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Member postings for Tim Stevens

Here is a list of all the postings Tim Stevens has made in our forums. Click on a thread name to jump to the thread.

Thread: Unusual Watchmakers Tool?
27/10/2021 17:55:25

The round copper object could possibly a token from the days when no-one could bring themselves to speak in an outright manner. We still don't have a name for the process by which we void waste, and this is the proverbial 'penny' that we claimed to be 'spending'.

Cheers, Tim

Thread: Mysterious Russian Emails
27/10/2021 17:24:55

They might not be random letters. There are several systems in use for turning letters and numbers into digital messages. So, your message may have set off in Russian or at least Cyrillic (to match the picture text) but was not understood by your computer - which did its best but produced garbage.
Some words in this system you are reading now come out in odd characters - especially for punctuation, fractions, etc.

Cheers, Tim

Thread: Wanted - Someone to make some screws
25/10/2021 17:41:17

There are 10mm screwdriver bits with 1/4" hex fitting. And adaptors for hex drive to 1/4 square. And ditto with 5/16 hex and 3/8 drive.

There is no distinction between engineering and ingenuity.

Cheers, Tim

25/10/2021 17:35:46

A thought -

If a supplier is not willing to supply because sending arms abroad is forbidden, order them 'For repairs to a Vintage Car'. It is not clear how a screw can 'always' be identified as 'arms' - what happened to the American idea of interchangeable parts?

Hope this might help

Tim

25/10/2021 14:30:17

Hello from Wales

Changing the length is easy, as long as it involves removal of metal. Other changes are not so easy, it depends on what shape you need, what shapes are available in that length, and what material. So, if you can offer a sketch or a photo of what you need, as well as some detail of what it is for, we can offer further (perhaps better) advice.

Regards, Tim

25/10/2021 14:30:16

Hello from Wales

Changing the length is easy, as long as it involves removal of metal. Other changes are not so easy, it depends on what shape you need, what shapes are available in that length, and what material. So, if you can offer a sketch or a photo of what you need, as well as some detail of what it is for, we can offer further (perhaps better) advice.

Regards, Tim

Thread: Sewage dumping
24/10/2021 12:16:30

The system will not be changed until it causes the death of the children of rich folk. For evidence supporting this view look at the delayed response to the Cholera epidemics in victorian times.

Which actually is when most of our sewer systems were built. Now, they are well overdue for a rebuild, and the population has grown significantly.

Cheers, Tim

Thread: Correct Drill Bit For 3/8 UNC Tap
24/10/2021 11:50:31

from the Machinery's Screw Thread Book:

3/8 UNC - 99% = 7.6mm, 94% = 7.7mm, 89% = 7.8%, 5/16" = 82%, 8mm = 78%,

8.1mm = 73%, 8.2mm = 68%, 8.3mm = 63%, 21/64" = 61%

Cheers, Tim

Thread: Saving the Planet or is it ?
23/10/2021 15:45:57

This started with a comment about 10p bags for life. Waitrose now say : Our new 50p bags are twice as durable

So that must mean they last for two lifetimes. Look out, children, they are an investment and you may need to pay death duties if you inherit one. Or could it be that the bag-for-life lasts exactly as long as a bag-for-life lasts?

Cheers, Tim

Thread: Oxy propane welding kit
23/10/2021 14:54:32

Actually the residue from Calcium Carbide - yes, its calcium hydroxide - is really excellent as an absorber of carbon dioxide. The result is limestone. So, taking that process alone must be good for the environment ...

But of course, the science must be looked at in the round, not in isolation. Carbide is made by heating lime with coke, and the lime is made by heating limestone - giving off carbon dioxide. Yes, exactly as much as will be absorbed in the carbide residues.

The big problem with model boilers is that they are made from copper, and so draw the heat away very quickly. And it is difficult to hold the bits firm while surrounding them with insulation.

Cheers, Tim

Thread: Lathe query.
21/10/2021 17:48:03

If your garage is covered by your house insurance, it might be necessary (or at least helpful) to get the electrics checked by a qualified electrician, and a form signed saying what he checked and found OK. Unless of course you are such a bloke, in which case you ought not to need to ask questions like this.

Just a thought - its your garage and your life, after all.

Cheers, Tim

Thread: Painted granite surface plate
21/10/2021 17:33:13

For the record, Granite does indeed include a large proportion of silica - its the light crystals which can be milky or clear which are silica, and they wear least.

BUT - Basalt is finer grained, yes, and is made up of mixed plagioclase-feldspar and pyroxene, and perhaps some olivine. Very little silica or none. I'm sure Wiki will tell you more.

The main character they both have, as surface plate material, is inertness, stability, and readily available in fairly big lumps.

