SQ 51- Why the gap

[WaggaSteve]

I see many lathes have a gap in the beds at the tailstock end. Makes sense if the idea is to allow for larger bowls(for example) still supported by tailstock but almost invariably the gap is too short to allow for much work and often (once chuck engaged) none. What am I missingbedgap.JPG

[NCArcher]

There is probably more room using a face plate rather than a chuck.

[smiife]

I see many lathes have a gap in the beds at the tailstock end. Makes sense if the idea is to allow for larger bowls(for example) still supported by tailstock but almost invariably the gap is too short to allow for much work and often (once chuck engaged) none. What am I missingbedgap.JPG

Hi steve, yeah I was going to say the same as the archer
Screw the faceplate straight on to the headstock!

[Lumber Bunker]

Even with a faceplate, I'd imagine that the timber would be limited in thickness? 25-50mm???

Quick search pulls up this

old lathe.jpg
with this quote from the advertising

"On all versions the base, bed, headstock, tailstock and tool rest of both models were properly made in cast iron and, unusually for a wood lathe of that size, the bed was fitted with a gap that allowed work up to 15.5" to be turned. The swing (over the bed) was 12" and the capacity between centres was a very useful 38". "

http://www.lathes.co.uk/walkerturner

[orraloon]

More room to use a spanner on face plates or chuck perhaps. It also would allow the banjo to slide off at the headstock end. Just my 2c worth as I have never had a lathe with that feature.
Regards
john

[soundman]

Remember big bowls are not realy functional pieces ....... most of those older lathes with gapped beds where commercial items ...... most lathe work until recently would have been commercial and functional, done either between centres or on a faceplete.

There are many functional archectrual uses for large flat turnings ( ceiling roses, door knob surrounds). Much wood turning was also used in patterns for metal casting ..... again reasonably flat items like wheels, brake drums and hubs.

The large turned bowl and the chuck are a reasonably recent artificat of artistic and hobbyist turning.

cheers

[Lumber Bunker]

That's some logical input right there.

[NeilS]

The early jawed chucks (Tenatool's pre-SuperNova and the Bonham) that were contemporary with those lathes that had the bed-gaps were relatively 'shallow' compared to the later deeper chucks, like the one in WaggaSteve's photo.

With the shallow chucks you could turn the bottoms of a shallow bowl on a faceplate and then reverse onto one of those early chuck to turn the insides of the bowl.

The spindle heights on those bed-gap lathes were often only 6" and the gap allowed for a slightly larger diameter bowl/platter than 12". With deeper beds and swivel headstocks the gap is an artifact of the past, although the Vicmarc VL600 prototype lathe had a variation of that system.

[joe greiner]

... It also would allow the banjo to slide off at the headstock end.
Regards
john

I've used mine only for that purpose. With the nut retracted just to the bottom of the eccentric bolt, the entire banjo can be removed in one piece without further disassembly.

Joe

[Paul39]

Wadkin in the UK made some serious gap bed and sliding bed pattern makers lathes:

http://www.lathes.co.uk/wadkin/

http://i927.photobucket.com/albums/a...IMG_0080-1.jpg

As did Oliver in the US:

NOT For Sale my collection/inventory - Oliver #66-AC Pattern Maker's Heavy Gap Bed Lathe, 1950. Swing is 30" w/ gap closed and 48" w/gap open. Between centers is 6' 6" w/gap closed and 8'6" w/gap opened. Got this from a foundry up north that was going to scrap it! The lathe hasn't been used at all for 17 years, and looks like it wasn't used much before that. I also had the somewhat rare opportunity to speak with the retired patternmaker that used this lathe, that was really cool. We replaced headstock bearings and converted to oil bath bearing while we were at it. What a great call that was, it was well worth the effort because now it runs unbelievably smooth! I am listening to my son and we are keeping this one for the big gun in our shop. Yes that is a pen mandrel; he had to be the first to turn a pen on an Oliver #66.

http://www.hesswoodwork.com/5-15-201...20ps%20500.jpg

http://www.hesswoodwork.com/5-23-2011%20030%20ps%20500.jpg

From: http://www.hesswoodwork.com/machinery.html

[Uncle Al]

Thank you for a most interesting post. The last link ( From: http://www.hesswoodwork.com/machinery.html ) is a must read for anyone interested in old machinery. I would love to have one of the 'Snowflake' bandsaws, they look absolutely awesome!

Alan...