Converting a Sears 12" bandsaw to metal cutting

[8man]

As the title says, I want to be able to cut metal. I know the current set up produces too much speed for it to be used to cut steel. I've looked at YouTube and they mostly do it with pulleys. To do that I'll need to add some pretty large pulleys.

So I was looking at a 440 lb, single line cable crane hoist to replace the current 1725 rpm motor. If the hoist gear reducer is sufficient, it may work.

I'm looking for ideas and maybe what others have done.

Thanks.

 

[racecougar]

Link to the hoist you're considering utilizing to power your saw? Is it rated for continuous duty? What is its output rpm?

 

[Packard V8]

No matter what the motor and speed reduction used, a Craftsman 12" band saw just doesn't have the frame rigidity to sufficiently tension a steel cutting blade. BTDTNA

Since 4" x 6" horizontal saws are so thick on the ground, usually $100 or so used, why not start with one of those?

jack vines

 

[exmaxima1]

No matter what the motor and speed reduction used, a Craftsman 12" band saw just doesn't have the frame rigidity to sufficiently tension a steel cutting blade. BTDTNA

Since 4" x 6" horizontal saws are so thick on the ground, usually $100 or so used, why not start with one of those?

jack vines

+1
I had one of those at work for cutting up packaging foam and cardboard, but it was very flimsy. The few times I tried cutting aluminum (with correct blade) it didn't have enough tension to cut straight. It would be unusable for ferrous metals IMHO.

 

[8man]

I have a Milwaukee band saw with the Swag stand, it just doesn't cut as wide a cut as I need. I have an old Craftsman horizontal band saw that cuts, but it too is too narrow. I didn't want to spend the money to get a real 12" metal band saw, and saw some guys who did it.

I'm cutting 14 to 20 gauge steel for the old trucks I'm rebuilding.

I am trying to find out more info on the hoist, but so far no joy on that. Here is the link https://www.ebay.com/itm/440lb-Elec...70a4cec53f6121ffd6c060|iid:1&autorefresh=true

Thanks for helping.

 

[macgee]

8man,

The above posts made some very good points but for the occasional job it should be fine however you need to understand you literally have to reduce the current speed of that bandsaw down by almost 90% of its current speed. It's a lot to reduce

You'll need to fabricate a jack shaft or find a gear ratio box that is appropriate. Craftsman did make one for the 12" back in the day, nothing special and can be found occasionally on fleaBay. For steel 275fpm is good.

The concept of using a hoist motor more is interesting, I'll be curious to hear as well.

 

[8man]

I can do it by adding to the existing 3" pulley on the 1725 rpm motor and 5" pulley on the saw itself, but I need to add 2 v-belts, 2 jack shafts with pillow bearings and 4 pulleys. This will get me to about 200 fpm on the blade.

I think that is too complicated and the mechanism is cumbersome under the saw. If the hoist motor will work, that would make it easy. I'm trying to find out the speed of the shaft going into the cable spool. Then I can see how many pulleys it will take to get the speed down.

 

[lilredex]

Have a look at this solution....

 

[MJD1]

Rigidity and blade tension is the big issue. For what you propose to cut, laying the sheet metal on 2" styrofoam and using a jigsaw would enable you to easily make those cuts.

 

[BD1]

I can do it by adding to the existing 3" pulley on the 1725 rpm motor and 5" pulley on the saw itself, but I need to add 2 v-belts, 2 jack shafts with pillow bearings and 4 pulleys. This will get me to about 200 fpm on the blade.

I think that is too complicated and the mechanism is cumbersome under the saw. If the hoist motor will work, that would make it easy. I'm trying to find out the speed of the shaft going into the cable spool. Then I can see how many pulleys it will take to get the speed down.

Have you considered motor Rotation ??
Not sure about your saw but the HF 4x6 bandsaw is CCW .


Sent from my iPhone using Tapatalk

 

[ambenz]

For less than $300 you can get a metal band saw bench, why bother with a jury rig they will never be as good as a dedicated brand new unit? Because you can I suppose, I just think you might be better off selling the wood bandsaw and use that money to subsidize the purpose built saw.

 

[ChefRex]

No experience, yet, treadmill motor and speed control?

 

[subroc]

I have a few of these band saws here. Well, 3 and some parts. I picked up 4 of them for next to nothing. I don't think I have $120 in the lot of them. I set one up as a wood only saw.

I have a 2nd saw that I am going to set up similar to the link above with a jack shaft and pulleys. Just need to finish the switch, mount the motor and mount the pillow blocks. Still need to decide on some pulleys and get them.

My thinking on these saws isn't to replace a good horizontal saw, it is an inexpensive solution to a metal cutting saw for occasional use. I batted the idea around of picking up a deep cut or similar from any of the current offerings or do the jack shaft on one of these saws. I expect it is probably a wash. Anybody know for sure? If it doesn't work, at least adequate, I'll take the pulley assembly off and use it with a wood coping blade and maybe keep a resaw blade or GP blade on the pictured one. After looking at the youtube video above, that would be acceptable performance for my needs. OP, does that seem adequate or less than acceptable?

Either way, I am on the look out for a small horizontal saw as a project. Just missed one a few weeks ago.

