Member postings for gerry madden

Thanks for the good leads !

Mike - I'm glad you said that about the coating. In the past I have tended to remove the enamel by gripping it between fine emery paper. I had a feeling this particular wire wouldn't be strong enough for this technique and when I tried it on a short sample, it proved it ! A flame, ....excellent.

Gerry

I have found the coil in this 1960 mains electric clock to have gone o/c. (It was working fine when it was last used in 1995 and I was looking forward to using it again in my new workshop. Typical!)

I did wonder about attempting to re-wind the coil myself but the wire is so fine I can hardly see it, never mind feel it. So I think such an attempt would be a disaster. (I have measured the wire to be around 0.065mm diameter)

So I'm just wondering now if anyone knows of a source for a replacement ? The coil is approx. 30mmL x 17mmOD x 1/4"(square)

I imagine (and I may be totally wrong !) that the electrical characteristics are not too critical just as long as doesn't draw too much current.) Please let me know if the coil laminations and rotor need to be closely matched in order to function. If so, I might need to think about a quartz movement but that's just MORE batteries and therefore doesn't appeal so much.

Gerry

Sorry Robin, you sneaked in while I was typing

Michael, oh dear, we seem to be going all around the houses on this one! For your straightforward question the straightforward answer is this:

The energy of a lump hammer head falling freely from a height and landing on its target can be found quite simply by: m x g x h For example 2kg x 9.81 x 2metres = 39.24 Joules.

In practice the bloke swinging it will accelerate it a little more than 'g'. A rough estimate could be 30%. So 1.3 x 39.24 = 51 Joules.

Of course it wont be 30% when he's done that a few times though, and more importantly your machine can deliver it's energy probably multiple times a second for as long as you want.

As you say, all the other things are by and large, constant.

Gerry

Looks like I'll have to bite the bullet and start filling with Arditex or similar, then and rub it all back. Hopefully I'll only do this once.

Thanks for all your comments.

Michael, yes you are right. Many seem to have a protruding rim and I thought it was this that was preventing the paint etc from flowing into the hole and filling it. So I ran some sandpaper in a block over the surface to find that many didn't have a rim at all ! This type, one might think, would help the paint run in but it doesn't seem to make a difference.

Does it matter ? Functionally no, but its the spoiling the ship for a hap'orth of tar thing. I think the knifed in filler might be the way ....but 20 sqm..... thats going to take some time.

For interest I've just brushed in some aircraft dope (as a trial) that I had on the shelf for 25 years. Its low viscosity and seems to go in the holes but then up comes a bubble which skins immediately due to the high volatility of the solvent. These then need rubbing down.

Gerry

Edited By gerry madden on 10/07/2023 14:10:44

After a lot of debate I had my workshop flooring completed with a self-levelling latex material. Its actually much harder than I imagined, not cold to the touch, and doesn't seem to chip with tool impacts. I expected there to be some permanent set / indents where heavy objects rest on it for a long time - but it doesn't do this either! So generally I'm very happy with the choice of material.

What I'm not happy with is the finish. I believe that the builder mixed the resin too fast and filled it full of air bubbles. On laying it, these managed to rise to the surface but the material set before the hole was filled by inflow. The result was a myriad of pock-marks. The pic below shows how it looks ...

At the time I wasn't too worried by this as I expected a final coat or two of paint would easily fill up all the holes. Yesterday I started on the floor painting but had to stop as the holes just wouldn't fill up, regardless of what I tried !

I experimented with my technique. Vigorous brushing or flooding the area with excess paint seemed to work initially, but by the time the paint had set the holes were back. In an effort to get some flow into the holes I diluted the paint. This was equally ineffective.

Convinced that lowering viscosity was key, I treated some small areas with a runny cellulose lacquer. I poured it out on to the floor then tried to 'card' it into the surface and force it into the pocks. Even this didn't work properly and on subsequent painting, most of the original holes annoyingly re-appeared.

I can't be the first person in the world suffering from this and feel there must be a simple known solution or product that can rectify 20 sq.m. quickly. Does anyone have any suggestions ?

Unfortunately, I cannot add a new substantial layer (i.e. millimeters) of anything as this will create a step somewhere, and I don't want this. In any case, the builder applied 3 layers to get the thickness I needed (40mm), and the bubble holes he created in the first layer, seemed to persist right through the second and third ! .....and no I don't want to call him back to rectify the job. After two months of them being in the background making noise and asking endless questions, its nice to have peace and quiet again

Gerry

I thought I recognised that !

It's a miniature replica of a bell in the temple at Kamakura, Japan. I purchased mine in 1985 on my first trip to Tokyo. Mine is currently in regular service. It gets rung out of the kitchen window when I'm in the workshop and a meal is ready. Contrary to expectations, it does have a very clear and loud ring, hence its current employment.

You never know, they might still be in production.....

Thanks all for taking time to comment but as SOD put it, its still as clear as mud, at least to me ! In the most recent occasion that this issue occurred (that prompted me to make this post) it was with a pdf. I think, everything I read refers to word documents.

