Ah, I'm not familiar with programmable logic controllers, way above my head there, 

Dave

Ha ha neither am I really but they are fairly simple things so I manage.
 Ladder logic is simple if you want simple or can get complicated if you need complicated and the Automation Direct DL06's use graphical ladders so it works for me as I prefer picture books . The part of the ladder for the new turret took me a while to work out but got there in the end, things like switches and analogue inputs are basic stuff and easy.

Hood

I prefer picture books . 

Now you're talkin - 

Dave

Looks great Hood, nice job.  Are you using a pocket PLC?

Its a Koyo D0-06DR from Automation Direct.

Hood

Have decided to do away with the twin 6 position turrets on my lathe and make a new 12 position for the rear and have a fixed block on the front. The reasons are it is sometimes a bit scary when first running code with the dual turret setup, it is mainly because the front turret sits much further forward than the rear and it is the front that holds boring bars and drills so clearance really has to be thought about. If I had managed to sit the front turret further back or if it had been the rear that held drills things would have been a lot easier. It was the dia of the front turret that dictated that it be so far forward as it had to have the tools that far forward to clear the apron.

I have decided on a 12 position rear turret which can hold normal square shank turning tools, have had to go down to 20x20 from the 25X25 I currently use. The turret will also be able to have the tools right way up or upside down which will be a big benefit. I will also have drill/bar holders that can clamp to the periphery of the turret plate and they can hold a max of 40mm dia.
 On the front of the saddle I will have a fixed block, the block will be bored for 50mm dia drills/bars and will also have a dovetail so that I can, if needed, use the holders I presently have on the front turret.
 I have had a frient rough out the turret plate outline for me from a chunk of 380mm x 380mm x 60mm plate on a water jet and hopefully I will get that next weekend and be able to start machining the slots etc.

Below is a pic of what I am proposing, I will still have the hydraulic clamp/unclamp and will aslo use a servo, as I have on the front turret, for the indexing. That will, like the front turret, give me bi directional, shortest route positioning.
It will likely take quite a while to get this project done but now that I have things drawn up I have a clear view of how to proceed
Hood

My friend brought through the rough cut turret plate, I was pleasantly surprised with how good it was. He had said it was the first time they had cut 60mm thick steel and it had wandered a bit (normally its glass they cut with the water jet), it wasnt too bad and as I had allowed 5mm extra on all dimensions I had given him it is well within spec, kind of wish I had only allowed 2mm now
I had also managed to include 8 drill/bar holders in the dxf I gave them and they too came out above my expectations

First job will be to chuck up the plate and face and counterbore the back so that I can fit half of the curvic coupling in, I will then mount the other half on the milling table and this will allow me rough out the slots and then for the final cut to size I will only move in 1 axis with a 40mm cutter and cut to size each slot in turn, rotating and clamping the turret on the coupling each time. This should make things very accurate as the coupling is extremely accurate. I measured it today and when both halves are clamped there is exactly 32.10mm measured over the thickness of the two halves and that is no matter where I measure or whether I rotate and clamp again, so its a nice coupling. Outer diameters are also exact and line up perfectly to each other so that the edges of them have no difference at all.
 Once I have the plate made I intend to make the body of the turret and face the bottom and front true to one another, I will then fit the coupling to that and sit it on the milling table and clamp the turret in the upright position. I will then be able to drill the holes and mill the keyway for the drill/bar holders one at a time, rotating again on the curvic for each one, again this should make things very accurate.
 Once the turret is made and fitted to the lathe I will then use the lathe itself to bore out the holders to the 40mm dia. I have a 39mm U-Drill that I will place in the chuck and once done I will then put in a boring head and adjust that to exactly 40m and hopefully that should work well and mean drills and boring bars will be exactly on centre.
Hood

Hi Hood, would you please give us a little more info on the curvic coupling you are going to use, where you got it, etc. as an aid to us prospective turret builders.
Thanks
Steve

I got the curvic coupling from a friend that had it for a spare for his lathes turret. That turret is the one I have on the front of the lathe at the moment, I got it from hime when he was about to scrap the lathe. Dont know how much he paid for it but it was a while ago he bought it and I think he would have got it cheap(ish) as the company was selling off all spares they had for that model lathe.
Hood