# Material for large pulley



## JPMacG (Aug 16, 2017)

I'd like to make a new pulley for the counter shaft of my lathe.  The pulley is 9 inches in diameter and has two sheaves.

My question is what to make it from.  Searching online, it seems that the two most economical options are 6061T6 aluminum and grey cast iron.  Either would cost around $60 for a 9 inch diameter 1.5 inch thick piece.   Is there another option that I should consider?  Of course, I would like something less expensive.


----------



## RandyM (Aug 16, 2017)

Are you in it for the fun of making it?

Because you should be able to buy one. Mind you, I am thinking v-belt.


----------



## David S (Aug 16, 2017)

Would it be any cheaper to make it in two pieces from 3/4" plate?

David


----------



## mmcmdl (Aug 16, 2017)

I'm with Randy on this one . I had a job way back making large pulleys in my first shop , way too large to plunge with a form tool . Ended up plunging with an Iscar carbide parting tool and then doing a lot cranking on the compound which was not fun . Seems to me buying one would be the cheaper solution . But hey , the fun is in the making !


----------



## benmychree (Aug 16, 2017)

If you NEED to make one, do the aluminum, it would have less inertia, faster starts faster stops, if that is an issue, also, cast iron, which I dearly love, is less apt to run balanced than aluminum.  That being said, buying one MAY be cheaper.


----------



## RJSakowski (Aug 16, 2017)

You can get a 9" dia. by 1.5" thick piece of 6061 from online metals for around $50.

For a less expensive alternative, you might look at casting your own blank.  A foam pattern could be made and the lost foam process used for casting.  If you wished, you could use Zamak for a lower the melting point.  When I used to cast Zamak, I got my metal from old automotive castings but it is used in a wide variety of products.


----------



## woodchucker (Aug 16, 2017)

benmychree said:


> If you NEED to make one, do the aluminum, it would have less inertia, faster starts faster stops, if that is an issue, also, cast iron, which I dearly love, is less apt to run balanced than aluminum.  That being said, buying one MAY be cheaper.


If I had to make one, I would consider the heavier weight a benefit. Especially with an low powered unit. Inertia is like horsepower, it helps you get through the parts on flywheel . it also creates an even speed for the spindle, which leads to smoother cuts.
That would be my opinion.. But AL is much easier to work.


----------



## RJSakowski (Aug 16, 2017)

JPMacG said:


> I'd like to make a new pulley for the counter shaft of my lathe.  The pulley is 9 inches in diameter and has two sheaves.
> 
> My question is what to make it from.  Searching online, it seems that the two most economical options are 6061T6 aluminum and grey cast iron.  Either would cost around $60 for a 9 inch diameter 1.5 inch thick piece.   Is there another option that I should consider?  Of course, I would like something less expensive.



A bit more on the Zamak. It's melting point is about 700ºF, similar to lead, and its density id about 7 g/cc or about the same as cast iron.  Zamak is an aloy consisting primarily of zinc, with aluminum being the major alloying metal at around 4%. 

To make a simple disk would require around 25 lbs of metal.  That could probably be cut in half or better with a pattern more closely resembling the final shape.  I

f I were doing it, I would make the pattern of two stacked disks slightly larger  in diameter than the final dimensions.


----------



## Bob Korves (Aug 16, 2017)

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=9"+pulley&_sacat=0
8008 results for "9" pulley".


----------



## Superburban (Aug 16, 2017)

The surplus center, has some 3 grove pulleys in 8&3/4, or 9&3/4", that you might be able to use.

I made a large serpentine belt pulley for a pump, out of a weight lifting barbell weight. Made the bore fit a split bushing hub that I had. The weight did not matter to me, but one could take a bunch of the weight off the center if it needed to be lighter.


----------



## 4GSR (Aug 16, 2017)

Made a couple of step sheaves in my youth made from burnouts from steel plate.  Took about a week after school cutting on it to get it to size on  dad's 9" SBL.  Finish size was about 8-1/4".  Would I do it again?  I would do it again in a heart beat on a bigger lathe!

Edit: I notice you have a 12" Atlas/Craftsman Lathe. Is this what the sheave is going on to?


----------



## mmcmdl (Aug 16, 2017)

4gsr said:


> Made a couple of step sheaves in my youth made from burnouts from steel plate.  Took about a week after school cutting on it to get it to size on  dad's 9" SBL.  Finish size was about 8-1/4".  Would I do it again?  I would do it again in a heart beat on a bigger lathe!
> 
> Edit: I notice you have a 12" Atlas/Craftsman Lathe. Is this what the sheave is going on to?




Yep , thats what I was wondering . What size lathe is going to be swinging this pulley ? If it's that little lathe , he'll never have the torque or the low rpms needed . But once again , I've spent 100 hours to make something that I could have purchased for $40 . That's the illness in us !