My use is occasional DIY.

OP, good luck with your decision.

 

[macgee]

Personally I would put a 8"+ pulley on bandsaw side and swap out the motor for a brushless DC servo motor (cheap) that are now being used on industrial sewing machines with a 1.25" pulley that gets you half way FPM wise, use an AX belt. You can then slow the speed way down and still have tons torque and then speed it way up if you want to cut soft wood, it's variable speed. You wont need a jack shaft with this setup; motor to bandsaw. I think a hoist motor will be slower than you want but maybe you could add add a bigger pulley on motor side to speed it up.

No matter what you do, there's money and time needed to make it happen (all the small stuff starts to add up). As far as I know, there is no silver bullet for this solution but hoping someone comes up with one.

https://www.amazon.com/gp/product/B07HFTMR8Z/ref=ox_sc_saved_title_9?smid=A2RB21RUGRFV4T&psc=1

 

[RTM]

This is 3rd or fourth thread on this in my year plus here. Couple of Delta or Craftsman , might help to find those for more references.

And Macgee, I think you meant by 90%, not to 90% above.

Here are a few recent ones

https://www.garagejournal.com/forum/showthread.php?t=472346&highlight=bandsaw+speed

https://www.garagejournal.com/forum/showthread.php?t=470417&highlight=bandsaw+speed

https://www.garagejournal.com/forum/showthread.php?t=437948&highlight=bandsaw+speed

https://www.garagejournal.com/forum/showthread.php?t=255784&highlight=bandsaw+speed

https://www.garagejournal.com/forum/showthread.php?t=466485&highlight=bandsaw+speed

https://www.garagejournal.com/forum/showthread.php?t=435632&highlight=bandsaw+speed

 

[8man]

Thanks RTM. I didn't ask the question of "search" the correct way, because I had not found any of those before I posted my question.

The Craftsman does not have the ability to do the pulleys like shown in a couple of the Delta threads.

I looked at the crane with gear reduction, but it is so slow I'd need to gear it up to get the blade to the recommended 200 fpm.

I don't think I'm ready to tackle the treadmill motor swap, as I've not found one that costs less than the pulleys and stuff.

So I'm still thinking and researching this.

 

[8man]

Macgee, that sewing machine motor is interesting. I don't understand enough about electrical in this situation to even be dangerous, except to myself. I do know that I don't have room for the 8" pulley on the machine and keep the guard in place.

I am still looking at this, but no decision on how to go yet.

 

[RTM]

Thanks RTM. I didn't ask the question of "search" the correct way, because I had not found any of those before I posted my question.
s.

I think I used bandsaw speed as the terms, then chose only the appropriate ones.

 

[seber]

I've done it with a jackshaft and step pulleys but if I were doing it today I'd use a treadmill motor and speed control. You can pick them up for $50 pretty regularly and everything you need is included.

 

[8man]

Seber, I am looking at the treadmill motors. I don't have a working knowledge of them and/or how they work. I'm sure I can hook it up to the saw, but how do I know the rpm so I can calculate the blade speed? How do I hook up the motor? I saw where on was something like 5800 rpm. I know it will slow down, but will it have the power at low rpm to cut metal.

If there were a tutorial, I'd gladly read about this stuff. From what I've heard the treadmill motors are great for other things. I'd try it if I just know more about the dc motor.

 

[seber]

You don't need to know anything about how they work. Just mark the connections as you take it apart so you can hook it back together without all the extraneous parts. RPM will be another problem. You are going to need some kind of tachometer. Modern digitals have gotten pretty cheap. I'm still using an ancient Starrett that is just a counter you use with a watch. They can be had for around ten bucks on Ebay. Once you know the RPM you will need to do the math to get FPM. Then you can mark the control panel to correspond.

 

[torqueman2002]

Mr. Pete - YouTuber, has a series on converting a DELTS 14".
Converting Delta Saw to Metal Cutting #488​ p1 pull gear tubalcain

 

[ChefRex]

I found this guy informative,

 

[8man]

I found a used treadmill priced very reasonably, so I am looking at that option.

It appears that a DC treadmill motor turning about 160 rpm, with a 2" pulley on the motor and a 5" on the lathe will turn the blade about about 200 fpm.

My question is "will a treadmill motor turning at 160 rpm have enough power?"

Obviously I don't have a working knowledge of DC motors.

 

[seber]

Treadmills generally run one to two hp. More than enough for a 12" band saw.

 

[8man]

Thank you Seber.

 

[rpcraft]

I found a used treadmill priced very reasonably, so I am looking at that option.

It appears that a DC treadmill motor turning about 160 rpm, with a 2" pulley on the motor and a 5" on the lathe will turn the blade about about 200 fpm.

My question is "will a treadmill motor turning at 160 rpm have enough power?"

Obviously I don't have a working knowledge of DC motors.

Yes they will have the power and more importantly they have it at low RPM as well. DC motors are amazingly great at lower power torque.

 

[8man]

Thank you all.

I'm going to go with the treadmill motor. I'll report in a separate thread how it goes.

 

[rpcraft]

I'm curious to know if you have had any headway on this project?