Member postings for Douglas Johnston

I am building a dc power supply for a project and am using a toroidal transformer along with an electrolytic smoothing capacitor and bridge rectifier. Now I want to make the whole thing as compact as possible and noticed that the capacitor fits very neatly inside the hole in the centre of the toroid but I worry that this might not be a good idea due to the magnetic field in that space. I know that there are people with electronic brains the size of planets on this forum so is this a good idea or a definite no-no ?

Doug

That is interesting but since I live on the east coast of Scotland I am nearer the new transmitter, although there may be geographical considerations at work. I nearly threw the radio out when it first started to misbehave but tried placing it in a number of locations until I found one that worked.

Doug

I have one of those radio controlled clocks that refuses to lock on to the signal and slowly gains a few seconds a month. When the clocks change in October and April I have to take my clock to a high point in the back porch and leave it there for a day or two and it finally does the conversion. When it was new it worked fine for a number of years, then decided to annoy me for some reason.

Doug

I insulated a similar sized wooden shed about twenty years ago with the foil bubble wrap stuff and it does seem to work pretty well. One of the biggest benefits is keeping the inside temperature down in the summer. Before fitting the insulation the shed was unbearably hot in the summer but became much more pleasant after the insulation was fitted.

Doug

I have used oven liner material to provide a swarf guard, it seems to stand up to hot chips very well and is very flexible.

Doug

Also check the diameter of the plain section at the top of the R8 (0.9495" in drawing above ) . I have bought a few R8 collets that would not go in my mill because that part was just a tad oversize for my machine (although still within the R8 spec ). Removing about 0.0005" from the diameter cured the problem.

Doug

When I did my engineering degree in the sixties a slide rule was one of the first things I had to buy. I too still have it although it has not been out of the box for a very long time. It was amazing what one could do with it but I would hate to go back to using it.

Doug

I have a Speed 10 with the long bed and if you are worried about lifting the lathe that should not be a problem. I easily lifted my one with the motor and tailstock removed (mind you that was rather a long time ago ! )

Doug

I have a 12mm carbide cutter that tends to do the same thing when held in an R8 collet. The shank is very smooth and as mentioned above this may be the problem. I must try slightly roughing the surface and see if that helps. It is downright annoying when it happens and I now use one of Arc's indexable carbide shell mills on an R8 arbor when there is any danger of creep from an endmill. As an aside these shell mills are superb and give a very good surface finish.

Doug

This is often the problem with articles which only demonstrate a device. Such articles are not meant to be used to make the device but merely show what is possible. They can be very interesting and inspiring but can also be frustrating if you want to build the item in question. I too read the hobbing article and would love to build something similar but would need a lot more information to make that feasible.

Doug

I think it is unwise to use engine oil that has been in an engine. I'm sure I read somewhere that there is a cancer risk with that approach. I use cheap supermarket rape seed oil and that works well for me.

Doug

Thanks for providing that email address John. I contacted John Moran and he has sent me the relevant files. This will keep me in reading matter for a while, then I will decide whether to make one.

Doug

That is an interesting 4 facet grinder. Does anybody happen to have a copy of the article from HSM as I would love to have a look at it.

Doug

I would have thought a light treatment with a very fine diamond hone would get the edge/point back to good sharpness.

Doug

This topic has cheered me up no end by telling me that others share my problem. I used to be able to put a tool down and pick it up again a short time later. Like some others this is no longer always the case and it drives me mad. I know I had it a few minutes ago, remember laying it down, then go back and find it gone. I run about looking everywhere to no avail then give up in disgust. The next time I go into the workshop, there it is in plain sight. I think as you get older your in-house gremlins get more cunning in their attempt to annoy.

Doug

In the past I wondered if I could get away with one bandsaw for wood and metal but it is not really a good option. The speeds are different and so are the blades. You would be forever changing the blades and that can be a real pain. I ended up with one of the 6 by 4" horizontal bandsaws for the metal and a vertical one for wood. A wood one will cut aluminium at a pinch but not large chunks of the stuff.

Doug

Hi Pete, that source you mentioned for ER collets looks interesting but I notice the website does not give any prices. If you don't mind me asking, what did you pay for the set you bought ?

Doug