Thread: Motor question on home made Horizontal bandsaw mill.

Get all the power you can afford. You WILL NOT regret it.

First, fill crank case with diesel fuel and crank engine over several times: DO NOT START !! Drain fuel from crank case. Fill with El Cheapo engine oil and start engine. Let it idle for about a minute. Keep changing the oil until it comes out clean w/ no "glitter". Might be 5 oil changes in the 1st 10 minutes of run time before it's clean. Then do a "break in" run of the engine: 1/2 hr @ 1/2 throttle (no load) Change oil again but with good grade oil. It will pay off in the long run. Chinese engines will last a long time if done right from the beginning.

As for blades, I'm not sure what you have available. You'll want to run a lower hook angle due to lower HP. Better lumber and engine performance.

Make sure the blade guide rollers are properly aligned.

Good Luck with the machine

Originally Posted by rwthom279

Get all the power you can afford. You WILL NOT regret it.

First, fill crank case with diesel fuel and crank engine over several times: DO NOT START !! Drain fuel from crank case. Fill with El Cheapo engine oil and start engine. Let it idle for about a minute. Keep changing the oil until it comes out clean w/ no "glitter". Might be 5 oil changes in the 1st 10 minutes of run time before it's clean. Then do a "break in" run of the engine: 1/2 hr @ 1/2 throttle (no load) Change oil again but with good grade oil. It will pay off in the long run. Chinese engines will last a long time if done right from the beginning.

As for blades, I'm not sure what you have available. You'll want to run a lower hook angle due to lower HP. Better lumber and engine performance.

Make sure the blade guide rollers are properly aligned.

Good Luck with the machine

Thank you very much for that sage advice (flushing etc), the reason l asked about diesel VS petrol is the torque factor, would having that low end grunt be better than the higher revving petrol? (slow and steady wins the race), plus no carby.

As for blades there are a few spots to get them from, l'll do a forum search for the best place, there is a bloke in Mount Gambier (S.A) that sells blades, not sure of his prices though.

l thought of say 1 tpi or even wider with your idea of the "lower hook angle"

Cheers
Steve

You haven't said how wide a cut you would like to make.

Originally Posted by Not enough!!

Thank you very much for that sage advice (flushing etc), the reason l asked about diesel VS petrol is the torque factor, would having that low end grunt be better than the higher revving petrol? (slow and steady wins the race), plus no carby.


l thought of say 1 tpi or even wider with your idea of the "lower hook angle"

Cheers
Steve

Gas or Diesel... no different treatment on engine flush.

Check engine output specs. Chinese diesels and gas both run @ 3600 rpm. A 22hp Chonda Gas has similar torque output as a 20hp Chonda Diesel... 1/2 of the price for the gas engine ($625 gas vs. $1400+ diesel USD) and parts are abundant for the gas engines. Diesel has a more sustained torque curve but engine rpm's directly effect blade SFPM. Low blade speed makes for wavy cuts... among a long list of other factors. Both have +'s and -'s

A good blade speed is around 4500-4700 SFPM for the HP you are looking at.

7/8" tooth spacing is the most common. 1 tpi leaves a rougher/fuzzy finish. 4 deg hook will cut ANYTHING (hard and soft). 7 deg for softer wood if you find the need. Avoid 10 deg blades like the plague ... trust me.

You haven't said how wide a cut you would like to make

Max Cut width is 900mm.



Gas or Diesel... no different treatment on engine flush.

Check engine output specs. Chinese diesels and gas both run @ 3600 rpm. A 22hp Chonda Gas has similar torque output as a 20hp Chonda Diesel... 1/2 of the price for the gas engine ($625 gas vs. $1400+ diesel USD) and parts are abundant for the gas engines. Diesel has a more sustained torque curve but engine rpm's directly effect blade SFPM. Low blade speed makes for wavy cuts... among a long list of other factors. Both have +'s and -'s

A good blade speed is around 4500-4700 SFPM for the HP you are looking at.

7/8" tooth spacing is the most common. 1 tpi leaves a rougher/fuzzy finish. 4 deg hook will cut ANYTHING (hard and soft). 7 deg for softer wood if you find the need. Avoid 10 deg blades like the plague ... trust me.

Petrol it is.

