The Barker lathe – see lathes.co.uk – used round bed components in a rather different way and was also "triangular".

The really clever bit of this round bed,is the ability to rotate the saddle to adjust the centre height above the crosslide.

The round bed is much cheaper to make than the more complex patterns required for a conventional lathe bed, most of the work on the bed could be done on a lathe.

Ian S C

As always its a matter of striking a good balance between cost and capability given the needs of the intended purchaser, the depth of his pocket and the equipment in the factory.

In this case simple to make to good basic accuracy, versatile if the saddle and tailstock are made to rotate around the round bed. Major disadvantage of the system is that its intrinsically a right pain in the butt to get properly re-aligned after rotating things. Another, less than obvious issue, is that there are no reference surfaces. Everything is set relative to the (imaginary) axis of spindle rotation. Theoretically the sides of the slot under the bed ought to be reference but such are not accessible in normal use and, if the examples I have seen are anything to go by, are not defined in rotation relative to the spindle axis. Just longitudinally.

Of course in that day and age a conventional machine would have been unaffordable for the vast majority of potential customers. So the inherently fiddly nature and impossibility of truly accurate replication of set-ups had to be accepted. Modern multifunction machines aren't, in practice, that much better.

Two important things about then and there are often forgotten these days. First is the much greater relative expense of machinery in those days purely due to considerably less capable factory equipment requiring rather more direct, handwork, man hours at local pay rates. No cheap offshore or "China Inc". Secondly essentially no used machines around suitable for amateur use. So folk had to start off with a new machine. No working your way up market from something at saved paper round or first couple of weeks wages money dug out of your mates or Dads mates shed. (From Portass S with broken headstock bearing to Smart & brown 1024 over 35 or so years in my case.) Hence affordable new machinery was needed so significant disadvantages relative to "proper" designs were acceptable. Think below bottom end import mini-lathe today.

Things have changed. Here and now its a curio and, as a lathe basically total piece of crap. When I first got the bug back in 1970 a round bed was still marginally viable. But the world has moved on. A thing of its time and its time has passed.

Clive

Edited By Clive Foster on 02/06/2019 15:36:18

Although cheap compared to other lathes in it's day, it was still very expensive for the average worker, that's why a number of little lathes such as the Super Adept came out in the between wars period.

Ian S C

I have a Drummond round bed. I have graduated the hand wheels and cleaned and fettled the lathe. I find it surprisingly good, once you have got used to it. I don't find it difficult to set up either.

The one thing that lets it down is lack of a back gear. I wished I could find one of the aftermarket back gears that were made for the old round bed.

I have more modern lathes than the Drummond, but it gets used quite a lot, so that must say something about the lathe. Clive would probably say it says a lot about me!

Andrew.

The little unimat sl uses 2 round rails for the bed, I'm supprised at how rigid this setup is for such a tiny lathe. I,ve always thought a larger lathe based on this design using newer technologies like linear bearings could produce a very good economical lathe. You could eliminate the need for gibs for example! How nice would that be?

Edited By Hollowpoint on 04/06/2019 17:17:24

I have to put in a good word for the roundbed. A handy machine if used within reason and still very popular. You do need to bin the insert tools and learn to grind HSS . Also think rigid with all your set ups. I've seen so many forum posts about poor finish on old lathes and the problem is nearly always a carbide tool in a QCTP with more overhang than a pagoda. A good roundbed that's well equipped will still fetch a good price because it's capable, compact and light.

I find that I use insert tooling quite a bit on my Drummond roundbed, so don't dismiss it too readily, and yes they are HEAVY. A bare roundbed ie just the lathe without drip tray, motor or stand is about 50kg, definitely not one for carrying upstairs single handed. If you look at the long bed version (an extra foot in length) then the drip tray for that alone is well above any weight you want to carry.

That's one aspect of Health and Safety that I approve of. Split a load whenever possible and 25kg is ideal for most people except with 'lads' with something to prove.

My 'new' combo amp weight 43kg. Poor lad who sold me it got a mate to help him shift it.

When the old fart picked it up, carried it to the car and popped it in the back, his mate thought it was most amusing

Neil