OK, so I’m seriously considering a major upgrade to my CNC electronics. Including getting a motherboard for a Pc with parallel port and going with a more traditional parallel port driven controller and maybe Linux CNC
Any thoughts or recommendations?
Everything is on the table at this point. I’ll probably look to upgrade the motors, drivers, controller etc. Must have opto-isolators for good immunity to emi.
Whilst mechanical upgrades will come in a much later update I am thinking future proofing for a serious size machine. I’d appreciate any links. I’m based in UK so will need to consider shipping etc.
@Mark_Collins I guess I could add a lpt to laptop. That still leaves the controller/drivers/motors/power supply to upgrade. But I thought I’d read bad things about laptops and noise/grounding compared to a straight up PC.
Yea don’t use a laptop I’m using one of my old desktop mainboards with built in port and added a PCI card as the second for more I/O also using cnc4pc c10s breakouts with external LPT ports fitted to the headers
Do a search for one these:
" Lenovo M57 Desktop PC Core Duo E6750 "
Read good things about them, and there seem to be a lot of referbs on the market now. Perhaps some on your side of the pond as well. Around $100 USD, with a parallel port, and windows 7. According to Tom’s Hardware, the CPU is as fast as the AMD I’m using here, which seems to run LinuxCNC 10.04 plenty fast.
@Mat_Helm from some initial searching lots of recommendations seemed to be pretty dated now and no longer in stock. Given I have a PC case and power supply I was hoping I could pick up a motherboard/ram/HDD relatively cheaply but still fairly new, at least from an availability stand point.
@Daniel_Would Well you know that I have listed several different parallel port MB’s in the other DIY cnc community. You could search by the brand and model number to see what’s available over there. The hard thing I found was finding the ones with parallel ports… But by the time you buy a CPU n MB, you’re at the same cash wise as that $100 referb PC…
@Mat_Helm actually you assume too much of my memory. I’d forgotten you posted some motherboard links, maybe subconsciously that was what I was thinking of.
I’ll do some searches on those names to see if I can find UK suppliers.
That then leaves choice of controller and drivers. There seem to be some interesting options on eBay complete with power supply and motors.
I did try a laptop with PCMCIA parallel port with no success, but another laptop with built in parallel port works like a charm. It just need to be quick enough. I run it without networking configured on Windows xp and mach 3.
I think you might do better buying the components separate. A 5 axis break out board. 3.5 to 5 amp individual drivers. That way you could just take your time finding a good deal on whatever motors… And then on the power supply needed to push them…
Keep in mind that on the AMD boards, the old AM3 type CPU’s are not all that cheap now days. But you can still find deals on ebay for Athlon II’s (2 cores). Haven’t priced intel cpu’s lately. And while I don’t know the effect on things it will have, I know the ASUS bios allows you to only use one core, which I’ve read makes for better latency.
Definitely not recommending laptops. Linuxcnc includes a latency tester, and I’ve seen a couple laptops hold excellent latency numbers for thirty minutes, then have a half second jump. That would be a disaster. I got a foxconn atom off ebay and ran a latency test for two days, and set my max jitter based on that. It’s been excellent.
As regards electronics, if you can afford geckos go that way. If price is an issue, the thb6064 drivers seem to treat people pretty well for higher amperage steppers.
@Kyle_Kerr Yeah that’s right, forgot about those. But in my case, I already had a CPU and those boards were around $100+ bucks I think. Plus they show to be a tad on the slow side according to Tom’s Hardware speed charts. I would do some research to make sure it can run Linuxcnc 10.04, or maybe at least XP if you decide to go with mach…
Why not a single board computer like the beagleboneblack at 45$ running LinuxCNC? There are ‘shields’ available similar to ramps. Charles Steinkuehler’s excellent machinekit image gets you running in nothing flat. I am going this route on a little sherline lathe and a 3d printer of mine.
@Daniel_Would
Laptops are considered poor choices for real time systems. It has to do with resource management in the laptop, specifically power management routines that desktops don’t do.
Here is Linuxcnc’s recommendation for an add on parallel port card
I have a NetMos and it is great. I made my own buffered Break Out Board for it though. They’re available commercially but they’re usually pretty expensive for what amounts to a few 50 cents chips and resistors. OK I guess barrier blocks can cost some coin but I have a bunch of those I got for free.
