Member postings for old mart

The outer bushed hole is for external tapers and the inner is for internal. If your model A hasn't got the rest of the taper attachment, it hardly matters if it is cut off.

One perennial topic that is guaranteed to cause a wailing and gnashing of teeth is whether a three jaw chuck needs a tight or loose register with it's backplate.

You get the best of both worlds having a raiser block for the vise as well as the column. On a small mill, both blocks could be made from aluminium. A swivel base for a vise comes come in useful occasionally, and, as mentioned, adds height. Most vises with a base will fit on the table without the base. 

Edited By old mart on 29/01/2020 21:13:00

I remembered a picture of our Model A cross slide casting in my album.

If you don't use one much, just get a cheap one, but don't forget to salvage the stainless steel shafts out of the old one before getting rid of it. There is very little chance of ink cartridges which fit a ten year old machine fitting a new one unfortunately.

Similar rubbish like" if a tree falls in the forest and nobody hears it, doe's it make any sound?, or something like that. Argument for arguments sake.

People often disagree with me when I'm wrong, and sometimes when I'm right.

Good idea, you might even consider 75mm , but the existing height, quill movement and lowest clearance while milling very low work have to be taken into consideration.

I looked at Model L photos on the Lathes UK website, and most of the detail parts are identical to the ebay one. I sent the seller a message advising them to revise the listing to probably from the model L. The model L I looked at did not have a saddle.

Regarding genuine Mitutoyo, I was the only person in the factory who had their combination square set in the calibration system, and getting that approval was high praise for the set, made in Japan. I gave Brian, who did the certification of the employees measuring tools, my Rabone 12" rule to look at, and he said that it was a fine rule, but NBG as a straight edge.

I have two Mitutoyo surface gauges, one Japanese, and the other Brazilian, and they are equally well made.

From the ACME thread calculator that I use, the core will be at least 5/8", or a bit more, certainly achievable. **LINK**

If you are lucky enough to have a mill and rotary table, why would you ever need a female broach?

If you have the means to machine a replica, I would look at Kingston Engineering ACME leadscrews and nuts. They do a 3/4 X 8 ACME left hand and a variety of nuts off the shelf, and you would be better off with new m and f parts even if the pitch was halved. The new threaded part could be coupled to the front part of the old leadscrew, or a new replica.

Edited By old mart on 28/01/2020 14:33:50

I have lots of the serrated jaw sets, some were for larger chucks. You can get larger 1/16" serrated jaws to fit if you make custom tee nuts with the threads and pitch to suit the bigger jaws. the edges of the jaws where the serrations are may have to be narrowed slightly. I also have two sets of hard jaws, one standard and one a size larger. They did not run very well, and were slightly bellmouthed, so they got ground and run dead true now. I also had to number them to match properly. The underside of the larger ones had to be narrowed slightly, and as they are hard, I used a solid carbide end mill on them.. You sometimes get job lots of used ones on ebay really cheap, which is where mine came from, some well used and some nearly new.

Maybe stub ACME, but the Model A cross slide thread was 1/2 X 8 ACME and the core wasn't very big. 

The thread pitch, or lead can be checked by looking at the dial engraving, 4tpi would mean 1/4" , 250 thousandths, per turn.

Edited By old mart on 27/01/2020 22:39:33

The bit on the underside was confusing to me as I would have expected it to fit on the saddle directly. Would a bed clamp allow the cross slide to be used as a parting off fixture with the saddle out of the way?

I was interested initially, as the cross slide on the museum's Model A is cracked, but looking closer, the one on ebay is much shorter and doesn't have the taper turning attachment holes.

Edited By old mart on 27/01/2020 22:31:15

Got it in one, Mick, the parallax free Mitutoyo's have prismatic slideways and were more expensive than standard ones, that's probably why they are no longer listed. The one in the picture is 6", 150mm and has a spring loaded thumb lock, and the other 5", 127mm one has a locking fine adjuster like most height gauges. 

Mitutoyo have a facility in Andover, Hampshire UK, I bought a circuit board for a digital mic from them a few years ago.

Edited By old mart on 27/01/2020 21:44:43

Edited By old mart on 27/01/2020 21:46:38

Tracy tools sell some ACME and Trapezoidal taps:

**LINK**

Could you recheck the size? 4tpi seems very coarse for a 7/16" size.

What part is it?

Edited By old mart on 27/01/2020 21:28:51

Edited By old mart on 27/01/2020 21:31:27

I chanced upon this listing on ebay, and thought it looked a lot like a Smart & Brown cross slide, maybe Sable, M or L. Anyone know for sure?**LINK**

I did give the sellers good feedback, incidentally.

I still have two pairs of Mitutoyo Vernier calipers, they don't seem to make them any more. See if you can identify the improvement over the ordinary type.