Member postings for old mart

The general danger from grinding aluminium is from the wheel rupturing as already mentioned. Dust build up is mostly forgotten, which reminds me of an incident with the toolroom vertical bandsaw. Apprentices had been busy cutting tooling lugs off of titanium workpieces when the saw burst into flames. The fire was put out with CO2 and after that incident, the saw was kept vacuumed out regularly.

At the museum, bench grinders are about to be banned, as there are so many people who don't seem to be able to use them safely. The only ones left will have diamond laps and one will have a slow moving wet wheel for wood chisels and plane blades. I won't miss the damn things.

Edited By old mart on 13/03/2020 20:29:37

Mt2 is a very small and flexible tooling size for milling. That is why I converted the same model of machine to R8. If it couldn't have been done, the mill would certainly have been done up and sold rather than kept for the museum. There was no way we would have downgraded the size of all three axes as well as the spindle capacity from the existing drill mill.

You can use the mill to take off the required amount off the bottom of the lathe tools. HSS cutters may not fare well on the steel of the tool shank. I buy 20mm tooling and reduce the height to 17.52mm using a shell mill with carbide inserts intended for steel. The inserts do not last long doing this.

If you use standard tanged MT2 drill chucks, then a plain rod of 3/8" diameter can be used to extract using a copper hammer. As for collets, I would recommend an er25 with the MT2 shank. You can easily get a length of 10mm studding and nuts to make a drawbar for it. The er25 holds up to 16mm end mills and slot drills. For shell mills, an arbor of 22mm diameter for MT2 and it is possible to get 40mm shell mills holding four APMT 11 inserts. 50mm shell mills are more common, but may be a bit big for MT2.

I use TNMG frequently, the 16mm size which is too big for a Myford unfortunately, and have never seen smaller ones. I have about 6 different grades for steel, cast iron and stainless, as well as the aluminium grade which is good for finishing cuts on all types of ferrous except the harder steels. You get six edges per insert unless loosing an end ruins the other side at the same time. If yours are too big to use on your lathe, then they make great scrapers screwed on to a handle, and the edges can be sharpened by rubbing on a coarse diamond lap.                                    Because they do not have any relief, they are held in the tool at a 7 degree downward angle on an axis through the tip and the centre hole.

Edited By old mart on 12/03/2020 19:32:44

Further to the variable power outputs when running a three phase motor from a VFD, this 3/4 hp 1500 rpm motor is typical of the type fitted to Myford lathes, note the figures quoted by the manufacturer.

**LINK**

I would like to see a picture of the cutters designed for these collets.

You don't have to pay much to get a reasonable 16mm boring bar. And CCGT09 inserts for aluminium will also fit it.

**LINK**

I f you don't have the luxury of a taper turning attachment, you have to advance the compound by hand. This makes an even speed very nearly impossible. The depth of cut may be too deep for the diameter of the boring bar and the insert may not be sharp enough for finish cuts. The tip needs to be at or just above the centre line (+0.005". I would use the biggest boring bar that would fit the hole. You can probably get a larger diameter bar to fit your lathe. Measure the height of your bar above the bottom of the toolpost , it may be possible to get a 16mm one if the 12mm one has 4mm of packing shims under it.

I remember way back when all straws were made of paper, that is after the original straw straws stopped being used. Cotton buds now have reverted to biodegradable paper handles also.

I never would have guessed they were for holding a cutter with a threaded shank, very different from the common threaded shank cutters.

I have two test bars, both Indian origin, a 7" and an 11", MT2. I bought them some years ago, so have no up to date info on their availability at present. Checking the sellers feedback before buying on ebay is always recommended.

The rings in the bore are said to enhance the grip. The threaded end could be used to provide a depth stop, but due to the design, not 100% repeatable.

Having a test bar such as this one comes in very useful and its not too expensive. It can be held between centres also.

**LINK**

I would also go for a solid carbide for aluminium, the uncoated type. How the plastic will cut using the parameters you are confined to remains to be seen, good luck.

I don't know whether this will help: **LINK**

Welcome, Jeff, you will be able to give good advice to our less experienced members, and me as well, no doubt.

It would also be worth buying some of the most used sizes and keep the set for best. I buy drills in lots from ebay suppliers, such as "cnc poor boy" who sell top brand names. Your investment also makes having a decent drill sharpener worth while. I'm sure there will be some recommendations based on actual experience for a sharpener. I use a Proxxon one at the museum, it can manage drills from 3/16" to about 9/16". The smaller drills are too short to fit in the machine without putting them in an er8 straight shanked collet of similar. It can give good results with practice.

The downward spiral began when the News Of The World went bust, you know what they always said of that paper.

Anyone qualifying for a pneumonia inoculation who hasn't had one yet should think seriously about getting one.

Welcome Drew, it looks like you will be able to teach us a thing or two, I look forward to learning.