Member postings for Chris Pearson 1

I am struggling to see the point of the OP. Is it to cadge a VFD, gauge opinion, or a combination of the two?

There is no need to be a registered competent person because that is to do with fixed wiring. (I was one once.)

It really is a matter of following the manufacturers' instructions and tidy workmanship.

When we moved here, 27 years ago, the house had no number. This was a nuisance because it never showed up on the databases without which some firms cannot cope. So we are now no. 1. Next door is no. 17.

Just to add to the confusion, a solicitor recently couldn't accept a water bill (the only one on paper nowadays) as proof of address because the address does not match - the postman always delivers it and I had never noticed. For the water board, we live in a different street entirely. And that street has been renamed, albeit many years ago.

Back to the OP: Evri are pretty hopeless, but I have also seen DPD and UPS drive past and be unable to find the address. There are only 12 houses in the entire street.

I have, I hope, learned to stop when I begin to get tired.

Same with me.

I was curious about the top slide gadget, but I wondered what it is for. A bargain if you ask me. I was surprised that the VSD was still working.

Alan, thank you for giving the matter further thought. I was beginning to think upon similar lines so when I have some spare time, I shall strip it down again and try measuring with a micrometer. I rather doubt, however, that an ordinary micrometer would be precise enough, but we shall see.

IIRC, there is no circlip groove.

IIRC, it is a pretty simple job.

The leadscrew covers are potentially dangerous, but if you take the saddle all the way in one direction, you can slip a cable tie around one half; and then move it the other way and do similarly.

Again, IIRC, the leadscrew and feedshaft are just withdrawn to the right.

Then you just unscrew the bolts which hold it to the saddle.

If you drain the oil first, you will probably make less mess.

The oil seals are perfectly standard and widely available.

HTH.

Alan, thank you. I have tried your suggestion, but unfortunately, it did not help.

If the closer (which isn't really the closer) is too loose, the red sleeve will reach the end of its travel to the right without closing the collet. If it is too tight, the red and blue sleeves are pushed back to the limit of their travel to the left and the lever becomes fixed.

The chuck works nicely for gripping the workpiece, but I can still not see any means of moving the red sleeve to the left.

This is v. frustrating, but I was only using it to obtain the best possible concentricity for a grinding wheel arbor, so I think that I can live with it.

I cannot even find operating instructions for any similar chuck. Surely there must be something out there!

Edited By Chris Pearson 1 on 06/11/2022 12:43:28

Thank you to everybody for your contributions - it has been a busy week and I did not expect so many after the lack of interest in my original posting.

I am not sure how much use photographs would be because they do not show the innards. However, if push comes to shove, I could disassemble again.

Instead of photos, here is a diagram, which is certainly not to scale, but I think does show the operation of the chuck.

The dark green is the spindle and the light green is the fixed portion of the chuck. The collet (grey) is held in position by the closer (yellow) and if it is not moved, then clearly the collet remains in the same position. Operation of the lever (black) moves the blue sleeve to the right and the taper pushes the balls (6) inwards. This in turn moves the red sleeve to the right. 1 inch of movement in the blue sleeve results in about 50 thou of movement in the red sleeve, and perhaps 10 thou radially of the collet. So as the red sleeve is moved rightwards, the collet grips the workpiece.

When the lever is moved to the left, the pressure on the balls is removed and the red sleeve is free to move to the left and release the workpiece. However, it seems fairly obvious, due to the taper, that springiness of the collet will not exert much force on the sleeve. Moreover, the red sleeve is a push fit in the light green one so there would have to be some positive force to move it to the left.

I cannot see how the chuck could have been assembled wrongly and I do not see how anything could have gone missing. Whilst there are witness marks to show the force of the balls to the right, there are none to the left.

Further contributions will be much appreciated.

Edited By Chris Pearson 1 on 05/11/2022 19:05:39

Edited By Chris Pearson 1 on 05/11/2022 19:07:09

I am having another go at this one please.

I have had the chuck in pieces and there is no possibility of assembling it wrongly. The sleeve which holds the collet is a very firm push fit in the body of the chuck.

