8020 belt driven 3 axis

[Ross77]

I spent the morning wiring up a test rig to see if I can get the stepper to turn

Been there, worked fine indoors as a trial but when i set it up on the machine nothing...... 1/2 hour of head scratching and I realised I hadnt done the driver test for mach to take over windows, as usual operator error....lol

Anyway back to your machine. Over engineering is fine but there are a lot of redundant parts in that design, before I stick my oar in I need to know a few more details

Are you using the skatebearing arrangement, what are you cutting, what is the power of your motors and what are the sizes of the 8020?

[compfranon]

>1/2 hour of head scratching and I realised I hadnt done the driver test for mach to take over windows, as usual operator error - tell me more

yes i'm using the carriages with bearings etc
plan to cut acrylic, various woods, aluminium alloy if I can

Motors are from Zapp SY60STH88-3008BF wired bipolar parallel

8020 (or equiv) sizes for base frame tba
8020 (or equiv) for gantry is 90 x 90 sq section, supported on 2 x 45x45 sq sections

[compfranon]

Managed to get doing a wee bit today.....

I wired up the unregulated power supply, outputs 58Vdc

I also wired up the optoboard, M752 driver and one of the steppers, unfortunately I couldn't get the motor to turn YET !!! made the relevant settings in Mach3, but no joy. Is it a null modem cable - think so, it's an old laplink cable. Tested using a laptop, the parallel port appeared as ECP port. Opto and driver boards show power leds fine, on power on the stepper "clamps"

Enjoy the pics.

[mel_earp]

Is it a null modem cable - think so, it's an old laplink cable.

I hope you have made some progress but thought that a couple of things might help. First off, I guess that your comment about "null modem" is a red herring, or at least I hope so. A null modem cable only ever refers to a serial comms cable. All this is very old hat now and you rarely see them. It was all about whether the transmit and receive lines were straight or twisted (one only of each) The vast majority of laplink cables were serial, so if it really is one of those then you have the wrong cable - but then you would have had to hammer it quite hard to get it to fit a breakout board!

Even genuine parallel cables can be insufficient. Some were produced for restricted use, typically old printers, and don't have all the conductors. For cnc use you need them all. It is worth checking the continuity of all the conductors in the cable.

On a more constructive note, this thread on the build your own CNC forums describes one guys attempts to overcome a similar issue and has helpful lists of his parallel port settings.
http://www.buildyourtools.com/forum/post/1049298

[mel_earp]

And just in case it really is the less common parallel laplink cable (introduced later for speed) then this site might help http://www.indiacam.net/pinout/ It shows the differences on the cable wiring. If this is where you are, then it could still work for you, but you would have to treat all the BOB connections differently - nightmare.