Lathe construction - desirable features to look for
There are dozens of lathes to choose from at prices ranging from less than a hundred pounds to over four thousand so where do you start? At the time of writing (March 2010) you can buy a decent full size "hobby" grade Far Eastern lathe for £270. It is unfortunately very difficult to obtain a lathe actually manufactured in UK (despite appearances, they are imported and then re-badged) but the Far Eastern engineering quality has improved immensely in the last few years so you would be OK at that price level. If you can, get a lathe with the following design features.
- Cast iron headstock and tailstock.
- Cast iron bed.
- Pivoting headstock with solid mounting, positive clamping and convenient means of returning the headstock to the "straight ahead" position.
- Solid bowl turning bracket or "extension arm" which does not flex.
- Secure and convenient locking, clamping and repositioning of toolrest, tailstock and barrel.
- Nicely shaped toolrest which adjusts 1/2" above and below centre height.
- Four speeds minimum with lowest speed 500 r.p.m. or lower. Highest speed 2000 rpm or higher.
- Variable speed system to save fiddling with pulleys and belts. Otherwise a belt and pulley arrangement that is easy to get at
- Dust proof induction motor of 1/2" H.P. minimum. Should have capacitor start and centrifugal switch for high starting torque.
- Push button switch with "no-volt-release" and sealed against dust.
- Heavy duty ball or roller bearings not solid or sleeve bearings. But see "bearings" later.
- Widely spaced bearings which preferably support both ends of the spindle.
- Morse taper sockets in headstock spindle and in tailstock barrel plus convenient means of ejecting taper fitted accessories. Number 2 Morse taper is better than number 1.
- Easy spindle locking (so you can unscrew the faceplate or chuck easily)
- Standard headstock spindle nose thread to enable you to buy chucks from a wide choice of suppliers not just the lathe maker.
- Register on the headstock spindle nose for true running of chucks.
- Tailstock with hole right through enabling you to drill flex holes in lamps using a lamp auger.
- Long tailstock travel for drilling and proper hand wheel which is easy to turn.
- Good reliable make. Well known makes have better resale value.
- Good dealer backup and spares availability.
Features to avoid
- Light sheet metal construction.
- Spindle with a bearing at only one end.
- Tailstock with threaded barrel which rotates in the housing when you tighten it.
- The necessity to use a spanner to reposition toolrest and tailstock.
You will be lucky to get all the good features above combined in a budget lathe (under £400) and the quality of the engineering will be - lets say - a bit third world. The motor and electrics will be a bit iffy (not unsafe but rather primitive) and the finish on the castings may be poor. However there are decent lathes with all the features necessary for a starter lathe for under £400 available imported from the Far East. You must expect some cheaper components such as the motor being the inferior "capacitor start and run" type instead of the higher performance "capacitor plus centrifugal switch" motor. Nevertheless it will do a fine job and thousands of these lathes have been sold in the UK and they are giving their owners a lot of pleasure.
Many budget lathes incorporate a mechanical lever operated variable speed mechanism which saves handling vee belts and pulleys every time you want to change speed and these work very well. However If you want the best system which is an electronic variable speed control with an inverter then you need to add around £300 to £400 as these fancy boxes of electronics are still very expensive.
If you want something better quality - nicely finished heavier castings with a ground bed, a proper capacitor start motor with plenty of starting torque and a decent standard of engineering, then there is quite a jump in price - expect to pay nearly £1000 for a machine that you may never need to upgrade. Top of the range lathes aimed at the serious enthusiast range from £2000 to £4000.