Adding a 2 groove pulley to motor shaft

mickri said:
In my humble and not very knowledgeable opinion not having the exact same speeds as original won't make a bit of difference in the operation of your lathe. You are going to find speeds and feeds that work for you with whatever pulleys you have on your lathe. 2" and 4" pulleys are so close to original that you will never see any difference. The difference between a 1.93" pulley and a 2" pulley 3.5% faster. Your 15 rpm will now be 15.5 rpm The difference between a 4" pulley and a 4.39" pulley is 9% slower. The fast speed on my Craftsman 12x36 is 2072 rpm. With a 4" pulley it would be 1885 rpm. Still not enough difference to make any difference in the operation of your lathe.

You can find 2" and 4" pulleys with a 1/2" bore all over the place. You can probably find a 2"/4" step pulley too. Surplus Center has 1.75 and 4.45 1/2" bore pulleys. McMaster Carr and Grainger have them too.
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Yeah, I figured the same thing. I don't need the exact speeds it originally came with, but it would be nice to have more than I do.

I looked at all 3 places and could not find the 2 groove pulley (2"/4") I needed. I was actually surprised. The issue with using 2, single-groove pulleys is there is not enough space on the motor shaft, and they would hit the cover. I'm hoping the stock pulley I just ordered will fit. The motor I have is not original, so there may be issues. We'll see!
 
This thread got me interested in the possibility of making a pulley. Found an old article on how to machine a pulley. And this video on making one

 

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The main problem with using stock diameter pulleys (usually available in only 1" and 1/2" diameter increments) is that the original motor and countershaft 2-step pulleys have their odd diameters chosen specifically so that the same belt fits both grooves on both pulleys when tensioned to the same point, not just so that they would result in having the 8 speeds match the chart.

And as far as the perceived part and shipping cost is concerned, it merely reflects the typical hourly rate and shipping rate in the US versus those in China. Shipping costs alone are up at least 10X over what they were 30 or 40 years ago.
 
If it were me I would cast a blank in aluminium and turn it to the size required but then again I am cheap.
If you dont have a furnace you could melt the scrap in a large enough tin with charcoal and a hair dryer.
Once its set just peel the now thinner tin from the block, this will have shrink voids in the centre that may be too large for the small 1/2" bore so a sand mould and proper pour would be better, the tin as a crucible will do ONE melt with no problems but not two.
 
Link belts aren't the smoothest running. I understand why you would want to use one to avoid pulling the spindle but you may want to use a standard belt for the motor belt. The large driven pulley looks like it has significant wobble.
 
UPDATE/CONCLUSION:
The pulley came a few days ago. I just put it on. Had to adjust the motor location relative to the pulley so the larger pulley wouldn't rub on the cover. With my 2-speed motor, I now have 32 speeds, ranging from 16 to 2158 RPM. I used an RPM meter from Harbor Freight to determine the speeds.
 
OK. Sounds as though that problem is fixed. Where did you find the pulley?
 
wa5cab said:
OK. Sounds as though that problem is fixed. Where did you find the pulley?
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I ordered it from Clausing. I can't call them directly, so I used a local vendor given to me by Clausing.
 
OK. I didn't notice earlier that you live in California. Due to something to do with their state sales tax laws, you have to deal with a CA located distributor. However, due to a US Supreme Court ruling either last year or late year before last, that is probably going to change. The situation is probably going to get worse rather than better.

Did you happen to ask them whether or not they also still had M6-427? That is the larger 2-step pulley on the Counter-shaft.
 
Sorry, I did not check about the M6-427. I usually email my contact person, but to keep it less confusing, I only ask him about what I need.
 
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