Denford Software & Machines

I have an 1984 Orac with the 8 position ATC on it. It powers up and goes through all the normal set-up procedures but it will not run either axis (manual or program). Looking in the rear panel I noticed there are allot of connectors sitting loose and they seem to be for the ATC. The wires from the molex connector for the ATC are loose as well as several other wires (from power supply and a white "deadman's" switch beside the ATC molex). It seems like there is a card missing from the back of the machine. Also the power supply is loose in the chassis. It definitly seems like someone was working on it as some point in it's life. It's from a teaching collage so it may have been crashed and they were trying to repair it. The control serial number is 4806-0570. If there is a replacement card avalible can someone point me in the right direction. If not then I may gut it and upgrade the controls.

TIA
Adam

Hi

The deadmans switch is the manual turret rotate.

The machine should move without the turret connected. Have you hit a limit switch. Try going into manual mode, then hold the left hand button on the right hand side of the machine under the front panel. Kepp the button held in while trying to jog the axes.

To be honest with you, the toolchanger was an add-on for the machine. As a result it can't do fully automatic toolchanges - i.e. you still have to hit start after each toolchange which is rather inconvenient If you plan to do lots of jobs that require toolchanging then a controller upgrade may be the way to go.

Cheers

Dave

davidimurray wrote:Hi

The deadmans switch is the manual turret rotate.

The machine should move without the turret connected. Have you hit a limit switch. Try going into manual mode, then hold the left hand button on the right hand side of the machine under the front panel. Kepp the button held in while trying to jog the axes.

To be honest with you, the toolchanger was an add-on for the machine. As a result it can't do fully automatic toolchanges - i.e. you still have to hit start after each toolchange which is rather inconvenient If you plan to do lots of jobs that require toolchanging then a controller upgrade may be the way to go.

Cheers

Dave

HI Dave,
I figured the button was either for a manual change or an external e-stop switch for the teacher but I was leaning towards the tool change idea.

When I first got the lathe and fired it up the axis display was reading the X and Z axis were well out of their working range (400+ mm each axis). When you use the manual feed buttons the display reads that it's moving but no axis movement at all. I tried both switches and also manually moved each axis by hand to the mid point in their movement. I was hoping it was just because of the missing board but I seem to think it's something deeper. As I stated before the power supply is loose in the chassis so it seems like there's something deeper. I may end up going the retro route. I do have two other Orac lathes one has been partially converted and the last one I haven't picked up yet so I don't know what condition it's in. The first one has been partially converted and it was just a poor job I'm in the process of re-doing it completely. I was hoping to get this one running with minimal work so I can start making chips.

Any other ideas would be appreciated. If not then there may be some spare parts up for sale soon.

Thanks
Adam

Bloody hell - sounds like you've got quite a collection there.

Probably best you open it up and have a look at the stepper drivers - should be some lights on them showing the status. THere are also some fuses on the PSU. We seem to be getting a lot of dead stepper drivers in here at the moment - maybe they had a self destruct day

If the drivers are ok then you may be able to reuse them with a Mach style refit - thats what I have done with my Starturn - see the thread - and hooked up the old drivers to a breakout board via some transistors.

Let us know how you get on

Cheers

Dave

I didn't have a chance to check the led status as my step up transformer dosen't have enough amperage to test it any further. Hopefully I can look into this deeper before I go any deeper.

If I do gut it and fit new controls I'll probably go with a Xylotex controller and a 1 ph to 3 ph power supply for the motor. I think trying to keep the old cards would be too much work for me. The power supply in my first lathe will control spindle speed, forward/reverse and electric motor braking. Right now I'm just using switches for the direction and a pot for the spindle speed. I need to interface it with the optical tach on the spindle so I can controll it with Mach 3. With the Xylotex controller I can still use the limit switches and steppers. I have it hooked up this way in the first lathe but I may still upgrade the steppers to 450 oz/in as the stock 180 oz/in I feel aren't strong enough to take heavy cuts in 6061.

The biggest concern I have with retrofitting this lathe is the ATC. I don't know how it's controlled by the lathe. From what I've heard it's an electric motor that when engaged it moved to the next cam and then reverses to stall the motor onto the cam to prevent movement. I can be wrong on this though. If so how can this action be replicated with an aftermarket controller? This is why I hoping to find a replacement changer controller to us even if I decided to retrofit it.

I was actually looking for a Triac Fanuc ATC when I stumbled accross these two. If anyone has one for sale in North America I would be interested in a trade

Adam

Hi Big Bear

A xylotex will just about do you from memory as I think they support upto 3A. You may be better to go the slighly more expensive gecko route and allow you to upgrade in the future.

The spindle motor should be 3 phase - there should be an inverter in the machine - may be a Barry Wright Parajust.

180oz/in motors - surely they are bigger than that!!! I think they are rated at 3.1A and something like 2V - my guess was that they would be around 400oz/in. We've cut EN24T steel and 7075 ali at 1mm depth of cut and 50mm/min without trouble. The motors are probably Cetronic ones so you can check them out here - https://www.cetronic.co.uk/category.asp?ID=25

With regard to the ATC I will direct you to the Mach forum - https://www.machsupport.com/forum/index.php?topic=1882.0 = thats the guy with the Starturn 5!

In particular - because I'm too lay to write it again - here is my comment -
"Hi Max

So you're the guy with the Starturn 5 - we've just been discussing your lathe over on the denford forum (www.denfordata.com/bb). I've got a Starturn 4 converted to Mach at home, a mate of mine is converting an Orac, and I also use an Orac and Triac at work.

The basic working of the toolpost is quite simple. The toolpost should only rotate in one direction, and there is a ratchet that prevents it being pushed back. Basically the three optosensors shine light onto a BCD coded disc. So what you will get back is 3 lines giving you the tool number. When the correct tool number is detected, the toolpost motor is switched into reverse and the toolpost drives back against the ratchet.

So in theory only 4 wires are required. You will need to find the circuit that controls the toolpost motor and see how this is turned on and off. With regard to the signal lines these run at 12V which is a bit more inconvenient and will require you to make up some optoisolators. I started a project to do the electronics for my mates toolchanger - unfortunately he is yet to get his lathe going so i've only tested the electronics on the bench.

Basically I used an AVR microcontroller - I then wrote a program that read the an RS232 string - converted this to the toolnumber - activated the toolpost motor and then rotated the tool until the correct one was detected. It then sent an RS232 string back to Mach to tell it that the toolchange was complete. John Pearson has done something similar - see the VB code to drive the RS232 comms here -https://www.machsupport.com/forum/index.php?topic=1658.0

Hope thats some help

Cheers

Dave