lathe to cut 26tpi

I restore british motorcycles so a new lathe that can cut cycle threads is needed.

any recomendations would be welcome regards Bob

Hi Robert,

Welcome to the forum. You don't say what your budget is but may be a lathe with a 10 in. swing, and I assume you want an imperial version if you cut a lot of imperial threads. If you want a new lathe the Warco 250V is one option and seems to be available in an imperial version. A second hand British made lathe in good condition would be another option.

Thor

Hi Robert welcome to the forum. I don't know what expectations you have or what budget or evan the space that you have but for working with motorcycles may need a larger size lathe do you can pass such things as a fork leg through the spindle. Many of the smaller lathes can cut both imperial or metric threads but I get the feeling that you could be better off with a slightly larger stand alone lathe just check that it comes with the change gears to cut both types.

David

The Imperial 250 does not secifically list 26tpi on it's chart but it should not be too hard to work out a gear train to give it.

Really any lathe will cut 26tpi or very close to it depending on what gear train you use.

Welcome Robert, I to restore British motorcycles and agree with David George re size of lathe. Mine is a 14"x40" with a 40mm spindle bore and is ideal for bike work without being to big to fit in the garage with the Bridgeport mill. As Jason says most lathes will cut 26 tpi but you will also need to do 20tpi as well as other pitches if working on later bikes. Where are you based ? I am not far from Lichfield in the Midlands if you want to see the set up. Chris.

thank you all who replied

I trained as an apprentice fitter turner in a machine tool company northeast england in the late sixties so now semi retired but still do all machinining in our workshop. The lathe we were using was a boxford 4 1/2 aud mk2 which we had from virually new but has suffered catastrophic damage during a fire and building collapse, all is now fine but I need to fit out new workshop.

I have talked to Warco they have told me that only the WM280v or the GH type of lathe they stock will cut 26tpi due to the unavailability of the correct size of change gears on the smaller lathes. Chester say the 920, craftsman and larger GH lathes will do 26tpi

I unfortunatly have no experience of the new lathes listed above and finding a decent old lathe is proving difficult. The boxford was a small lathe but did most things we needed. any advice or recommendations on the above or other lathe types are welcome

regards bob

Hi Robert,

I have a Chester Craftsman long bed lathe which will cut 26tpi straight off. It cuts quite a wide range of threads,both Metric and Whit,and has a 1 1/2" bore. Might be wort looking at.

Not sure of the pitch, I think it may have been 20tpi, but it was the second job I did on my metric BV20.

Sadly the thread cutting chart on the lathe gave me the wrong change wheels so I had to have a second attempt using the wheels given in the instruction manual!

The very first job was making a smaller pulley for the lathe so I could slow it down to cut the thread.

Might help if Robert could give a few more details, like budget, size of parts, and how hard the machine will be worked.

I own a Warco 280VF and - although it's a hobby machine - I'm happy with it. It's about the same size as an AUD but somewhat more lightly built. It has a more powerful motor (1500W) and a wider speed range - 30 to 2500rpm. I guess it's on the small size for motor bike parts should they have to fit through the headstock - the spindle is only 26mm inside diameter.

I've found the machine fully effective for hobby work, that is it isn't worked hard all day every day. Though capable it's not as well finished or as solidly built as a Boxford. Whilst it's simple 3-speed gearbox saves some time I'm always swapping change wheels - a full gearbox and a clutch would be nice.

The Warco is better featured than an AUD, but I'd expect the Boxford to have more stamina and to be less fussy about maintaining tolerances. In short, the Chinese lathe is probably best across the range unless you have to work accurately against the clock. A Boxford's advantages become more obvious when time is money. Of course this assumes the Boxford is in good condition. If you can't find a good one, fixing it up will become a project in its own right!

The GH is a step up from the 280. Not used one, but it's bigger and has more time saving conveniences. Similar comments about stamina apply - the Warco and similar Chinese machines are built down to a price, a new industrial-rated machine of similar specification is 6 to 10 times more costly.

If you take your time and know how to spot junk, decent ex-industrial machines can be had at good prices. As buying secondhand is always risky you might buy a new Boxford. Otherwise Chinese new is a good choice provided you have the workshop time needed to get the best out of it.

Dave

Edited By SillyOldDuffer on 15/01/2019 14:15:26

Most of the import lathes at the moment with knob type gearboxes are designed to give some metric and some imperial threads for any given arrangement of change wheels unlike a Norton box giving you all imperial or many metric at one set-up. Inevitably when you want two threads on one job the second thread will require wheel changes.

Rather a poor show for Warco to say the gears are not available. They should be making sure they are available.

It's not clear if you are spending your own or the company's money. If it was your shop burned down then commiserations. I think as a pro you should be looking at an M300 or Colchester.

There is no reason to stop you buying off the shelf MOD gears to get the tooth numbers requiired in much the same way a Myford owner may need to buy extra gears.

It may also be a question of what can physically fit on the banjo, I know when I have cut 26tpi on my 280 it was quite a close fit for the train using the supplied gears but I could probably have got round that by adjusting with aftermarket gears.

I love my chipmaster, cut both 19tpi (1/4 bsp) and 13 tpi (1/2 unf) straight off the gearbox. Mine replaced a Boxford AUD and I’ve never looked back.

Also check the pressure angle of any additional change-wheels match too.

£8900 + vat for a new Boxford and they put cheap crappy hand wheels on the machine!

Perhaps Boxford spent the money on the important bits

.

My apologies for drifting off-topic, but I continue to find this assertion [from Dave's linked page] 'interesting'

[quote]

The only manual lathe you can buy which is still truly Made in Britain

[/quote]

.

MichaelG.

I think most of the Colchester roundheads will cut 26 tpi out of the box, certainly my student and the Dominion will, and we know from above post that the chipmaster will, so how about a bantam or a student?

My Bantam had 26tpi on the gear chart.

thanks for advice

It looks like a choice of Warco 280v or Chester Craftsman for new or secondhand Boxford etc, I am going to look at a secondhand boxford tommorow so wish me luck. my budget is £2500/£3000

regards Robert

Am sure that a Chester Craftsman would do what you want. You may be able to find a secondhand Warco BH600, or Engineer's ToolRoom BL12-24. All have a 38mm bore Mandrel (5MT, but should come with a 5MT - 3MT sleeve).  All three are almost identical other than the paint job.

As I recall the BH 600 was available either Imperial or Metric, the Craftsman was Metric, and the BL12-24 is Metric, but dual dialled. (I work in Imperial almost all the time)

The swing is 12" over the bed, with 18" if the gap is removed.

They are heavy, 300Kg and should come c/w 3 and 4 Jaw chucks, Faceplate, Fixed and Moving Steadies.

Bedways are Induction hardened.

In standard form these are 12 speed machines, a 2 sheave Motor pulley driving a 3 sheave pulley from countershaft to the Mandrel, plus Backgear.(which gives a range of 6 lower speeds)

(Having VFD, my BL12-24 has only 6 speeds + Backgear, all varied by the VFD).

On one of these, with a 3mm pitch Leadscrew, the gear set up, for the Norton Box for 26 tpi is

40:120/127:40 C -7.

With a 8 tpi Leadscrew the set up is

40:127:40 with the Norton box set to C - 7

The Leadscrew is only used for screwcutting, for Power traverse, there is a separate power shaft.

If you need the warning, Cycle threads are 60 degree, whilst B S Brass are 55 degree Whitform.

Howard

Edited By Howard Lewis on 15/01/2019 21:48:23