EMC2 problems

[RedLabel]

I've recently finished my machine. I use the 3-axis xylotex board with 3A/phase 497 oz-in steppers.

The machine jogs nicely but I have no luck for the rest.

One of the problems is that when I increase the speed I've noticed lockdowns(noise comes from stepper but no movement), when it happens I have to leave the button and push it again. Decreased the acceleration and it helped some but did not solve the problem entirely. I think it is about the pulse shape but I have no idea how to change that in EMC2.

Another thing is scaling. Well I don't know how to calculate(or what is) encoder counts, i can see that this is a counter's value when the stepper turns one round but this is not clear (the logic behind the program is clear for me but there is a lot of ambiguity in the labeling, ex: cycle period refers to period of which cycle?). I read the manual but a lot of things is not explained. So I still could not adjust the lengths correctly? If there is any help I'll be very happy.

I've wrote these in my DIY thread too but I think I can get more attention here.

I hope I can get some help...

[Big John T]

Sorry but I can't help much. I hope you get your answer. I am not as far along as you as I have not built a machine yet. Scaling I'm guessing is the number of counts per unit of input. If your servo has 500 counts per revolution and it takes 10 revolutions to move 1mm then your scaling is 5000 per mm. I hope this helps in some small way...

John

[RedLabel]

Thanks. The calculation was obvious hovewer the problem was the meaning of encoder counts. Well I've done it in a traditional way. Since input count and the length is directly proportional , I've just cut a line segment 10cm length, measured the real length on the object then from their proportion calculated an accurate input count. Result is quite nice, so far I have noticed very little error.

Now there lies the problem of G-code generation. Is there an open source simple program for generating codes from dxf or simpple dwg?

BTW I've tried mastercam and couldn't find a way to generate code for EMC2. Any help will be appreciated.

[RedLabel]

No answers. Let me clarify my question. Mastercam X is available at a friend's company(I have little time to work on it though).

Is there a way to create g-code compatible with EMC2 by Mastercam. I think I need a post processor for EMC2 but I don't know where to find it.


Thanks

[andy55]

A Fanuc or Mazak post-processor will usually work with EMC2. Some small changes might be needed.

Your lockdowns might be due to the stepper motors also. At what velocities do they occur?

[RedLabel]

Originally Posted by andy55 A Fanuc or Mazak post-processor will usually work with EMC2. Some small changes might be needed. Your lockdowns might be due to the stepper motors also. At what velocities do they occur?

The lockdowns occur over 21" per minute. They are not frequent but annoying.

I'm new to post processing and Mcam, can you give links for Fanuc or Mazak and what modifications do I make to get them working with emc2?

[Big John T]

Originally Posted by andy55 A Fanuc or Mazak post-processor will usually work with EMC2. Some small changes might be needed. Your lockdowns might be due to the stepper motors also. At what velocities do they occur?

Andy,

I tried the Mazak post and it was not close to the RS274/NGC language that EMC2 uses. The Fanuc might work if you know how to change it some... Any other suggestions?

John