Pulling the lever to the right squeezes 6 ball bearings inwards, which pushes the sleeve and collet away from the headstock and on to the closer. Pulling it to the left releases the ball bearings, but there is nothing to push the sleeve back towards the headstock so it stays where it is.

As mentioned previously, one option is to unscrew the closer. Another one is to give the workpiece a sharp tap with a leather hammer, and the third is to use the tailstock to push the sleeve back.

It still seems odd and I wonder whether anybody knows any more please.

Building Regulations (2010) or Wiring Regulations (BS 7671:2018)?

Fixed to a masonry wall will be fine, but not a wooden fence please. That is because a wooden fence may rot.

You need to know how to terminate it into the proper glands and of course, if you are fitting a new CU, it will need to be notified.

My apologies if anybody objects to my thread drift.

Myford is offering some taper turning attachments, which seem to have been cluttering up their shelves. £400-odd could be a lot for something which you use once or twice, but nice to have even if never economically sound.

Or get somebody with a small Myford to do it for you.

Dare I say that an adaptor can be pretty useful if you want to keep the workpiece centred in the chuck and transfer to the dividing head?

As others have suggested above, the 254 series lathes were fitted with a BS 4222 spindle nose. That defines the taper (1:4 on the diameter) and the PCD and size of the bolt holes. They are the same whether studs or cam-lock pins are fitted.

D1-3 back-plates fit the Myford spindle, but you will need to make up some studs with, as you have identified, an M10 x 1.5 thread. (The holes are 10.5 mm diameter.)

Then it gets more interesting. Don't assume that just because the thread on the spindle end of the studs is metric that the other end is. The cam-lock pins for a Pratt-Burnerd back-plate are threaded 7/16" x 20 UNF and not M11 x 1.25.

ETA: 7/16" x 20 = 11.11 x 1.27 mm. How do you think that I found that out? 

Edited By Chris Pearson 1 on 12/06/2021 18:20:05

There was a Myford 254 rear tool post on fleabay recently, but surprisingly, with a starting price of only £90 it didn't sell.

I am also very pleased with mine. It's about the biggest lathe that will fit in my indoor workshop. Anything bigger would have had to go in the garage, which does not appeal.

I think very much better than the 7" Myford, but no more expensive!

Edited By Chris Pearson 1 on 14/04/2021 18:24:33

One of the advantages of the 254 (plus) is that plenty of Super 7, etc. stuff can be used. The "elephant's foot" tool clamp, 4-way swivelling one, and "Dixon" one are common to both.

In practice, it isn't a problem, save when the pin which secured my parting off tool holder sheared. I am not sure that the baby lathe would have had enough power to do that - it might just have stalled.

Edited By Chris Pearson 1 on 13/04/2021 22:26:22

Neither "crossslide" nor "cross-slide" appears in OED. I suppose that the term really should be "across-slide".

Are you able to measure the frequency of the vibration (against spindle speed)? That ought to give you an idea where to look.

As far as I can recall, there is a wee hole at the bottom of the flange so that any oil which is carried into it may drain back into the headstock. There certainly isn't any form of rubber or scroll seal. The hole could be blocked by debris. I fear that dismantlement of the headstock may be required. Not an easy task!

I have recently acquired one, which has barely been used, if at all. Mine is the bespoke Myford one, so no backplate as such.

The adjustment is brought about by conical screws in the body bearing upon tabs which project forward internally from the base. If the body and base are clamped together tightly, it is difficult to see (i.e. IMHO impossible) how one could be moved over the other; but how tight is too tight?

On my particular chuck the screws which unite the body and base enter from the back, but with a separate baseplate, I imagine that they must enter from the front.

I have found that 1 Nm allows adjustment to be made with quite gentle force. 2 Nm makes the force a little more than I would like, but it is possible.

The next question is how tight do the screws need to be when turning? Possibly no more than 2 Nm. Remember that the manufacturers intend these chucks for grinding, so certainly not for roughing out. IMHO 5 Nm is plenty for a 4" chuck. The difference requires barely any movement of the screws.

If you don't have a torque driver, I would suggest that for adjustment, the screws be nipped up holding the short arm of a hex key between finger and thumb; afterwards just the normal good twist holding the long arm in the palm of the hand in the normal way.

HTH.