Converting a hobby bandsaw (10" Craftsman 3 wheel) to a miniature metal cutting saw.

[RaisedByWolves]

Years back before I even thought of having a mini shop in my basement, a neighbor gave me a non working Delta 10" 3 wheel bandsaw. The blade wouldn't track and just kept coming off, and he was too frustrated (and mechanically inept) to figure out why it no longer worked.

This is that saw.





I figured out the tracking adjustment screw went AWOL and replaced that (Strange setup, it was hidden) and have used it for years now. The only problem is the blade speed is way too fast for anything other than woodworking. Even though I make my own blades for this out of good blade stock, the second it would touch anything harder than sheet aluminum or brass it would send a shower of sparks off of the blade and the blade would be toast.

So, one of my back burner projects was to figure out how to adapt a variable speed motor to this saw to slow it down to a reasonable speed for metalworking. This particular saw was direct drive via the motor shaft being the shaft that held the third (Left) wheel. Conjuring up different ideas over the years of how to go about using a bearing/shaft/pully to make this work I hit on another variation of this same saw that is driven by a toothed belt. This would make the conversion much easier and more compact than hanging a bunch of junk (Motor/pullies/belts) off of the back so I began looking for one.


Found this one on FBMP for $50 and snatched it up. Perfect!







Its the exact same saw save for this one having a slight 1.4-1 drive ratio vs running 1/1 off of the motor.


Here's the belt and pully in stock form.






And a closeup.






First order of business was to hit the McMaster catalog and see what their toothed pully selection held. I found a 62 tooth pully that looked just right and ordered it.


Test fitting it for clearance and such looked like it would be a good fit. There was a 76 tooth option, but I thought that might put the belt too close to the ships coming off of the blade.


This should work.







I have a belt on order and need to figure out how to mount the pully over the old pully, but I think I have that worked out. This arraignment will give me a much slower 4.7-1 drive ratio which will be a huge improvement if not solve the issue all together. Well have to wait and see.


In the mean time I sold my old saw for $15 more than what I paid for this one and removed the vacuum port I made for it to reinstall it on this new saw.

It fits right over the sawdust port? on the bottom of the saw and worked great hooked to a little shopvac hidden under the bench just for this.


Inside the saw under the blade wheel where the chips fall. You can even see some chips in there leftover as I ran it without the vacuum hooked up making the new zero clearance guide plate.







Backside where the vacuum hose attaches.









ETA: Parts used.

57105K33	$17.61
XL Series Lightweight Timing Belt Pulley, 3.8" OD

6484K227	10.50
XL Series Timing Belt, Trade No. 170xL037

 

[Garage Dog]

I have the same bandsaw. A friend gave it ti me about 20 years ago and I never used until about a week ago. I just cut a 1 1/2 " round piece of 6061 today. I moved the material as slowly as I could and it cut it ok but I think that was about the limit for the saw. I'm really interested to see how you modification works.

 

[RaisedByWolves]

I have the same bandsaw. A friend gave it ti me about 20 years ago and I never used until about a week ago. I just cut a 1 1/2 " round piece of 6061 today. I moved the material as slowly as I could and it cut it ok but I think that was about the limit for the saw. I'm really interested to see how you modification works.

You have the belt drive?

What blade were you using?

 

[Garage Dog]

Yes, mine is belt drive exactly like yours.

I bought this blade on Amazon and it works quite well so far. I've only made a few cuts so far so don't know about the longevity yet.

Amazon.com

 

[RaisedByWolves]

Yes, mine is belt drive exactly like yours.

I bought this blade on Amazon and it works quite well so far. I've only made a few cuts so far so don't know about the longevity yet.

Amazon.com

Cool, thanks for that. I may have to actually buy a blade if I can’t find blade stock that is similar. Now I understand how you got through that thick of a piece of 6061 on this saw.

For the most part these saws are underpowered in stock form for metal working aside from the high speed, so a thin blade is a must.

My blade stock I’m currently using is .025-.030 meant for a much bigger and more powerful saw. If I leave it sit for too long with this blade it takes a set around the wheels and needs to be kick started to get going.

The drive reduction should help with that considerably.

Speaking of drive reduction, for once I think I hit the easy button on one of my projects.

Initially I wasn’t sure how I was going to attach the new larger pully to the existing drive wheel. I thought about milling the center square and using epoxy, but I wasn’t sure how it would hold onto the acetal pully as far as torque under load was concerned.

So I started out just chucking the gear up in the lathe and boring the center out to have a .005 interference fit.

This wound up being one of those things that came together so fast I didn’t have time to think of taking pics, but it’s straightforward enough to be understood.

After a little persuasion I got the new bored out pully over the old pully and seated and it was a nice tight fit.

Then after looking at it in situ, the answer of how to affix it was clear.








Drilled and tapped for 8-32 button head cap screws, and spot faced the holes as the surfaces didn’t line up evenly.

