Bandsaw conversion to DC drive…Wood to Metal Cutting Conversion

I have a horizontal bandsaw for cutting steel stock to length. It is an amazing time saver and a great asset if you do a lot of metal fabrication.

This type of saw can be used in the upright position to cut metal on a small table. But it is inconvieneient to convert to this position. I wanted an upright metal cutting bandsaw.

But MAN, are they expensive. Way too much $$ for a small home hobby shop. So I bought a small three wheel portable bandsaw and attempted to slow it down with an AC Speed Controller.

BAD IDEA!  This thing had very little power and although I could cut thin aluminum and thin sheet metal, anything more and it would bog down. I sold it and bought a floor mounted, 14″ Woodworkers band saw fro Harbor Freight. At the time, with a coupon it cost me around $200.

But even on the lowest of its three speeds, it was too fast for thicker metals and it ate steel cutting blades.

So converting it to a DC motor with variable speed control was the way to go.

A few years ago, Surplus City offered “Tread Mill Motors” with control boards for $39.00 each. I bought a dozen of them and have used them on all kinds of woodworking equipment. They are great for this type of use. I figured I’d addapt one to the band saw also.

It was quite easy to replace the AC motor with this DC Treadmill motor.

I left the pulley system in place so I could manipulate the speed as I wished,

And I mounted the control board nearby:

The potentiometer was mounted on the front of the band saw:

A couple of simple paint brushes were brought into play to keep chips off the drive wheels:

New “Cool Blocks” were used to replace the plastic blade stabilizers

This was the way I used the saw for a number of years. But truth be told, the Tread Mill motor was not up to the task and stalled when cutting anything over 1/8″ steel. It needed ca better, stronger, motor.

I had converted my JET 12 X 36 BD lathe to DC drive using a Dayton, 90volt, 3/4hp motor with an SCR controller and it has been magnificent.

http://rvbprecision.com/garage-entertainment/metal-lathe-dc-motor-conversion-jet-12-x-36-bd.html

So the search was on for another DC, 90v, 3/4 HP motor.

Best price I could find was AMAZON.COM An AMARINE, 90v, 3/4hp motor was $179 including shipping. I ordered it on Friday and it was at my door on Saturday afternoon!

Permanent Magnet Dc Motor, 3/4hp, 56c, 90v/1750rpm

  • Highest quality oriented magnets
  • F insulation class
  • CE listed, CE file No. DW2011CE0047 01
  • 56C face and Removable mounting bases for dual mounting versatility
  • Continuous duty; Dynamic balanced armature for smooth operation; Totally Enclosed Non Vent; Double seal ball bearings with permanent grease filling for long life; Long life brushes;

This new motor was even easier to install than the treadmill motor. All the mounting holes lined up perfectly.

I modified the mounting plate with a couple pieces of threaded rod to maintain constant pressure on the drive belt

A new DC controller was needed. I turned to SURPLUS CENTER for a SCR board

This is a great controller that I also used on my lathe conversion

90/180 VDC SPEED CONTROL W/POT

ITEM NUMBER: 11-2269                   PRICE: $81.95

Wiring was extremely easy.

This can also be found on the SURPLUS CENTER web site:

http://www.surpluscenter.com/_MoreSpecs/as11-2269.pdf

and here:

http://www.surpluscenter.com/_MoreSpecs/i11-2269.pdf

 

Just to be nice, I gave the old gal a new speed control knob;

Here is a video showing the saw cutting metal:

http://public.fotki.com/Rbertalotto/machine_tool/bandsaw-wood-to-met/p1010001.html

 

Also on YouTube:

 

Hope you enjoyed this little article

Lots more here:

www.rvbprecision.com

 

Thanks for looking!

 

UPDATE 12-14-20

There was a need to start cutting thicker material on the Bandsaw Conversion. Although the original conversion was fantastic for 1/8″ material or less, cutting 3/16″ up to 1/2″ material was a challenge.

