Bad finish

Jason has hit it on the nail and others who suggest turning it as a 'knob'.

'Balanced handles' are much better.

Neil

No-one would think twice about using the power feed for plain turning, and the second photo shows what an excellent finish the OP has produced using this method. I can't see a problem using some sort of power feed for the top slide as I'm sure it would produce similar good results. All those advocating more practice at hand feeding - I wonder if you all use treadle lathes

For someone relatively new to turning, being able to produce good results is probably more satisfying than spending hours trying to perfect a technique that will, in any case, come with time as experience develops. So I suggest a quick try with a hand held electric drill + suitable socket to check that it is indeed the method of feeding which is at fault. And maybe his next project could be to make a motor drive for the top slide.

One problem with putting a power feed on the topslide is that if turning tapers with tailstock support it is very likely that the stepper motor or whatever is used will hit the tailstock , there is often not much room to get a the handweeel letalone motors and gears/belts and all those hours spend fitting a power feed will have been wasted and better spent on learning the basics of good turning.

Like others have said I was taught at school to use two hand on the rim of the wheel and it has served me well.

If you do want power feed cut for tapers then offset the tailstock or fit a taper turning attachment and use the provided carrage feed.

Edited By JasonB on 21/11/2016 13:11:42

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[quote] 'Balanced handles' are much better. [/quote]

Agreed ... provided that the size is appropriate to the user's hand size.

The photo that VCR kindly posted suggests to me that any type of 'balanced handle' would prove impractical.

[his best compromise, therefore, is probably to remove the little handle]

MichaelG.

An interesting experiment would be to remove the feedscrew and convert the topslide to lever feed.

[it might also come in useful sometime, as a slotting device]

I suspect that the finish would show a dramatic improvement.

MichaelG.

I agree with an earlier post that suggested stripping the top slide down, cleaning and lubricating then adjusting the gibs for slack free but smooth movement, rotating with the handle at consistent speed will produce a good surface finish. The same method works with a Unimat SL so should with the Emco 5.

Emgee

I certainly agree it is essential to get everything cleaned and adjusted to minimise play, but I have also found it sometimes helps if you apply pressure with the free hand on the top of the slide to help counteract any tendency for it to move as you turn the handle.

Obviously you can then ony use one hand for turning, but it worked better for me on my Unimat SL which was really too small to comfortably work two-handed anyway.

Mike.

Im with Jason use two hands or fingers, nice and smooth continuous cut and feel for whats happening.

Op's picky its ripped, that can be numerous reasons why. What you can do is take a reverse cut dragging cutter as a cleanup cut.

Looks like 6082 T6 to me evident with continuous strings no chip breaker will cure.

Thank you all for your help. I am convinced that the problem is not being able to achieve a smooth and continuous movement. I will disassemble, clean, lubricate and reassemble everything with care. I've also been training my hands and it's a little better. Soon I hope to have a better result and a photo to post.

Vasco Reis

On a mini lathe you can fit a short stub of allen key in a portable drill and use it in the securing screw of the top or cross slide handle to provide a slow, steady power feed for critical tasks. You may be able to rig up something similar for a Unimat.

I agree with others who advocate using the fingers of both hands on the wheel rather than the handles. I actually use this method on the cross-slide as well. And on the leadscrew when I can't be bothered with engaging self-act, eg on a short section, or where there might be potential for an unfortunate collision.

On my lathe, I have discovered that the tightness of the 4-way tool post clamp can significantly affect the topslide. Too tight and the topslide becomes very stiff to move. Obviously there is some flexibility on my lathe causing this, but with the toolpost clamp correctly adjusted, it isn't a problem.

Another idea is to use a HSS tool with a slightly rounded cutting point.

Cutting in the reverse direction is, I believe, a combination of the above (HSS) idea and a blunt tip, it being sharper in the "wrong" direction.

Finally, I always use paraffin on aluminium for finishing cuts, especially as I have a quantity of electrical grade, ie almost pure, aluminium. For roughing, I don't bother too much with the paraffin, but using it I can get a very smooth finish. The downside is that it's smelly!

Regards,

Peter G. Shaw

No doubt the main cause of the poor finish on the taper is uneven feed rates. However, the finish on the parallel portion under power feed, while better, isn't perfect. It may be a trick of the light, but it seems to have light and dark bands, I'd expect the finish to more uniform. That implies that the cutting process is unstable. So it might be worth looking at the basic cutting parameters (insert type and height, depth of cut, feedrates, rigidity of the set up etc) before going to the trouble of powering the top slide. It ought to be possible to get a decent finish by hand feeding.

Andrew

Neil,

Vasco has the Emco 5 lathe so I believe he will need a socket rather than an allen key, also a smaller socket for the DB or SL.

Emgee