Member postings for Martin Dilly 2

This sparrowhawk turned up last year for a light lunch of woodpigeon

Oldvelo asks earlier in the Trump thread what one on Trump has to do with model engineering. I suggest that it’s a lot more relevant than this thread that follows it, about ANZAC Day, which, incidentally, I found most moving. Remembering Gallipoli is unlikely to get the world involved in a major military conflict, whereas having an unstable ignoramus in charge of a nation with probably the most potential to destroy us all, model engineers included, needs our attention. If focussing our attention on this via a spot of humour upsets the religious offenderati then I suggest listening to some of Christopher Hitchens or Bill Maher’s pieces on YouTube might change their perspectives.

Presumably the need for thread-tensioning droplets only applies to outdoor webs, with things like wind and insect movement to compensate for. Indoor spider webs don't seem to have such droplets, as they mostly operate in still air. A very interesting video; I assume the silk is attracted to the surface of the droplet by surface tension. Does the spider produce the droplets, I wonder, or just wait for a spot of rain? Probably the former if the principle is observed in arid areas.

I personally wouldn't touch British milk chocolate with a bargepole of any length; cloying, yucky stuff with a minute trace of chocolate in it. Interestingly some years ago the EU was, very sensibly, planning to refuse to allow Cadbury's mile chocolate to be so described, but instead it was to be called chocolate-flavoured confectionery as it contained so little actual chocolate. Not sure what happened though.

For my money any chocolate needs to be at least 80% chocolate, and Lidl's 85% is pretty good in my book. Why, by the way, do we now see high percentage chocolate described as 'dark chocolate' rather than 'plain' which it always used to be called?

Bob Well's horrific land yacht accident was actually at Bassingbourn Barracks, which was the airfield during the War where the original William Wyler documentary Memphis Belle was shot. Bob didn't actually lose the leg but was very seriously damaged. Most of London free-flight moved there after the M3 made Chobham Common unsuitable for contest flying.

Only slight thread drift here. The media have a great deal to do with the average British person's perception of engineering. So often on radio or TV people refer to 'the creative professions' and you just know by that they mean theatre or art or music or ballet or literature, and probably think the chap lying under their car clutching a greasy rag is an engineer. In fact the one really creative profession, without which absolutely none of the rest could exist is, of course, engineering. Without it there'd be no theatres built, no paper or canvas, no musical instruments or recording, no dance floors and no printing presses.

Thanks for the suggestions, gents. I'm in the Croydon-Bromley area, in case an orderly queue wants to form to buy a couple of sheets of this. I'm pretty sure it's not Dibond, as it's consistent through the thickness and has no obvious surface treatment.

Is there any way, apart from paying a fortune for metallurgical analysis, that I can make an educated guess about what I've got? It produces more of a clunk than a ping when you drop a piece!

I've acquired a couple of sheets 5mm x about 4 feet square of light alloy left over from a water-cutting job producing letters for a shop sign.

I'd like to sell this as it's taking up workshop space but have no idea how to describe it. It's a bit 'puddingy' when drilled or milled, so probably isn't anything high tensile. Any suggestions please as to what it might be (or indeed offers to buy!)?

A bit of a pause there while other projects came along. However, I've made a fairly crude version of the two-bricks- and-a-torch hearth shown here: https://www.youtube.com/watch?v=ifTIuNt3aNY

However, I have a problem. When I fire up the propane torch and introduce it into the hole the flame goes out.The torch's air intake holes are outside and clear of the brick. The main internal width is around 2 inches, but it's not actually circular in section. I suspect it may be connected to the flame point 'bouncing back' from the wall it faces; if I leave the top half of the hearth off all's well till I put it back, at which out goes the flame. Suggestions welcome.

Good idea, John, but sadly our Ideal boiler, which would have done the trick I'm sure, got the heave-ho in 1987 when we installed central heating.

Thanks to the rest of you, too. I suspect it's a case of chinesium, which may defeat my best efforts.

Many thanks, gents, for your rapid and helpful replies (and for figuring out what on earth 'hedat' meant). It may well be a low grade steel, but I thought it worth trying to see if it hardens. At present you can scratch it with the tip of an X-Acto blade.

I've bought a set of El-Cheapo woodcarving chisels and want to try hardening and re-tempering them. I need to get them to cherry red before quenching. I have a gas stove and a butane torch, but using both together doesn't quite get the metal up to cherry red. Any suggestions as to how to get things a bit hotter, short of building a furnace?

Success at last! A friend suggested a spot of heat might help. I gave the quill about five minutes blasting with a heat gun, applying it all round the circumference, and a light tap released the collet. The quill was barely warm but that did it.

So thanks, gents, for the suggestions, but there's another one to add in case anyone else has a similar problem.

Thanks, Howard. I've just realised that, even if I can dislodge the collet from the taper it will still have the headless drawbar screwed firmly into its top end! Luckily the Hobbymat mill has a head that can be rotated to about 45 degrees, so it ought to be possible to get the whole thing out.

I know it's a rather old post, but I was a bit concerned too about the fan intake being so close to where I was producing a lot of dural swarf, which occasionally got sucked into the works of the fan motor. I ended up making a very crude sheet ali. shroud that held onto the grille with a magnet, so it could be easily removed if the work in the chuck required the outside of the jaws to protrude so they'd have hit it.

Many thanks again to those who've come up with more possibilities. One difficulty is that the drawbar minus its hex head is jammed in the threaded hole in the top of the collet taper, so the top of that is all I can tap, smite or batter. I suspect its slight flexing when hit may reduce the shock load on the actual collet.

Many thanks, gents, for the replies, and so soon! I'll go and have another try later. Meanwhile a bit of belated Googling suggests that a Y-shaped wedge applied between the business end of the collet chuck and the quill might help to force things apart without applying hammers, lump, lead or otherwise.

Thanks for the input, Bill. I should have mentioned that the cutter is still in the milling collet. As far as I recall each end of the collet is a blind hole anyway. I'll try to get the cutter out anyway; reducing the mass of the whole stuck unit may not be a bad plan anyway, and it'll avoid having to have something soft to catch the thing when/if it eventually comes out.

I have a Hobbymat milling machine with a bit of a problem. After doing some work on a rotary table I now find the milling collet is jammed in the taper. I normally unscrew the drawbar a few turns and give it a slight tap and out it pops. This time nothing happened and when I unscrewed the hex nut on top of the drawbar a bit more the nut came off. I suspect the thread on the nut has stripped to some extent, as when screwing it back on it now just keeps turning.

I thus have only the end of the drawbar to tap. I'm reluctant to use anything harder than my lead hammer, and have left a good squirt of WD-40 in there overnight in the hope that it might seep down and free things up. So far no change.

Any suggestions that don't involve buying a new machine would be most welcome.

That seems to have tightened things up a lot. Apparently there were two editions of the manual and mine does have the right screw labelling after all.

Next project is a possible fine feed adjustment for the Hobbymat mill; reaching round the back and cranking round the wheel at the top is a bit of a pain, and the pump handle's pretty unreliable.

Many thanks again for your help. You've made an old lathe very happy.