Interesting bore dimensions

[GB SISSON]

I can't begin to figure out how that lathe would work. Since we got far away from measuring cylinder bores, here's what I finally had to do today so I could catch the early morning ferry to look at the old 12x36 lathe I've heard about. In 2 weeks I have been off my ten acres for a total of one short trip to town. Been snowbound for a week. Even if I plowed my 1/2 mile steep gravel road, the county roads were impassable. 58 sq miles and 2 plows, maybe 3 if you count the road grader. Well we heard the county road had thawed and melted clean, but the snow up here fell on very frozen ground. Every day hoping to take ferry, see lathe. Well it got slushy today so I hooked my homemade snow plow to the forks on my '82 case skidsteer. I made it from a 3 point grader blade. The angle is rotated with a jailbar steering box with a crank where the wheel was. A spring loaded pin drops into the hole as it is cranked around. Chains on the front, about 35 degrees out but gotta head down hill in the dark at 5:45 am tomorrow in empty 4wd pickup, so plowed away. This is my 3rd year with it, works great. I also adapted honda disc brakes down inside the thing. Couple of really close calls on my mountainside with hydrostatic drive. Ok, will be back on Tuesday and get this thing unloaded.

[Mart]

As a retired transmission engineer I sat down and mapped all the available ratios. Many ratios are duplicated and the result is actually 7 usable ratios. The ratio spread, which is most important is a useful 29:1.
Again using common ratios for the 3 boxes and assuming a motor speed of 1500 rpm and a final drive from the last gearbox output to the spindle of 1.5:1 I compiled the following table.
On top of all this there might be alternate final drives via the flat belt and a back gear.

But here is what I found:

[38 coupe]

Originally Posted by Mart

As a retired transmission engineer I sat down and mapped all the available ratios. Many ratios are duplicated and the result is actually 7 usable ratios. The ratio spread, which is most important is a useful 29:1.

Mart, your list, which is better than mine in most ways, left out the option of using the reverse gears. You can also get approximately 40:1 and 52:1 by doubling and tripling the reverse ratios. Are these simply too low for practical use?

[Mart]

Yes, reverse could be used. As it was just an academic exercise I didn't want to make it over complicated. You would have to use two boxes in reverse to maintain forward rotation.

[petehoovie]

Originally Posted by GB SISSON

I can't begin to figure out how that lathe would work. Since we got far away from measuring cylinder bores, here's what I finally had to do today so I could catch the early morning ferry to look at the old 12x36 lathe I've heard about. In 2 weeks I have been off my ten acres for a total of one short trip to town. Been snowbound for a week. Even if I plowed my 1/2 mile steep gravel road, the county roads were impassable. 58 sq miles and 2 plows, maybe 3 if you count the road grader. Well we heard the county road had thawed and melted clean, but the snow up here fell on very frozen ground. Every day hoping to take ferry, see lathe. Well it got slushy today so I hooked my homemade snow plow to the forks on my '82 case skidsteer. I made it from a 3 point grader blade. The angle is rotated with a jailbar steering box with a crank where the wheel was. A spring loaded pin drops into the hole as it is cranked around. Chains on the front, about 35 degrees out but gotta head down hill in the dark at 5:45 am tomorrow in empty 4wd pickup, so plowed away. This is my 3rd year with it, works great. I also adapted honda disc brakes down inside the thing. Couple of really close calls on my mountainside with hydrostatic drive. Ok, will be back on Tuesday and get this thing unloaded.

