If you have a well running Sphinx cnc (or a similar leadscrew design) what Grbl settings and microstepping are you using? Just want to know what to expect for acceleration and max feed. Thanks, Andreas
Old post, but also interested. Working on my first build, sphinx based and just wrapping up the mechanical build. Using a pretty standard openbuilds kit: 8mm leadscrews, DQ542MA (planning on 1/8 step (1600 pul/rev)), Nema 23 high torques. Was searching around trying to see what others were running but I've yet to come across a straight forward answer. It'd be awesome to have a sticky or resource of known configurations on the forum ( or better yet, linked on the product pages ) I started my 'build' but haven't stopped long enough to get it into a suitable condition to pull it out of draft mode here, need to clean up and add lots of info. Look forward to doing that once I stop long enough to take a breath. Will also be sure to post all my grbl settings up front for easy reference
These are the settings I've been using. Running DRV8825 drivers and 1/16 micro stepping it seems. I've only missed steps once when the cooling fan broke down. They have been working excellently for the price! I have new drivers around and I'll be upgrading one of these days. $0=10 $1=20 $2=0 $3=2 $4=0 $5=1 $6=0 $10=1 $11=0.010 $12=0.002 $13=0 $20=1 $21=1 $22=1 $23=1 $24=25.000 $25=500.000 $26=250 $27=1.000 $30=1000 $31=0 $32=0 $100=396.200 $101=396.200 $102=398.200 $110=4000.000 $111=4000.000 $112=4000.000 $120=500.000 $121=500.000 $122=500.000 $130=805.000 $131=809.000 $132=74.000
I finally got around to upgrading my controllers from DRV8824 to DM542T from stepper online. They're running with 1/8 micro stepping. I was able to push the machine quite a bit further (like 15000mm/min) without the steppers missing steps. However the lead screws started whipping like crazy on my 1x1m machine. In the end I settled for 8000mm/min which is about the best you can expect at 1/8 micro steps. After that the Arduino isn't able to generate pulses fast enough. I also had to set the steppers in "always on" mode in order for them to work reliably. It seems like the drivers want a bit of delay between getting enabled and the first step signals. Some comments inline below. $0=10 $1=255 <---- Always on $2=0 $3=2 $4=0 $5=1 $6=0 $10=1 $11=0.010 $12=0.002 $13=0 $20=1 $21=1 $22=1 $23=1 $24=25.000 $25=500.000 $26=250 $27=1.000 $30=1000 $31=0 $32=0 $100=198.100 <---- 8mm lead screw and 1/8 mm micro-stepping. $101=198.100 $102=199.100 $110=8000.000 <--- 8000 mm/min, about max at 1/8 micro steps. $111=8000.000 $112=4000.000 $120=500.000 <-- I could push this to 2000 but it felt hard on the machine. $121=500.000 $122=500.000 $130=805.000 $131=809.000 $132=74.500
