Member postings for Maurice

I recently acquired a nearly new Proxxon milling machine from the estate of a deceased friend. When it is turned on, there is a lot of noise from the motor brushes/comutator. I mean A LOT. Is this common? How have others improved this; assuming that they had a similar problem. I was considering undercutting the insulation between the copper segments. We used to do this on some motor driven generators where I worked.

Regards Maurice

Thanks for the suggestions on the website via the link. Having given it some thought, and just finding a large redundant cylinder cover as source of material, I think I will remove the existing flange completely and fit a larger one. I shall loctite it onto the turned down cylinder end, then drill and tap small holes on the joint line, and inset plugs of threaded rod, again with loctite, to form a mechanical join as well as glue. Probably not needed, but I am a belt and braces man. Thanks again

Maurice Cox

Anyone out there built the Major beam engine? How did you fasten the cylinder casting to the bedplate? The drawing shows 4BA studs and nuts through a flange at the base of the cylinder. However, the flange is barely wide enough for 6BA nuts, and even then the moulding just above the flange, has to have small arcs cut in it to clear the corners of the nuts.

Maurice Cox

When you file or mill away the steel to produce the flat, make sure to finish it a few thou over half the diameter, or the "side" will have a cutting edge, and will remove material fro the side of the hole.

Maurice Cox

You might consider “J.B. Weld. I used this on a job, and placed the parts incorrectly. When this has happened with “Arraldite”, a smart tap with a hammer has broken the bond, ready for a retry. Not with J.B. Weld. All that hitting it with a hammer did was to dent the surface. I had to heat it up with a torch to get it apart!

Maurice

This talk of safety valves brings to mind a friend who used to work in Stuart Turner Models when they were still in Henley. One day a school teacher came in with one of Stuarts oscillating engines with a boiler. He had some issue with the engine, but the chap in Stuarts was horrified to see that the teacher had removed the spring and ball from the safety valve 'because it kept sizzling" and replaced it with a screw and nut. The teacher(?) got a good telling off before he left. I hope he learned something!

Maurice

A. J. Reeves stock bronze balls of the size that you want. I have used them to make governors in the past. Drill and tap quite easily.

K.N Harris,s oscillating paddle engine model, detailed in his book, has an eccentric driven plate valve, the timing of which could be varied. The book was called "Model stationary and marine steam engines".

Maurice.

Perhaps using a between centres arbor in the lathe to do your slitting might enable you to cut as you wish, that cannot be managed on your mill. Just a thought.

Maurice

I had this problem on some "Clarkson " castings many years ago. On advice, I put them in our coke stove, banked it up well with fuel, opened the damper to get everything nice and hot, then let it go out and cool overnight. No more hard spots in the castings! I realise that coke stoves are probably rare now, but heating and then slow cooling seems to be the answer.

Maurice

I was very pleased with myself, when I managed a Meccano version of the gear, having just see it in the Science Museum when I was twelve. I was just wondering if it had been used on treadle mahines or hand operated water pumps, or something. It seems too good to have had a single use.

Maurice.

Just out of curiosity, has Watt's sun and planet mechanism ever been used for anything other than its original purpose, of doubling the speed of a beam engine crankshaft?

The replacement, or possibly adjustment of gib strips was the subject of an article in M.E. many years ago. I recall that it recomended that the adjusting screws should have a short parallel end and a flat tip, locating in similar shaped holes in the gib strip. The reason given was that the usual pointed screws have a wedging action when the slide is moved, causing a wrong "feel" to the slide. I have no opinion on this, it's just something that I remember (getting less each day!) and may be of help.

Maurice.

I have one of these chucks. I bought it for a few pounds at a club auction many years ago. Mine was used by a firm called "Hills" and was used to make the adjusters for violin bows. These are hexagonal, a shape that these chuck seem to be made for.

Regards Maurice

Geoff may have the older version of the Super 7, which has an expanding clutch ring inside the cone pulley. This requires a screw pug to be removed from the bottom of the grove of one of the larger steps of the pulley. Then, holding the cone pulley still, the interior is rotated until a hex grub screw appears. This is a locking screw. It has to be removed to expose the head of the adjusting screw beneath. No wonder they changed it!

Maurice

It was said on TV the other night, that the virus will survive about 72 hours on a plain surface.

Maurice

A "man from the ministry" said on TV today that common soap and water is more effective than bottles of hand wash.

Maurice

What are your cylinders made from? If they are gunmetal then don't use piston rings.If they are cast iron, then piston rings are ideal; teflon impregnated soft packing is good if the slot is a good fit. "O" rings are fine if the bore has a high finish, or else they will wear rapidly.

Maurice

I am a passed master at putting things in a safe place and loosing them, but my worst example was last year. I was carrying a padlock and chain into the workshop. The key fell from the lock, and I heard it hit the floor at my feet. Never been able to find it since! Spooky!!

Maurice

I have a slab of material, about six inches by nine and an inch thick, which has a label describing it as gunmetal. Is there a way to tell if it really is gunmetal and not brass, other than chemical analysis please?

Maurice.