I need to make a 6 sheave pulley

[benmychree]

Most cone pulleys use setscrews, not keyways.

 

[mattthemuppet2]

That's a large chunk of alu to be hacking into a multi step pulley! I'd make the smaller steps out of one piece, then make the larger steps out of plate/ round then pin them to the small steps. Or use a central cylinder and press/ pin all the steps to that. You can rough out part of the Vs on each step, then push them all together and mount them on an arbor turned between centers, then finish the Vs. Cutting to the bottom of the Vs is a challenge - most parting blades that can reach will be too flexible, but using a form cutter = ton of chatter at full depth. I think the SB HTRAL book has a tool grind pictured specifically for V grooves.

The above is kind of how I'm going to make a 3 step poly V countershaft pulley for my SB. Piece of thick wall tubing with end caps, then each step will be pressed on and pinned. I'll turn a 1/2" rod between centers, mount the assembly and then cut the poly V grooves. That should get everything concentric and it should be pretty well balanced.

 

[mksj]

I think it would be difficult to get all the groves uniform, have you considered have it fabricated?

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[extropic]

Long hours for sure
No, what I meant was the area in the jaws would have to be removed at some point. I am not sure how I would trim that to size.
I'm thinking of using 6" Durabar for the project.
On the other hand, the material would be plenty snug with .750" in the 10" Bison 4 jaw.
I could probably live with it. Heavy pulley.
I haven't thought this all the way through, I'm just kicking the tires with you guys how you would go about it.

I'm wondering why you want to do it in cast iron? Is the spindle pully CI?

Besides the mess and general "harder to work than aluminum" issue, my concern is that dimensional concentricity does not guarantee it will be dynamically balanced. Even at 1750 motor RPM it could be unpleasant. I'd have to have a very good reason to choose CI over aluminum (for reduced mass). If you have access to inexpensive balancing, no sweat. It cost me $150 to have an 8 or 9", 2 sheave iron pully balanced a couple of years ago.

I didn't have any real arguments against the procedure you outlined in the OP except I'm not clear how you are going to apply the rotational force to the workpiece. You mention an arbor. If there is a dog to drive the arbor, how is the workpiece secured to the arbor? Also, I think I would cut the larger diameter grooves before the smaller (make it easier as you go).

If I had the workpiece held in a chuck (3, 4 or 6 jaw) I sure as he11 would use a push plate or center in the tailstock.

Edit: I don't know your equipment, What lathe are you planning to use?

 

[pdentrem]

I just finished making a new pulley for the auger side of my snowblower. I used a parting tool as well, was thinking of grinding a double ended HSS tool and leave the tool post square to the work but since this is a one time thing I didn’t do so. Took a while being careful to watch what the tool was doing and a couple sharpening along the way. Stalled the spindle a couple times which a belt drive is much more forgiving when that happens. Aluminum will be much different than the steel one I made. Cast iron can be problematic with undiscovered hard spots and the mess!
Have fun!
Pierre

 

[woodchucker]

I have a 4 sheave pulley if you are interested. It's zinc..
if you are interested I'll get sizes to ya.

 

[davidpbest]

Long hours for sure
No, what I meant was the area in the jaws would have to be removed at some point. I am not sure how I would trim that to size.
I'm thinking of using 6" Durabar for the project.
On the other hand, the material would be plenty snug with .750" in the 10" Bison 4 jaw.
I could probably live with it. Heavy pulley.
I haven't thought this all the way through, I'm just kicking the tires with you guys how you would go about it.

Durabar ? OMG. I was thinking aluminum. Is there some reason 7075 aluminum couldn’t be used? That would sure be a lot easier material to work with for all the cutting operations, and if wear is your concern, a hard anodize might be just the ticket. I just had a 12x12x1” 7075 table plate hard anodized locally for $90 (their minimum), and it ends up very durable.

Have a look at this analysis:

(PDF) Hard Anodizing of Aerospace AA7075-T6 Aluminum Alloy for Improving Surface Properties

PDF | In the current research work undertaken, an oxide film was grown by performing hard anodizing process on a pure aluminum layer deposited by PVD... | Find, read and cite all the research you need on ResearchGate

www.researchgate.net

Do you already have the broach and press to cut the keyway? Describe how you intended to cut the keyway please.

 

[kcoffield]

J,

I made several 2-step pulleys from blanks I cast.

Atlas/Craftsman Lathe Motor and Countershaft Pulleys

I converted my 12” bench top lathe to a under drive cabinet model, and mentioned in my intro and refurb thread here: https://www.hobby-machinist.com/threads/new-caretaker-of-two-12-craftsman-lathes.87335/ …when I bought the lathe cabinet surplus, I got everything except the 2-step countershaft...

www.hobby-machinist.com

Whether starting form a casting or billet slug it's just a matter of material removal, but one thing I think you'll find, unless the grooves are very generously spaced, you can't cut the inside angle of the v-groove with a parting tool and compound angle because of interference/lack of clearance from/to the next adjacent sheave. If you have a stout enough lathe then you can grind a form tool for the v-groove, then yes.

Best,
Kelly

 

[Janderso]

J,

I made several 2-step pulleys from blanks I cast.

Atlas/Craftsman Lathe Motor and Countershaft Pulleys

I converted my 12” bench top lathe to a under drive cabinet model, and mentioned in my intro and refurb thread here: https://www.hobby-machinist.com/threads/new-caretaker-of-two-12-craftsman-lathes.87335/ …when I bought the lathe cabinet surplus, I got everything except the 2-step countershaft...

www.hobby-machinist.com

Whether starting form a casting or billet slug it's just a matter of material removal, but one thing I think you'll find, unless the grooves are very generously spaced, you can't cut the inside angle of the v-groove with a parting tool and compound angle because of interference/lack of clearance from/to the next adjacent sheave. If you have a stout enough lathe then you can grind a form tool for the v-groove, then yes.

Best,
Kelly

Oh man,
You guys are really awesome.
Oh, by the way, I counted wrong.
It’s a 5 sheave pulley.

 

[Tipton1965]

Durabar ? OMG. I was thinking aluminum. Is there some reason 7075 aluminum couldn’t be used? That would sure be a lot easier material to work with for all the cutting operations, and if wear is your concern, a hard anodize might be just the ticket. I just had a 12x12x1” 7075 table plate hard anodized locally for $90 (their minimum), and it ends up very durable.

Have a look at this analysis:

(PDF) Hard Anodizing of Aerospace AA7075-T6 Aluminum Alloy for Improving Surface Properties

PDF | In the current research work undertaken, an oxide film was grown by performing hard anodizing process on a pure aluminum layer deposited by PVD... | Find, read and cite all the research you need on ResearchGate

www.researchgate.net

Do you already have the broach and press to cut the keyway? Describe how you intended to cut the keyway please.

I agree with using aluminum and then have the part hard anodized. Back at the shop I worked at some of the smaller machines we made used aluminum gears. We always sent them out to be hard anodized after the machining was done. The work life of the gears was really really good. I had a good foreman, he would let me throw in a few of my own personal after work parts as long as they weren't too big!