----------



## JPMacG (Aug 16, 2017)

Thanks everyone.   Yes, it is for my Craftsman 12-inch lathe.  The original pulley wobbles.  The original is Zamac, by the way.

I searched but did not find a suitable pulley online.  It has two sheaves - diameters are about 9 inch and 7 inch.   I did not check with Clausing (Atlas) for an original part, but their stock of parts for old Craftsman/Atlas lathes is thin.  If they happen to have it they would want big $$.  Used parts do show up on eBay frequently, but they are not inexpensive and I worry that a used one might have been abused.

I had good success turning smaller 2-sheave pulleys, so I'm tempted to attempt to this one.   It would be by far the largest part I have tried to turn.  It might be a good learning experience or a it might be a disaster.

I have not ventured into casting at all, so for me that would be a new hobby in itself.


----------



## Superburban (Aug 16, 2017)

Places like Tractor Supply have blank pulleys, and separate hubs, that you weld together. I bet you could take the hub, and turn it so it holds two pulleys. Or just turn your own hub.


----------



## CluelessNewB (Aug 16, 2017)

JPMacG said:


> I have not ventured into casting at all, so for me that would be a new hobby in itself.



Yes and another opportunity to acquire more tools!  Whoever dies with the most tools wins!


----------



## 4GSR (Aug 16, 2017)

I have a piece of aluminum that is 12" OD x 6" long.  Too big for my saw.  If you have a way to cut it,  I might try to cram it into a flat rate box and ship it to you.  That would be 66 lbs.!  The post office would really hate me dragging it to the counter!

On a serious note, if you have a little time on this, let me do some digging around and see what I can find for you.


----------



## randyjaco (Aug 16, 2017)

benmychree said:


> If you NEED to make one, do the aluminum, it would have less inertia, faster starts faster stops, if that is an issue, also, cast iron, which I dearly love, is less apt to run balanced than aluminum.  That being said, buying one MAY be cheaper.



I don't get your rational on that statement. For a lathe I would inertia should be your friend (up to a point). The inertia should help with surface finish and cut regularity. I guess the lack of inertia would be best for an emergency stop, but that would be the only plus I can think of. 
Randy


----------



## Mark_f (Aug 16, 2017)

I would make it from cast iron, plus it is great to machine.


----------



## 4GSR (Aug 16, 2017)

JPMacG said:


> Thanks everyone.   Yes, it is for my Craftsman 12-inch lathe.  The original pulley wobbles.  The original is Zamac, by the way.
> 
> I searched but did not find a suitable pulley online.  It has two sheaves - diameters are about 9 inch and 7 inch.   I did not check with Clausing (Atlas) for an original part, but their stock of parts for old Craftsman/Atlas lathes is thin.  If they happen to have it they would want big $$.  Used parts do show up on eBay frequently, but they are not inexpensive and I worry that a used one might have been abused.
> 
> ...


Another thing to keep in mind when you make the sheave.  Bore it for a taper lock bushing.  That way you don't have to worry about the sheave crawling around on the counter shaft causing havoc later.


----------



## Ulma Doctor (Aug 16, 2017)

i like the idea of creating your own pulley from scratch.
sure you can buy one, but making one is satisfaction beyond measurement 
every time you use that lathe, you'll know that you fit the pulley that turns the spindle, that turns the new creation 

i didn't use the 2nd step on my Atlas TH42 at all
maybe you should consider whether you will be using the lathe at its higher speeds.
if you aren't using the high speeds, 
you may wish to omit the high speed pulley and make a single pulley instead of a double pulley to save material and make the job a lot simpler


----------



## JPMacG (Aug 16, 2017)

I should have thought this through more carefully before posting.  I just made some measurements and I now realize that a 9 inch diameter is too large for my lathe. 

Although my Craftsman is called 12-inch, and the bed will clear a 12 inch diameter, there is no way I could cut the tapered sheaves of a 9 inch pulley.   I might be able to make a face cut on a 9 inch part, and I could possibly cut the diameter of the part with the compound and Y axis almost to their travel extremes, but I would not be able to cut the sheave with the compound adjusted for the desired Vee angle.  The part would be trying to occupy the same space as the tool holder.

Ulma Doctor's idea of omitting the small sheave is interesting.  I can buy a 9-inch pulley.  

Thanks everyone, and I apologize for spinning you up on my dead end.


----------



## 4GSR (Aug 16, 2017)

JPMacG said:


> I should have thought this through more carefully before posting.  I just made some measurements and I now realize that a 9 inch diameter is too large for my lathe.
> 
> Although my Craftsman is called 12-inch, and the bed will clear a 12 inch diameter, there is no way I could cut the tapered sheaves of a 9 inch pulley.   I might be able to make a face cut on a 9 inch part, and I could possibly cut the diameter of the part with the compound and Y axis almost to their travel extremes, but I would not be able to cut the sheave with the compound adjusted for the desired Vee angle.  The part would be trying to occupy the same space as the tool holder.
> 
> ...



