Graham Meek?s Tailstock Dial – MEW279

[Steamer1915Participant @steamer1915]

Posted by Martin Kyte on 23/05/2020 10:31:31:

No, I've got a planing fixture and it takes about 20 mins to index round so it's quicker in the end.

regards Martin

I'm with you on this Martin. When I make a batch of Graham's Saddle dials, I use a rig where the slotting head drives a rotary table via a seven tooth ratchet wheel. Each dial takes around 7 mins and the "knurl" is perfect everytime. The dial on your lathe was done exactly like that. There are 504 "teeth" if you care to count them. I shall use a similar rig when I get around to making the tailstock dials. I have made a 6 tooth ratchet for that job – that produces a very similar pitch to the saddle dial even though the diameter of the knurled diameter is smaller.

Best regards,

Steve.

 

Edited By Steamer1915 on 23/05/2020 11:13:30

[Graham MeekParticipant @grahammeek88282]

Posted by DMB on 23/05/2020 10:09:21:

Martin,

How about a separate thin knurled piece, when satisfied with result, affix it (superglue?) to the dial? I would do it like that as I wouldn't be very happy having done all the other work then bugger it up.. Have made some dials but not woth any knurling.

John

Hi John,

The straight knurl here was done with a single wheel straight knurl. While it is not as crisp as Martin's or Steve's it comes a close second. After making 500+ Myford handwheel dials using the same technique I thought I would share with you how I do this.

I never knurl a dial after the graduating, and the knurled diameter is always lightly skimmed. The skin of barstock is not the best thing for knurling wheels.

The Knurling wheel is set in the toolpost such that the wheel is canted towards the tailstock by a few degrees. This way the leading corner of the wheel is touching the work first. Prepare the knurled portion and have a chamfer at the beginning and the end of the to be Knurled surface.

For a 5/8" knurl I usually run at 65 RPM for dials of this size. The feed is about 0.1 mm or 004" per rev. Make sure the knurling wheel is absolutely clean. Touch on the diameter with the knurling wheel and then move towards the Tailstock. Put on a cut of about 0.2 mm or 0.008" deep. Engage the feed and apply a drop or two of cutting oil, preferably out of an oil can, and never with a brush which has been used for turning. The brush will not only end up in the knurl but it has little bits of swarf that will damage the knurl.

It may take a couple of cuts to get close to depth. Finally put the knurling tool in the toolpost square on and present to the work with the work revolving. Approach slowly so that the knurl can pick up the work. If you are not happy doing this just bring the knurling tool up to the stationary work and with your free hand just work the knurling wheel back and forth until it engages. Start the spindle and continue to apply light pressure. Move towards the tailstock but be sure to keep the knurl engaged. Re-engage the feed but at half the original feed rate.

Using the chamfer tool clean up the chamfers to remove the displaced material.

As regards Blacking.

I use Curator Antiquing Fluid for Brass, Copper and Steel. De-greasing is paramount and I use Isopropyl as a first step with an old toothbrush. Followed by a wash in warm water which contains washing-up liquid, followed by a warm rinse and a quick dry with the airline. Before immersing in a solution of 10% Curator and water from the workshop dehumidifier. It takes 2 minutes according to what it says on the bottle. I have to admit I was sceptical about this but it does exactly what is says. If trapped air bubbles form on the knurl give it a rub with a clean old toothbrush. The part is removed, rinsed in water and blown dry with an airline before being given a coat of Shell Enisis.

The Dial above has been in service for quite a while now and shows no sign of deterioration of the blacking. The bulk of the Curator Fluid bought is still in the bottle ready for the next big item. The made up solution is kept in an air tight container and is still usable for blacking small parts, nuts, bolts etc.

Regards

Gray,

[Martin KyteParticipant @martinkyte99762]

Eventually, and I'm nearly there, I shall have completed my Stepper driven headstock dividing head. I have already built a Pic based controller to divide by anything you like. That would reduce the time to about 5 mins.

regards Martin

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