I had the opportunity to purchase a Contact Tachometer from Ebay that also reads SFM. This allowed me to verify the actual SFM (Surface Feet per Minute). To my surprise I was three to four times faster than recommended.

https://www.sawblade.com/band-saw-blade-speed-and-feed-chart.cfm

This is a great resource to figure out your SFM of a bandsaw

http://vintagemachinery.org/math/sfpm.aspx

So I needed to slow it down more than the DC motor and pulleys allowed

A bit of research lead me back to Surplus Center and right angle gear reduction units.

I purchase a 50-1, left hand unit that had a 56C mounting option . This would mount directly to the DC motor I’m using. (See a picture of the motor above with the 56C mounting flange)

 

 

From the gear reducer I used a series a few different size pulleys, removing the idler pully to get down to somewhere around 200SFM

But there were issues with belt slippage. The motor never came close to stalling, but with a 50-1 gear reduction the output torque is enormous and the small pulleys needed to get the speed down did not afford enough “Pulley Wrap” to stop slipping.

Back to Surplus Center and an order for a couple chain drive sprockets and some 40 pitch chain….

A 17 Tooth sprocket on the bandsaw drive wheel and a 30 tooth sprocket on the gear reducer gave me 256 SFM with the DC motor on maximum speed. I can slow it down to 50 SFM and anything in between with the DC controller.

That did the trick!

Obviously, a chain ain’t gonna slip!

Now I have huge cutting power and the saw cuts through 3/8″ plate beautifully.

I also upgraded the entire blade alignment system with ball bearing blade guides that I found on Ebay. These made a huge difference in the accuracy of the cut. Much better than the simple guide blocks I had been using.

Hope this is of some help to those of you trying to cut metal with your wood bandsaw.

Be sure to check out other garage nonsense at www.rvbprecision.com

Thanks

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11 comments on “Bandsaw conversion to DC drive…Wood to Metal Cutting Conversion”

  1. Steve Reply

    I did the conversion just yesterday using the DC motor. Found both parts on Ebay a bit cheaper than Amazon. Bolted right up and works. Thanks for taking the time to make this video.

  2. Jason Reply

    Any chance you could email me some closer pics of the wiring of this setup I have never wired anything before and am confused by the diagram.

    Does the outside power come through the controller before it goes to the pot and the motor?

    The diagram asks for fuses between the controller and the stop switch? Did you do that?

    Any help would be greatly appreciated.

    • Roy Bertalotto

      Sorry, I do not have any better drawings of the wiring. I’d suggest you contact Surplus Centrr, where I purchased the control board got more info. Yes, I did usd fuses where needed.

  3. Rick LaPlante Reply

    Curious about whether you found it necessary to use the heatsink that Surplus Center sells sepately to pair with the SCR speed control.
    P.S. enjoying the heck out of your posts.

  4. Rick Laplante Reply

    Price on the DC motor is down to $130 at Amazon. Excited about the project. Trying to figure adding to an old Walker Turner. Wondering if I need to add a lay shaft like yours uses or can manage with graduated pulleys. Can’t tell from the article which way to go. Would obviously prefer the latter.

    • Roy Bertalotto

      I wouldn’t think you would need an intermediary pulley. I think the DC motor would have enough torque for what you want to do. Let us know how it works out.

  5. GrevB Reply

    Was wondering what you used for a Potentiometer, for the speed control… I know 10 ohm, but is there one that works better than others ?

    Also, yes a wiring diagram would help.has there been any drawn out yet ?

    Was you intermediate Pulley Shaft, OEM or added by you ?

    If OEM, is there a part number in the Manual, for that part to be added to my Saw ?

    Thanks fo your time, great write up, I will be trying this soon.

    • Roy Bertalotto

      The potentiometer came with the DC motor controller when I purchased it. I would imagine any POT would work fine. A search on Surplus City Web site will show a wiring diagram for that control unit.The intermediate shaft was on the saw I purchased. Hope this helps

    • wally

      A potentiometer alone will not work. You’ll need a DC motor control. I have had good luck with the ones on ebay. You can pick them up for $20-30

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