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Member postings for David Colwill

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

Thread: New series by Tim Hunkin
21/04/2022 19:16:18

He has started to release a new series of the secret life of components on his Youtube channel.

Enjoy.

Regards.

David.

Thread: EMCO Maximat Super 11 - Headstock & Gearbox Oil
19/01/2022 13:23:06

I have ordered some which should be here in 3 to 5 days.

I will PM you when it arrives.

Regards.

David.

18/01/2022 21:23:49

I keep other Castrol oils in my eBay shop ( I have AWS 68 ) but not this. I will ring my suppliers and see if I can get some as it may be worth stocking.

Regards.

David.

Thread: Slip gauge question.
17/01/2022 14:04:03

I have made precision ground stones and find them very useful. However for gauge blocks I find a small ruby stone (very cheap off ebay) seems to work very well. It is very hard, seems to be very flat and does not scratch the surface of the gauge block. As to the blocks you have, even worn they are very useful as packing and for other setups. I always pick up odd junk ones when I see them.

Regards.

David.

Thread: Lathe tooling
13/01/2022 14:56:06

The toolposts listed look to be Dickson clones. Whilst they work well, making extra holders is not straight forward.

I use an Aloris clone Arc Euro model 200 or 222. These take 16mm tooling and will fit your lathe. The holders are (I believe ) cheaper and certainly easier to make.

Whilst I agree that QCTP's are not always quicker to go from tool to tool, they do make life easier if using a DRO (and you have enough holders).

I wouldn't be without mine!

Regards.

David.

Thread: Royal Fail
11/01/2022 18:02:47

Sadly it isn't just RM, they are all suffering from delays. One thing in RM's favour, they will eventually deliver. Hermes / Inpost just throw it in the bin!

Regards.

David.

Edited By David Colwill on 11/01/2022 18:03:37

Thread: Laser Cutter
30/10/2021 07:17:56

I have its very much cheaper cousin and am surprised at how good it is. There is a ton of youtube videos out there that go quite deep into the ins and outs of them.

Regards.

David.

Thread: Guided bus lane
26/10/2021 08:01:27

How about this.

Another example of over enthusiastic traffic calming.

Thread: Workshop content
08/10/2021 12:44:02

Can you give us a rough idea of where you are?

David.

Thread: Hardinge HLV H
01/10/2021 07:25:09
Posted by Pete Rimmer on 27/09/2021 19:30:38:
Posted by David Colwill on 27/09/2021 07:20:25:

I believe that there is a difference between the British and American built machines. The British Machines have a 4 degree taper as opposed to the 3 degree 59 minute 30 second of the American machines.

Not a problem if you are working to the taper on your machine.

David.

I make it roughly 0.00017" difference which is no difference at all given that the big and small ends have a 7 tenths allowance on the drawing.

I have to say that I never bothered to work out what the difference was. I just knew that the British machines are 4 degrees.

Sorry for making everyone rush for their calculators.

David.

Edited By Pete Rimmer on 27/09/2021 19:34:35

27/09/2021 07:20:25

I believe that there is a difference between the British and American built machines. The British Machines have a 4 degree taper as opposed to the 3 degree 59 minute 30 second of the American machines.

Not a problem if you are working to the taper on your machine.

David.

23/09/2021 21:35:24
Posted by Mark Rand on 23/09/2021 20:26:43:

It's very easy to turn the hardinge nose taper to make chuck back plates.

Indeed it is.

That was this mornings job, spurred on by this thread.

David.

23/09/2021 07:36:32

I have never seen a chuck on a Hardinge backplate in good condition. Like Pete above I have the older HLV. This had a chuck with it that was worn well past the dangerous to use stage. The taper mount was built into the chuck but I was able to machine away enough to allow me to mount a Chinese 100mm 3 jaw chuck which works okay for the odd time I need it.

David.

Thread: What to drive a J & S with ?
09/09/2021 21:33:56

I run mine on a rotary phase converter with no problems.

It may help if you can answer the following question.

Are you going to be working for NASA?

If the answer is no, then a rotary phase converter will be fine.

If the answer is yes then get a brand new surface grinder , the correct supply and stop trying to be cheap!

David.

Thread: It would be nice to know........
09/09/2021 09:51:02

When power tapping would be the obvious one.

Regards.

David.

Thread: 9/32 hex steel bar
03/09/2021 08:32:54

Hi,

I have asked a couple of my stockholders and they don't keep it.

West Midlands Bright Bar was mentioned as worth a try.

David.

Thread: Marking steel
01/09/2021 14:07:50

I have a need to be able to mark steel. Paint markers are okay but on my Coventry die heads this soon wears off. I don't want to etch or engrave and whilst I could fix some kind of tag this seems like bother.

The idea came to me that if I put some Blackfast solution into an empty marker pen, I could end up with a pen that would produce black writing that would not easily rub off.

It works... Sort of!img_20210901_134235_004.jpg

There are some issues.

Firstly it is too thin!

Secondly it doesn't stick very well.

The only thing I had to hand to try and thicken it with was some clay. This produced the result in the photo. I wiped the surface with IPA (not the bitter!) Then wrote on the steel. I waited about a minute and wiped it clean.

The writing can be taken off with scotchbrite but would appear to be pretty resistant otherwise.

Does anyone have any ideas on how to improve this?

David.

Thread: One for the youngsters
28/08/2021 06:50:25
Posted by Bob Stevenson on 28/08/2021 06:36:35:

They no longer allow conventional clock faces in school exam rooms because the 'strange' & 'weird' face adds considerable stress to the kids......

I think I need something solid to bang my head against!

Thread: Is there a Gitzo tripod expert in the house ?
24/08/2021 14:13:02

This sounds like the sort of problem that could be solved with a 3D printer.

A 3D printed 2 foot stillson would certainly solve the problem whilst producing gasps of horror from anyone watching you use it!

David.

Thread: Chinese "K40" laser
21/08/2021 12:25:29

Having done various trials with this i am inclined to agree that it isn't really practical.

My first attempt did mark a piece of graphite and although it wasn't deep it didn't rub off. However the surface of the graphite was cut with a bandsaw and in reality the ridges of the cut were protecting the marking.

Another go with a smoother surface produced a similar marking but this time it was easily rubbed off.

Using slower speed for the engraving didn't make any difference nor did using air assist.

David.

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