Member postings for old mart

Push down on the splined end of the spindle. The lower inner bearing will come out and the top bearing will remain in the quill. There are some drawings on the Denford Forum, this one shows the original MT2 spindle above an R8 modified one. There is a sleeve in the bore of the quill which can be removed. My R8 modification is broadly similar to the drawings shown. If you need new bearings, they are both the same size, and Timken imperial ones are easy to get from somewhere like Simply Bearings. Don't overpack the new grease, leave at least 50% air space. I used a common lithium high melting point grease used in cars and motorcycles.

There are some pictures in my photo album.

**LINK**

Edited By old mart on 08/06/2022 20:10:45

Edited By old mart on 08/06/2022 20:15:12

Edited By old mart on 08/06/2022 20:17:41

Since the thread has morphed into power tool leads, I will add my bit. I had a Black and Decker SDS drill from their professional range about 25 years ago. It dropped some comutator segments about 15 years ago and was replaced by a cheaper DeWalt which I still use occasionally. The first part to be salvaged was the nice supple black power cable which was immediately fitted in place of the horrible stiff lead originally fitted to my Bosch drill.

The thorium in the early jet engines was to help retain strength in the aluminium at higher temperatures near the combustion chambers. We have several examples of these engines at the museum, made by Napier in the 1950's. They are pretty well harmless as long as dust is not allowed to form from corrosion. One of the best corrosion and dust preventers is a liberal spraying of WD40 inside the engines, and keeping the exterior paint up to scratch. As I mentioned in the other thread, grinding dust is the danger, and even modern non thiorated electrodes will have the cobalt binder for the tungsten floating about to ingest if not ground carefully, preferably with a vacuum cleaner used. Cobalt is poisonous.

OK, it looks bad, but fortunately will have little practical effect on your milling. When the museum inherited the Tom Senior light vertical mill, the table was covered in scars much worse than that. I milled off 1.5mm from the surface and we then spent months rubbing it on the surface table to remove the milling marks. The surface table was covered with 120 wet and dry paper held on with double sided tape. I knew from experiance of using this method on aircraft parts which were then checked for flatness by the inspection department that 0.0005" or 0.012mm was easy to achieve. The mill bed has now only 5% of the damage showing. If the damage was similar to yours, I wouldn't have bothered.

Welcome to the forum, by the way.

The Tom Senior which was left to the museum in a will was taken to pieces and then strapped to 3 pallets, that way we didn't have the high centre of gravity to worry about. We did the same with the Atlas lathe, on 1 pallet while its stand was easy to handle.

Make sure they are modern electrodes, not the old thiorated ones, as the dust will be radioactive.

Visit an electrical firm which supplies electricians and ask them what the options are. I had a little gadget that worked very well and could be checked against known wiring easily. I got rid of it as soom as it became unreliable.

Go for the three milled flats then, they only have to be as deep as the ends of the jaws and will not matter with a small er32 plate. Shame about the thickness, though. I would stick a parting blade in about 1/4" and use the groove for a hacksaw guide. I bought some Starret blades for plastic and aluminium with 14tpi, but even with those it would take a long time to cut. If you go for partial parting, then use the tailstock to steady the work, it will be safer.

We used mostly monel on aircraft oxygen systems, I thought tungham was only for ground use. It was nearly 50 years ago, and as far as I recall, the fittings were made in the USA. Our old system was stainless steel put in before I worked there, and there was a funny story about it. When they fitted it, part ran through a small room used as an office up near the ceiling. The door opened inwards and there was a joint with the olive fitted backwards. It blew off when the pipe had a few hundred psi in it as the system was being tested for the first time, and pressurised the room just enough for the people in there to be trapped until the reciever emptied.

Take the jaws out of your chuck, assuming that you have some external ones and place one at the radius required by the workpiece. You can assess the number of teeth on the jaws which would be engaged by the scroll, it may be enough for safety. I would not be happy with less than 3 teeth engaged. You need not tighten the jaws much to allow facing cuts and maybe reduce the diameter carefully and then turn the work around. Three flats would certainly be a safe way although the work would probably run eccentrically at first.

You people from the other side of the pond often look down on their lowly relatives from the UK, but at least we never have to think about getting shot, ever.

You have to allow for a reviewer comparing a budget item with a top quality expensive one. Value for money can take a rear seat at times. Also, the occasional bad review can be caused by certain people not reading or understanding the instructions properly.

The aluminium will make perfectly good backplates for smaller lathes. You can try a test cut in the metal to ensure it is nice to work with or not. I doubt if the aluminium would be a nasty soft type to machine grade seeing where it came from.

I plumbed in a 5000psi air system in my old firm using tungham tube. This looks like brass, but stronger. The joints were made mostly using a setting tool in a vise to set the olives which had a small sharp edged step in the bore which cut into the tungham. This allowed better repeatability of joint strength than forming in situ. I seem to remember that the fail pressure for that size, about 9/16" od was about 20000psi. The pipe fittings and olives were made of steel.

Edited By old mart on 03/06/2022 13:50:10

That is how carbide should be used, however, you need to be absolutely sure that the last pass will be exactly to final size. That is why creeping up on the finished size is popular. There is a great deal of difference between steel alloys in their machining qualities. Same with aluminium, the pure metal is horrible to machine, the stronger alloys are much better mostly. You can google metal alloy properties and some sites give relative machinability.

By experimentation, you will soon find the best ways to machine metals.

Edited By old mart on 03/06/2022 13:39:39

Not too clever to have a browser setting like that on by default, not many people would ever need it.

Plain bearings would be best, and if you are concerned with temperature, you can get a tube of ceramic bearing grease which will be more than adequate, and plenty left over for other jobs.

Looks like you have stumbled on an obscure Windows shortcut key combination.

The sharp inserts intended for aluminium will work very well with lighter cuts in steel, both for mills and lathes. The cheap ones have got far better in recent years and if you are happy to use them instead of the steel grades, then go for it. Small cuts will take more time, but will extend the tip life greatly The radius differences are only significant if you want a sharp corner, and the tiny bit left could be removed using an ordinary end mill.

Edited By old mart on 31/05/2022 17:48:41

The Atlas 12 x 24 which we have been getting ready to sell at the museum has been raised about 40mm with a solid aluminium block at the headstock end to allow the fitting of adjustable screws at the tailstock end for "leveling". Rod ran some tests and found that the lathe was true even without the tailstock end being tightened up. So "leveling" should be easy. I posted this photo some time back when the subject was last brought up. The principal is like ega's photo in this thread.

A very good reason for riser blocks is to get the working height comfortable for older backs.

Edited By old mart on 31/05/2022 17:39:06