Need accelerations lower than 9.0 mm/s^2

math_indy

I have DDCSV2.1 installed on a surface grinder.  The Z-axis takes 40 turns per inch (= 1.6 turns per mm).  

Because of this I need acceleration parameter that is less than 9.0 mm/s^2.  

Is there any way to turn acceleration and deceleration parameters to anything less than 9.0 mm/s^2?

math_indy

OK, so the work around that I am thinking about trying might solve this issue.  Here is it:

I am thinking about leaving my DDCSV2.1 in metric (mm) mode (parameter #115) and, instead, scaling the pulse equivalent axis parameters (#34,#35,& #36) by a factor of 25.4.  In this way the displays will be calibrated in inches but I will have 25.4X finer control of the acceleration parameters that are causing my trouble.  This work-around might also fix the G-Code feed rate issue (mentioned in other threads) as all G-Code motion AND feed-rate will be scaled up to inches by the 25.4 scale factor.  The only drawback of this work-around is the DDCSV2.1 display will still say "mm"--a large sticker indicating that readings are in inches will be my solution for that.

Will_D

Are you confident enough to edit a system file?

If so you need to edit the eng file to change the min value of #99

#99 -t1 -s1"operation acceleration" -s2"mm/s2" -m4 -min=9.000 -max=9999.000
becomes
#99 -t1 -s1"operation acceleration" -s2"mm/s2" -m4 -min=1.000 -max=9999.000

math_indy

Will_D Posted at 2018-9-18 17:09
Are you confident enough to edit a system file?

If so you need to edit the eng file to change the m ...

I edited the eng file as you suggest and this fixed this acceleration issue for me---THANK YOU!!!

In addition to parameter #99 I also lowered the minimum allowed accelerations in the eng file for z-axis parameters #47 and #265 as I think parameter #99 is for circle motion--no?

It is nice to know how to edit those files--would be nice also if I could make a parameter file that would re-load when ever I re-flash the software revision (rather than typing over defaults manually)