Member postings for old mart

Parting is a dark art, even using modern industrial blades does not guarantee success. Their inserts are tapered and are wider than the holder with much more sophisticated geometry than HSS, but can still crash. I quite often start off with a parting tool and finish with a hacksaw.

Part of the problem is not having enough stiffness in the system. A four jaw independent chuck also holds the work much better than a three jaw. There are lots of pictures posted which show the parting tool hanging in the breeze like a wet noodle.

Edited By old mart on 08/06/2020 20:42:34

Makes me glad to have the use of two mills, although not while the lockdown stops the museum from opening.

There is a YouTube video of either Sandvik, or Kennametal demonstrating parting off a section of railway line in a lathe. Personally, I wouldn't have the nerve to try it.

Looking at the super model oscillating steam engines in the forum at present, I was wondering if any had been designed with variable port timing?

I had even considered an eight pole motor until I saw the price.

Evan, would you mind if I posted your info on "The home shop machinist" forum in the USA? There are a lot of South Bend users there who would love it.

Smart & Brown Sabel users would benefit also.

I was also confused at first, and ended up checking the "all topics", and 3D printers was at the top of the list.

I don't think the method of drive matters much, just get whatever comes along. Having belt drive has a slight advantage, as already mentioned.

It would be best if you ended up with a smaller milling cutter and cut each side bit by bit to get an accurate slot.

You need clearance to expand split dies for the first cut. Then they are closed down a little at a time to get the final exact size. This gives the best finish on the thread. I have a set, but have never used them, as I prefer to single point using the lathe.

Welcome, Jerry this is a very active forum, there will be good advice on every subject you can think of, especially steam models.

If your Warco mill is not top quality, then its a gamble trying to get a replacement which is guaranteed to be better. It might be better to get all the advice you can on making the best of it, there will be known improvements, especially for this type of mill, they are plentiful.

Have you looked at the lathes UK Dore Westbury section?

**LINK**

Welcome, Carl, that is a very new looking Myford. It reminds me of the time the boss bought us a brand new super 7 long bed to go alongside the old ML7 we already had. This was when I worked in Cranleigh, and the lathe was supplied by Warco in their early days. The stupid charge hand switched it on and the chuck promptly unscrewed, bounced off the bed and on to the floor. Unfortunately it missed his foot. I had to stone the bruise on the bed before the lathe even cut metal. I don't think our one had the QC gearbox, it was back about 1980 or so.

What is that mill you have in the background of the photo?

I would not recommend any grease on the threads, a light coating of oil is better. The threads should be cleaned properly occasionally. As already mentioned, be sure to screw the chuck up firmly, then the shock of starting the lathe will not tighten it further.

ARC have 100mm four jaw scroll chucks for £59 with both sets of jaws which would probably be a lot better than your tired old Pratt.

The Smart & Brown model A has a feed shaft which can be used for both sliding and facing in both directions, but I cannot say which is faster. The facing uses the cross slide screw and sliding uses the rack to move, so there is probably going to be a difference. I usually use the leadscrew for ordinary turning which goes down to 76tpi, good enough for most things, especially if using a large nose radius insert.

Make the Mk2 with a 45 degree slope and see if it is any better or worse. It would be possible to use the other end of the existing tool and remove the unused cutter, or even use the other end of the cutter. I am always thinking of ways to reduce overhang on a much bigger, heavier lathe. Should you wish to try carbide, small diameter blanks are easy to get on ebay. To cut them, you need to score around the diameter with a diamond file, put the carbide in soft jaws in a vice and snap of at the score. It quite often breaks just where you want it to. Wrap the end you are holding in some rag just in case it shatters.

Edited By old mart on 06/06/2020 20:11:35

The other thing is to set your depth stop at just under the required depth and creep up on the final depth. As already mentioned, the lowest speed is best.

 By the way, I just noticed it was your first post, welcome to the forum.

Edited By old mart on 06/06/2020 19:55:55

I'm so used to three jaw scroll that I didn't notice that it was four jaw. Not much chance there as they are rare. The chuck can still be used as long as the capacity is reduced to a jaw opening which gives three undamaged teeth engaged in the scroll. I had thought of buying a four jaw scroll once, but they don't really have much practical use compared to an independent.