As part of the lathe restoration project I started here, http://forums.thehomefoundry.org/index.php?threads/dro-mount-for-lathe-restoration.1397/ and here, http://forums.thehomefoundry.org/index.php?threads/lathe-gear-cover.1398/#post-32103 I converted it from a bench top to a cabinet model with countershaft under the lathe. When I bought the cabinet surplus, I got everything except the 2-step countershaft and motor pulley. I temporarily borrowed and installed a 2-step countershaft pulley but only have a single step motor pulley. Seems folks on eBay think the large pulley is worth $150 and the motor pulley $60-$70. With shipping that would be $260+ and that aint happenin for a couple pulleys. I looked/watched for 3-4 months and made offers but apparently the sellers would rather have a part that doesn’t sell so I decided, screw it……..I’ll make them…..after I cast them, it’ll be a good first project to commission the lathe. So I made some lost foam patterns for pulley blanks on my pin router. I need one of the larger countershaft and two motor pulleys. It was easy to make a spare of each pattern since it’s basically all set with only a few minutes of machine time. Here’s the initial pass, After I hotwired the large diameter pulleys to thickness they warped. The large one about an 1/8” out of flat. So I bent them by hand the opposite direction until the they had enough memory to stay flat and then weighted them when I glued them together. Then back to the pin router to finish them up. The castings are designed to be about .060” material rich in the OD, faces, and grooves. I may have to do some massaging of the castings to make sure they remain flat enough to turn with the available machine stock……we’ll see about that. …sprued them up. Coated and ready to be poured. I’m dithering as to whether they will be Zamak or aluminum. -Waiting for weather to improve for casting. Best, Kelly
Just to sort of quality work we've come to expect from this forum's resident "king of foam"!! I'm curious though, what type of cutters are you using, especially the one for the v-belt groove?
Thanks Rocco. For the groove, the first thing I grabbed for was one of the wings off a finger joint bit but the angle was too shallow. I was going to resort to using a straight bit and slightly more elaborate fixture then remembered I had some style and rail cabinet door bits and low and behold, the wing on one was the correct angle of 17 degrees. I just set the fence and depth of cut, clamped that white scrap board in place as a stop, then slid the fixture (board with a pin) against the fence and stop with one hand while I spun the foam disc with the other. Then flipped the disc over and repeated. Think your pulling my crank there Andy cuz I've seen your castings and they are impressive. Happy Thanksgiving. Best, Kelly
Aluminum it is. Cast the first two and they looked fine… So I cast the others and degated and media blasted them. They’ll need to be heat treated but I have some pulley castings. The entire morning’s bounty. Best, Kelly
Those look really nice, but dumb question guy here... Why didn't you just turn some new pulleys on a lathe??? Or is this a which came first chicken/egg thing?
The larger pulley is 9" in diameter and 1.25 thick when finished. I didn't have a chunk of stock that size and buying one would have been cost prohibitive and machining it on one of these lathes would take forever. I'd probably hog it on the rotary table on my mill and finish machine it on the lathe if I went that way. It'd be more practical for the smaller pulleys which are 4.5" OD. The castings will still need to be turned on the lathe and balanced as even though I try my best on the foam patterns, they wouldn't be near close enough to just bore a hole and broach the keyway.....they'd shake like all get out. Now, that's probably the first operation I'll do when I machine them, then make an arbor to mount it and machine the grooves and faces. Then they'll need to be balanced. I can only statically balance them but that should be good enough. Here's a picture of the OE pulley. Look at all the weight removed to balance this one...... You can buy these pulleys on eBay but sellers want $150 for the larger and $70 for the smaller ones. I don't think the lathe is worth enough to spend that on two pulleys but on the other hand, I wouldn't sell the ones I made for that......why go to the effort? The same reason a dog licks his......(that one's for you Jason)....because he can. LOL!! You can buy single step pulleys more reasonably but then you wouldn't have the large speed range. I have a 3ph motor and VFD but you can still select your happy speed. These lathes still have quite a following amongst collectors and hobbyist thus the parts prices. When they were introduced (not sure when but they were full steam by 1930s) they were a hit with hobbyist because they were relatively inexpensive, portable, and made .001" precision a reality for a home gamer.........but consequently, they are not very rigid and a very light duty lathe. By my standards they are a bit of a toy and certainly not the machine I would have bought for myself, but given I inherited (actually two) them and the family history (since 1947), it could be in the family for 100 years when/if it passes to my son.....but I needed to make upgrades like DROs, QCTP, VFD, to increase speed and ease of use or I wouldn't use it as much. As is it will be relegated to small parts and the odd job cuz you can realistically only take .020-.030" per pass on steel......when it sat in my Grandfather's shop it's big brother was a Monarc that sat in back to do the real turning. But if you have skill, it's like my friends at the track used to say.....I'd rather be known as someone who can drive a slow car fast then a fast car slow! I have a thread on it over at the Hobby Machinist Forum linked in one of my lathe part threads here. Even mentioning an Atlas/Craftsman lathe at the Practical Machinist Forum will get you banned......no kidding. Best, Kelly
Static balancing is certainly good enough for slow speeds, especially if done with a polished shaft on two straight edges. I drive slow cars slow, Kelly. Yeah, Jason, why do women comb their hair at a stop light?
Yeah that bunch at practical machinist are quite the bunch. I avoid it at all costs.. Why Andy? Cuz they can?
Gave the castings the T5 treatment and finished up the machining. It was all my little lathe could handle.....but gott'er done........Tools making tools. The blow-by-blow is here. https://www.hobby-machinist.com/thr...or-and-countershaft-pulleys.88765/post-827894 Best, Kelly
Got the pulleys installed. Both pulley combinations tension the same and it seems to run nicely. I’m going to call this one a wrap. Best, Kelly
Ugh! Broaches! They were SO much trouble when cutting keyways. (At Sunkist, circa 1987-8) Nice parts, otherwise.
