Newbie - what Mesa card to choose?

More
5 years 7 months ago - 5 years 7 months ago #202902 by Michael
Congrats!

Before you get too deep, perform the latency test in this pc. It will determine if and how fast the computer base thread will be able to run step generation.

Latency test is not as important when using a mesa card as you will only need a decent servo thread.
Last edit: 5 years 7 months ago by Michael.

Please Log in or Create an account to join the conversation.

More
5 years 7 months ago #203320 by MattK
The parallel port cable came in today and I went through the stepper config tool using the printed out manual the person selling me the cnc had and all I got were a bunch of clicks but each time it was the right axis and it was moving ever so slightly.

I found this post
forum.linuxcnc.org/16-stepconf-wizard/34...port-config-probably

and ran the command sudo cat /proc/ioports |grep parport and got the results of
0378-037a : Parport0
037b-037f : Parport0

I used 0378

Then it was still just clicking not not moving much so I researched a bit more and found this post
forum.linuxcnc.org/16-stepconf-wizard/39...iguring-6040z-issues

and from that I updated the following parameters and bingo I now have a config where I can move all 3 axis.
Step Time 10000 ns
Step Space 10000 ns
Direction Hold 10000
Direction Setup 10000

I've got to research some more as it is not moving the correct distance and the mach 3 parameters in the documentation seem too high at
Micro Steps/Rev 640
Driver microstepping 16

Please Log in or Create an account to join the conversation.

More
5 years 7 months ago #203328 by andypugh
Is it out by a factor of exactly 2? That can happen with a microstep miss-match.

16x microstepping is normally 3200 steps per rev. 640 would be 3.2x microstepping, so that has to be a typo.

Please Log in or Create an account to join the conversation.

More
5 years 7 months ago #203341 by MattK
I did some RTFM here 360/1.8degree = 200 and then opened up the controller case and determined 8x multi stepping based upon the dip switches.

Seems to be doing better now. I did the jitter test and it was horrible, The PC is a 6-7 year old dell, 8GB Ram, new Sata SSD so it shouldn't be that bad. My next thoughts were about the graphics display sucking pond water, I removed the ati graphics card and went with the one built into the motherboard and when linux came back up the display was smooth. The max jitter still wasn't spectacular but it was 45,000ns.

For some reason after the display card was removed, I couldn't get the machine to jog yet if I went into the stepper config and tested each axis it would. After a few attempts I createx a new config and it seems to work. Putting a ruler on the x or y axis and jogging 5mm 2x seems to move it 10mm consistently.

Please Log in or Create an account to join the conversation.

More
5 years 7 months ago - 5 years 7 months ago #203409 by MattK
since I do not have homing switches and don't know what I am doing, I ran into some issues with errors on joint size, after RTFM
on linuxcnc.org/docs/html/config/ini-homing.html I realized the software limitations set in the config file were getting me so I made all the sizes in the config file way too big ( I realize what that can do and won't step away from the machine )

any which way I was able to make sawdust - 3rd try this time I played with the height of z by setting the z height with a slip paper, removing the board, setting z 1mm lower and homing z
overall view of setup

photos.app.goo.gl/nLdvxD5udKHxSf368

I realize I've got a lot to learn on this and some of my actions are going to get me in trouble if I do not take the time to learn this homing setup as well as get some limit switches installed, but it was nice to see the machine make a cut and it turn out looking good.
Last edit: 5 years 7 months ago by MattK.

Please Log in or Create an account to join the conversation.

More
5 years 7 months ago - 5 years 7 months ago #203480 by jbraun
That's a fair bit of progress in 6 days starting from zero.
The lack of Home switches doesn't prevent you from defining Home positions and having nice things like soft travel limits. If the motors are feeble enough you can buzz them against a hard travel limit and call it Home. A kinder method would use alignment marks. If the machine is returned to Home positions before powering down it's good to go next time (as long as the Z doesn't drop a bit). Not as accurate as switches but I get away with it for several consecutive power up cycles.
Last edit: 5 years 7 months ago by jbraun.

Please Log in or Create an account to join the conversation.

Moderators: PCW, jmelson
Time to create page: 0.086 seconds
Powered by Kunena Forum