New PC - motherboard parallel port differences

[Neale]

I run LinuxCNC and it's fine for most use. I haven't found too many limitations with it. I recently had to change the motherboard in my PC as the old one blew up (I suspect that letting the CPU heatsink fill with dust once too many times did for it!) and as many have found, cheap motherboards do not have parallel ports any more. I bought a cheap PP PCI adaptor from Novatech and that has been working fine with LCNC, in conjunction with a cheap BOB. However, my current router is not too demanding in terms of pulse rate. I'm using a low-end AMD CPU and the latest LCNC download. There's plenty of info available for doing things like changing the PP address so that LCNC can find it when you are not using a standard motherboard port; this is the kind of thing that Windows usually manages for you.

What are the limitations? Some of the free CAM software generates G2/G3 arc instructions, and LCNC is incredibly fussy about these. It wants the start/finish points to be correct to some large number of decimal places and bitches if not. I spent a lot of time in the early stages tweaking gcode by hand to fix this. However, since I switched to using Vectric VCarve for most of my CAM, I haven't seen this as an issue. Bigger problem is that LCNC really doesn't support twin leadscrew designs in that it can't handle homing/squaring properly. This has been an ongoing issue in the LCNC community for years. My new router will be twin ballscrew, so this is a problem. It is also very limited when it comes to external motion controllers (really, I think it just supports/is supported by the Mesa cards). There are apparently very good, but that's the only option. I'm going to be moving to Mach3/Mach4 (haven't yet decided) and CSMIO/IP-M motion controller, hence I shall also have to move to Windows. There are plenty of people who will tell you that the LCNC control screens are an old-fashioned heap of junk, but I use the standard screen setup that comes out of the box and it works.

My first router was a bit of an experiment, cheaply built, to see how I got on. I used LCNC to keep cost down, and never regretted it. I don't see why it shouldn't do a perfectly adequate job with the cheap Chinese routers and I wouldn't hesitate to use it in that situation.