It's not a dead end.  Just have to think about the ways to hold a piece of 9" OD material.
When I turned the 8" sheave on my 9" SBL, I took and drilled and tapped four 3/8-16 holes on the face of the disk on a appropriate bolt circle.  Then install four socket head cap screws about 3/4" long.  Turned the jaws around on my 4-jaw chuck and chucked on the heads of these socket head cap screws.  I was able to cut and finish the entire three step sheave in the one chucking.  I think I even did the taper lock bore in the same chucking.  Last, all I had to do was remove the cap screws, chuck on one of the steps and face off the other side.  The four threaded holes won't hurt anything later.  It's just a means of holding a piece of material to cut on.


----------



## Bob Korves (Aug 17, 2017)

JPMacG said:


> Thanks everyone, and I apologize for spinning you up on my dead end.


There are other ways to hold tools besides what you have been using so far.  Think outside the box...  One example.  Take a decent sized boring bar, 3/4" or bigger, install it on the side of the tool post facing you, bar going to the left and cutting edges facing toward the spindle center.  Then "bore" the O.D. of the large work.  That is just one idea that would not take me any tooling I do not already have.


----------



## markba633csi (Aug 17, 2017)

How bad does the original wobble? Perhaps you could do a handy dandy straightening job? Or is it not concentric with the bore? 
Mark S.


----------



## Superburban (Aug 17, 2017)

If the bore is off, one can chuck the pulley by the outer edge, and cut a new bore. Then simply use a sleeve to mount the pulley.


----------



## Jimsehr (Aug 17, 2017)

I made a few  pulleys from drops of Corian that I got from a Habitat for Humanity
Surplus store. The material came from where they cut out the sinks. It can also be cut on a table saw. Dulls blades . I bolted two pieces together. And cut the V on a rotary table on the mill.
Jimsehr
Ps material cost me about $5 and I have enough left over to make more.


----------



## JPMacG (Aug 17, 2017)

The original wobbles about 1/4 inch left-right, looking at the lathe from the front.  It is enough to cause a noticeable vibration on the lathe bed.   I suspect that a previous owner bent it when he removed the pulley from the shaft, as I see hammer marks on the back side of the hub.

As Bob Korves said, I could probably work out a way to cut the Vee on 9-inch material using some sort of clever tool post extension.  I do worry about rigidity.    

I could try to bend it back, but I'm not sure if the Zamac would cooperate.  Probably better to bore and sleeve the hub, but  I'm not sure if there is enough material there.  In any case, I would need a replacement pulley while I work on this one.  I could buy one on eBay and resell later, it if the repair is successful.

I will think it all through - no rush.  I have a useable lathe now, I just want to make it better.   You all have given me many good ideas.  Thanks!


----------



## GoceKU (Aug 17, 2017)

I've used car flywheel its balanced and usually free from any mechanics shop, you could use an forming tool to cut the belt shape


----------



## GoceKU (Aug 17, 2017)

Here are couple i've removed the starter ring gear from.


----------



## ELHEAD (Aug 17, 2017)

Superburban said:


> If the bore is off, one can chuck the pulley by the outer edge, and cut a new bore. Then simply use a sleeve to mount the pulley.



I second this idea
Dave


----------



## dulltool17 (Aug 17, 2017)

I love this.  Folks on this forum don't think outside the box...they simply refuse to recognize that there is a box.


----------



## Bob Korves (Aug 18, 2017)

dulltool17 said:


> I love this.  Folks on this forum don't think outside the box...they simply refuse to recognize that there is a box.


We create our own boxes in life, even where none are required.  Stand way back and look over your own shoulder with a clear mind.


----------



## tq60 (Aug 18, 2017)

If bent fix it

Sent from my SAMSUNG-SGH-I337Z using Tapatalk


----------



## Ulma Doctor (Aug 18, 2017)

i was just looking through the grainger catalog.
they have many fixed bore pulleys of cast iron, zamak, and glass reinforced nylon
a fixed bore pulley will be sufficient for your needs
you'll probably want an A belt(4L) pulley


----------



## Desolus (Aug 25, 2017)

CluelessNewB said:


> Yes and another opportunity to acquire more tools!  Whoever dies with the most tools wins!



Yup...

If I were going to do it I'd cast a blank, but then I'm set up to do not only casting, but to alloy metals and to heat treat those alloys in an inert gas oven. The tools are pretty cheap, a wooden box and some casting sand for cheaper material like steel and aluminum. ... A wax pump and investment for the centrifugal casting machine mounted next to my bench grinder for things like gold, silver, platinum etc. (you'd think I'd have made a shield for it already given that if a mistake is made there's molten metal flying around the room at waist level...) I wish I could afford a large vacuum casting machine, those things are sweet.


----------

