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Maybe this helps:
forum.linuxcnc.org/media/kunena/attachme...049/oracchanger.comp

leexi wrote:

hi,
with Pulse and direction top speed and precision calculus are clear  but

But how to calculate the bandwidth on a Ethercat servo drive and precision?
let say leadscrew pitch 0.100inch encoder servo 10000 ppr?
if bus cycle time is 1000000 and refClockSyncCycles=1
how to determine the top speed IPM and minimal resolution in  Inches (minimal cut).
 

With ethercat servo drive operating in velocity mode, your main limitation will be the servo's rated/max speed. The resolution limitation will be time based, if I'm correct LinuxCNC EtherCAT will have something like a 2mS feedback latency on a 1mS thread, so this will limit your positioning accuracy during very fast moves. I am not aware that a regular machine tool is capable of reaching this speed limit.
Here is a detailed explanation how it is timed.  

cmorley wrote:

When I looked at this and it seems you have both encoders connected to index-enable.


 

I agree this sounds off. I suspect it will very likely always find the one index first, and I expect that to be the servo index, unless home switch is quite near to scale index. I think ideally you'd want to use only the scale index.

Hi all,
Attached please find a pdf describing the math for the proposed jerk limited planner to be added. It is done by AI, and I want to put it up for community comments.  
I would be happy to discuss the approach and incorporate suggestions and make modifications to this plan as the discussion evolves.
-automata

I wanted to add this to our docs some where for a guide to others.
When I looked at this and it seems you have both encoders connected to index-enable.

This seems wrong in my head, as it would depend on which encoder index fired first.

Any opinion or insight?
Thanks

Hi
i recently acquired a Denford lathe and am wondering if the comp is still around?
the wiki download is ending in a error 404. 
The only other similar thing I found was this link: 
www.machinekit.io/docs/developing/toolchangers/
But I am not sure it is the same thing.

Does anybody have access to the component from the original Wiki willing to share?

kind regards

2.9.10
Thank you for remind us to update the documentation.

I have a lot of questions for you, but no answer.

Hi all,

I just have a quick question regarding what version I should use for LinuxCNC. In your guide you say that version 2.9.8 should be used, but in the download section you say that 2.9.10 should be used. I just would like clarification on which ISO I should download and use.

Thanks

Does anyone know where I can get a free license for DeskProto 8.1?

leexi wrote:

hi,
with Pulse and direction top speed and precision calculus are clear  but

But how to calculate the bandwidth on a Ethercat servo drive and precision?
let say leadscrew pitch 0.100inch encoder servo 10000 ppr?
if bus cycle time is 1000000 and refClockSyncCycles=1
how to determine the top speed IPM and minimal resolution in  Inches (minimal cut).
 

In amateur machines, none of this matters.
You can count it for hours and buy a Chinese ball screw with a backlash  0.1 mm like me...

hi,
with Pulse and direction top speed and precision calculus are clear  but

But how to calculate the bandwidth on a Ethercat servo drive and precision?
let say leadscrew pitch 0.100inch encoder servo 10000 ppr?
if bus cycle time is 1000000 and refClockSyncCycles=1
how to determine the top speed IPM and minimal resolution in  Inches (minimal cut).

today.... get some stuff working...

i managed to eliminate the coupling of axis a to b axis a to c and axis b to c.

then i get it work to home on my edding marks with index signals from the encoders.

i think i am near to a working world mode?! but Z axis doesnt look ok... i upload some videos....

joint mode for handling stuff works perfect... but my world mode.. doesnt work correct... possible someone know the issue of my z axis? i double check all length and offsets for the DH parameters.... the angles are still the same (alpha).

right hand rule.. thumb as Z up.. i must doo the stuff i think... i will make some stuff from cradboard.. after this weekend..headache..


here some youtube shorts

www.youtube.com/shorts/QVSaIWWKXsQ

www.youtube.com/shorts/nbMT6QoQUbg

www.youtube.com/shorts/eSobhr9gZZ0

www.youtube.com/shorts/EBi62z3gkNc



possible i am on the wrong way with my DH parameters and rotations of each axis.. thats why i make a tool from cardboard to identify the issue


thanks

leexi wrote:

interesting to know what are the step output card band with
 

Don't worry. In a real machine feed and acceleration are limited by mechanical parameters.
Whereas increase microstepping decreases effects. In other words there is big different for 1/2 and 1/4 and small different for 1/128 and 1/256...

The maximum step rate will be limited by the step length and step space parameters.
In a working system, these parameters in turn are limited by the drives minimum timing values.

If the clone cards uses that same clock scheme as Mesa cards ( Stepgen base clock= 100 MHz ),
step rates to 10 MHz are possible.