Member postings for Douglas Johnston

I did this a while ago and found that a HSS drill was no good. I ended up using a solid carbide drill and this proved to be ideal. You could use a clamp type fixing which would eliminate the need to drill the scale.

Doug

With current income and 1970 prices life would truly be pleasant. We can only dream.

Doug

Enjoyed the first episode very much but did need a babel fish in my ear to pick up all the dialogue.

Doug

Just been to my local (UK) Aldi shop and picked up a set of 10 diamond needle files for a fiver. Nice neat size and look a decent quality (for Aldi! ) .Be quick if you are interested as these tend to go fast.

Doug

Living in Scotland the major exhibitions are too far to travel and I have to rely on the mail order companies for equipment. Over the years the standard of service from these companies has improved considerably. I can remember waiting weeks for orders to arrive in the past, whereas delivery now is often next working day.

Just a little plug for Arc Euro, I ordered some items yesterday from them and shortly after received an email telling me I will get them on Monday (next working day) and will be given a 1 hour delivery time slot on Monday morning. Thats what I call impressive service (free carriage as well having spent over £60). Well done, that's all I can say.

Doug

It is not a matter of working to an accuracy of 1 micron, the 1 micron resolution simply makes it easier to get a decent accuracy. Remember resolution and accuracy are two different things.

Doug

I've uploaded five pictures of the DRO into an album.

Doug

Hi Maurice, the magnetic sensor is only approx. 5cm long, 1cm wide and 1.7cm high and fits onto an L shaped bracket fixed to the back of the cross slide base. I had to machine a flat area on the base to achieve this. I have a long cross slide on the lathe and I extended this by another 5cm with a block of aluminium bolted to the end, then machined a 1cm wide area about 1mm deep along the underside of the slide and aluminium block, into which the magnetic tape was located using superglue. A thin non magnetic metal plate was fitted over the magnetic strip to protect it from any machining oil or debris.

Careful alignment was needed to achieve the right gap between the magnetic tape and sensor and to avoid conflict with the cross slide screw. The cable from the sensor was routed under the lathe bed and connected to the same digital readout used for the mill. I made a switchover box so that I could select the output from either the mill Z axis or the lathe cross slide sensor.

If anyone is interested I can take some pictures and post them if I can work out how to do it.

Doug

I have just fitted a 1 micron magnetic scale to the cross slide of a Myford Speed 10, fitting the scale under the slide to keep it out of the way. I was always put off fitting a scale down the side of the slide because it would get in the way of things, but this way works a treat. It is a bit more work to do it this way but well worthwhile. The only downside would be a clash with a rear mounted taper turning attachment (as well as the cost -these magnetic scales are not cheap but you soon forget the expense)

Doug

Yes very strange that the broaching oil appears in the latest catalogue but is not available on the website. Usually items will be listed even when out of stock, but not the case with this one.May no longer be available.

Doug

Just had a look at the Toolstation site but no mention of broaching oil at £4.29 a litre. There is pipe threading oil at £6.63 a litre and tapping and drilling spray at about £3.50 a can. I have used the spray before on aluminium and it worked fine but a spray can does not last long. I may give the pipe threading oil a go for general machining and see if it is worhtwhile.The free carriage is a real plus with Toolstation, they can't make any money on small heavy orders.

Doug

I have used a thin metal cover over the magnetic strip Jon as I was concerned about metal swarf causing a problem since the surface of the strip has about the same magnetic attraction as a fridge door seal. the strip being under the slide should provide a fair ammount of protection but I might have to think about shielding the scale further if its going to be a problem.

Doug

I am in the process of fitting a Machine DRO magnetic scale to the cross slide of my Myford Speed 10 lathe. I chose the magnetic scale for two reasons, firstly because I could fit the magnetic strip under the slide (only 1.5mm space needed) and secondly because the reading head is very compact and will fit out of the way behind the slide.

By using a 6 pole changeover switch I will be able to use the display fitted to my mill and simply switch between the Z axis of the mill and the lathe cross slide thus saving buying a second display unit. I have a 1 micron resolution magnetic scale on the Z axis of the mill along with 5 micron glass units on the X and Y scales and find this combination very nice indeed. I nearly bought the 5 micron magnetic option for the mill because it was cheaper, but I find the 1 micron unit superb and worth the extra expence. The lathe will also use a 1 micron unit and I hope to have it up and running shortly.

Doug

That's one of the older ones that uses oil ,not grease, in the oil cups above the bearings. The oil nipple in the tailstock needs one of these pump action oilers that are notorious for leaking oil all over the place. I rarely use the tailstock oiler on my own machine, just smearing some oil on the extended tailstock barrel now and then.

Doug

Just a small point that has bothered me for some time. I keep reading about not using certain products because they contain silicone. Can anybody explain what the problem is with silicone?

Doug

Thanks for that Ramon, I will have a good read of the article when published in ME and have another go at anodising. I see you used writing ink which made me wonder if inkjet ink would work. I am now inspired to do a little experimenting so will report any decent results I get.

Doug

What magnificent engines these are Ramon. I assume the cylinder heads are anodised and was just wondering if you did the anodising yourself. I have tried anodising in the past with limited success but would love to try it again. If you did it yourself I may have some more questions to ask.

Doug

The drives also contain a pair of very strong magnets, although the magnets in the last one I dismantled were a bit more skimpy than older ones. Some very nice miniature ball bearings are also to be found. I simply cannot understand how this much high precision stuff can be made for so little cost.

Like others, I can't bear to throw this stuff out but will probably never use much of it. The humble inkjet printer is another thing that just has to be pulled to bits when it dies, and can provide some very nice precision ground and plated bars and small stepper motors. I had to use a lot of will power when my washing machine packed in recently and let it go without a post-mortem!

Doug

I bought a new VMB ten years ago and have always been delighted with it in terms of smoothness of slides etc although I have made quite a few mods along the way. At the time I bought mine Myford were saying they did a number of things to the raw Taiwanese import including extra oiling points. The ground surface finish on the table was extremely good and I suspect Myford may have been responsible for this since any other imported machines I have seen have never been as nice.

One of the problems with the machine is the vertical feed which needs one revolution of the handle to move 20 thou. To make this more convenient to use I made power drive which works very well.

Doug

Just as an aside, when I use spray on photo resist I use a spinning turntable (made from an old small motor and aluminium plate) and find this gives a very even coating. By altering the spin rate you get different coating thickness, although slower is better for a decent thickness. Bung the treated board into a metal tin to keep the light out and stick it in the oven at lowest setting (about 60-70 degrees C ) for 15 minutes and after cooling the board is ready for use.

Doug