Then I just had to cut some screws to length and viola, a properly fitted pully over the old one.







My new belt should be here tomorrow so we’ll see how it goes when that arrives.



.

 

[Garage Dog]

Nice mod!

Here's a photo of the cut.

 

[RaisedByWolves]

Got my belt today and it fit perfectly.






This size belt maxed out the adjustment slot, but Id prefer a longer belt over a shorter for several reasons.

For those wanting to perform this mod for themselves there are the parts I used.

57105K33	$17.61
XL Series Lightweight Timing Belt Pulley, 3.8" OD

6484K227	10.50
XL Series Timing Belt, Trade No. 170xL037

So having everything installed I gave it the acid test on a piece of O-1 drill rod.........And its still too fast.







I kind of figured it was still too fast judging by the speed, but I figured I would still give it a go. It did get half way through before work hardening the material, but it still needs to be slowed down much more. It would probably cut mild steel OK up to 1/4" or so but I think it would still have a short blade life.


The cut on the left was the first cut and you can see it took out the teeth on the short side as the heat had nowhere to go. As soon as I tried the second cut on the right the blade just said NO.

I have two options at this point, a 24V motor out of a scooter, or a mini lathe motor I got as a NOS takeoff. I kind of wanted to save the mini lathe motor for a small drill press I'm wanting to convert to variable speed, but now I'm unsure which way to go.


ETA: I should mention that even though this was still too fast for my needs, it would still be a good mod to do for the power factor alone. The power was much better after the modification.

 

[ChazzC]

Got my belt today and it fit perfectly.



View attachment 483584


This size belt maxed out the adjustment slot, but Id prefer a longer belt over a shorter for several reasons.

For those wanting to perform this mod for themselves there are the parts I used.

57105K33	$17.61
XL Series Lightweight Timing Belt Pulley, 3.8" OD

6484K227	10.50
XL Series Timing Belt, Trade No. 170xL037

So having everything installed I gave it the acid test on a piece of O-1 drill rod.........And its still too fast.



View attachment 483586



I kind of figured it was still too fast judging by the speed, but I figured I would still give it a go. It did get half way through before work hardening the material, but it still needs to be slowed down much more. It would probably cut mild steel OK up to 1/4" or so but I think it would still have a short blade life.


The cut on the left was the first cut and you can see it took out the teeth on the short side as the heat had nowhere to go. As soon as I tried the second cut on the right the blade just said NO.

I have two options at this point, a 24V motor out of a scooter, or a mini lathe motor I got as a NOS takeoff. I kind of wanted to save the mini lathe motor for a small drill press I'm wanting to convert to variable speed, but now I'm unsure which way to go.


ETA: I should mention that even though this was still too fast for my needs, it would still be a good mod to do for the power factor alone. The power was much better after the modification.

Thanks for the details and photos. I have an older version Craftsman with variable speed that can handle up to 1/4” Aluminum at about 1/4 full speed (I used it to split a 6061 1/8” wall 2-1/2” square tube into two channels for my Mini-Lathe DRO project ]Jan/Feb HSM]). The gear reduction would increase its usability (I use a DeWalt portaband in a Swag Off Road stand for most of my metal sawing, but the deeper throat would be nice.

EDIT: Although I used this bandsaw just yesterday and cleaned it out, I didn't take a close look at the drive setup: the blade wheel has an integrally molded XL60T pulley:


When I first got the bandsaw I looked into a number of ways to slow it down, and they all cost more than the Dewalt/SWAG setup did, so I just use this for wood, plastic and thin Aluminum. However, I didn't consider buying/printing/machining an XL80T fully to fit over the XL60T, which would drop the speed by about 25%. I'll have to do some hunting to see what I can come up with.


Thanks again for the concept.

 

[slow-poke]

I have a similar 3 wheel Delta bandsaw (larger), however it has an optional small driven gear option for use with metal. I also have a metal cutting band saw, so I just use it most if the time.

 

[RaisedByWolves]

Thanks for the details and photos. I have an older version Craftsman with variable speed that can handle up to 1/4” Aluminum at about 1/4 full speed (I used it to split a 6061 1/8” wall 2-1/2” square tube into two channels for my Mini-Lathe DRO project ]Jan/Feb HSM]). The gear reduction would increase its usability (I use a DeWalt portaband in a Swag Off Road stand for most of my metal sawing, but the deeper throat would be nice.

Theyre pretty nice saws for their size. I have seen the variable speed versions but was leery of whether it would be to my liking.


I went and fired up the parts cannon and ordered a motor and drive pully.

Motor.

Amazon.com

Pully

Amazon.com

Realistically more than Id hoped to spend, but having experience with these motors and drives should give stellar performance. I could have found the motor and controller cheaper, but this one and its controller look like the most "plug n play" option.


Ill update when the motor comes in.

.