Typical and max diameter of faceplate for 8mm WW lathe?

[mbwatch]

A local machinery auction this week is liquidating some watchmaker's equipment. Actually a truly absurd amount of it, from a machine collector's estate, making me wish I had waited a couple of months to buy my lathe because there are so many options at low prices.

Anyway - there are a handful of faceplates on 8mm collet mounts up for sale and I think I can probably get one. Having never had one in hand, they seem kind of large as described though - all are listed at either 4in (101mm) or 3 11/16in (93.7mm) diameter. As I understand it, WW lathes are 50mm from spindle center to bed so it seems like the 4 inch faceplates would not have enough clearance. Could I expect the 3 11/16in to fit with a WW headstock and bed? What is a typical diameter for a faceplate?

Also possible the description of "4 inches" is only a rough estimate by the auction house and not actually accurate.

Example the 3 11/16":

I may have answered part of this - a lot of the listings on ebay from typical American lathe tool makers are specify about 3.75 inch diameters. Still I don't see any that specify 4 inches, but I am still guessing that is an overestimate by the auction broker.

[Klassiker]

Agreed, this is puzzling. Can you ask questions or inspect the lots before bidding? My Boley & Leinen Reform face plate is dia. 95mm exactly. It's possible that 4 inches is a slightly too large approximation, but why then make the distinction to 3 11/16 for the sake of 8mm? If the larger ones are truly 4" then they will clash with the bed, but then I have no idea which 8mm lathe would take them. All 8mm lathes have spindle height 50mm or less, as far as I know. The spindle height is, as you say, standard 50mm for W.W.

[mbwatch]

1 hour ago, Klassiker said:

Can you ask questions or inspect the lots before bidding?

I will email them to ask for an accurate measurement; they held an in person lot viewing a few days ago that I could not attend. There is so much I don't yet know, I could not assume that no 8mm lathe exists with a spindle height >50mm.

[caseback]

Both my ww lathes are a tiny bit over 50mm, so I guess 4" should just work. And, if needed, using a bigger lathe to reduce the diameter is easy.. If they're cheap: go for it!

Edited Tuesday at 05:23 PM by caseback

[mbwatch]

1 minute ago, caseback said:

Using a bigger lathe to reduce the diameter is easy.. If they're cheap: go for it!

Well I guess I'll have to buy a bigger lathe at this auction then! (there are many, many of them available)

[caseback]

You can never have too many lathes...

[mbwatch]

So far there are no bids on the faceplates, while almost everything else has several bids. So I am hopeful they'll stay cheap. There are several Levin cross slides too probably for less than ebay prices, but I don't know that I'll be able to spend that much at this time.

[nickelsilver]

WW is 50mm exactly. Levin, Derbyshire, Leinen, Boley Lorch and I'm sure most others making machines based on the WW standard are all 50mm. Marshall/Peerless are 2", or 50.8mm height.

 

Many lathe beds are slightly relieved in the center, so it could be possible to swing something a little over 100mm. More likely is the auctioneer had measured with a tape measure and called it 4" when it's like 98mm.

[Klassiker]

58 minutes ago, caseback said:

Both my ww lathes are a tiny bit over 50mm

I measured the Reform, and yes it is >50mm; somewhere between 50.5 and 50.7mm. This is measured using pieces of bar stock resting on the flats of the bed, under the lowest point of the faceplate. Still not enough for clearance on dia. 4" though.

If the axis of the headstock were centred over the bed, then the channel in the middle would allow a fraction more clearance, but it's not, not on the Reform anyway.

1 hour ago, mbwatch said:

I don't know that I'll be able to spend that much at this time.

Buy low, sell on ebay!

Edited Tuesday at 06:28 PM by Klassiker
Additional info about the measuring method.

[caseback]

35 minutes ago, nickelsilver said:

WW is 50mm exactly. Levin, Derbyshire, Leinen, Boley Lorch and I'm sure most others making machines based on the WW standard are all 50mm. Marshall/Peerless are 2", or 50.8mm height.

 

Many lathe beds are slightly relieved in the center, so it could be possible to swing something a little over 100mm. More likely is the auctioneer had measured with a tape measure and called it 4" when it's like 98mm.

You're right. My first measurement was done using a guessometer (calipers). 

My 88,8mm diameter faceplate just clears a 5,6mm stack of gauge blocks. So: exacly 100mm. 

The relieved center might indeed give you a bit extra.

But, stepping a bit: It wouldn't make sense for a faceplate manufacturer to make a faceplate that wouldn't fit most 8mm lathes. So 4" is not very likely.

Edited Tuesday at 06:53 PM by caseback

[mbwatch]

3 minutes ago, caseback said:

But, stepping a bit: It wouldn't make sense for a faceplate manufacturer to make a faceplate that wouldn't fit most 8mm lathes. 

Exactly, that's why I wanted to ask.

[LittleWatchShop]

Try to get one with the centering pin. They are often missing.