In the past they were usually pressed on. These days it's usually a close fit plus a high-strength retainer, which makes quartering driven wheels a little less fraught.

Neil

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Me too [especially as I have it in stock]

… but I think Neil is being honourably even-handed.

MichaelG.

Edited By Michael Gilligan on 14/08/2018 10:29:51

I dare not use the L-word qualified by a number or not!

I got chucked out of B&Q for going round with a sharpie writing 'retainer' on everything…

Neil

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Would that have been a Sharpie, Neil … or just some generic fibre-tipped writing instrument being passed-off as the real thing ?

MichaelG.

Does this mean we'll stop writing 'I machined it on the Myford' and just use lathe instead?

I think Clive Hartland is referring to what is often known as a Dutch key with half the thread in each component. Given the inevitable thread clearances and the probably unquantifiable distribution of tightening loads between each component I often wonder what the actual strength of such threaded keys is when compared to more conventional keys. Or even a simple round pin held in place by a bolt and washer. Whenever I've tried to think rationally and thoroughly about it the result has been a "whole bottle of whiskey hangover" strength headache.

So far as additional mechanical retainers applied to a loctite joint my understanding was that any such usually reduced the strength of the joint. Often quite significantly due to stress raisers et al. The absolute strength of a properly made loctite joint is surprisingly high due to the relatively large area over which loads are carried.

Weak point of all adhesive systems is peel strength as very high loads can be applied over near negligible area at the angle between the two components being separated.

Clive.

Edited By Clive Foster on 14/08/2018 13:50:59

Am NOT a loco man, but realise that the wheels on each side of a steam loco must remain in the same relationship to each other to ensure freedom of movement. (In an extreme case, a two cylinder loco would not be self starting).

With regard to the strength of anaerobic sealants, they can be extremely strong. For many tears cars have been manufactured where the crown wheel is secured to the differential by such "adhesives", happily transmitting upwards of 100 bhp to the wheels.

In my own experience, I bought two ER chucks (ER25 and ER32) for use on the lathe, but had to fabricate backplates. Having smeared very old anaerobic retainer over both faces, the ER taper was clocked and tapped until running true within 0.0005", before tightening the retaining bolts. Some years later, I obtained and machined some Backplate castings to suit the ER Collet Chucks. Having slacked the bolts on the original set ups, it was impossible to remove the ER chuck from the fabricated backplate. (Stopped when I began to fear damaging the chuck with the strength of the blows from a copper/hide mallet) WAY past its "safe to use " date, but the retainer was extremely tough. So does anyone want a couple of 2.25 x 8 tpi threaded cast iron backplates?

Howard

Experience suggest a real Sharpie is essential. I think I scored 2 out of 4 for the last lot of 99p ones…

Neil