Myford Super 7 Tailstock Micrometer Dial

Thanks to Steve I am able to share with you a photograph of the Metric dial assembled onto the Tailstock. Looks as though it has always been there.

Regards

Gray,

Gray

Just a small aesthetic point. Was there a good reason for not matching the reduced diameter of the base to the diameter of the tailstock casting?

Mike

A perfect complement to the saddle handwheel.

Hi Mike,

I and my helpers have deliberated over this very point. One problem which exists is the eccentricity of the tailstock casting. On some tailstock bodies the eccentricity is very pronounce and this would show up even more if the abutment face was larger in diameter. Trying to match the two would be impossible and would always leave a step somewhere around the diameter. To make the backplate just a plain diameter would I feel detract from the current set-up and make the assembly look bulky. Of course there is no reason why anyone making the attachment cannot add their own flair in this region.

Nothing is carved in stone with my designs.

Another point in favour of the reduced diameter comes when fitting this attachment to the 254 lathe. It appears from the photographs I have seen that Myford have "spot faced" the tailstock in this region to take the same part as is fitted to the S7, so a larger diameter here would be a problem.

This then was some of the rational behind why I have done what I have.

Regards

Gray,

Thanks for that explanation Gray. I knew it would not have been unconsidered.

Looking forward to seeing a write up somewhere and making my own copy!

Regards

Mike

There has been some recent interest in the proposed Myford Super7 tailstock micrometer dial design by Graham Meek. I'm fortunate in owning one of the imperial version prototypes made by Graham himself and thus am able to report on same.

The design, in similar fashion to Graham's saddle handwheel dial design, uses a gear train built into the assembly to rotate the dial such that tailstock barrel travel can be accurately determined from the dial graduations. As Graham has mentioned in one of his posts the gearing methodology is perhaps counter intuitive but he has cleverly achieved the required ratio in a reasonably sized unit. The unit incorporates needle roller thrust bearings which in addition to the Myford tailstock thrust races, which are retained, give a silky smooth handwheel action. The dial can be positively set to zero with a smooth action using a friction arrangement as on the saddle wheel. Perfectly reliable.

Aesthetically the design is very pleasing, and is complementary to both the lathe and the saddle handwheel micrometer dial. It doesn't look like a bolted on after thought. Note that a complete turn of the handwheel gives 0.3" travel to the barrel whereas a complete turn of the dial indicates 0.5" travel of the barrell. This sits readily with the 1/8" graduations on the barrel. No alteration is required to the tailstock feedscrew or barrel nut.

Graham has been described elsewhere as a worthy successor to the late George Thomas. He also designed a tailstock micrometer dial but I believe that Graham's design is an advance on that with a larger parallel dial that improves readabilty and an improved correlation between the dial and the barrel graduations. The friction lock for the dial is much simpler.

In conclusion I happily recommend the dial for those in pusuit of accuracy, those who have the saddle wheel version will not need telling.

My understanding is that Graham will eventually publish a constructional article, possibly MEW would be an ideal candidate. There is also a possibilty that someone, albeit not Graham, will take up commercial production.

Michael

Hi Mike,

Just to let you know the article is finished and has been offered for publication, no further news at the moment as to where that will be.

Regards

Gray,

Thank you for the update Gray.

Regards

Mike

Hi Mike,

I shall be sending the article to Neil over the next couple of days.

Regards

Gray,

For those of you that will be attending the Doncaster exhibition next weekend, I will have on show one of Gray's prototypes that is fitted to my S7 tailstock. This will be on the Hull and District SMEE stand and I also hope to have the dismantled Metric version (again, Gray's prototype) available so that people can see the working of the gear sets.

I should be around most of the three days to answer any questions.

It is hoped that these will be available to buy later in the year.

Best regards,

Steve.

Steve, as to that timing, should I be putting one of these on my birthday or Christmas lists?

Cheers, Colin

Hello Colin,

I would say Christmas... ...unless your birthday is in January, February, March or April...

My best regards,

Steve.

I attended the Doncaster exhibition and there was a lot of interest in Gray's Tailstock dial that I have fitted to my own S7 Tailstock. I was able to demonstrate the gearing of the dial using the Metric version that was set up on Gray's test rig.

I was intrigued to see the "similar" offerings on the Myford stand, which leads me ask the question "Has anybody bought one of these items, fitted it and made any sense of the graduations?"

Unlike Gray's design, these dials (fitted to a shiny new handwheel) have no internal gearing and are sold as a direct replacement for the existing handwheel. The links to the eBay listings are here for the METRIC version and here for the IMPERIAL version.

One turn of the S7 Tailstock handwheel moves the barrel along by 0.300" or 7.62mm. This applies to both Imperial and Metric S7s

Taking the Imperial version first, I'm struggling to understand how 0-60 graduations relate to the 0.300" lead, much less relate to the graduations that are engraved on the barrel.

The same applies to the Metric version, which is graduated 0-3mm and again bears no relation to the engraving of the barrel on a "Metric" lathe.

Rather strangely, the Metric dial would give a better degree of service as an Imperial dial, given the 0-3 (mm) divisions. Indeed, the chap on the Myford stand tried to tell me that "They have just been swapped over mate" until I pointed out that the Imperial dial would not be marked 0, 0.5mm, 1mm, 1.5mm etc. His reply was "Don't know then mate"

Am I missing something obvious here? I don't think so but I'm happy to be corrected.

Best regards,

Steve.

Edited By Steamer1915 on 02/06/2019 11:05:42

Edited By Steamer1915 on 02/06/2019 11:06:45