Member postings for Douglas Johnston

Thanks to John and Ega for the information provided. My collet chuck body has been sitting in my workshop for a while now while I have been doing other things, but I must bite the bullet and have a go at machining the taper.

Doug

Hi ega, I would be very interested in the details of the taper turning gauge you mentioned. If it is possible could you upload details of the construction to this site.

Doug

A while back I was looking for a new decent drill since I had the old problem of a sloppy fit between the quill and drill head casting. All the usual suppliers seemed to have very similar Asian imports of dubious quality so I gave up the search. I ended up drilling and tapping a couple of holes near the bottom of the head casting at 120 degree spacing and fitting bronze pads to limit the sloppy fit. Seems to have worked for the time being, but time will tell if it is a long term solution.

Has anybody come across any supplier that sells decent quality drills at a higher but not unreasonable price?

Doug

I've just got round to reading the article starting on page 38 of the latest MEW and was amused at the state of the milling table shown on page 42. That poor machine must have had some terrible history. Perhaps I am too fussy but I feel like shedding a tear if I get a small scratch on my table.

Here is my challenge; can anybody match that picture in MEW or provide one even worse.

Doug

Just noticed the posting by Ken King where he mentioned using thin MDF board for making a vacuum table. How thin are we talking about here and how much grip do these tables give? Is it possible to do light milling on an aluminium sheet or would that be rather dodgy.

Doug

When I fitted one of these arrays just behind the quill on my mill it struck me that it would need some protection and I fitted a polycarbonate shield. It has been in use for some time and produces great illumination just where needed, but when I inspected it the other day little bits of swarf had got under the shield and it needed a good clean. Your solution of totally enclosing the arrays is a better idea and I will probably have to do something similar to keep out the swarf.

Doug

Well John I will be 65 in September so still very much a youngster. I have added some pictures to my album and as you can see there is still quite a bit to do. The trouble is I keep needing to use the milling machine for other things so progress is delayed.Any questions, just ask.

Doug

Very true John, not cheap but very nice! I've reached an age where saving money is less of a priority, no point in dying rich, although I intend living for quite some time yet.

The drive is not complete yet but I will dust off the camera and see what I can show so far.

Doug

I am in the process of building an X axis driver and found that the latest 400Ncm stepper motors give a decent torque without being too large and heavy. I got mine from CNC4YOU along with a driver which uses an ac power supply (up to 60V) which makes the power supply simpler to construct as all you need is a transformer.

You can do clever things with multi stepping, rapid traversing and using the enable control on the driver to remove power from the motor when it is not driving the table, which prevents the motor from overheating. Some form of variable pulse generator is also required to operate the motor driver.

Doug

That is a pity Greenwood don't do HSS ones anymore, although I have used carbide ones for years without too many problems, just as long as you are not too rough with them.

Doug

Greenwood tools used to supply HSS threading inserts, I bought a couple a number of years ago and they are still going strong. Don't know if they still supply them.

Doug

Thanks for the replies, the tip about placing a bar in the collet when testing the fit is one I will follow.

Doug

I am in the process of making an ER40 collet holder and have just finished the end that threads onto the lathe mandrel. Now comes the tricky bit of machining the 8 degree taper on the collet end of the holder.

Is there a way of accurately setting the topslide to this angle or is it best to set it as close as possible and then check with a collet and then nudge the topslide and take another cut until a good fit is obtained.

Doug

Hi Ian- I did'nt explain myself very well, the "key" I was referring to was not a keyboard key but the small white arrow in a blue circle on the top left hand corner of the screen in Windows internet explorer. I tend to use it to go back to the homepage after I have read a posting so that I can click on the next interesting posting topic.

I do however realize that I may miss some postings if they have slid off the homepage.

Doug

Thanks for the replies,looks like its my computer that is causing the problem. Just to make matters worse I am about to change my broadband provider, with all the hassle that will produce. Ah well back to the workshop for some therapy!

Doug

Is it just my computer or is there a problem with the backpage key. Just lately I find the key works fine most of the time but on a number of occasions nothing happens even after repeated pressings and I have to go to the home page to go back to the latest postings list.

Doug

Just been looking for Castrol Ilocut 486 but it only seems to be available in 20 litre cans costing the best part of £100. Is there a supplier able to provide smaller ammounts?

Doug

I have had a 6 by 4 bandsaw for years and have only ever used ordinary blades and they do seem to last quite well on mild steel and aluminium. I am using my last stock blade and was thinking of giving the bandsaw a treat by buying a bimetal blade because I will be cutting some stainless bar in the near future. Is there a good UK supplier that people have used and can recommend for these blades?

Doug

When I built a quorn grinder many years ago I tried to find hard chrome plated round bar but could not find a supplier willing to sell a small quantity. This may be easier to find these days and would have the advantage of being rust resistant.

Doug