleys.

I am not thinking of a winch that winds up all the cable on a drum, but something like a flat, wide pulley: It just makes 1 or 2 loops over the pulley (enough loops to get the required traction) but its only attached to the frame, at the front and rear of the frame.
The silage block cutting spades they sold over here in the 70's, had a spade movement based on the same principle.

I think i have most required materials for the frame, sawband guides and motor in house. As soon as i built the new frame for the road sweep, the band saw is next.

Please share your ideas !

 

[Donman]

Renze, where do you get the tree logs to cut into boards? I didn't know Holland had that many trees. I have never been there but my ancesters came from there.

 

[Renze]

Renze, where do you get the tree logs to cut into boards? I didn't know Holland had that many trees. I have never been there but my ancesters came from there.

Holland has a very diverse landscape. The province of Limburg is a tip inbetween Belgium and Germany, where the higest hill is are up to 320 meter high. There is a major calcium mine there, for a cement factory. traveling from the highest elevation of said province into the northwest, the elevation will gradually drop. The landscape will vary from river delta clay, to forests and heather fields, into the bottom of a former sea tongue enclosed in the land (minus 5 meter below sea level the famous polder) into a peat area of drained lakes in the mid west, into a sand dune row along the coast, which is higher than the middle part, with its riverdelta clay, and lakes and enclosed sea tongues that have been pumped dry.
That's why we say Nederland, and abroad they say Holland: when you make a section view of our country, its hollow: the hills of Germany and Belgium drop to below sea level, and rise again at the coast where the sea current has sedimented sand dunes thousands of years ago.

I live in the east, where there is very cheap dusty dry sand soil. Locally our ancestors have planted pines on the poorest soils, and fence rows along pastures are full of oaks that farmers grew for firewood.
Its a waste to burn all the mighty oaks in our stoves and meantime import expensive bangkirai from Indonesia. Oak is as good as any other tropical wood. Because farmers dont need the oaks for firewood anymore, many of these have grown much taller than desired for their original purpose (as a wind screen between pastures) which makes them excellent for lumber.

 

[Donman]

Thanks for the excellent geography lesson!

 

[Renze]

Donman, if you ever drop by, i'll give you a free tour around here !!

 

[Knotbored]

Someday I would also like to build a bandsaw but I was thinking far less power, perhaps one of those cheap 6.5HP from Harborfreight.
My initial idea is to use a burned-out house trailer frame with pipe welded (shimmed level first) for rails, and pullys for wheels supporting the log.
Using auto tires to support the sawblade (maybe those undersized spare tires with little tread.)
I see damaged or outdated trailers free or cheap often in Craiglist and the local newspaper.
I hope this message thread continues with other suggestions and comments-its very interesting.

 

[Renze]

YouTube - Sawmillin' Upstate NY - Homemade Band Sawmill
this is a very basic, but working variant: The rollers arent car tires, but just some cast iron trash bin wheels with rubber tire volcanised around it.

YouTube - 'Necessity being the mother of all invention'
this is an even more basic, and not really working variant, using a chainsaw: i'd define this as a last solution against boredom...