None of the '3 files' is ever readable to me so I cant work back and work out what caused this to occur. There must be some special conditions at play as this isn't the norm when I save files. Let me see if I can find the conditions that reproduce the fault and I will come back for more help.

Gerry

mmm... I'm still wondering about this statement. Keeping it simple, if 'vacuuous' vessel under a hydrostatic pressure suddenly just disappeared, the velocity of the fluid would be zero at that time and point. It has mass, therefore it accelerates. It must be the fluid at the boundary of the collapsing cavity that has maximum velocity, as it has nothing to stop it. The velocity of the fluid crossing the original boundary line will drop off quite quickly due the diminishing flow-rate, as the cavity volume tends towards zero.

My thinking is that if this chap wanted a headline to give to the baying press, he would quote that of the 'final velocity' of the fluid at the very centre of the vessel/cavity, and not that of the fluid "entering the imploding vessel" (ie. crossing the original boundary), perhaps ?

......perhaps I'm getting a bit carried away. Its not as though I have nothing else to do. I think I still harbour a lingering irritation over those people that used to say, things like "if you don't wear a seatbelt you will hit the dashboard with the force of an elephant"

gerry

Roger, an interesting comment. I'm not disputing that the collapse would be very fast indeed, but where does the figure of 2200 ft/sec come from ? I guess there is some simple hydrodynamic theory related to the inward acceleration of the surrounding fluid under a hydrostatic pressure into a void, but can you give me a little more of a lead please ? Thinking about, it I suppose its cavitation theory... ?

Gerry

Probably a simple question for the computer literate please...

Every so often when I go into my file explorer to open something I have saved, I find the file missing and these three 'files' in its place.

Where has the original file gone and is it recoverable from the remains ?

What causes this to happen please ? I've had it happen many times over the years.

Gerry

Thanks chaps, really useful and timely info, as always.

Gerry

I have seen a few Albrecht chucks for sale on an auction site. These almost certainly have the wrong arbor size for my machines. I might try to pick one up though if the prices remain sensible. But before I do, just wondering if anyone confirm if the arbors fitted into these chucks replaceable without loss of accuracy ? I'm just wondering if they are ground after installation to help achieve their famed accuracy.

Gerry

Thank chaps. Those points have opened a few new lines of investigation.

Francis, yes Im 99% certain the fault was the LED. If I squeezed it in a certain way with tweezers it worked perfectly which to my simply mind was like I was remaking the junction.... of course I may be totally wrong again A miniature G clamp would have been perfect if I'd had one in the tool box.

Gerry

I have a duff LED in a series solar light units in my garden. This particular model of light unit has gone out of production so I'm trying to avoid the cost of a new set.

The LED is a surface mount type but, unlike other types I have seen, it seems to have a inductance coil on its reverse side.

Firstly, out of curiosity, what does this coil do, and, secondly is it possible to buy anything like this so that I can attempt a repair ? Ive has a scan on the web but cant see anything resembling this but I may not be using the best/right terms.

Gerry

oh and interestingly their hardness builds up steadily with time so one needs to wait a month before they are at their best.

Yes Pete, that was useful. My builder also said that latex based materials were hard. I didn't quite believe him but I've dug up the relevant standards (BS13813 etc) and they do seem to be pretty strong !

Thanks again for all your guidance and experience.

Whilst I like the idea of a 'plastic' floor (especially the epoxy resin), I think a cementitious (that's a new word for me!) screed is probably going to be the best final solution. But the jury is still out. Today the hardwall plastering began. That will be completed tomorrow. Then whilst it dries, the electrician and then plumber will be doing their bits. So I have plenty of time to come to a firm decision on the floor finish.

I must have walked on of thousands factory and laboratory floors during my time on this earth. I just wish I paid more attention to them now....

Gerry

Thanks everyone for you thoughts and comments so far.

The floor has been very robustly made with hardcore, DP membrane and 100mm of Celotex underneath the 150mm of reinforced concrete. Despite the Celotex, that mass of concrete will act as a nice heatsink for the feet and I should consider that.

PEAK4, I had previously dismissed the idea of underfloor heating but your comment has made me rethink this. I have it in the house and its wonderful! You only need a few degrees of warmth in the floor to make the whole room feel warmer. So this could be a useful benefit of a 40mm cement screed. I could finish it with a simple paint coating on top. A latex or epoxy material probably wouldn't let the heat dissipate.

I didn't realise screeds could be self-levelling, so I've learnt something else today!

My concerns about the latex / epoxy was not so much about it cracking, but more about whether it would take on a permanent set or even extrude over time when I raw-bolt my J&S into the concrete that's below the builders proposed 40mm plastic coating. The idea of using solid pads made by a few, could be away around this. Once I know where the machine will be, I could just cut the plastic material away with a hole-saw, insert some steel and sit the machine on this. Lots of food for thought, though.

Gerry