Orac and Triac retrofit

[stevep]

Last year I bought an Orac and a Triac off eBay with the intention of upgrading to modern controls. I have decided to go the mach3 route, re-using anything I can in the machines. They both have ATCs. I've been checking out this forum, and it looks like all the info I need is here, so I thought I'd keep you updated with my progress, in case my mistakes end up being helpful to someone else. I've decided to start with the lathe. And I'll probably have some bits going spare if anyone needs them (both machines power up fine, and I've run the mill, but didn't get round to testing the lathe.) The Orac is quite a late one I think; the stepper drives are Digiplan SD3, and the VFD is an IMO Jaguar Cub dated 1987.

Anyway, I'm sure I'll be asking for help here, but hopefully I'll be able to offer some too (I'm familiar with programming PICs etc, which might come in handy for the ATC bits. But that's bottom of the list for now.)

Don't expect a speedy completion- a now 6 month-old baby stalled the project before it began, but I'm hoping to get the odd 10 minutes in...

[bradders]

Good luck and keep us upto date with your progress

[Andy B]

Admin - can this thread be moved to either 'Projects' or 'Machines'?
Should make it easier to find in future....

Oh - and hope the project goes well when you manage to get going with it!

Andy

[Denford Admin]

Ok - moved now.

Please do keep us informed of your progress, I'm particularly interested in what software and hardware you end up controlling them with.
There seem to be loads of options appearing at the moment.

Unfortunately I'm not keeping up with the forum at the moment because I'm working 100% on a new project, which I'll be posting about (much) later

[stevep]

Well, I got a chance to open the Orac up this week, and did a sketch of the wiring before starting to take bits out. I was a bit confused at first at the wiring of the emergency stop switch and what I thought were homing switches- seems a bit odd that these are connected together, and to the main power relay, when you're not familiar with the concept. Once I did a bit of research on this forum, however, I realised that they were limit switches, and it started to make sense. I bought a breakout board from CNC4PC, with charge pump and analogue out included, and I want the machines to be self-contained (my workshop gets dusty and would kill an exposed normal PC quite quickly I think,) so I bought two small form-factor 3Ghz IBM PCs for 80 quid off ebay to fit inside the machine cases. I also splashed out a bit and bought two industrial 15 inch touch screens, also off ebay. I managed to get all the bits mounted inside, and some of the wiring done, in a couple of afternoons. I made a new end plate for the rack with a slot for the parallel port connection, and fitted an aluminium shelf inside with the breakout board mounted on top, and space for a couple of boards below (for when I get round to the ATC.)

One question- is there a normal way to connect the emergency stop? I'm a bit confused as to whether to just hook it to a pin to send a signal to mach3, or if it's better to make it kill the power to the spindle too. I guess it's better to allow mach to stop the spindle and drives in a controlled fashion, but I'm a bit unsure as to how to combine the charge pump, the output enable pin, and the emergency stop button. If anyone has any tips, I'd be grateful.

I've attached some pictures..

Oh, and I noticed some posts on the forum regarding converting the 5v of the breakout board to the 12v of the drives. It seems to me, however, that the inputs of the drives are pulled high internally, so they require pulling to ground, which means it's not really a voltage shift, you just need the input to go low. I decided to try using a ULN2803 chip that I've used many times in the past, since all the series resistors etc are all contained within, so all you have to do it connect the input to one side, and the output to the other. And there are 8 drivers in there, all capable of sinking 500mA each. I'll let you know how I get on with it, since it's a lot easier than using individual resistors and transistors, especially if your soldering leaves a bit to be desired...

[stevep]

er, seems like I forgot to reduce the image sizes- now I have to scroll horizontally on my 17" laptop to read the thread... Sorry about that!

[Denford Admin]

Its OK - I've reduced them

PS If you haven't tried this already, its a nice and easy way to reduce images- and its free from Microsoft:

https://www.microsoft.com/windowsxp/down ... rtoys.mspx

[shakey j]

Any updates on this as my axis drives have gone on my Orac again so i'm thinking of having a go at this.

Are there any step by step guides on how to do this and what is required for the job?

Any help with this would be appreciated

Thanks,

Mark

[stevep]

Do I win the record for the slowest retrofit? I pulled out the Orac guts in 2007 and today I got it running

[TDIPower]

Not yet... I'm working on beating you. I bought my Starturn in 2014. So far i have bought VR turning software, a control board and that is so far!