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working on newly acquired lathe

hi, thanks for everyone's help so far. i'm trying to calculate what size pulley i'll need and what should be the speeds at the chuck. i visited several "star" brand lathe websites, found one with an old catalog. the entry in the catalog for the jackshaft they sold for this lathe to convert it from treadle power to steam power said "...speeded up to

200 rpm." i figure that must mean the maximum recommended speed for the jackshaft (and hence the input speed for the lathe) would be 200 rpm. so i've been trying to come up with a pully combination that'll supply the lathe with (as close as possible) a 200 rpm input speed.

what i've come up with so far... motor 1725 > motor pulley 2" > reduction drive v belt pulley 14" (largest i can find in die cast (=inexpensive), the cast iron pulleys go for between sixtysomeodd bucks ~ $140 (w/o collar!)) > with formulas i found on the web that makes 244 rpm for the input to the cone pulley reduction. the reduction cone pulleys are 4.5"/5.625"/6.5625" the cone pulleys on the lathe are 5.4375"/4.3125"/3.1875" that, according to my calculations, with a 244 rpm input, will produce, at the chuck, 20.17/318.25/502.34 rpms. it seems unbelievable there's such a huge difference in the speeds between #1 and #2. is 20 rpm (and that's even w/o back gears) too slow?! i don't even KNOW what it'll be in back gears. is 502 rpm on the highest speed too slow too? i'm a little concerned about speeding this lathe up too much, it has bronze bearings (and they don't look perfect, there is some scoring.)

b.w.

Reply to
William Wixon
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You slipped a decimal place on your low cone calc. It should be a reduction of 4.5/5.43= .82 times imput speed of 244 rpm would be 202 rpm, not 20.2 rpm.

7:1 reduction using 'V' belts is pretty much a pain due to the huge size of the driven pulley. As big $$ as you already found out. You can get some weld-up pulleys sold in the farm stores that consist of a suitable hub (various standard bores, a couple of standard external diameters) and your choice of stamped steel pulley. $6 for the hub, $20 or so for the 14" pulley,

I th> hi,

Reply to
RoyJ

thanks Roy! jeez, i did that calculation like 5 times and kept coming up with the same answer, must've kept making the same mistake over and over again. (i went to art school, what can i say)

(more below...)

i've used those (large diameter) two piece spot welded stamped sheet metal pulleys in teh past but couldn't find them on-line and figured they must've stopped making them.

thanks very much Roy for the suggestions, recommendations, advice. (!)

holy crap i found some nice (relatively inexpensive) large diameter cast iron (!) pulleys at

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they have some (nice?) electric motors there too, reversible, etc. was going to ask you guys for suggestions on where to get a nice reversible electric motor, i was hoping for a honking big 2 hp motor but maybe (with teh prices for 2 hp) i can settle for something smaller .

b.w.

Reply to
William Wixon

Willam If you determine for sure you need a big pulley, I have one on a lathe I'm parting out that is probably 12" OD, single groove, takes a

1/2" belt. It is mounted to the left end of an Atlas 10" spindle, so it's ~1.5" ID. Cast iron, good condition.

email me privately if interested.

rex at txol.net

Reply to
Rex B

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