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Member postings for duncan webster

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

Thread: M5 x 0.5 threaded bar supplier
19/09/2018 00:43:09

make a die holder to go in the toolpost and then you can power feed the die at the right pitch. Relying on the die self feeding will guarantee pitch error which might or might not matter. If you have a travelling steady you could screwcut it down to say 3/4 depth then finish with die

Edited By duncan webster on 19/09/2018 00:43:29

Thread: Cycle chain drawing
19/09/2018 00:40:21
Posted by HOWARDT on 18/09/2018 20:42:53:

The circle command is TTR, tangent-tangent-radius.

But you don't know what the radius is, you need ttt

18/09/2018 19:57:20

The easy way is to use the ttt command in CAD. This gives a circle 13.66 diameter centred 9.08 from the centreline.

Otherwise I think you are into Algebra rather than Geometry.

call the radius ofyour big circle R. The distance from centre of big circle to chain pin is (R+4.25) From centre of big circle to centre line between pins is (R+2.25), so by Pythagorus (R+2.25)^2 + (12.7/2)^2 = (R+4.25)^2 which can be easily solved as te R^2 terms cancel out.

Thread: Small Carronade model - 68 pdr.
16/09/2018 10:15:47

No confusion, the recipe calls for both

Thread: Arc
15/09/2018 23:20:51

If we're getting into politics (I thought that was banned?) perhaps after March Ketan will have to be Arc Not Trading With Europe

Thread: Small Carronade model - 68 pdr.
15/09/2018 22:20:34

Looking at ebay, sodium nitrate is quite expensive, potassium nitrate is quite a bit cheaper. It is used in curing ham amongst other things. No idea whether it would work as well, perhaps some chemist out there can comment

Thread: Beer and Grapefruit
14/09/2018 22:04:36
Posted by SillyOldDuffer on 14/09/2018 21:42:57:
Posted by Neil Wyatt on 14/09/2018 17:04:27:
Posted by SillyOldDuffer on 14/09/2018 10:44:27:...

May you spend eternity supping on a creamflow nitro-keg...


Mmmm, full of sugary goodness. A flamboyantly forward brew with a hint of ripe peach, refreshingly doux, bright, austere, and unerringly voluptuous. Sadly it's a refined delicacy impossible to appreciate without a having a well educated palate. The enigmatic delights of fizzy beer are rarely valued by rough beardy men...


I'm on the verge of being offended (see my photo)

Thread: Small Carronade model - 68 pdr.
14/09/2018 21:07:47

found the brew on the interweb, as I said liquids boiling at 140C. I wouldn't try this on the kitchen stove, if it works let us know**LINK**

Thread: Beer and Grapefruit
14/09/2018 20:28:04

When I were a lad there was a pub in Arncliffe (Yorkshire Dales) which had the barrels in the cellar but no pumps. When you wanted a pint the barman would shout 'anyone else want one? and disappear carrying an enamel jug. Absolute nectar.

And as for Silly Old Duffer and his Watney's Starlight, I'd suggest washing your mouth out with soapy water but if you'll drink such a diabolical brew you'd probably enjoy it.

I also remember Lump Hammer Bitter and Desperate Dan Cow Pie from when I had a contract running at Thompson Nuclear. You definitely didn't want 2 pints at lunchtime, evenings another matter altogether.

Thread: Small Carronade model - 68 pdr.
14/09/2018 20:14:01

I have a recipe given to me 40 years ago for a witch's brew containing sodium nitrite and caustic soda (from memory). This is to be made into a strong solution which boils at considerably more then 100C. Sounds like a recipe for disaster to me which is why I've never tried it but if you're interested let me know and I'll try to find it. I have a vague idea where it is! If you do decide to try it, use a bit of scrap first, it would be a shame to mess up all your excellent work. I'm assuming it is steel, if cast iron all bets are off.

Thread: Beer and Grapefruit
14/09/2018 08:37:18

Those of us in the north west will remember Greenalls. Horrible stuff. When they stopped brewing the chief brewer set up Coach House. It's in a wriggly tin shed on an industrial estate so you don't expect much but it is really good. Other good ones in the area are Wood's Shropshire Lad and Titanic Plum Porter.

What I do find silly is transporting beer hundreds of miles, it's 95% water and we've got plenty of that. I had some Doombar last week, all the way from Cornwall. It's good stuff when I'm down there on holiday, but either it doesn't travel or (more likely) the pub had let it go off.

Thread: Boiler terminology
13/09/2018 16:58:52

Our North American brethren would call this 'foaming', which is a much better term. See article at


for a good description. It often happens in new boilers, the residues of flux etc seem to set it off. Seems to settle down after a few changes of water

Thread: Speed Controller - Mini Lathe
07/09/2018 19:30:47
Posted by Martin W on 07/09/2018 09:45:54:

A much more worrying aspect about this is that it appears that the NEUTRAL line is fused instead of the live line. If the fuse was to blow it would leave all the electronics at mains, 240VAC, potential which could prove lethal.

In this state the lathe will not comply with basic standards and certainly it will not comply with european/UK regulations. I would demand a full refund and get the seller to collect the lathe. If UK based then I would also raise this with the relevant trading standards authority.


I've bought stuff form China where red was connected to neutral pin and black to live. A simple continuity checker would reveal all. I've also bought kit made in China but bought from UK which had a UK style plug but without a fuse. Trading Standards never got back to me so whether they followed it up I have no idea.

Thread: How to cut a 2mm slot in this?
07/09/2018 19:21:31

I like Tim's suggestion but it looks as tho the ends would have to be thicker to get some sensible size bolts through.

Failing that how about 4 pieces of stainless silver soldered together

Thread: Putting correct profile on someone elses wheels
06/09/2018 00:18:44

There is an SMEE standard for wheel profiles in various gauges. It appears in Tubal Cain's 'Model Engineer's Handbook@. I mean the real Tubal Cain (TDWalshaw) not that American upstart.

Thread: The size and shape of drill holes
06/09/2018 00:13:38

If you want a reamer for a through hole machine a slanting flat on the end of a piece of silver steel and harden it then stone the flat. I don't know how it works, but it does

Thread: Never Throw Anything Away
05/09/2018 23:55:55

More then 40 years ago I scrounged an impeller from a Rover gas turbine. About 20 years ago I threw it away. Now I want it to make a blower for my little Topsy organ. NEVER THROW ANYTHING AWAY

Thread: sch 40 pvp pipe
05/09/2018 23:53:51

Looks like the sort of thing we used to make when I was a scoutleader, use a length of timber (a pioneering pole in ScoutSpeak)

Thread: bridgeport spares stockists
05/09/2018 23:49:48

There is a company in Bridlington who refurbish Bridgeorts, they might be able to help


Thread: What did you do Today 2018
04/09/2018 10:18:28

I trust we're to look forward to an article in MEW about anodising. I'm making some bits in ally which would look a lot better black.

Edited By duncan webster on 04/09/2018 10:18:47

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