Member postings for Steamer1915

Mick,

PM sent.

Steve.

As KWIL says, a Rotabroach is the way to go, especially if you have a few to do. I use a 20mm dia for the initial hole in the dial bodies and backplate. The main advantage is that they only cut a 4-5mm annular groove so not all the "hole" is turned to swarf. Use coolant though.

Steve.

Hello Joep,

You might not achieve the desired results with a commercial gear cutter. The diameter of the cutter may be too big. You need to achieve full depth for about 4mm and if the cutter is too big, the teeth will break into the slit on the sleeve gear for example. Graham Meek's original article recommends a single point cutter which scribes an arc of about 45mm diameter. The drawing above shows the idea.

All my dial gears are cut this way. the only difference being that mine is ground HSS as opposed to silver steel hardened and tempered. This allows me to cut a batch of 10 sets (40 total) of gears before grinding about 5 thou from the top of the tool to restore a sharp edge.

Best regards,

Steve.

Edited By Steamer1915 on 10/04/2015 18:39:07

Edited By Steamer1915 on 10/04/2015 18:40:24

Welcome to the forum Claude. There is a lot of useful information on here.

Best regards,

Steve.

Hello Paul,

I don't know if this would suit your purposes, but it's a good method to know anyway...and it works!

Best regards,

Steve.

Hello Scott,

The first thing to do is lose a nought off the lathe spindle speed. 250 RPM would be a much more realistic work speed for grinding something that diameter.

Best regards,

Steve.

Plus one for the A&R holders.

Best regards,

Steve.

Note the date of that report.

By Ed Cumming

12:08PM GMT 20 Jan 2014

Best regards,

Steve.

Hello Martin,

Glad to hear that the handwheel dial is giving good service.

Best regards,

Steve.

Mine arrived this morning. Very pleased following a quick look. A great deal of info for your pound/dollar etc

I was lucky enough to drive a 15F a few times at Vereeniging depot in 1988, so these will make good reading and remind me of great days.

Steve.

Edited By Steamer1915 on 14/01/2015 15:04:19

Hello,

The sleeve gear is 31T 40DP as is the other bronze gear. The steel gears (including the centre shaft) are 29T 40DP. The 29T steel gears are 0.775" dia and the bronze gears are 0.825" dia.

Hope this helps,

Best regards,

Steve.

Hello Graham,

I sent a PM on this subject earlier today.

Best regards,

Steve.

PM sent.

Steve.

Hello Les,

These are the terms that were placed on the eBay listing. "Returns: 14 days refund. Buyer pays return postage". Not sure how this relates to a faulty component but I think I'm on a bit of a sticky wicket anyway, as this was purchased 2nd September. I have only just got around to fitting it. In hindsight, I should have tried it when it first arrived.

I'm not sure that the output would be at mains potential. The motor is rated at 5.86V DC. I've been running the driver at 110V ac from a site transformer. I made this decision because the 220 volt limit made me think that UK mains voltage might be slightly too much.

Steve.

Thanks Les,

I'll try to take some photos tomorrow but I don't know how good they will be.

Steve.

Hello all,

I have been working on a CNC conversion for my Bridgeport Mill. The original idea was to just motorise the X axis and a 6” dia HV table so that the machine could cut gears whilst I got on with more mundane tasks.

The rotary table was done first with a NEMA 23 motor from Arc Euro and a cheap single axis TB6560 driver. BTW, I have found this driver absolutely fine for the NEMA 23 motor, despite hearing and reading many things to the contrary.

The X axis was the next to be undertaken using a Nema 42 motor and a DM2722A driver from Longs motors, again based in China. This was completed successfully and runs very well when driven with Mach3. For the gear cutting, I can live with the backlash on the X axis, but there are hopefully some ball-screws being brought into the UK for me next month.

Work has progressed on the Y axis conversion and I was all set last Friday to run both axis at once and cut a circle, albeit in fresh air. Unfortunately, the Y axis driver has shown an alarm from initial power up and refuses to work. I swapped the drivers over so that the “older” driver drove the Y axis and the motor was fine.

I have contacted the suppliers in China and they pretty much say that I must return the driver to them for testing, despite all my explanations and photos. I feel that they have me over a barrel really and the cost of posting to China and accompanying delays, doesn’t help my situation.

Is it going to be a practical proposition to have this driver repaired and is there anyone on this forum that could undertake such a task? I feel so frustrated because I came so close, even though I can still cut the gears ok.

Best regards,

Steve.

Edited By Steamer1915 on 27/10/2014 20:15:23

Edited By Steamer1915 on 27/10/2014 20:17:42

PM sent.

Hi Derek,

I can recommend John Dunn Engineering, he advertises in the Model Engineer magazine.

Best regards,

Steve.

The original article was published in 1960, not 2014.

Steve.