Member postings for old mart

When I was an instrument mechanic, we used to get the red/green fault reports from the RAF with the kit they couldn't fix themselves. I remember an exhaust gas tester, (rather like an AVO meter) sent to us with the glass broken and full of wet mud with green mould growths in the works. on the fault report was "doesn't ackle",it made us all laugh as we scrapped the meter.

Edited By old mart on 30/11/2022 18:40:54

Not so good in an unheated workshop as the winter draws on, but thats the only drawback I can think of.

For home use with a low powered machine the large diameter shell mills can only take small cuts, but as the user is not usually expecting to make a living out of their work it does not matter at all if the cutter is lightly loaded and takes longer.

When the museum was left a Tom Senior light vertical mill in a legacy, I did two things to it at first. The spindle was changed to R8 from MT2 and the 1/2hp single phase motor was changed to a 1hp 6 pole three phase one. This is powered from single phase mains via a Schneider Altivar 12 programmed to run between 450 and 1350 rpm,(25-75 Hz) with remote control. Together with the 4 speed belt drive, the spindle speeds have a good range. Top speed as set is 3000rpm, and could be 4000rpm with only 5 minutes added programming which is easy because of the excellent "quick start guide" from The inverter Drive Supermarket, which also makes the wiring a piece of cake, none of the whinging about not being able to understand how to set it up so common on this forum.

Edited By old mart on 30/11/2022 18:20:52

The 80mm shell mill will work with your mill, but the bore might need an arbor for it rather then being able to share with the existing one. You will soon notice the sound of the motor struggling if you try to take too big a cut rate. You will find that having some inserts for aluminium as well as for steel is a boon. With an even number of inserts, you would not be out of balance much using it with one cutting on its own, and even less if a worn out insert with its edges ground back a little was fitted opposite. With an odd number of inserts with only one cutting, you could turn up a couple of steel thick washers to attach using the insert screws on the opposite side. I have never run one with only one insert, it might not be noticable at the speeds these mills can achieve.

If you can get one that uses the same type of insert as your existing shell mill, all the better

Edited By old mart on 29/11/2022 21:05:50

It would lessen the impact forces on the threads and nut if the quill was locked before removing the tooling.

Vee anvil micrometers usually are 60 degrees, to highlight the most common type of lobing on shafts which has 3 highs and lows. There was a recent thread concerning one of those micrometers.

The steel that the rack is made out of leaves a lot to be desired. I wonder if the sections were originally made with a symetrical profile, so they could be turned round?

That poor thing is crying out for a new home and lots of TLC, it could still work well.

I got both of my Dasqua instruments from RDG, but Chronos is a good firm I have dealt with in the past. If ARC sold that make, I would probably have bought them there.

I would try straightening it in a press, but I have a lot of experiance with such things. You could try it in soft vise jaws with shims. A shim taped on either end and one in the middle, shim width about 10% of the overall job. the object is to only spring it in small stages, about 1mm at a time and check each time before adding shim thickness. The best result would to make it about the original bend, but in the opposite direction. Then apply pressure in the reverse direction and it will straighten and stay there. If I was cutting gauge plate, I would cut the long axis in line with the grinding marks.

Edited By old mart on 27/11/2022 19:00:55

Edited By old mart on 27/11/2022 19:03:40

I agree with Clive about having more than one chuck. A replacement 16mm chuck will not be able to hold drills under 2.5mm and would not really be happy with drills under 6mm. The ability of a smaller chuck to hold, say 10mm down to the smallest you have is helped by the chuck body being much smaller, it won't get in the way so much. A 10mm size would need an arbor to fit, the joint between the chuck and arbors is not meant to be disturbed during the life of the chuck.

With a standard keyed chuck, I back off the jaws and drill through the thin wall between the body and the end of the arbor. Then a drift can knock the arbor out of the chuck, much easier than wedges. The arbor can be used again with a new chuck if the main Morse taper if not damaged, most 16mm chucks will say J6 or JT6. In your first post, the code on the arbor, 2J6, looks like 2 Morse taper and 6 the size of the chuck end.

It was the removable tip with carbide scriber, the fine adjust and that extra height that made it worth the extra from the 6". If you ever wanted to measure 9", the fine adjust can be removed. There was an earlier thread regarding the Dasqua brand, and the comments were very favourable, On the strength of that, I bought my 6" digital calipers, and was not dissapointed. I do like quality measuring instruments, I still have masses of Mitutoyo's.

I would have added a picture, but I'm having trouble with them and the post timed out before I had got the pic into my album. Here it is at last.

Edited By old mart on 26/11/2022 17:37:04

I have had a height gauge for many years, originally bought for use at work. It is a dial type, metric and 2mm per turn of the dial. I find it easy to missread, especially as I get older, and have longed for something easier to use at the museum for some time. One of the poor quality Lidl 6" digital calipers is being modified to sit on a Mitutoyo scribing block, and will be useful on the machines when it is finished, I will post photo's them. Meanwhile, I looked at Dasqua height gauges, 6", 8" and 12". The 6" is good for small work, but I liked the look of the 8" one with the removable carbide tipped scribing tip. It came today by DHL after ordering it on Thursday evening, and I am very pleased with it. A nice strong plastic case, two 2032 cells and it can reach 8 1/2" high.

I was under the impression that to save bother with removing the spindle from Myford lathes, a linked belt was an excellent idea. If you are unsure of the size, quality and length required, Lathes UK sell linked belts.

The Smart & Brown model A at the museum has a linked belt from the motor to the gearbox as standard, Mike took one link out of it as it was at the limit of adjustment years ago, I bought a new belt just in case, but it is still in the cupboard.

Starting with the chuck, it would seem to have a J6 taper inside the body. This is like a very short Morse taper. The chuck is a common size, 16mm /5/8" the maximum drill size it can hold. The 2.5 (mm) and 3/32" is the size of the smallest drill it can hold. The long taper will be likely MT2 or MT3. the chart will give you an idea of the exact size.

**LINK**

After getting the replacement consignment quickly, and being able to fit them, after a slight modification because my valves are pretty old (boring out the bottom 1/4" of the hexagon base to 0.850" diameter), I needed some more to fit all the house radiators. Another seller had 6 for £18, even cheaper than the original lot, and they came today in a proper box delivered by Yodel. I only needed 3, but they would have cost as much as the 6 that I bought.

I had a thread regarding a smaller version which was laying about at the museum, unfortunately even after buying a suitable Morse taper to chuck adaptor, it didn't run very well and it has been consigned to the bits box. Also Crown brand.

Edited By old mart on 25/11/2022 15:29:35