Hi Nick,

Welcome to the forum. My small lathe is without a gearbox but I don't cut threads that often so it is not a problem for me to set up the correct change wheels for the few threads I cut. If you often cut threads with different pitches a gearbox is very handy and it will also be easy to set different feedrates. If you can find a Boxford Model A or a Bantam in good condition and at a reasonable price you will get a good lathe.

Thor

Welcome to the forum, Nick.

A lathe with a leadscrew benefits from more than just threading operations, the finer thread pitch settings are useful for simple turning giving a power feed for the saddle (carriage) in both directions. The lathe that I use can cut threads down to 76tpi and 152tpi if the change gears are selected to halve the leadscrew speed. That is down to 0.013" and 0.007" per turn of the spindle. This particular lathe also has a feed screw which will allow power facing and turning down to 0.001" per turn, but that feature is normally confined to the more sophisticated and expensive types.

For your particular size of work, the Myford range would be ideal.

Gearbox for me also, much more convenient also able to vary feed rates easily.

Tony

I got used to a Colchester Triumph 2000 at work for my motorcycle tinkering, great range on the gearbox suited me. On retirement I sold my old Southbend "Heavy Ten" And bought a 14" x 40" Exel lathe, a good machine but a real faff some days with the change gears. Sometimes cutting 20/24/26 TPI the change gears can be left alone and the gearbox used, throw in a few other pitches and metric it becomes tedious. I don't mind the actual changing over of gears but the faff to get them meshed quietly sometimes annoys me. So a gearbox gets my vote if it will cover the range you require.

All the lathes you mentioned also require the changewheels to be moved around for metric threads or imperial if the other version, even those with a QCGB.

Nick, see if you can find a good Bantam, aside from the gearbox loads of additional good features. I saw a nice one advertised recently but cannot remember where.

Chris Gunn

Gearbox wouldn't be top of my list because maybe the money is better spent on something else, like a lathe that's in better condition.

Remember it's a not a gearbox, it's a SECOND-HAND gearbox, history unknown. Make sure it's in reasonable condition, because missing teeth, knackered bearings, bent shifters, broken shear pins and oil leaks can turn a nice-to-have into a basket-of-pain.

Likewise, when buying a second-hand gearbox-less lathe, make sure all the change-gears and banjo parts are present and correct. Much easier to correct than a trashed gearbox, but finding or adapting change gears for old lathes isn't painless.

I'd much rather spend £2000 on a basic lathe in good condition than an iffy machine with all the bells and whistles.

Jon Lawes said 'Better to spend the extra and be wrong than not spend it and be wrong..' Dubious advice I fear, because buying second-hand is risky, like betting on horses. You shouldn't bet the farm on a nag just because the winnings will be maximised if it comes home, and if it should happen to win you'll regret not going all out. The odds and amount of money spent make no difference, what really matters is the state of the horse. Ditto old lathes.

Dave

Where would I find such a list? I'm not sure how useful it would actually be, as one of the main reasons for screw cutting is when you have to make a one-off part with a thread you don't have a die for. Or one that is too big for your tools, like the M20 threads I had to cut on a clapper bolt

If its sewing m/c parts mainly, you will be needing some peculiar thread pitches, some metric, some imperial and some (like Ba not simple multiples). Do you need a lathe as big as a Boxford etc, and just a small precision lathe. Gearbox lathes can by use of additional gears cut just about any thread form different from the standard gearbox set. Again, do you want an imperial or metric lathe.

From the net, I found that :

Singer used fraction of inch and normal TPI pitches, Nähnorm 100 also, Practical Machinist indicated that most machines used imperial measurements (But was that for older machines ??).

If you have decided on Myford or Boxford, then there is only one choice. BOXFORD with a gearbox – Ha Ha, I am biased though.

Yes, an ELS is a distinct possibility for me.

A gearbox is very convenient for the feeds and pitches in the standard setting of the box, anything out of the standard range and you will be back to adjusting the gear train driving the box. Some people will probably never need to use anything other than the standard range but if you regularly swap from metric to imperial then some drive train changes will be needed. Electronic motor driven lead screws are generating quite a bit of interest and commercial options are available but will still require the motor and encoder to be mounted on your lathe.

Mike

I would vote for the Boxford AUD (as I have one). Whichever lathe you choose make sure it comes with the possibility to cut metric and Imperial threads. For example you need a 100/127 gear ( or a variation of) for an Imperial Boxford to cut metric threads. Also if you go for the AUD make sure you get the change gears that should be with it. Not sure on the Myford but plenty of members can point you in the right direction.

regards