Here is a list of all the postings Douglas Johnston has made in our forums. Click on a thread name to jump to the thread.
|Thread: EMCO Compact 5|
Great little lathes and very well made, I used one for years. Value is very difficult to say since condition is the main thing, but one in very good condition could fetch £500 I would think.
Right Clive, I pulled the dial off and took a few pictures. I used three spring loaded ball bearings as you can see, the balls run in a groove on the inside of the moveable dial. This technique gives a very smooth operation of the moveable part but may be overkill. Fitting the springs and the balls without losing some of the bits provides a great exercise in manual dexterity. If assembly is done inside a plastic bag flying ball bearings will be caught.
I did this to my Speed 10 many moons ago and it was well worth doing. It was so long ago I have forgotten exactly how I did it but from what I remember I used the original engraved dial, bored out the middle to form a ring and made a straight knurled outer part for adjusting the scale. If you want more information I can dismantle it and take some pictures.
|Thread: fly cutter or face mill|
Looks like a blunt cutter to me or poor chip clearance. Poor tramming of the mill can also give this result where a trailing edge messes up the finish.
|Thread: Lubrication of Quorn grinder spindle|
I built my Quorn many years ago and think the book does mention something about lubrication if my memory serves me correctly. I think it needs a small amount of oil and to be honest I think I just put a little oil on the bearings during assembly and have never added any since over the last twenty years or so (perhaps I should ).
I too have seen the use of Sodium Bisulphate on the web and have also bought some of it to experiment with but have not got round to trying it yet, so your efforts have encouraged me. I was wondering what strength of solution to use and see you opted for a 25% solution. Was that percentage based on anything other than a stab in the dark?
I have heard that the solution does not keep well which may be a disadvantage. The chemical is not that cheap so could be quite expensive if it is a case of use it once then have to throw it out. It might however be the only way to anodise if Sulphuric Acid is impossible to source.
|Thread: Parting tool|
I have just got my latest purchase from China via ebay and am rather pleased with it. It is a 2mm wide parting tool complete with 10 double ended inserts and a very nice torx screwdriver all for less than a tenner. I feared I was wasting my money but the thing has greatly impressed me. The quality is perfectly satisfactory, while not brilliant, and the inserts seem to cut very nicely indeed, slicing through steel very cleanly.
The tool has a 12mm square shank which I had to reduce to 8mm to fit my Speed 10 lathe. I was worried that the shank would be very hard but a carbide milling cutter cut it very easily with a few passes at 50 thou depth of cut and left a very nice finish. Well worth a punt at that price.
|Thread: ML7 feed screw wear|
Just had a look at the Myford/RDG prices and have to say the word "cheap" did not come to mind, but perhaps that says more about me than anything else. Over £400 for a topslide , good grief you could buy a whole Chinese lathe for that.
|Thread: Where's my Dykem blue gone - there's no need to read this|
The trouble really starts when you forget what it was you were looking for.
|Thread: Poor finish using indexable lathe tools on steel|
+1 for the sharp polished inserts sold for aluminium. As said they work a treat on steel. Was doing some 50mm diameter mild steel this morning and the finish was superb, but you need to be careful since the edges can be damaged quite easily if mistreated. And yes keep the speed up.
|Thread: Notre Dame|
Very sad to see such an iconic building in such distress.As has been said there have been a string of high profile fires during renovation and I can't understand why there are not people on site around the clock to reduce the risk to the buildings.
|Thread: stepper driver|
This may well be a theoretical problem with the 6560 drivers but I have been using a number of these for quite a few years and have never had one fail. Even if one did fail they are so cheap it would hardly be the end of the world. Also they seem to withstand back emf's when manually turning the stepper motor ( can be very handy with double ended motors when you also want manual control )
|Thread: Boring on a light mill|
When using a boring head in the mill is it better to provide the downward feed with the head locked and using the quill or the quill locked and using the head feed. I have used both methods in the past with success but have often wondered which way is best from an accuracy point of view.
|Thread: Mini boring tool|
Seems to be only available to companies when I looked. I suppose I could try to invent a company to fill in their form but I'm sure they would show me the door.
|Thread: Looking to purchase a new 4 jaw chuck|
When I bought my Speed 10 from Myford over twenty years ago it was supplied with a 5" 4 jaw chuck and a 4" 3 jaw. I have found the 5" 4 jaw very good for this lathe so up to 125mm will be fine. Both chucks screw directly onto the lathe mandrel which keeps the overhang to a minimum.
|Thread: Heads up! Granite discs, £2, B&Q.|
Granite discs can also be used for the base of things like tapping fixtures. Nice and heavy and stable and cheap as chips if you can get them for £2 a pop.
|Thread: Smoke detectors|
Surely the biggest problem with workshop smoke alarms is this; most workshops are probably in an outside shed with nobody there when the alarm goes off. I suppose some form of remote sensing could be used so that an alarm went off inside the house in the event of a workshop fire.
|Thread: More Workshop space, shall I or not..?|
Just remember that the amount of stuff you have just expands to fit the available space, so there is no such thing as the perfect size of workshop. My workshop is about 5m by 3m and is too small for all I want to put into it, but I know better than increase it's size. 6' by 4' must be very snug and cheap to heat but swinging cats come to mind if one can still use such expressions.
|Thread: DIY Epoxy Frame based CNC MILL|
That is a very impressive build John. With all the embedded parts did you have a check list to ensure you did not leave anything out before pouring the epoxy mix. If it was me doing it I would be sure to miss something out and you would hear the scream in Australia from me in Scotland!
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.