TDS 1/1 GBL Lead Screw Dial

[dakes55]

I am looking at making a lead screw dial for thread cutting, I just wondered what sort of gear i will need for it and would one of those generic types available on ebay do the job, any advice on this would be most welcome, or would there be anyone in the forum who could make a gear for me please as I dont have access to a milling machine or dividing head.

[Pete.]

You don't strictly need a dial if your motor reverses. I never used a dial on any of my lathes. You can just back the tool out, reverse the motor and run the carriage back to the start of the thread.

[dakes55]

Thanks for that, I already thought of that but the problem is my motor doesnt reverse because it was 3 phase origionally but the guy who wired it up for me didnt know how to wire up the 3 way switch for reversing single phase, so im stuck with it running forward at the moment

[LesT]

Thanks for that, I already thought of that but the problem is my motor doesnt reverse because it was 3 phase origionally but the guy who wired it up for me didnt know how to wire up the 3 way switch for reversing single phase, so im stuck with it running forward at the moment

Single phase motors can be reversed, but whether it is practical or not depends on what type of motor it is and whether all of the connections can be accessed easily. Single phase motors are usually two phase actually, either with a speed switch on the start winding or a capacitor in series ( capacitor run motor). If you reverse these connections it will go the other way. Alternatively you could get a 3 phase motor and an Inverter drive, that would do it for you. Google is your friend...
(Reverse single phase motor...)

[dakes55]

when i had the wiring conversion from 3ph to single done the motor was running the wrong way so i just swapped the yellow and blue wires on the start winding and it ran the correct way, the problem is i cant figure out how to wire the original forward and reverse switch to work correctly, it was wired exactly accoroding to the Viceroy single phase wiring diagram, but for some reason it only runs in forward position, its managing to get my head around the switching postions on the switch, i find the workings of the switch difficult to understand, looking at a myford type switch seem pretty straight forward but i want to use the original switch. maybe it would be better to rewire the switch so it swaps the start winding polarity, i need to work it out.

[Pete.]

Put up some photos I'm sure we'll get it sussed.

[DavidB]

Keep at it it can be done, I rewired my Kerry 1140 some 30+ years ago from 3 phase to single phase and worked out the wiring for the reverse switch from the switch details and the connection straps at the motor which gave the strap connections for the direction required, just needed to work out how to do that at the switch. Keep in mind that a 3 phase motor can be reversed by flipping the direction control when running whereas a single phase motor of whatever type IIRC needs to be stopped or slowed sufficiently for the start winding to come into effect, it depends on the motor type, or the motor won't reverse. IIRC the motor on my Kerry was from Machinemart and a permanent split capacitor motor so low starting torque but the lathe has a clutch between the motor and headstock so not an issue.

[dakes55]

Ok, ive spoken to the guy who wired up the brook crompton motor and he has told me that the terminals are wired as follows
AZ-LIVE
Z-NEUTRAL
T-LIVE
Z&T START WINDING
AZ&A RUN WINDING

If the blue and yellow wires are swapped then it will run in the opposite direction.(the yellow wire has faded colour and looks white)
I can wire the motor ok, but its how to wire the 3 position switch thats confusing

[dakes55]

Does anyone know how the thread dial indicator fits onto the saddle?

[Pete.]

The thread dial has a peg sticking out of it that plus intonation hole and it's secured by a grub screw.

[dakes55]

All sorted now thanks, ive got it wired to run both directions now

[paulmo101]

Hi Dakes55 not sure if your machine is metric or imperial - I have the metric version. I can sort you a picture of my TDI if that will help?
Also search for thread "Another thread cutting calculator" within this forum for some good info and a download spreadsheet with all the clever stuff already sorted as regards pitches and changewheel info. Also within that thread there is a member named molyneux.mike who was making some gears for the TDI`s and I believe some complete units - not sure if the chap is still active on this forum but he was a very talented engineer and I purchased a different size gear for my TDI as you need at least 2 to cover most of the pitches I believe. Not sure where you are but if you are close to or passing by Stoke on trent you could call in to have a look if that would help?

All the best
Paul