Topics

1

VB and the development of wizards / Lathe turret ID and installation

« on: April 04, 2015, 08:23:13 PM »

I scored a nice turret on ebay but have no documentation or even a clue to the manufacturer. I think maybe Duplomatic or Pragati... Can someone with previous experience please provide a little guidance on how this needs to be set up and how the control of it should be performed? Thanks in advance!

2

Show"N"Tell ( Your Machines) / VDF/Padovani Rescue

« on: March 18, 2015, 07:35:05 PM »

Still a work in progress but it starts to look like we can finally settle on Mach3 and start putting things back together without worrying about taking them off again 5 minutes later! We were looking for a large lathe and came across a suspiciously cheap big old lathe. VDF is a German brand so I was willing to take a look. The machine was in pieces, could not be seen running but I was assured she was ok. Yea, sure... Mechanically she looked ok and the price was barely above the scrap metal rates. Little to lose, much to gain. Sold! 800mm max. diameter and 2000mm bed, quite a large lathe and just what we need to complement our other machines.

We got the machine back to our shop and surprise surprise she wouldn't start. The backup battery had failed. But here is the weird part. The machine was actually a home-brew retrofit of a Padovani system with a Sinumerik 805. But to reset the parameters you needed either an original Sinumerik keypad or this special software. The keypad was 500eur at best on ebay, and the software was impossible to find. We called a service center who immediately tried to screw us over and wanted 2000eur to reset the machine. Enter MachIII. We spent a few days reverse engineering the machine as we had absolutely no documentation. We opted for a smooth stepper, PMDX126 and PMDX107. The control panel has a PC built in instead of the PLC but this is not operational yet due to cable length issues. The machine is running from laptop but not yet really finished or reliable as we would like. There is also a strange backlash issue, which appears to be electronic in origin as the mechanical system is backlash free. Still we are cutting metal with it.

All in all, it is great to now have a control with new parts and an active support system. Our other machines are still running on older controls and we constantly have troubles with support, which is actually not a bad thing as we are now quite adept at diagnosing and repairing our equipment! Even though the machine is not ready yet we are already planning to fit MachIII to our oldest CNC lathe as it is built amazingly well, also German but the machine is far more complex so we leave that until Christmas shutdown!



Machine arriving on back of truck.



Red screen of death!



Original Sinumerik 805 installation



PMDX, Smooth stepper and CNCdrive parts after installation



In service!  

This is the next step. We found an 8 tool turret on eBay for 200 American dollars. A CNC lathe that cannot change it's own tools is not much of a CNC when in a production environment. We have no idea if this thing works, how it works or even who made it. We have to reverse engineer it just like we did with the machine. For the price, like the machine, we are willing to give it a go. When the wins are much bigger than the potential losses you are crazy not to attempt it, even if we fail we will have learned something.

3

General Mach Discussion / Weird backlash issue

« on: March 18, 2015, 06:47:55 PM »

I had to set the backlash of an axis on our lathe to 0.5mm! There is actually almost no backlash at all, it's a ballscrew. After some messing about I found that the servo just doesn't react quickly. If I turn the handwheel for the axis I can go 45 degrees in either direction before the servo fights back. The weird thing is that axis does actually move in this time. This is consistent and the machine is accurate with the 0.5mm correction but clearly something is wrong here. Perhaps a software setting on the servo driver? I use CNCdrive from Hungary and the motors are SEM with Heidenhein encoders. Can anyone offer some insight please?

4

SmoothStepper USB / Cable length issues

« on: March 18, 2015, 06:38:43 PM »

So I bought a SS with the USB port because I didn't think it through. Our MachIII installation is on a lathe with a 2000mm bed, with the cabinet at one end and the control panel at the other. We decided to rip out the Heidenhein guts and simply put a PC inside the panel. Unfortunately it seems that 5 meters is too long for the USB cable, the SS is not detected properly (off/on/off/on really fast - weak signal?). The cable is supposedly active and useable at 5 meters, I guess maybe is ok with a printer or something less critical.

I already tried a couple of different brands of USB cable and also a USB to Cat5 converter. I don't want to buy a new ethernet SS but I see that there are powered USB hubs with amplifiers. Given that we already tried an amplifier cable I'm a bit suspect about it. Has anyone else had this issue? What was the solution? Can someone recommend a known USB amplifier hub that actually is proven to work.

For anyone about to buy a USB smooth stepper, don't believe these claims of the USB cables.

5

General Mach Discussion / Custom alarms?

« on: February 05, 2015, 07:01:22 PM »

I've been searching for an answer to this with no avail... Our machine has a PMDX-126, and I want to use the fault reporting of our VFD and servo drives. So far I have them working, by designating them as limit switches for axes we don't have (no conflict). But I would much prefer to see "Spindle Alarm" or "Servo Alarm" as opposed to "Limit switch triggered" Does anyone have a tip for this?