Member postings for David Standing 1

I have suggested useful reading material to Chris on more than one occasion, he has not responded.

Book 6 in the Workshop Practice series, Measuring and Marking Materials, by Ivan Law, would answer this question too.

The preferred option appears to be to bombard the forum with questions instead.

Have you done a search?

This question is asked about twice a week........

Where are you located Chris?

I can only suggest, once again, you buy the five 'Workshop Practice' books I listed in your 'materials' thread.

Harold Hall's Metalworker's Data Book, no. 42 in the series, contains a huge amount of info on threads, and more.

The books are as cheap as chips on eBay, and worth their weight in gold.

I have two copies of no. 42, a dirty working copy in the workshop, and a clean reference copy in the man cave indoors.

Chris

Do you have the 254 manual?

Silly comment, but if either the cross feed lever (10) is raised, or the leadscrew feed lever (9) lowered, either will lock the apron/saddle from longitudinal movement.

Is the saddle clamp screw (15) slackened off?

Also, do you need to slacken off the gib strip at the rear of the saddle (1)?

You didn't read Ian's post at 09:23:55 then?

Jason

You are right, and I should know that, having old British bikes and rebuilding them!

Ian

Plenty down here too!

My guess it was wedged deliberately - their shape means it is unlikely one will flip up if driven over.

Did you park in a multi storey car park prior to discovering it?

Ah, 'hippy crack', N2O - you have no doubt parked in a quiet corner of a public car park, where the sniffers gather.

I suspect some smart Alec deliberately wedged it under your tyre at an angle, so it did what it did and penetrated the tyre.

Richard

The constant pitch threads are just a subset within Unified, as are UNS, the specials. They aren't in common use, but a standard does exist for them.

As you correctly stated earlier, BSCY is also a constant pitch thread at 26 tpi, as is BSB (Brass), which, although also 26 tpi, is confusingly NOT the same as BSCY!

I have a number of reference books I use for for threads - Machinery's Handbook, Kempe's, Newnes, IMechE, but my go to first choice for the most common threads is normally Harold Hall's Metalworker's Data Book, no. 42 in the Workshop Practice series.

Edited By David Standing 1 on 28/08/2019 09:51:57

You probably have heard of UN threads.

UN stands for Unified, and is is the standard US thread standard.

Within that you have UNF (unified fine)

UNC (unified coarse)

UNEF (unified extra fine)

UNS (unified special - custom/non standard UN threads drop into this category)

Chris

Buy some reputable books on the subject, and have a read!

I don't mean that facetiously, but look through the 'Workshop Practice' series of books, everything you need is there, start with nos 3, 30, 34, 42 and 45.

I agree, and to to reinforce Vic's comment, if you have a 'slightly sloppy spindle' and poor finish, why is the collet chuck so far from the headstock?

Jed

If you don't mind me saying so, you have much more than desirable tool protrusion with that setup in the penultimate photograph, and are only clamping the insert holder with two screws, which is because you have to pull the tool holder out to clear the other tool holder dovetail on the tool block.

If you turn the toolpost 90 degrees and use the other tool dovetail, you will have around 10 mm or more reduced tool protrusion, and a more rigid setup, with correspondingly better results.

Yep, exactly what I was going to say!

Stevie Wonder?

Ketan

Please add my best wishes to Adam for a speedy recovery.

Have you tried the manufacturer - 600Group/Colchester Machine Tool Solutions?

**LINK**

Barrie

And obviously my borrowing/lending books comment was not pointed at you, Christopher, or anyone else on here

Same here. Have had a few fallings out over exactly that in the past (books that were borrowed from me, in one case the borrower having subsequently 'lost' it).