Lathe Restoration And Improvements - Making The Pulleys, Then I Hit A Major Problem

This is the second video in the Lathe Restoration And Improvements series. In this video I make the pulleys for the lathe spindle and motor. These are cast in sand. This is the first time I have done sand casting and it was a good learning experience. Many thanks to Mark Presling for his sand casting advice - / @preso58
Unfortunately I hit a big problem where the included angle (30 degrees) for the belts I am using does not allow for enough travel in the pulley. Therefore, I can not get the speed range that I need. These belts and pulleys simply wont work, so I now need to do some redesign, source other belts with a 22 degree included angle and build new pulleys.
I have left the pulley build in this video as it may still be useful information for others.

[@mikestaunton7081]

Hope you and family are safe from the flooding

[@thehobbymachinistnz]

Thanks you for asking. We are actually on a bit of a hill so we were not affected. That said, it was really bad in other places. The news showed videos of only the tops of street signs poking out of the water. Even the airport was flooded and had to be closed. I have never seen that much rain falling in such a short time.

[@jonsworkshop]

That's a shame Jon, still, as you say those pulleys will do something else in the future. Well done on your first sand casting though, very good results considering it was your first try. Excellent project, enjoying following along. Cheers, Jon

[@thehobbymachinistnz]

Thanks for your comments Jon.

[@berniesr]

This is very interesting I have always wondered how the variable pulleys work. Looking forward to the next instalment.

[@thehobbymachinistnz]

Thanks for watching and your comments.

[@ab-shop]

This is very interesting, it is the real "DIY", as you made also the alluminum pulleys at home !! Hope one day to can make something like you with the alluminum, really nice !! See you soon, ciao from Italy !! Alberto

[@thehobbymachinistnz]

Thanks for your comments Alberto.

[@KravchenkoAudioPerth]

Not a bad first set of castings. At least they were serviceable. I appreciate watching the design process and changing gears when you need to. Very few times does anything work perfectly the first time. Mark

[@thehobbymachinistnz]

Thanks for watching Mark. The issue is that there is very limited info on YT for making these CVTs. I have only found one other video of someone building one, and he has not finished yet. So its a bit of trial and error, and change the plan as you go. I'm sure that I will get there though...

[@Xynudu]

Interesting subject Jon. The trouble with wider/deeper rubber belts is that they also generally become stiffer, so minimum curve radius may become an issue as well. I will be keen to see how it all works out. Cheers Rob

[@thehobbymachinistnz]

Thanks for you comments Rob. I overlooked that included angle issue so its been a bit of a challenge. I think I have it sorted now, I just need to find the right belts.

[@Preso58]

Good functional castings Jon. Draft does make it easier to get your patterns out. About 2 degrees is OK. I had a variable speed drive on an old drill press called a "Robley Variator" it was easy to adjust but it absorbed a lot of torque.

[@thehobbymachinistnz]

Thanks Mark. The wood was not that good to use. There were knots etc. and I tried painting it to make it smoother. I think I will 3D print the patterns going forward. That way I can easily add a draft as well.

[@MattysWorkshop]

Gday, I wouldn’t be disappointed, you have found a way around the issue and the belts and pulleys will be used somewhere in the future, the castings turned out good to, im really looking forward to seeing the next instalment mate, great job as always, cheers

[@thehobbymachinistnz]

Thanks Matty. I found a belt and picked it up this morning so I should be back on the build with no delay. Cost a bit, but I have it now.

[@boltonky]

Good series and quality videos. I like the use of the mold for making the pulley blank to start, i am kinda lazy and typically just pour it into a cylinder or pot and spend to long cutting away material...thank f*s for lathes

[@thehobbymachinistnz]

Thanks for watching. Up until this casting I did the same as you. The CVT pulleys will be 6" in diameter and I will need somewhere to hold them in the lathe so I can machine them. Therefore, that would be a huge chunk of aluminum, and I would turn a lot of it away. So I thought that I would experiment with casting these pulleys first. With the new 22 degrees included angle belt I can make the CVT pulleys out of steel as I have some suitable steel. I'm building them now so there should be another video within a week.

[@joell439]

👍👍😎👍👍 Fascinating

[@thehobbymachinistnz]

Thanks for watching.

[@BensWorkshop]

Well done. Lots of mistakes made during casting... that'll teach you though so all good. I haven't actually done any casting since school but have plenty of books on the subject which I have read! I had to service the variable drive on my cousin's Shopsmith Mk V lathe which is interesting because it has a cam acting via a screw to close and open the pulley. Fairly sure it has an intermediate one too.

[@thehobbymachinistnz]

Thanks for watching Ben. I have seen a drill press that had a cam to operate the pulley. I was going to use something like that in this design, but I will get to that a bit later.

[@BensWorkshop]

@@thehobbymachinistnz Look up the ShopSmith Mk V. It is quite a lot of what you want to achieve.

[@kentuckytrapper780]

Going to be nice...

[@thehobbymachinistnz]

Thanks.

[@petehottois2856]

If you need a new variable speed pulley, Speed Selector makes pulleys that replace the Reeves, Hi-Lo, TB Woods and Lovejoy pulleys that went out of business or got bought. Most are in stock or Speed Selector will custom make if needed. They have an actual engineering department; very helpful.

[@thehobbymachinistnz]

Thanks.

[@ianhartley5071]

I think I would proceed with making the 22 deg CVT pulleys and find a way to re profile the 30 deg belts to 22 degs. There looks to be plenty of width in the belt to be able to grind away the sides. Not ideal, I know, but it would make an interesting side project, besides the belts are not likely to be subject to high loading on that size of a wood working lathe so should be able to cope after modification.

[@thehobbymachinistnz]

Thanks for your comments and suggestions Ian. I found a belt and picked it up this morning so I will go with that at this point. I can use those other belts and pulleys in other future projects so they will not be wasted.

[@MyLilMule]

Interesting dilemma. I have machines with both kinds of drives. My shaper uses the reeves drive type with 2 belts and three pulleys. And my Bridgeport mill uses that single belt system. Although I think the latter has fewer moving parts (or does it?) and seems simpler, I think the mechanics of spreading the driven pulley apart might be a little tougher to figure out. Your original idea may actually be simpler to build. Not sure on this one. I'll be interested to see how you work it out.

[@thehobbymachinistnz]

Thanks for your comments. Do the variable speed drives work well on your machines?

[@MyLilMule]

@@thehobbymachinistnz They work very well. I've taken apart the Bridgeport and can attest to the power of the spring on one half of the CVT. Takes a lot to compress it. The Reeves drive on my shaper is still something I haven't torn into just yet, so I can't say much about that.

[@Noote54]

Will there be any issue with torque through the belts

[@thehobbymachinistnz]

Hi, do you mean with slipping? If so then I don't think so. The belts are designed as variable speed belts to be used in CVT pulleys. I will know more once I have finished and tested it so I can give an update then.

[@Noote54]

@@thehobbymachinistnz I used to use a test bench with this system on it. It couldn't start if the speed control wasn't return to its lowest setting. The motor stalled

[@thehobbymachinistnz]

@@Noote54 Thanks for the info. I only have a 1/2HP motor at this point. I will have to see how that goes once the project is complete. Best practice is that the lathe should always be started on a lower speed. I will need to get into that habit once it is operational.