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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: Facing off backwards
17/02/2020 10:59:32

It may be because the bulk of material is being removed by a different part of the tool which may not be subject to wear and so is reducing cutting pressure.



Thread: Why does everyone disagree with you
28/01/2020 10:07:29

Well I may be many things but wrong isn't one of them smile p.

I think a major cause of disagreement here is people not reading or understanding the OP. I have certainly fallen into this category more than once.

Although I would hope that I'm not too objectionable in my replies.



Thread: Scraping a magbase
24/01/2020 08:40:48

If you have something that is rocking the bluing can be misleading. Imagine trying to blue a convex lens. As you move it it will roll and the blued area will be larger. A better strategy as Mike says would be either work from one corner or try to ascertain where the ridge or high spot is and remove it by rough scraping.



Thread: Buying metal - caveat emptor.
20/01/2020 10:46:53

I I keep 6 different grades of steel in stock and use electrical tape to ID them.

As I sell the stuff I have to be careful as once cut it is nigh on impossible to tell them apart.

All full bars have a ring of tape around them as they come in. I use a ring of black tape to show imperial which makes it easier to see on the rack.

Different suppliers use different colour schemes so don't assume that if it is green it must be EN1A.

The colours my supplier uses (and by extension I use) are :-

Green = EN1A

Purple = EN1Apb (leaded)

Blue EN3B (BMS)

Yellow EN8

Brown EN24T

White EN16T



Thread: Chinese DRO opinions
16/01/2020 11:02:59

I have had 2 sent from China. They were from different suppliers. Both were fine.

I'm pretty sure they came off ebay. So I was reasonably sure that I would be looked after if there were any problems.



Thread: Driving Small Taps
16/01/2020 10:56:51

I had to tap 1000 holes M3. They were for a grubscrew and were through a 4mm wall. I decided to buy 3 sets (of 3 taps) as I was bound to break some. I used a battery drill to drive them and needless to say didn't break a tap.

I should point out that whilst accuracy was not of concern, I was surprised at how easily a taper tap aligned itself. As I recall there were no rejects.



Thread: Collet identification
13/01/2020 11:04:40
Posted by old mart on 12/01/2020 17:08:16:

At the moment there are a number of accessories for Smart & Brown on ebay UK, at the hugely inflated prices wanted, it is no wonder that most of that stuff is just sitting there month after month unsold.

Well this then leads to the question of what is a fair price?

I would probably offer them as individual collets.

How much for an imperial and how much for a metric?



12/01/2020 09:44:22


I have only just seen the last two replies.

Thanks for taking the time to dig out this information.



Thread: New legislation that could affect us all.
08/01/2020 10:28:03
Posted by Neil Wyatt on 08/01/2020 09:57:25:

Proposed new ISO Standards for 2020 are now out for consultation:

ISO 100-5E47 - Protocols for the placement of toilet seats and their covers.

I generally place these above the toilet. I did try putting one 5 feet to the left of the toilet but this led to a pretty awful smell and it had to be moved to the correct position.



Thread: First mill
08/01/2020 09:02:10
Posted by Gazz on 08/01/2020 01:40:04:

I've been offered a (i presume chester) lux mill with an MT4 spindle,

Am i right in thinking that making an adapter to go from MT4 to R8 is not possible... without having it stick out the spindle bore quite a way.
And that changing the spindle to an R8 one wont be cheap or easy.

of course an MT4 to MT3 sleeve will let me use easier to find second hand tooling, when using a reducing sleeve do i need to use a different drawbar to the one that works with MT4 tools?

Stefan Gotteswinter on youtube has one of these (with a 4 morse taper) I'm pretty sure he did a couple of videos about why he chose it and how he got on with it.

It's well worth checking his channel anyway.



Thread: Ebay being clogged up by certain sellers
06/01/2020 14:25:09
Posted by Neil Wyatt on 06/01/2020 12:54:03:

The best solution, if you can afford it, is to buy from suppliers who support our hobby rather than saving a few percent by going to random suppliers on eBay...


I do support our hobby. I just do it on ebay smile p



06/01/2020 12:45:20
Posted by Robert Atkinson 2 on 06/01/2020 07:30:40:
Posted by peak4 on 06/01/2020 00:26:36:

Old Mart, what was it you were searching for?

I do appreciate the problem as sometimes when I seek a particular item, one seller includes dozens or even hundreds of the same item.

i.e. I look for a generic item for my motorcycle and one particular product is listed dozens of times by the same seller as xxxxx-Honda, xxxxx-Honda CB250, xxxx-Honda Xl500 etc etc. It takes forever to scroll past to find the next vendor selling a different product.


Report them to ebay. They are not supposed to list multiple copies of the same item. There is a limit of 10. There is a "Report item" link on every listing. This comes under listing practices.

Robert G8RPI.

The way round this is to have multiple shops, which many do. They often have similar names and list pretty much the same inventory. At this time there is no reason why you can't do this.



06/01/2020 12:37:20
Posted by fizzy on 05/01/2020 21:17:37:

dont take any notice of the location filter - the chinese all say they are UK based. Take a look at delivery time, anything over a week is suspect. I get annoyed by the advertised amount bearing no relationship to the actual amount...its a minefield!

As an ebay trader I was notified last year that they were going to clamp down on this as it was a major source of complaints.

I would expect improvements to this. Whilst ebay may be slow and ineffective in many things they tend to be much more effective when their bottom line is at stake.



Thread: Collet identification
04/01/2020 08:17:11


Thanks for taking the time to find that.

Presumably they fit one of the model L headstocks.

Many thanks.


03/01/2020 10:34:58

I have a number of collets bought in a job lot.

They are marked with various makers logos including Crawford and S&B.

The number that identifies them is 5159.

They are 2.5" long and the rear diameter is .937"

Does anyone know what they fit?

I may be up for some horse trading if they are any use to someone.

Also does anyone know why collet and collets flag as if they are spelling mistakes but are not corrected as part of a spell check?



Edited By David Colwill on 03/01/2020 10:35:19

Thread: Alexander master toolmaker
22/12/2019 07:48:37

On some tapered gib arrangements there is a screw on each end of the gib. These are used to keep the gib from moving once set. If it isn't properly held it can act as a wedge and I would suspect that this is what is happening on your machine. Try to find out how the gib is secured and back it off. If that frees it of readjust and try to look for movement of the gib when moving the slide.



Thread: Seeking advice on suitable lathe
09/09/2019 10:02:36

If you do go down the route of a lathe perhaps look out for an EW lathe. Details can be found on

These are small but have back gear and while you won't get anything of note through the spindle it would at least have some torque at low speed.

Instead of drilling and boring out consider using an annular cutter or rotabroach. These will leave a slug of metal from the centre thus saving work.

If you are anywhere near Nottingham I do have both an EW and a set of rotabroaches that you can look at / play with.



Thread: Any one used a digital microscope for micro turning on a lathe
06/09/2019 10:27:43

I haven't been too impressed with the digital microscopes that I have (and I have 3 or 4 of them). I am considering one of the Chinese stereo zoom microscopes and had thought of making some kind of quick change mounting so that I could move it about.



Thread: Any one recommend a supplier of 1/4 inch lathe blanks
24/08/2019 07:51:58

MSC J&L have them on offer at the moment (till end of August) The 10% cobalt are £2.52 plus vat etc.



Thread: Wasp trap - suggestions please
19/08/2019 14:13:55

Obviously this needs to scan on a pan tilt mount and be able to track the wasp!



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