Looking to buy a Metal Lathe

[porker]

To learn I would buy some aluminium and something like EN1a free cutting steel. You will pay a bit for it in small quantities from online sources unless you can get some bar ends locally from a machine shop. The reason I recommend this is because as a newbie there can often be a load of reasons for poor cutting or finish and one of these is a nasty bit of metal that won't cut well so I would eliminate this straight away and start with a known quantity.

Sent from my SM-G920F using Tapatalk

 

[graduate_owner]

I bought a Mazda Demio about 18 years ago and that had indicators and wipers the opposite way round. It was a bit of a pain because our other car had the usual layout. I can well remember the time an oncoming car made a dangerous overtaking manoeuvre and nearly hit us - boy, I didn't half wash my windscreen at him.

K

 

[Keith 66]

You have made a good choice, i have a Boley & the build quality is light years in front of a Myford or far eastern lathe.

 

[sunnybob]

you will have trouble finding a lathe that will do what you want for less than double your stated price range.
Theres another very important point I doubt you realise.
Just about every thread on a japanese motorcycle is in metric fine (1.25tpmm).
Standard metric thread, also known as metric coarse (1.5tpmm),is what all normal threading machines are set up for, and will NOT screw into a motorcycle part.
Yes you can make spacers on the lathe, but the only way to put threads on any thing would be to buy a metric fine bolt and weld it on.

 

[Wildman]

you can thread any sort of thread with a coventry die box assuming you can get the right dies for it, all of the old /cheap machines will be imperial not metric so watch out for that as well.

 

[graduate_owner]

You can get gear wheels that will allow imperial lathes to cut approximations to metric threads. According to the conradhoffman website you can use 127 and 100 tooth wheels, or 47 and 37 tooth wheels for a slightly less accurate approximation. 80 and 63 is another combination. These apply to 8 tpi imperial lead screws. I have seen new 80 and 63 gears for sale on the Myford.co web site for about £50 inc VAT. I don't know how easy the others are to get hold of though. So if you need to cut metric threads all is not lost with an imperial lathe. I suppose these are the sort of bits that you accumulate as time goes on and the need arises.

K

 

[chaoticbob]

In principle you can cut any metric thread on a lathe with an imperial leadscrew (and vice versa) if you have a 127 tooth changewheel, as graduate_owner says. Reason being that an inch is (by definition) 25.4mm and 127 and 2 are the only prime factors of 254. Whether you can source the wheels and fit them the space available in is another matter of course....

Given what the OP is intending to do, I wonder if screwcutting capability is really that crucial - anything up to M12 (coarse or fine) I'd be reaching for taps/dies.
Rob.

 

[woodfarmer]

In principle you can cut any metric thread on a lathe with an imperial leadscrew (and vice versa) if you have a 127 tooth changewheel, as graduate_owner says. Reason being that an inch is (by definition) 25.4mm and 127 and 2 are the only prime factors of 254. Whether you can source the wheels and fit them the space available in is another matter of course....

Given what the OP is intending to do, I wonder if screwcutting capability is really that crucial - anything up to M12 (coarse or fine) I'd be reaching for taps/dies.
Rob.

It is not always as easy as that. My Holbrook has a 42 tooth wheel on the input spindle which drives the reversing mechanism and eventually exits onto a 42 pitch wheel on the leadscrew input shaft. This goes through a gearbox which gives me about 24 different pitch threads. A 127 wheel on the leadscrew shaft would not give me any metric gears at all. I wanted 3.5mm and to get this a 43 /12 tooth wheel is needed with 7tpi selected Alternatively I could use an 87 tooth wheel and select 3 1/2 tpi which would be close enough. However that is the only metric pitch that an 87 tooth wheel would give me. (leadscrew is 1/4" pitch). Would need different wheels for different pitches and then only approximate. Metric threads are the work of the devil. Not sure then if the multi start would work although both rh and lh threads would be fine.

 

[SChop]

you will have trouble finding a lathe that will do what you want for less than double your stated price range.
Theres another very important point I doubt you realise.
Just about every thread on a japanese motorcycle is in metric fine (1.25tpmm).
Standard metric thread, also known as metric coarse (1.5tpmm),is what all normal threading machines are set up for, and will NOT screw into a motorcycle part.
Yes you can make spacers on the lathe, but the only way to put threads on any thing would be to buy a metric fine bolt and weld it on.

I only really touch old English or American stuff and would retap where nessary
Where there is a will there's a way

 

[DTR]

I've cut metric threads on my Myford with just the standard set of gears (20, 25, 30 etc up to 70), albeit using two 20T gears. Yes there will be some slight inaccuracy but that only comes into effect over long lengths of engagement. For typical fastener lengths the error is negligible.

Having said that I agree with chaoticbob; taps and dies are the easiest way unless it's some kind of special job. In my case it was cutting an M14 x 1mm thread into some kind of kryptonite alloy. The die wouldn't touch it :?

 

[SChop]

you will have trouble finding a lathe that will do what you want for less than double your stated price range..

I do believe I have found the exact one I want and not too far off my budget from a very kind chap on here might need a little attention to a couple of the gears but looks to be perfect for the job

Thanks also everyone for your advice and interest much appreciated

 

[Wildman]

I suggest you start with aluminium, which is cheaper and cuts fairly easily, but needs sharp tools for a good finish. Lubricate with WD40.

A mill attachment on the lathe is fine for light work.

I have a potts milling spindle I would sell no idea of price though but it is same sort of vintage as the Drummond (M) and almost certainly featured in Lawrence Sparey's book " the amateurs lathe" a brilliant book by the way that has never been bettered.