[cas3]

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A+ on the ratio assignment for both you boys! And GB gets an A+ also for that fine contraption. I use a blade on the front of of my 863 BobCat also, but I cheated and just had to make a mount for an old blade off a pickup

[GB SISSON]

Had a great trip South. Left here at 6 am, got home at 11 pm. Was a CL ad, didn't know what to expect, but guy was closing up a little hole in the wall auto shop. Lots of cool stuff crammed into a small space. He kept saying "You want this?", "Can you use something like this?",. I left with a lot of stuff, but the lathe was the crown jewell. I have been studing at youtube U for a couple weeks and this thing passes the usual tests for play/slop/wear with flying colors. No chipped teeth or missing parts. Not a lot of extra lathe tooling but sure got a bunch of neat stuff nobody wants or uses today. Well, almost nobody. Adjustable reamers, more measuring stuff. Mitutoyo large dial caliper, mituyoyo dial indicator/magneric base. Stuff. Today I was supposed to build some stuff for a contractor in my wood shop. I got as far as making a fire in the woodstove and went down to look at my stash in the pickup. Then my buddy Tim showed up to help unload, then it was 3 in the afternoon. I can build that guy's stuff tomorrow. I'm finding at 70, a guy has to have his priorities straight. Next priority is coming up with a nice 3/4 hp single phase motor to replace the 1/2 hp 3 phase. 1/2 hp was standard, 3/4 an option.

[tubman]

I like that lathe. It looks to be just the size I've been looking for. Everything I've found is either huge and heavy or too expensive. Good call on looking for a new motor. I got a real good deal on a floor model drill press with a 3-phase motor. To keep things simple, I used an electronic phase converter and found out that you lose a lot of power that way.

[GB SISSON]

Originally Posted by tubman

I like that lathe. It looks to be just the size I've been looking for. Everything I've found is either huge and heavy or too expensive. Good call on looking for a new motor. I got a real good deal on a floor model drill press with a 3-phase motor. To keep things simple, I used an electronic phase converter and found out that you use a lot of power that way.

Ditto on all the above. I have been looking at older lathes for about 2 months. First I wanted a 6x18 Craftsman/Atlas, but fell in love with a South Bend 9x36 until I found out with the countershaft/flywheel out back, they sit 37" off the wall to the front of lathe. The 12x36 Atlas Clausing models 100, 200 and later 4800 series are way more compact in that direction. In the last 4800 models, an undermount motor in a cabinet was an option. Mine is a 4818 with that option. Face of machine is 22" off back wall. The cabinet without motor weighs just under 350 lbs and is made from 3/16 material. The lathe weighs 550 or so. I also looked into static phase converters, but with only 2/3 use of the 1/2 hp motor sounds a bit puny. The one I bought has the old time look for my '40s-'50s style auto repair shop, but on a more practical base. And yes for sure there are 10' lathes on CL 8000 lbs and get no offers when listed at 600 bucks.

[cas3]

Very nice lathe, I'm a fan of Clausing. Clausings do the math for you. Say you want to cut .010 off a part, you sent the dial to .010. It then makes a .005 cut, so .005 of each side of a shaft is .010 reduction in size. On many lathes, if you want to cut .010, you set the dial to .010 and have made a .020 cut...10 off each side.

Now to argue with Denny, I have three 3 phase machines in my shop running off cheap 3 phase converters from ebay. About 60 bucks for the small ones up to a 3hp motor. I have never seen any change in my electric bill, but they get used a couple hours a month at absolute most. May sit for months with no use, but I would never be without them. Good score GB!

[petehoovie]

Originally Posted by GB SISSON

Had a great trip South. Left here at 6 am, got home at 11 pm. Was a CL ad, didn't know what to expect, but guy was closing up a little hole in the wall auto shop. Lots of cool stuff crammed into a small space. He kept saying "You want this?", "Can you use something like this?",. I left with a lot of stuff, but the lathe was the crown jewell. I have been studing at youtube U for a couple weeks and this thing passes the usual tests for play/slop/wear with flying colors. No chipped teeth or missing parts. Not a lot of extra lathe tooling but sure got a bunch of neat stuff nobody wants or uses today. Well, almost nobody. Adjustable reamers, more measuring stuff. Mitutoyo large dial caliper, mituyoyo dial indicator/magneric base. Stuff. Today I was supposed to build some stuff for a contractor in my wood shop. I got as far as making a fire in the woodstove and went down to look at my stash in the pickup. Then my buddy Tim showed up to help unload, then it was 3 in the afternoon. I can build that guy's stuff tomorrow. I'm finding at 70, a guy has to have his priorities straight. Next priority is coming up with a nice 3/4 hp single phase motor to replace the 1/2 hp 3 phase. 1/2 hp was standard, 3/4 an option.

