DIY Bandsaw Build / Wheel Question

**Frank S** · Jan 30, 2018, 01:31 PM

You will also have to construct a way to drive 1 of the wheels making a bolt on hub or adapter for a pulley to be mounted on would be my suggestion but in order to prevent the stresses from breaking the center out of the wheel I would recommend the hub have at least 1 bearing in it.
Another option may be to fill the cavities between the spokes with an epoxy then mount the pulley directly to that with as large of a bolt circle as needed

**nhengineer** · Jan 30, 2018, 02:36 PM

Originally Posted by made2hack

Well, the drive wheel would have to be connected to the motor somehow, either by pulley & belt combination or gear, maybe direct drive. I was planning on having the shafts static and the wheel spin on the bearings.

Better give it a bit more thought, Mr. Made2Hack, before you go too far with this. It is good to have a rubber faced drive wheel if you can swing it. Maybe knock out the bearing and press in a solid disc, bore a hole and broach a key seat.

**made2hack** · Jan 31, 2018, 01:08 PM

Hello,
Thanks for the suggestions. I will have to strengthen the wheel before adding power to it.

I was wondering if anyone knows what kind of speed to run for metal? It has to be slower than wood for sure, but I'm not sure by how much. I have a motor that runs at 1500RPM and I guess the wheel will spin slower. Should I calculate meters or feet per minute and figure out how slow to run the wheel?

Thanks,
BTW it's Eddie if anyone cares!

**Frank S** · Jan 31, 2018, 01:35 PM

Here is an exert from Marks standard handbook for mechanical engineers 11th eddition

""Band saws, vertical, horizontal, and universal, are used for cutting off.
The kerf or width of cut is small with a consequently small loss in
expensive material. The teeth of band saws, like those of hacksaws, are
set with the regular alternate type, one bent to the right and the next to
the left; or with the alternate and center set, in which one tooth is bent to
the right, the second to the left, and the third straight in the center. With
high-speed steel saw blades, band speeds range from about 30 ft/min
(10 m/min) for high-temperature alloys to about 400 (120) for carbon
steels. For aluminum and magnesium alloys the speed ranges up to
about 1,300 ft/min (400 m/min) with high-carbon blades. The band
speed should be decreased as the workpiece thickness increases""

I just leave mine at around 135 FT/min it is a little slow for mild steels but as currently I do not have coolant on it the slower speed helps for blade life I also normally use a 4/6 TPI but sometimes for thinner stuff I change out for a 5/8 TPI
what that means is the tooth count is a multiple pitch having 4 and 6 teeth pitches per inch roughly you wind up with 5.3 teeth per inch there are some brands with a 4/7 TPI and a 5/9 TPI and bands specifically designed for thin cylinder tubing having 14 to 18 TPI and even up to 32 teeth per inch on smaller blades.
A good rule of thumb is to have a minimum of 3 teeth in contact and a maximum of 30 which is not always possible on real thin or real thick materials
Having a rotary brush in light contact with the side of the teeth helps to reduce build in the gap between the teeth up especially when cutting softer materials

**made2hack** · Feb 1, 2018, 06:10 AM

Hi Frank,
Thanks for the info. My local supplier has bandsaw blades that they cut and weld to size from the American company M.K Morse and from their "what to use" documentation, I figured I needed an 8/12 variable tooth blade with 0 degree rake.
Now, the question is whether to stay with the thinner 12.7 mm blade (1/2") or go with the larger 27mm (1") blade. If I go to the 27mm, I have a choice of getting a better blade, ie the "Achiever" label as opposed to the regular M42. But then again, I think a basic M42 will mostly take care of almost everything I will be cutting.

**Frank S** · Feb 1, 2018, 10:11 AM

Tough call, A lot depends on your intended production rate but since you are going with a complete home built machine using either the rubber or wooden wheels it is safe to assume you are not going to set up an industrial saw shop with the need for high speed cutting action. plus I believe you mention planning on around 460 mm centers that would be pretty tight for any blade larger than 12.7 mm 460 mm is not much more than the port a band saws have so the blade twist if you are making a horizontal saw is going to also be a determining factor. since the wheels axis will be set at up to a 45° angle to the cut. If making a vertical cut saw then there would be no twisting of the blade, so a 27 mm would work great on that one, and would even be a better choice as long as the wheels are at least 300 mm in diameter 260 mm would be a tight bend radius for blade life for the 27 mm, My little 6" saw I forget the brand, has 9" wheels on 600 mm centers it uses the 1/2" blade my 10" saw has 40" centers about 1 meter it uses the 1/2" blade. My industrial 12" that has a 3/4" (19mm) blade has 60" (1.5 meter) centers on 16" (406 mm) wheels
the homemade saw is 48" 1200 mm) centers on14" (355 mm) wheels all are horizontal @ 45° wheel axis.

**nhengineer** · Feb 1, 2018, 02:01 PM

Originally Posted by made2hack

Hello,
Thanks for the suggestions. I will have to strengthen the wheel before adding power to it. I was wondering if anyone knows what kind of speed to run for metal? It has to be slower than wood for sure, but I'm not sure by how much. I have a motor that runs at 1500RPM and I guess the wheel will spin slower. Should I calculate meters or feet per minute and figure out how slow to run the wheel?

Thanks,
BTW it's Eddie if anyone cares!

This ( https://www.sawblade.com/band-saw-bl...feed-chart.cfm ) may be of some value.