7/8" equates to 1.1/4tpi i'm guessing or there abouts.

4 deg's sounds the go over here, especially with some of the hardwoods we have.

Thanks again for all your help.
cheers
Stevo

Originally Posted by Not enough!!

You haven't said how wide a cut you would like to make

Max Cut width is 900mm.

In that case I doubt you'll be max cutting with even a 16HP engine.
The usual rating for engine power V width of cut is between 0.6 HP/in to around 1 HP/in
The lower end is for softwoods and the upper end is for Ozzie type harder woods.

To cut 900 (36") in hardwood without waiting for grass to grow needs something a 30HP engine.
16HP will be good for 20" and the odd 24" cut.

The setup I'm using uses a 1.3" per tooth, 27HP Kohler, 890 mm wide cut and I would not want to go any smaller than this.

Thanks "Bobi", for the that summary, if l do get any big logs ll can get the guy with his chainsaw mill to slab them.

l only want it for the <700mm timber.

Cheers
Stevo

Originally Posted by Not enough!!

Thanks "Bobi", for the that summary, if l do get any big logs ll can get the guy with his chainsaw mill to slab them.

It's a lot of work to slab a big tree with a chainsaw mill. There's no need to slab them, even if he just quarters or cuts them into bullets.

BTW the TPI or IPT in my posting above was incorrect, its 1.3 inches per tooth.

Thanks
Stevo

I think you need to be looking more at Blade speed than HP. I have a 13Hp Chonda with a cut of 650 mm in Hardwood. My bandmill works quite well because I have lowered the band wheel RPM to suit the HP. the best piece of advice I received was from the cooks website. I calculated the fpm of my blade to get maximum torque from the HP that I could afford, this gave me a constant blade speed based on the available HP. the link below explains the science behind it. this worked for me, i have a DIY mill that will cut any hardwood I want.

I would suggest you calculate your blade speed, you may not have to buy a new motor, It may jsut mean you change some pulleys! anyway have a look at the link below, it worked for me!!!!

http://www.cookssaw.com/index.php/in...bandwheel-turn

Originally Posted by newjon

I think you need to be looking more at Blade speed than HP. I have a 13Hp Chonda with a cut of 650 mm in Hardwood. My bandmill works quite well because I have lowered the band wheel RPM to suit the HP. the best piece of advice I received was from the cooks website. I calculated the fpm of my blade to get maximum torque from the HP that I could afford, this gave me a constant blade speed based on the available HP. the link below explains the science behind it. this worked for me, i have a DIY mill that will cut any hardwood I want.

I would suggest you calculate your blade speed, you may not have to buy a new motor, It may jsut mean you change some pulleys! anyway have a look at the link below, it worked for me!!!!

http://www.cookssaw.com/index.php/in...bandwheel-turn

I agree about using an optimum band speed but the motor power/torque used depends what someone considers a reasonable cutting speed

Just about any motor can be set up to drive a band at the the nominally most efficient speed, but that does not necessarily mean that band will even be able to start cutting or cut very fast.

The two other factors required for efficient cutting are
- for the motor to have enough torque to maintain a reasonable cutting speed
- a blade geometry to suit the torque of the motor.

If everything else is optimised a motor with more torque will always out cut one with less.

Newjon and Bob, thank you very much for both inputs, every bit helps.

Just have to buy the bleeder now, SWMBO will have a "pink fit" but l'm sure she'll come around after a decade or so! (MAN - they have long memories)

Cheers
Stevo

Originally Posted by Not enough!!

Thank you very much for that sage advice (flushing etc), the reason l asked about diesel VS petrol is the torque factor, would having that low end grunt be better than the higher revving petrol? (slow and steady wins the race), plus no carby.

As for blades there are a few spots to get them from, l'll do a forum search for the best place, there is a bloke in Mount Gambier (S.A) that sells blades, not sure of his prices though.

l thought of say 1 tpi or even wider with your idea of the "lower hook angle"

Cheers
Steve

Hi Steve,
Re bandsaw blade supply, I use LSW Group, 02 9708 0888, ask for Mr Kaire Hristosvki
A 25mm x 1.3tpi RedSteak carbon blade, 4220mm, costs me $30. A 1.3tpi Bi-Metal blade is around $70.
Hope this info is useful.
Mipela