Bandsaw mill build

G'day everyone,

Not sure if this is the right area to post this?

I have been wanting to get a small bandsaw mill for some time now but the cost has held me back. I have now decided to have a crack at building my own. Recently I picked up a couple of old flywheels off an old stationary engine. Would anyone have any advice on the suitability of these flywheels to use as the main and idle wheeks? They are cast iron, 56.5 cm in diameter and 6.5cm wide. Given they are off an old stationary engine would they be balanced enough to work?

Thanks in advance.

Hi Stevo, have a look at how this guy did it, might be easier for you. https://youtu.be/dFNpKC3JTVQ
Rgds,
Crocy.

Also check out Matt Cremona if you want another option/view on a build. A bit more elaborate mill and less re-purposing. Playlist here

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Originally Posted by poundy

Also check out Matt Cremona if you want another option/view on a build. A bit more elaborate mill and less re-purposing. Playlist here

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Thanks for that, i watched Matts build process and have been back watching again, i like the idea of minimal re-purposing. I haven't been able to find a supplier of suitable wheels here, and thought these looked similar to the ones matt used (understanding his are new and purpose made).

Cheers

Marty

Stevo,
Have you seen this thread? https://www.woodworkforums.com/f132/b...aw-mill-220445 There's some information in there about wheels as well as blades.

To keep the blade centred on those cast wheels you'll need either a crowned outer diameter, or some sort of flange plus a method to keep the blade teeth off the iron surface. I'd also be concerned about their strength because the speed needed for a bandsaw mill might be higher than they were designed for.

I'm nearly at the end of building my bandsaw mill. I've used 20 inch Vee belt pulleys. There's a belt stretched into the idler pulley for the blade to run on, and the main drive belt forms the crowned surface for the blade to run on on the drive side. This is what most mid sized commercial bandsaw mills do.

Good luck with the build.

Graham.

Thank you for the link graham, I hadn't seen that thread. Very valid point about the rpm the wheels I have and their original purpose. I had a look at some stationary engine specs and saw rpm of 650 to 1000 and not knowing what mine are actually off is definitely a potential disaster. As for keeping the blade off the steel wheel I dis have a thought about using an inner tube to give a bit of a softer surface. Probably could have used more though before I bought them.

Are you able to send me some pics of your build? I've had a look at surplus centre and waiting in a freight price.

Thanks

The surplus centre wheels are stated as good for 1200 rpm, which was one reason I went that way.

I'm not sure that a piece of inner tube would be substantial enough for bandsaw mill use, and how would you get the crowned profile?

My mill is all pulled apart right now for painting and final assembly, but I can send some photos of the band wheels etc. during the build if you pm me your e-mail address and let me know what in particular you'd be interested in seeing. I'll put a couple of photos here as well. I plan on writing up the build on the metalwork forum as it was basically a metalwork project.

Graham.

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Originally Posted by stevo81

Thank you for the link graham, I hadn't seen that thread. Very valid point about the rpm the wheels I have and their original purpose. I had a look at some stationary engine specs and saw rpm of 650 to 1000 and not knowing what mine are actually off is definitely a potential disaster. As for keeping the blade off the steel wheel I dis have a thought about using an inner tube to give a bit of a softer surface. Probably could have used more though before I bought them.

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For efficient milling you need between 3000 and 5000 fpm.
For your 56.5 cm wheels than translates to between 515 and 860 rpm - Id say if you stuck to the lower end you would be safe enough.
Quite a high tension is needed on the blade so I'd be worried about using rubber inner tube.

The saw mill I use has 700 mm uncrowned wheels and have V-belt grooves on the outside and uses V-belts to keep the blade from touching the wheels.

yeah it'll work, but you won't be able to half ass things like a lot of the homebuild guys do.

They get away with a lot because their wheels are lightly constructed. Yours aren't..... and that going to make it harder to set up, and better when you have.

Those wheels are fine at wood bandsaw speeds, they're fine at speeds far in excess of that. But because of the weight you are going to have to get them properly balanced. Thats okay.... its one more thing that gets done when you send them in to be properly crowned. You're in Burpengary.... talk with Jim Flanjack? at Combined Saw and Knife.

Next thing is - and Jim is the guy to talk to on this - your wheels have weight, and that going to change how it runs. Unlike all those lightweight thingys, you will have a fair bit of inertia. It means yours will carry a bigger band then the others. Thats good - was it me I'd be thinking get the wheels crowned for 3" and then run mostly 2" or 21/2" disposables on them. Band size equates to speed and accuracy, and no board is worth more because it took you longer to cut it. The size a wheel is crowned for is the maximum size it can run... but you can run smaller bands then that which gets you back to the home sharpen and set throwaways. 3" is good though because even though they arent at the throwaway size and you got to send them in for hammering occasionally... you also start getting real tooth options. Those little 1.25" things are just glorified hacksaws.

You may need a throwout pully, basicly a third small wheel that works like a clutch to put strain on the band. Thats because you need to remove the weight of the wheels off the motor for starting

You're going to need more HP too.

All this is good. It s a slightly more expensive setup but it will deliver in performance (I think). Your wheels are small diameter and that may present problems with band life because the tighter the radius of the curve they have to flex around the less time they last. Talk with Jim - he's probably the best bandsaw man in Qld.

At 57cm diameter you may find it a bit too tight for a 3" blade. But as John has already said, you can always go smaller.

thanks for all the info, good to get opinions for and against my proposed wheels and an idea on band speed and blade width. When i got the wheels i intend/intended to use i figured there would be a fair bit of inertia given their weight....they must be close to 30kg each. I didn't imagine i could possibly a 2 - 3 inch blade but bigger is sometimes better i guess. Nor did i think about the guys at combined saw and knife and their knowledge, i have bought several blades from them in the past for both my 14inch bandsaw and small metal cutting bandsaw. Ill go and see them early in the new year.

What sort of HP would be required? Ideally id like to be able to cut upto 900mm....although i doubt ill ever get anything that large. Watching the mill Matt cremona built he has a 10hp electric motor on his which seems to work well for him. I have 3 phase and now considering going down the path of electric motor as its a bit quieter.

Thanks

Marty

I based my mill on mikesfestivas build using bike wheels.
Has been working well for 3-4years now.
Dont use his idea for rails as thier not strong enough for aussie hardwood.
I can fit logs up to 1200mm diameter on the mill but only 950mm between the guides.
Band is 4.7 long and 11/4 wide.
HtH

The diameter of the band wheel dictates the thickness of the blade as a thick blade will create stress fractures around the the smaller circumferences. The thickness of the blade in turn dictates how much tension can be applied. This is from a booklet produced by Simonds Saw and Steel.

Attachment 451389

This a link to their Red Streak booklet:

http://www.simondsint.com/woodbandsa...%20version.pdf

Regards
Paul