Source for stepped pulleys

[DavidR8]

I recently bought a used Busy Bee 14” wood/metal bandsaw.
According to the manual I found online, the lowest blade speed possible using the existing pulleys is 700 sfm which is way too fast for metal.
Using some clever online calculators, I worked out that a 1.5” pulley driving a 7” intermediate pulley to 1.5” pulley driving a 8” wheel pulley will get me into to 290 sfm range.

Easy peasy right?
Not so fast, cowboy, good luck finding such pulleys. The largest step pulley I can find is 6”.

Of course the ‘easy’ way out of this is to make the pulleys. Never done this before but how hard could it be right?
Rough out the diameters and cut the grooves.
Of course a 8” diameter x 10” chunk of 6061 is not going to be cheap. If I can even find it.

I also wonder if I could add a 7” or 8” pulley to the end of the stack.

The other option is to switch to 3-phase with a VFD.


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[francist]

You could do either. I’ve made 4-step pulleys from scratch before and it is doable although a lot of work. And waste. Trouble can come from not having enough swing to get in front of that big diameter with your compound and toolpost so you end up having to come at it from the side using a backwards boring bar. Chatter-maker extraordinaire.

Nothing wrong with stacking another one on to the end either other as long as you can get them dialed in concentric with each other. Large pulleys tend to be spoked though rather than the nice flat die cast smaller diameters so that’d be a challenge marrying them up.

Have you talked to the guys at Troy Electric? They may be able to suggest something else. Otherwise there’s always casting a blank from aluminum and machining from there. I’ve had lots of stuff done at Achinback out off Station Ave, they’re old Vic Foundry guys.

I’m not sure about the 1-1/2 to 7 and whether that much spread would be too much power loss. You know, not enough wrap on the smaller pulley to effectively drive the big one without slipping.

-frank

 

[CalgaryPT]

I've seen guys build step ones by welding incrementals together, but usually in farm applications where smooth operations aren't the critical factor. You'd have to balance somehow.

 

[YotaBota]

Crappy Tire has 8" pulleys listed on their web site. Not sure of the shaft size but that can be adjusted. I remember seeing a rack of pulleys at Lordco as well.

 

[kevin.decelles]

Cast a blank and turn it? Or build one using princess auto parts? I built my first sand muller reduction drive using the weldable hub on 12” pulley




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[DavidR8]

You could do either. I’ve made 4-step pulleys from scratch before and it is doable although a lot of work. And waste. Trouble can come from not having enough swing to get in front of that big diameter with your compound and toolpost so you end up having to come at it from the side using a backwards boring bar. Chatter-maker extraordinaire.

Nothing wrong with stacking another one on to the end either other as long as you can get them dialed in concentric with each other. Large pulleys tend to be spoked though rather than the nice flat die cast smaller diameters so that’d be a challenge marrying them up.

Have you talked to the guys at Troy Electric? They may be able to suggest something else. Otherwise there’s always casting a blank from aluminum and machining from there. I’ve had lots of stuff done at Achinback out off Station Ave, they’re old Vic Foundry guys.

I’m not sure about the 1-1/2 to 7 and whether that much spread would be too much power loss. You know, not enough wrap on the smaller pulley to effectively drive the big one without slipping.

-frank

Thanks Frank, I'll give Troy a call tomorrow.
I might be able to turn it but it would be pressing the limits to be sure.
No matter what I'll have to get creative!

 

[DavidR8]

Crappy Tire has 8" pulleys listed on their web site. Not sure of the shaft size but that can be adjusted. I remember seeing a rack of pulleys at Lordco as well.

Thanks Mike. I'll pop by my local C'Tire and see what they have in stock. I think I understand why it's not available, maybe the differential is too large to be viable as Frank said.

 

[DavidR8]

I've seen guys build step ones by welding incrementals together, but usually in farm applications where smooth operations aren't the critical factor. You'd have to balance somehow.

I could probably make a mandrel to hold the whole mess together. I wonder if I could TIG them...

 

[DavidR8]

Cast a blank and turn it? Or build one using princess auto parts? I built my first sand muller reduction drive using the weldable hub on 12” pulley

Thanks Kevin, time to dig into their catalogue!

 

[YYCHM]

I take this is a vertical bandsaw?

 

[DavidR8]

I take this is a vertical bandsaw?

It is yes, a 14"

 

[francist]

This may be way out in left field but there’s a gear reduction unit on UsedVic right now for not much dollars. Puts the pulleys at 90 degree opposed and I have no idea what the ratio is, but I bet you could get it for $50 if you wanted to try it. Been up since June.

-frank

 

[DavidR8]

This may be way out in left field but there’s a gear reduction unit on UsedVic right now for not much dollars. Puts the pulleys at 90 degree opposed and I have no idea what the ratio is, but I bet you could get it for $50 if you wanted to try it. Been up since June.

-frank

View attachment 11002

Ok that is crazy...I was just searching for gear reduction units...
Thanks Frank!

 

[Crosche]

I have a stepped pulley listed that you can have for free if you pay the shipping.

 

[DavidR8]

So I did a bit of tinkering today. Pulled the pulleys
Measured them to be sure of their size.
Small is 1.75"
Large is 4.75 on the motor and jack shaft and 5.75 on the lower wheel.
I shifted belts so that the saw ran at it's lowest speed. Using the blade that came on the saw it had no problem slicing through 1/8" mild steel.

I think what I'm going to do is pick up a pair of 1.5" and three 8" pulleys.
I'll put an 1.5 and and 8" on the motor, same 1.5" and 8" on the jack and and 8" on the lower wheel.
Plugging those numbers into this calculator results in 323 rpm at the jackshaft. Using 323 rpm as the motor speed in this calculator results in 259 SFM. A tad fast but heaps better than 700 SFM!

Edited to correct the motor pulley info.

 

[YYCHM]

This terminology eludes me. Need images with circles and arrows LOL. Jack Shaft, Lower ????

 

[DavidR8]

This is a shot of saw like mine.
The pulley at the top is connected to the lower wheel.
The black one in the middle is on the jackshaft.
In the base of the cabinet is the motor and its pulley.

So I'm going to replace the top pulley with an 8" one,
The one in the middle will be changed to have a 1.5" on the inside and and 8" on the outside.
The motor will just get a 1.5" pulley.

 

[YotaBota]

What about swapping for a treadmill motor? There are usually free or cheap treadmills for sale and then you could have the two step pulley, one step for wood and one step for metal and still have speed control.
I've been toying with this idea for my band saw but just haven't gotten roundtoit.

 

[DavidR8]

@YotaBota that's definitely an option. I am a bit daunted by the dark arts of electrical motors so I've shied away from that route.
If I could find a tutorial like I did for the VFD conversion I would go the treadmill motor route.

Edit: just looked for free treadmills and came up empty...

 

[YotaBota]

I've seen a few freebies and lots under $100, compare that to how much money and time you will spend on pulleys plus it would be more compact.
Edit - I saw a treadmil on usedvic for $80