Member postings for David Colwill

Don't forget toothpaste is a very fine abrasive!

Also good for emergency CD / DVD repairs!

David.

I wonder if you could cast the part around the existing spiral rod in some kind of resin, perhaps adding powdered bronze to it. PTFE spray or similar as a release agent. I'm sure others on here will know more.

Good luck.

David.

I can't begin to fathom how the designers (of the machine) wrote the control software for it. An ordinary 3 axis mill yes but that thing. It gives me a headache just thinking about it

David

Yes yes yes I get the bit about shoes but nobody seems to be talking about the stuff that you shed from your hair / jumper / hairy arms or is this just me. I have on occasion got into bed after taking a shower only to find a tiny coil of steel digging into my back. How did it get there?

David.

Hi

If you cover the cost of the post I will send you 250ml to try.

David.

I use Ultrasonic cleaning for rust removal now. It works really well with the right fluid.

Regards.

David.

Mars bars are more expensive than petrol calorie for calorie!

With the power off and everything still engaged manually turn the chuck backwards. This may be very stiff. Check how the cross slide feed nut is secured, sometimes this is by socket cap head screws from the top of the cross slide. If this is the case undoing these will take the strain off it. Otherwise try taking the handle off.

Good luck.

David

The body of the drill varies according to quality, the better ones are made from a tough steel and the cheap ones from cream cheese. I have used this dodge on more than one occasion, usually involving a steel of unknown origin that has work hardened to the point that HSS won't touch it. I can sharpen drills by hand ( after a fashion ) and the technique I use for sharpening is to present the masonry drill in exactly the same way I would with an ordinary drill. I should point out that I have only used these drills for opening out holes already drilled. Also the carbide tips are very small and prone to breaking. I only really use this as a last resort.

Regards.

David.

As a rule interrupted cuts are okay. If you are using carbide then you need to take more care as it is quite brittle and may chip. Round off the corners of tools (or use an insert with a bigger tip radius ) as sharp points lack strength. If you proceed with caution (it sounds like you are) then you should get a feel for what is right. Obviously being to aggressive with feeds or speeds will end up with broken tools or worse things whistling past your ear. So make sure that the work is securely held.

Good luck.

David.

Yak!

Edited By David Colwill on 28/05/2015 09:58:38

Nod 32 also flags it.

David

Hi,

If you google BS4311 this gives you the tolerances for gauge blocks which looks to be .0002 mm. If you were to get 1 it might be useful to take it with you and ask them to measure it with the calipers they use.

Regards David

Hi,

MSC J&L do gauge blocks idividually. The 1.2mm is £11.70 see page 878 of their catalogue.

Regards David.

The only airworthy TSR2 was used as a ground target to observe the effects of gunnery on a modern aircraft. There is one at R.A.F Cosford which is well worth a visit.

Regards David.

Over the last couple of days I have been fitting tapered gibs to the mini lathe. I made the gibs from brass and have had some problems with distortion due to, I think, internal stress. I'd be interested to hear if anyone has any thoughts on this and if this is the case, to know how to stress relive brass. The lathe is back together and although the gibs are not perfect ( I'm going to remake them), the results so far are much better than before.

Regards.

David

My favourite is about objectionable people.

Those that mind don't matter, those that matter don't mind.

Regards.

David.

If you view the picture on a tablet you can turn the whole thing through 90 degrees, only to have it auto rotate to its side again