Hey Fawteen

Stories, News and General Yakking
GeneSC
Posts: 55
Joined: Thu Jul 18, 2019 6:50 pm

Hey Fawteen

Post by GeneSC » Sat Jan 25, 2020 10:21 am

Ever thought about building a Bandsaw??

Been having a ball with the grinder, Nice Work!

PHPaul
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Posts: 297
Joined: Fri Jul 12, 2019 6:43 am
Location: Downeast Maine

Re: Hey Fawteen

Post by PHPaul » Sat Jan 25, 2020 2:24 pm

Metal cutting bandsaw?

I built this:

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There have been a few times when I wished for more throat, but not enough to give up the floor space for a full-sized bandsaw.

For wood, I have one that goes on my Shopsmith.

GeneSC
Posts: 55
Joined: Thu Jul 18, 2019 6:50 pm

Re: Hey Fawteen

Post by GeneSC » Sun Jan 26, 2020 8:53 pm

Yeah, those that use the portable bandsaw looks pretty good but I was thinking of a full size floor model, I too have a small shop and know what you mean about floor space, (need to do some cleaning and clearing out!!) I have a full size Delta 93 1/2" saw and my brother wants one but they have suddenly become Very pricey? just wondered, since you did such a good job on the grinder
if you had ever considered building a bandsaw wood/metal?

I'm sure you have one and was wondering what blades do you use on it? wood and metal? I've bought 3 at Lowe's (Bosch) and they are not worth bringing home! got another at Harbor Freight but haven't tried it.

PHPaul
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Posts: 297
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Location: Downeast Maine

Re: Hey Fawteen

Post by PHPaul » Mon Jan 27, 2020 5:54 am

Other than aluminum, I don't cut metal on my Shopsmith bandsaw.

The big problem with metal vs. wood is that the blade speed on a metal bandsaw is MUCH slower. If you put a metal cutting blade on a bandsaw designed for wood, you'll burn it up. No matter if it's a Deep Homo cheapie or the best Lenox money can buy.

Being as the Shopsmith is variable speed, I could probably get away with it. Two problems: I'd need to check the minimum speed to be sure it's slow enough and Shopsmith uses a proprietary length so I'd have to have custom blades made up. Not cheap...

Check on YouTube for Mr. Pete, aka Tubalcain for videos. He's converted a couple and had good results. Basically taking a decent wood saw and using pulleys and jackshafts to slow it down.

GeneSC
Posts: 55
Joined: Thu Jul 18, 2019 6:50 pm

Re: Hey Fawteen

Post by GeneSC » Mon Jan 27, 2020 11:31 am

Thanks Paul, My Delta has two different pulleys for two speeds but I think it is still too fast, blades wear slick in just a few feet?

PHPaul
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Joined: Fri Jul 12, 2019 6:43 am
Location: Downeast Maine

Re: Hey Fawteen

Post by PHPaul » Mon Jan 27, 2020 1:53 pm

Two solutions for that, one cheap-ish and the other not-so...

You could set up a jackshaft and slow it down enough that way by choosing the right pulleys. Be something of a pain to change speeds, but it'd be economical.

OR...you could get another 3 phase motor and a VFD and have variable speed that way.

Building one from scratch wouldn't be cost effective by the time you got wheels, traction tires, bearings, guides and a nice table. Buying a second bandsaw off craigslist and repowering it would probably be the cheapest approach.

For steel, you want speeds something around 100 feet per minute or less. By comparison, you can run wood blades at 1000 fpm.

My Shopsmith bandsaw has 11 inch wheels. That gives a circumference of roughly 35 inches. 100 feet per minute is 1200 inches per minute. 1200/35 gives about 35 RPM.

GeneSC
Posts: 55
Joined: Thu Jul 18, 2019 6:50 pm

Re: Hey Fawteen

Post by GeneSC » Mon Jan 27, 2020 6:38 pm

You could set up a jackshaft and slow it down enough that way by choosing the right pulleys. Be something of a pain to change speeds, but it'd be economical.

Can you elaborate a little more? I am totally lost, I've worked construction all my life and don't have a lot of experience with
the "makeup" of power tools :cry: Economical is the KEY word

PHPaul
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Location: Downeast Maine

Re: Hey Fawteen

Post by PHPaul » Tue Jan 28, 2020 6:25 am

Glad to. I love this stuff, as long as I don't have to pay for it. :shock: :lol:

Let's assume our target is 35 RPM as calculated above. The slowest standard electric motor I'm aware of is 1725 RPM. There are others, but they're specialty motors and expensive. So we'll assume a 1725.

To get from 1725 to 35 RPM, we need approximately a 50:1 reduction (1725/35). Speed reduction via jackshafts is done by using a small pulley to drive a large pulley. If we could put a 2" pulley on the motor and drive the bandsaw with a 100 inch pulley, we'd have our 50:1 but that's obviously impractical, so we do it in stages.

Image

In the above image, the motor is running at 1725 RPM. Pulley #1 on the motor is a 2" pulley, #2 on the first jackshaft is an 8" giving us a 4:1 reduction, shaft is running at 431 RPM. (1725/4=431)

On the other end of the first jackshaft is another 2" pulley (#3) running to the 8" pulley (#4) on the second jackshaft. Another 4:1 reduction, jackshaft #2 is running at 108 RPM. (431/4=108)

Pulley #5 on the other end of jackshaft #2 is another 2" running to a 6" pulley on the bandsaw shaft for a 3:1 reduction or 36 RPM. (108/3=36).

You can arrange belt lengths to make the system as compact as possible and/or stack the jackshafts vertically.

GeneSC
Posts: 55
Joined: Thu Jul 18, 2019 6:50 pm

Re: Hey Fawteen

Post by GeneSC » Tue Jan 28, 2020 11:09 pm

MAN! you have totally lost me, It's a Delta bandsaw and the motor is 1 hp, 120/240 volt (wired for 110) 60 hz 9/4.5 amps
1700 RPM class B
was wondering if I could use a controller like I have on the grinder" or does it have to be a 3 phase motor?

PHPaul
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Posts: 297
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Location: Downeast Maine

Re: Hey Fawteen

Post by PHPaul » Wed Jan 29, 2020 5:50 am

It depends on the motor, but single phase motors that can be controlled by a VFD are unusual. They also tend to have much less power at lower speeds.

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