[tubman]

Originally Posted by cas3

Very nice lathe, I'm a fan of Clausing. Clausings do the math for you. Say you want to cut .010 off a part, you sent the dial to .010. It then makes a .005 cut, so .005 of each side of a shaft is .010 reduction in size. On many lathes, if you want to cut .010, you set the dial to .010 and have made a .020 cut...10 off each side.

Now to argue with Denny, I have three 3 phase machines in my shop running off cheap 3 phase converters from ebay. About 60 bucks for the small ones up to a 3hp motor. I have never seen any change in my electric bill, but they get used a couple hours a month at absolute most. May sit for months with no use, but I would never be without them. Good score GB!

No argument here; I mis-posted "use a lot of power", when I meant "lose a lot of power". (Since corrected.)

[GB SISSON]

So, Skip and Denny and others (Is there an electrical engineer in the house?). It would be nice to use the switching and controls that came on it. There is a large Allen Bradley box on the left end and the three buttons up front are forward, stop, reverse. Keep in mind my brain doesn't work with things I cannot see (like electricity). I recently bought a beautiful, huge 1/2 hp baldor pedestal grinder. It had come from Boeing surplus and looks brand new. Got home and 3 phase. I bought a 85.00 ebay static converter for it but havent hooked it up yet. I sure hate to lose that hp, but maybe I try it? I read about VSD systems, but don't understand. Do they not steal HP? I have talked to place in Ca that makes converters for like 250.00. I could spend that if necessary. I am very confused about how to power up this thing. Dang, I can ramble. Oh and Pete, another A+ for enlargement job. Thanks all, GB

[tubman]

Despite all my complaining about "losing a lot of power", I would try the phase converter and see if it is adequate for your needs. I got the drill press from a friend who had it in his shop, running on three phase power and had used it many times. Thus, the loss of power was quite apparent to me, but it is still eminently usable. I had looked for a replacement motor, but it seems everybody else is and they are getting scarcer and scarcer. If I found one, I'd buy it in a heartbeat, but in the meantime, I am still able to make those little curlicues of metal.

Like everything else these days, things electronic seem to be getting better and better as well as cheaper and cheaper, unlike the older stuff which is hard to find and expensive when you do. Just make sure the phase converter is rated for your equipment.

[Bob C]

I have a Variable Frequency Drive on my mill and love it.

[Bored&Stroked]

Originally Posted by Bob C

I have a Variable Frequency Drive on my mill and love it.

I looked up a few of them - can take 230V input (single phase) and output 230V 3-phase . . . powering up to a 3 HP motor. Price is very cheap (in comparison to most rotary phase converters).

Was wondering which brand/model you have and what horsepower motor is on your mill?

[flatford8]

People around here are using the big old ones for Yahd Arht……Mark

[petehoovie]

Originally Posted by flatford8

People around here are using the big old ones for Yahd Arht……Mark

[Bob C]

Bored&Stroked, my VFD is an Allen-Bradley running a 3 HP motor.

[Ronnieroadster]

Originally Posted by flatford8

People around here are using the big old ones for Yahd Arht……Mark

Heck I have two of them there Southbends each one with a 16 inch swing and 6 foot long beds they are outstanding machines. Large enough to swing early Ford axle housings when the need arrives. and large enough to hold a crankshaft as well.

A great machinist once told me its easy to make a large lath small and impossible to make a small lath big. For my laths I have a 3 inch diameter three jaw chuck for the very small jobs and chucks well up in size and of course weight.
Ronnieroadster