Converting a bandsaw from wood to metal?

[eeengineer]

I have a 20 Year old Homier 14" band saw that I have been using to cut metal for 5 years now without any problems. It cuts faster than my HF horizontal saw.
See first pix. Cast iron fingers for a MLA Steady rest.
No problem with the rubbers although one did rot away recently but I don't believe that it had anything to do with the metal cutting.

Now here is what I did.
1) I bought a 3/4Hp 1150 rpm 3 PH motor.
2) I bought a VFD.
3) I bought a 1/2" wide varitooth metal cutting blade.

I can slow the motor down to about 15 HZ. NO it does not heat up. That's about 290 RPM.
I can also speed the motor up to 90 HZ which is 1750 RPM and, cut wood. I can use the same blade a variable tooth blade to do both. Although for cutting curves you want. want a thinner blade.

Other than mounting the motor, which had no mounting plate, I made a pair of large U bolts from rod and threaded the ends, I have changed nothing else.

Downside, when I did this, was the need for 240 power. Today 120V VFD's are available.

Again this works well.

[BobWarfield]

Yep, my Rockwell Delta 20" bandsaw is a big ole beast that'll cut wood, metal, fingers, or whatever else you feed it. It's got rubber tires and no worries. I would think a bit about an arrangement to take the chips off the blade before the get pressed into the tires. Not hard to do with a brush-like arrangement below the blade.

It's great having a big bandsaw in the shop!

Cheers,

BW

PS When you get far enough along, the Harbor Freight blade welder actually works pretty darned well.

[KenHMT]

I have a jackshaft arrangement on my Craftsman wood bandsaw and routinely use it to cut steel. Belt slippage can be a problem if you push it too hard. The rusty-colored sheave on the motor rides on ball bearings when cutting metal, and turns about 1/16 of the motor speed. When cutting wood, I take the belts off the jackshaft and lock the rusty sheave to the motor shaft with some pins.

Very neat and useful mod!

I've added it to our growing database at homemadetools.net: http://www.homemadetools.net/convertibl ... al-bandsaw

Ken

[gaston]

I'm running my craftsman thru a reduction gearbox then I fine tune it by pulley changes can cut steel or aluminum with ease

[ed_h]

Here's mine, using a low speed gear motor for metal cutting:

http://bullfire.net/Bandsaw/IMG_0237.JPG

More pics:

http://bullfire.net/Bandsaw/WP_Delta_Bandsaw.html

[Rex]

Oddly enough I'm just finishing up such a project. I posted this on another board but there doesn't seem to be any interest

I bought this little Jet JBW14-MW bandsaw a month or so ago for $110. It has been sold for many years as a dual-purpose metal/wood saw.

However, once I got it home and researched it a bit I determined the lowest of the 3 speeds to be 700 FPM, which is fine for aluminum. I really wanted to get to around 100 FPM, which is about right for most steel alloys. My 4x6 stays at this speed all the time and it seems to work for everything.

The original motor is 110V 1725 RPM, 3/4 HP. It had a stepped pulley on the motor. There is an intermediate idler with a matching stepped pulley, and a 2nd belt that turned the bottom wheel with speed reduction
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So I looked at what was available from my selection of motors. I had a 1 HP DC motor with a bad controller, which I have been dying to use. This seemed like a good purpose. I found a DART controller board on ebay for $40 shipped. I spent Saturday afternoon wiring it up to suit the motor. Once I was finished, the speed range ran from 500 RPM to 1700 RPM. But it did not have enough torque at low RPMs - I could stop the motor by grabbing the pulley with my gloved hand. So I reluctantly put that one back on the shelf for a future use. At least it's ready to go now.

Then I remembered a big slow Dayton gearmotor I had acquired somehow. I drug it out and found it was 30RPM with a 58:1 geardown on a 1/2 HP motor. I Rummaged through the pulley box and found an old Walker turner v-pulley that fit the motor shaft perfectly.

So here I need someone to check my math:
Motor RPM is 30
Motor pulley is 6.375 diameter
Driven pulley is 6.0 diameter, on the same shaft as the bottom saw wheel.
Saw wheel is 13.68" diameter

So... ((6.375/6.0) X 13.68 X 3.14 X 30)/12 = 114 FPM

That's close enough if my figures are correct.

Last night I pulled the original motor, slotted the mounting bracket to suit the gearmotor, and got it all set up lacking only a belt.
Installed new poly tires.

My other bandsaw project is a Marvel 612. It had a 3-phase motor and a 4-step pulley, missing half the pulleys. I am changing it to single-phase 110V power.
The old Jet motor will fit that perfectly - slightly more power, same RPM, good multi-step pulley.
I'm a little uncomfortable mounting a Taiwan motor on an old U.S.-made machine.
I'll get over it.

[Fabitfast]

If the Taiwan motor is still in good condition, that old U.S. made machine would be such a use.

[rmac]

So here I need someone to check my math.

Motor runs at 30 rev/minute
Driven shaft runs at 30 * (6.375 / 6) = 31.875 rev/minute
Saw wheel circumference = 13.68" * PI = 42.98" = 3.58 feet
3.58 feet/rev * 31.875 rev/minute = 114.15 feet/minute

Looks good to me.

-- Russ

[Johnny O]

Hi Folks
I once faced the same task converting my 14" Delta Rockwell to cut metal. I found a man selling these slick little interplanetary geared three step pulleys that gave a reduction ratio of 4.5 to 1 and another at 7 to 1. They were set up with a lock pin for direct drive and a stop rod in back gear mode. Worked real nice and I'm still using the 7 to 1 I bought 15 years ago. The name was DarJay Industries as I recall. If I find the pics of it I'll try loading them.
Thanks
Johnny O

[Flybynight]

Yes, can be done, and easily.
Twelve years ago I converted a cheap HF vertical wood bandsaw to metal.
I did it like gaston did.
I located a variable speed gearbox.
and installed it with a pulley and belt from the motor, and a pulley and belt to the saw.
For just 1-2 hours a week of use it was inexpensive and works well.

[Johnny O]

Found the booklet on the Dar-Jay pull gear pully recently, will try to post it here. I had thought about trying something like this on my jet mill if I can find maybe a trans planetary gear arrangement suitable for fitting into a pully case.

[Rex]

looks like Dar-Jay ceased to exist about 10 years ago.