Cheers, Tim

Thread: Vice
21/10/2021 17:19:41

Look, we (who incidentally cobbled English together over 1,000 years), left the EU because we could be doing with their standards. So we don't look kindly on ex-colonials who forget that their own standards were only invented about 100 years ago.

There, nothing censorial about that, is there?

Cheers, Tim

 

Edited By Tim Stevens on 21/10/2021 17:20:09

Thread: Clattering Backgears
20/10/2021 11:02:38

If the back gear assembly is not in perfect balance, and is going round in gear but not actually driving, there will be a tendency for clatter as the clearance between the gears is changing sides (as the out-of-balance is pulled down on alternating sides by gravity). To test this, put a small load on the back gear spindle - perhaps by pressing a piece of wood against the plain shaft - and see if this reduces a) the rattle and b) the striping. To balance the shaft properly involves setting it (away from the lathe) so it can rotate completely freely - on a close-fitting shaft between new rolling bearings, perhaps. Then, allow the heavy side to fall to the bottom, and mark it. Then remove metal on the heavy side - or add to the light side, until it stops in any position with no tendency to settle in one place. It takes time, sorry. Or, find a way of moving it out of mesh when you are not needing it.

Cheers, Tim

Edited By Tim Stevens on 20/10/2021 11:07:58

Edited By Tim Stevens on 20/10/2021 11:08:10

Thread: Cutting Brass Sheet
20/10/2021 10:34:10

hello Brian

To straighten your brass sheets you might need to anneal (soften) them by heating to a dull redness, and allowing to cool. Then you could use a press to compress each sheet separately between two flat thick blocks of steel. A big vice might do to apply pressure if the pieces are fairly small. It really depends on how flat you need them, and the surface finish you are hoping for. Annealing to soften the sheets will (of course) reduce the stiffness and springiness, and reduce the shine. The length of time in a press is not significant - if nothing happens at once it won't help to leave it overnight.

Hope this helps

Cheers, Tim

Thread: Machining Cylinder Head Chamber Roof - DIY or Shop Tool
18/10/2021 11:42:33

When surface grinding, or fly-cutting a head to restore a flat surface, it is (of course*) necessary to keep all four chambers the same volume. It can be tempting to take a bit more off one end to rectify damage, but you don't want an engine with four different compression ratios, only to be rectified by a head gasket tapered in its length. No, I don't know where you'd get one, either.

* I say of course to pacify the purists, but my explanation is not for them. They know it all already.

Cheers, Tim

Thread: Reproduction ivory look hand grips
18/10/2021 11:28:10

Celluloid is indeed cellulose nitrate. Just remember that if ever you need to clout a pre-WW2 steering wheel ...

Tim

Thread: 316 Stainless
18/10/2021 11:20:01

You need to be a bit careful what you order, Steve. There is a lot of 'construction' steel about which is used for building roofs, etc, and it welds wonderfully but is difficult to machine in hobby workshops. If you order 'bright mild steel, leaded' you will pay a bit more but you'll get what you need.

And leaded means it has metallic lead in the recipe, so it machines nicely. Pronounced leddid, not leedid.

Regards, Tim

Thread: Seal selection
17/10/2021 18:28:14

Let me guess - the mag drives a magnetic pick-up, this triggers an electronic device (in the mag or separate) which feeds a coil the secondary of which is fed to the distributor on the mag spindle. If so, I would be interested in the design of the pick-up. I have a four-cylinder version of a Lucas mag with the same mods, for my 1928 Lea Francis Meadows engine, which has served well (so far) but I hope to sort a more adjustable pick-up.

Now your question: As long as the final feed to the plugs relies on carbon brushes (as early mags and two-cylinder versions often did) there should be no problem of corrosion arising from a fully waterproof sealed  system. This is because you should have no sparks generating corrosive gases. With the later mags and more modern coil distributors, though, there is a rotating spark gap which requires the space to be ventilated. Behind the radiator is usually dry enough, but of course not in your vehicle. I add this detail for anyone else with the same concerns but different.

Do get in touch if I can help further.

Tim Stevens [bobweight@btconnect.com]

Edited By Tim Stevens on 17/10/2021 18:31:07

Thread: t-bar material advice
11/10/2021 18:11:16

It seems a good notion (to me, anyway) to relate the sizes of new fittings added to a machine to the 'standard' thread system used in the manufacture. In other words, a new bolt added to a Myford should be a Whitworth size, or a BSF thread, for a mod to a post war Colchester use A/F Unified sizes, for modern stuff Metric. Then you have a better chance that the tools you keep handy anyway will serve, and if you always put such spanners away immediately in the slot on the wall where they fit, then you will know which set of slots to look in.

Cheers, Tim

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