EW lathe tailstock taper

[IanTParticipant @iant]

Yes, the chuck revolves counter clockwise when turning – and thank you for sharing your DC motor set-up.

Martin Cleeve wrote a long series of ME articles about improving the EW and I scanned them a long time ago. A few people here have requested copies and if you would like them too, then please PM me with your email address.

You will also find some potentially useful EW information here:

Norge – EW

Regards,

 

IanT

 

[SillyOldDufferModerator @sillyoldduffer]

The treadmill motor brings great responsibility – don’t abuse it!  Given the size of the lathe, I’d expect it to have been fitted with a ¼HP or ⅓HP motor.  The treadmill motor is way faster and more powerful than the lathe was designed for.  Roughly equivalent to me fitting a 22litre Merlin aero-engine to my sensible little car without upgrading the brakes, suspension, cooling system, clutch, gearbox, or tyres.  A roll-cage would be good because I’d be off the road at the first bend!

Three risks:

• the big problem with high power is what happens in a crash.   The treadmill motor is powerful enough to bend the lead-screw and tool-post, break cogs, twist the bed, scour bearings, and stagger the motor mountings.  And mangle the operator horribly if he gets caught in the works.
• high power tempts the operator to take deep cuts that might overstress the machine.
• high speed wears the bearings out.   Rule of thumb this type of lathe, about 1000rpm max.  (lathes.co.uk quote top speed of 606rpm)  Over-speeding rarely causes instantly obvious problems so don’t assume all is well just because it seems OK!  Bearing life is reduced. By how long life is reduced depends on the specific design of the bearing, the speed, how often, for how long, and the load, but one that would have lasted for 20 years at 1000rpm, is done after a few months at 4000.

On the other hand, having plenty of power and torque means spindle speed isn’t quite so critical – makes the lathe a bit easier to operate.  Just be careful with it!

Dave

 

 

 

[jarvParticipant @jarv]

Hi, point taken about the treadmill motor. I wouldn’t even go anywhere near full speed with it. I have proven the fact that in the event of something jamming the belt slips on the motor pulley.

Ive added an emergency stop switch similar to a conveyor where it’s placed to tap it with your knee as your hands may not be free, mine is placed so a slight twist in the hips means an instant stop(I removed the flywheel from the motor due to concerns with run on).

[old martParticipant @oldmart]

My little 7 x 12 lathe at home came with a 1/2″ chuck which is much too big for it and I have an 8mm chuck for most work. Leaving a little slack in the belts is always a good idea especially when getting used to the lathe and don’t forget that the plain spindle bearings were probably intended for around 1000rpm maximum. If the chuck screws on, then be very careful in reverse which could be used at very slow speeds say 60rpm when thread cutting. Also if there is any control of slowing down when stopping do not set it to stop very quickly because the chuck might unscrew itself.

[jarvParticipant @jarv]

Hi Mart , I have a new small chuck here that I previously bought 1.5-10mm.

It says B12 on the box so I’ve ordered an MT1 to B12 arbour. Thanks to all you guys I think I may be starting to talk lathe language! after all I didn’t know anything about tapers MT1 or B12 without your help.

I am looking at tachometers now, The treadmill starts at 0.5mph on the display, the chuck rotates slowly but I’d like to know the actual RPM and how it changes with each 0.1mph increment.

[Nigel Graham 2Participant @nigelgraham2]

A very wise precaution, that emergency stop-switch!

There is one on the controller for my Myford lathe’s 3-phase conversion, but it is hand-operated, inaccessible to a knee – and the instructions say it is for emergency use only as routine use could harm the unit. Normal stopping is with a separate red button.

 

I think I’d put some sort of physical limit on the maximum speed on any sort of electronic control I used for my EW lathe, so I could not accidentally or by temptation, run it too fast. No doubt that can be done by modifying the electronics itself but I’d likely need use a control-knob with mechanical rotation-stop.

 

Amplifying Old Mart’s point, and assuming conventional right-hand thread-cutting, the tool should be retracted from the work before returning it to the starting-point for the next cut. (For any but very shallow threads it is usual to cut threads in a series of depth increments.)

That will remove the braking effect that could encourage the chuck to unscrew. Nevertheless, running a lathe with screw-on chuck in reverse, should always be done with great care as the chuck’s own inerntia could be enough to loosen it.

To be honest I’d not worry about screw-cutting until you have gained more experience with general turning, because although it is not ever so difficult it does come with its own subtleties and peculiarities.

 

[IanTParticipant @iant]

I mostly use taps and dies to cut threads in the EW, as it’s generally smaller work. I have used a change wheel setup to cut an oversized thread but not under power. The fixed engagement of the leadscrew makes this tricky and I used a handwheel on the back of the spindle to do it. This is another very useful accessory for any small lathe by the way.

Regards,

 

IanT

[jarvParticipant @jarv]

Thanks for that Ian. There’s certainly a lot to think about. I will try and find an ideal top slide and tool holder. Then there’s vertical slide, The milling equipment, The tooling, Gauges, the die holder etc etc(can’t see the list would ever end!!

Do you think it would be possible to use the lathe to make dovetail cuts to make a slide myself?

How do I know what angle, The quality/make of tool. I also don’t know what you call the strip in the dovetail slide that the adjuster screws meet up to or if it’s made of certain metal.

I have received my back copy of Model Engineer and in 1957. £105 would get you a lovely new lathe

[Howard LewisParticipant @howardlewis46836]

Have sent a PM

Howard

[Howard LewisParticipant @howardlewis46836]

The chuck normally rotates anti clockwise when looking at it, so cutting forces will tighten the chuck

The danger of the chuck unscrewing comes when the lathe is run in reverse and a cutting l.,oad applied, such as using an inverted parting tool in the front toolpost, or stopping the lathe suddenly, which some electronic control systems can do, especially the Emergency stop!

I can help advise you on making a Centre Height Gauge, if you wish.

If you have, or intend to get a 4 jaw independent chuck, you will need a magnetic base and at least one DTI

Howard

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