UC100 with printer switch for two machines

I'm wondering about using the UC100 motion controller with a printer/parallel cable switch so that I don't have to physically plug/unplug the two machines.

At the moment I have a Triac mill running Mach3/parallel port and a Stepcraft router running with UCCNC via UC100, on separate PCs. I'd like to use a single Win10 PC for both.

Is the switch likely to affect performance? Anybody done this?

Thanks!

Richard

I used to work like this when using the parallel port on an xp machine so in principle it should be ok. It may depend on the drive capability of the uc100 and the cable length. I'm not sure how easy it is to get 25 way printer switches these days, by the time you've found one and the necessary cable it might be as cheap to buy another uc100. I've got one on the mill and another on the lathe, with manual changeover. It's a shame I gave away the switch and cables with the old pc but the new owner may have them spare if you want me to check?

It was never a cheap way to go with three cables and a switch box but CPC and Amazon both still list them.

Just watch out for seriously silly high prices!

I run Mach3 with Warp9 Smooth Steppers, so similar to the UC100, which means I can use any PC to run it. I have a cheap used Toshiba touch screen laptop from Ebay on one machine that runs Win10 and XP on a freebie laptop on another. I think you are better off getting away from using a parallel port and using an external motion controller to future proof (at least in a limited way, nothing lasts forever) your system. If you do it before the old set-up dies you can take time to do it at a leisurely pace.

Since a lot of external motion controllers have the equivalent of 2 parallel ports (the Smooth Steppers certainly do) on them it should be possible to run two machines from one motion controller, though most likely not at the same time. This would require two Mach3 setups which can be named to match the equipment and just run one at a time. One set up would only use port 1 and the other only port 2. This means the idea of a parallel port switch is probably unnecessary. Other options are to have 2 UC100 (£92 each) controllers and a USB switch or go for the UC400ETH (£128) which has 2 ports (and a slightly higher cost) and would require 2 interface cables (IDC26-DSUB25 £5.32) to go from the headers on the controller to your machines.

The recently bought Toshiba laptop was to replace the previous freebie laptop running XP that was getting old. The internal battery died and is not replaceable so every time I switched it on I had to go through the process of setting up the hard drive then the date so that was annoying. It also had keyboard issues and I have been using it with a wireless mini-keyboard but that, whilst it is good for some things like a remote pendant, is not so good for typing in commands. It would probably be comparable to the cost of a now rare parallel port switch and extra cables.

Laptops work fine with Mach3 despite dire warnings in the Mach3 paperwork. Just set them up to run like a desktop machine, that is to not sleep or power down in any way when powered from the external supply.

Martin C

OP says he has a UC100 already and wants to use this.

USB switches that work as required for this application (switching one USB host port between 2 USB devices) don't seem to be available, though it wouldn't be hard to make one. Unfortunately all UC100s have the same address so you can't plug 2 into 2 USB ports. That's why I ended up doing a manual changeover of the USB cables.

I found a cheap Dell Inspiron mini Win10 PC on ebay that works with my existing display and was a lot cheaper than a laptop for the workshop. Plenty of grunt for Mach3 though it struggles with CamBam.

There are a few parallel port switches on eBay for only a few squids.

In what way is it struggling with CamBam, as I've always found CamBam to be pretty good, except with heavy 3d stuff?

Martin.

CamBam works great on my Huawei laptop but on the mini PC it's just slow.w.w.w....

Have you fiddled with the Worker Threads or Display Mode to see if you can speed things up?

Martin.

Ah, no, I'll have a play. It's only an inconvenience really as I do the design work in my office and generate the g-code file then transfer it to the workshop PC. But sometimes it's nice to edit things in the shop. Thanks for the suggestion.

Many thanks for advice/suggestions, particularly to Joh Haine for his offer re. sourcing a switch- much appreciated.

No decisions yet.

The current computer running the mill does not produce a very smooth response using XP/Mach/parallel port,although it is certainly usable. Am I likely to see improved preformance if I switch to using newer PC with Win10/UC100/Mach (or UCCNC)?

The original designer of Mach3 admits that the use of the parallel port was a bit of a bodge job as it is being used in a way it was never designed to be used. Any purpose designed motion controller will give as good as or a better result than the parallel port, usually better. Faster speeds are often possible as a result of using a motion controller. I don't know if a motion controller helps reduce missed steps as I have hybrid servo-steppers which are less prone to missing steps and give an error if they do which can be used to stop the CNC program.

A faster PC will not make as much difference as a motion controller as once a motion controller is used the PC does a lot less work, a lot of it is taken over by the motion controller. What a newer PC is able to do is other things at the same time, for instance a marginal PC using the parallel port will not be able to play sounds without causing uneven running of the CNC program (Allow Wave Files and Allow Speech in General Config needs to be disabled for example).

There is one important thing to watch out for in buying motion controllers. If you intend to do anything like threading on a lathe or a mill (yes, you can do this, treating the mill like a lathe) then you need to ensure the controller caters for this, some don't.

Martin C

My experience with the uc100 is that it is smoother than the PP but not a lot. I need to upgrade the drivers on my lathe to get the benefit of faster stepping. What drivers do you have on the mill?

In 10 years using the PP I don't think I ever noticed lost steps.

The uc100 should allow lathe threading with Mach3 but I haven't yet tried it.

I'm just using Mach with the standard parallel port driver. The Triac has the original 1980s electronics with the addition of a board to connect to the parallel port. I would love to get rid of all this and replace it with a modern driver system but it's daunting. The control box is about 1m square by 40cm deep, full of aging boards with discrete components of course. Even the machine connecting cable is about an inch and a half diameter, with a huge number of wires inside. I did a basic modernisation on an Orac lathe, also on Mach, but theTriac is in a different league.

My mill is a Novamill which is basically similar except that I only bought the mechanical bit - fortunately! Actually connecting to the mill is quite easy once you get the right connector which is available. The documentation says the pins are all crimp but you can easily solder - the pins are separate with a little solder bucket, once you solder on the wire the pin is inserted into the connector body. Of if you have the cable of course you can use that, just cut off the connector at the controller end and separate the wires. All the connections are given on the Denfordata site.

Just using modern stepper drivers but the original motors will probably improve the machine quite a lot - I think the originals didn't use microstepping for example. But on my machine the motors still have some odd resonances which I can't tune out though it doesn't affect cutting. Better drivers and new motors would probably sort that, but as 2 of the motors are hidden in the column that isn't so easy.