Member postings for ega

Jacques maurel:

Wot, no animation? Great concept - have a ball in 2016!

"The Wilson lathe apron shown in the post above by Ega appears to have one either side of its single half nut"

Lathejack: Yes, quite right. The place of the "missing" half nut is taken by the TDI pinion when this is engaged (just visible in my photo).

Roger Head: see PM

Edited By ega on 03/01/2016 10:10:46

I think it would be normal to provide dedicated lubrication to this area. My photo shows the inside of the apron on my Willson slantbed: the small hole at one o'clock above the large bronze worm gear houses an oil pipe fed via nipple from the front and which drips onto the worm assembly. I believe that in its day, apart from the slantbed, this machine was conventional.

When I dismantled this I didn't find any swarf here although a misguided former owner had larded it with grease.

Roderick Jenkins:

Thank you for the gearbox table; at a quick glance the gearbox actuals seem to correspond pretty closely with the change wheel results.

Michael Gilligan:

"What a pity they didn't reduce the VAT inclusive price by 40p"

Well-spotted! You would almost think someone is having a laugh. Better yet if the price were £127.

Thanks for the NPL link which is a pleasing example of international compromise.

PS Has anyone calculated the corresponding "actual" column for the metric conversion set? It would be ironic if the (cheaper) standard machine is capable of greater accuracy.

As has been pointed out before, the alternative to the metric conversion set for gearbox machines is to use different spindle gears instead of the standard 24T.

Standard change wheel machines use two 21T gears. The metric conversion set does use a 21 driver but I think only for BA pitches.

Of course, one is free to use gears in any way that one chooses!

Roderick Jenkins:

Thanks for the table. The presence of the "Actual" column surprised me as my recollection was that Myfords did not include this (hence, perhaps, the uncertainty as to exactness). Having checked my edition of the manual (No. S.723N), it seems either that you have a different edition or have helpfully included a column of your own derived from Excel.

Can you please clarify?

Incidentally, I believe I mentioned the "not exact" point some time ago and it's certainly not new. My understanding is that a 127T gear would have to be involved to achieve theoretical exactness. The inconvenient size of the 127T gear has led to continuing attempts to find closer approximations but, as you imply, this has more to do with mathematics than engineering.

Neil Wyatt:

I sometimes think Postbag should have been called Punchbag!

Michael Gilligan:

Please see my PM.

Michael Gilligan:

"this conversion is not exact"

As you may know, his article elicited at least two lengthy and learned letters tp Postbag: one from GHT and another (quite critical) from A.Shackell. I did find the article interesting, however, not least because of the light it throws on the computing scene at the time.

Thank you both for the explanation. I have only sold one or two items on eBay and can't claim any expertise; but I do wonder whether it might be possible (and simpler) to list the number in stock as nil.

Michael Briggs:

"the blade lasted about three seconds"

Thanks for the warning! I use one of these blades on an old-style radial arm saw but have never tried it on stainless. The blurb on my blade doesn't mention stainless but I shall add a note about it in marker pen.

The blade (made in Japan) is otherwise excellent: a combination of thin kerf, chip limitation and, no doubt, choice of TCT.

Edited By ega on 28/12/2015 11:24:33

John W1:

Having noticed these "£900" offers on eBay in the past and been curious as to what lay behind them, I wonder if you can enlighten me?

Rufus Roughcut:

The source of your tables appears to be the ME article by Professor Cane at page 282 of issue 3628 which is well worth reading.

Tom Gullan:

Thank you for taking the trouble to explain. The wick, of course, contacts the spindle and I suppose there has to be radial hole in the bearing to allow this. I don't remember the grooves or their orientation and they don't seem to be shown in my copy of the manual but presumably they are axial ie parallel to the spindle.

Incidentally, one drawing in my manual seems to show the Mk 1 overhead oil reservoir.

Good luck with your replacement!

Tom Gullan:

You say you want to remove the front bearing. Can you tell us why?

When I had my well-used S7 headstock professionally over-hauled I believe the front bearing was scraped in in situ. Has your front bearing been damaged in some way?

John Haine:

"also fine for tungsten carbide" - Roy Child made the same point when I bought my wheel.

As someone said elsewhere on the forum HSS is a general label that covers a multitude of different formulations; I believe that the same is true for TC. These distinctions may not much concern the amateur, of course, and given the high price of CBN I imagine most will settle for one wheel that will work across the range.

Edited By ega on 22/12/2015 14:45:30

John Haine and Peter Connelly:

Thank you. I believe I may have bought the last of Peter Child's stock which was, of course, intended for grinding woodturning tools. I will follow up the Axminster and Toolpost references.

stan pearson 1:

"So do Loctite" - good to know and I'll bear that in mind.

Here's an example of what DHC had in mind: