Member postings for John Haine

If the gap is set to 1.26 mm by a licensed builder one would hope he uses something better than a vernier or digital caliper to measure it! I suggest that the OP should buy a Mitutoyo screw micrometer with calibration cert and a standard, and use that to make the measurement when the engine is collected fro the builder as a check, and also checks at the track after the scrutineer.

Or make one.

Photo please!

Patent filed in 1946. Even if granted it would have expired by 1966 at the latest. And even if granted and in force you could make one for your own use at home. I wonder if there could be mileage in something similar where the optical viewer is replaced by a laser pointer? Could be simpler to make in the home workshop.

I'd second Bowber, my Denford Novamill.

David, do you mean a tapered gib? Fitting one of those would involve machining out the dovetail to a matching taper. Both the mills I have had with with tapered gibs (an Aciera F1 mad the Novamill I have now the gibs are steel I think because they have to take quite a high longitudinal compression force without buckling.

I had a later version as a Christmas present once. Supplied ready made, thin cast iron open box section bed, plain CI bearings in headstock. Bit of a dog really....

How long and how fix to shafts?

Seconding Vic's suggestion, I expect all the carbon needed comes from the forge as well as being present in the steel to start with. In Samurai swords I think this is the case, and they only fold those over and over, beating out in between. This guy folded over and over, then twisted it! Amazing. But the glass one was better, nearly in real time, and as the jug got close to completion the risk factor became higher and higher!

Finally added the keypad overlay to my Ward division controller. Colour laser printed, laminated, stuck to an escutcheon milled from FR4 PCB material, screwed on to front panel. Looks serviceable, though not a design masterpiece. Will save me having to memorise what the keys do!

Check that there isn't a fragment of swarf between the mating faces. If all is absolutely clean check both faces flat.

David, er, no. For a reactive load the voltage and current are 90 degrees out of phase. The current will be rather low at low load and nearly in quadrature, and build up to the rated current largely in phase as the motor is loaded. And this almost certainly isn't a synchronous motor but an induction motor.

It's worth what someone will pay. You need to get it in front of as many people as possible and see what they bid, so eBay is your friend. There was one recently that went for over a grand IIRC, and that was one the seller had taken the motor off for some unaccountable reason.

Edited By John Haine on 25/04/2015 15:31:26

Keypad-controller cable came with Steve's kit if you buy the keypad. Other ribbon cable came from Maplin.

Last weekend got my digital dividing head working.

This is a Myford dividing head equipper with a stepper motor driving through a 2:1 timing belt reduction, mounted on the VMB table.

Built Steve Ward's controller kit with display borad from eBay and a Routeout CNC stepper controller that's been in a draw for years. Once the components were on the PCB and everything assembled, applied power and it sprang to life. Needed a slight tweaking on the config to drive the stepper. Still need to do the button overlay to label them and an escutcheon round the keypad.

This is inside the Eddystone box that houses everything. You cant see the display board because it's sandwiched underneath the controller at top left. I used my little CNC mill to make the cutouts in the lid for the buttons, the keypad fitted perfectly first time.

Cloase-up of the worm. I knocked out the taper pin holding it to the original shaft (which incidentally pushed it slightly out of true), put the worm in a collet and enlarged the bore to 10mm, fitted a new shaft with Loctite(10mm to fit worm, turned down to 8mm for bearings), bored out the bracket for needle roller bearings (8mm bore x 12mm OD), refitted worm with ball thrust races top and botton. There's an ali block bolted to the top of the bracket and the motor plate (1/4 aluminium) is bolted to that through short slots to allow some adjustment of belt tension. The bottom bearing of the bracket was removed to allow machining, but there is space to fit one back but no apparent need as with rolling bearings there's no play in the shaft when the bearings are preloaded.

Unit is powered with 20 volts from my bench PSU and takes about 4.5 amps when running. Steve's controller is an excellent item, highly recommended.

One more project (nearly) off the list! I may also add a motor to a little "Sharp" rotary table at some stage.

Edited By John Haine on 25/04/2015 07:33:13

If it needs more than a gentle tap, maybe you are tightening them too much?

Cnc gang toolholder?

I think brass would be absolutely fine! A DH doesn't rotate at any speed where bronze would make a difference and in its whole life is unlikely to make more than a few hundred turns. My Myford DH definitely sacrifices free rotation for low play.

OP said half a thou and a tenth, was that intended?