Grbl profile? New 4th in control? Control gcode syntax?

It was a fix that came to me as I was falling to sleep, plug in the usb dummy.

 

I have x32 usb connected to bb. interface does not work, firmware not read. Grbl not connected.

usb removed and interface works.

is that the way the system works?

 

Hello, is there a grbl program that will tell me how to calibrate my x axis or 4th axis. I am using a 100:1 drive. Maybe something that generates x steps and I look at a mark on the chuck, keep changing the steps until I get a full turn
Thanks John

 

"GRBL needs steps/mm which would apply at the circumference of the part you are machining for a wrapped toolpath." I am milling a 2 x 2" part out of the gadget. if the circumference of the square is therefore sq rt of 2 sq + 2 sq then is the diameter would be 2.83 inches. am i thinking about this correctly? Thanks for your help !!!

 

Thanks got the Lead lathe file and printed out, will relax and read. On the previous question about the circumference I got almost all the steps earlier except for the steps/mm and the circumference. does my question about circumference make sense?

 

Hello
I am trying to calibrate the steps/mm on my rotary setup using a short grbl program to spin my chuck. I have used Girac's math and i don't get a reasonable answer.

I have y and A running the y axis, z running the z axis and X tuning the chuck. I am trying to establish the correct numbers of steps per mm for the chuck spin. I wrote this grbl program but it will not spin the chuck or x axis as expected. Here is the program. G21;G90;G0 X0;G0 X360;M30.

G21 ; Set units to millimeters
G90 ; Absolute positioning

; Move X-axis to the starting position
G0 X0 ; Move X to position 0

; Rotate X-axis 360 degrees (assuming one revolution is 360 units)
G0 X360 ; Move X to position 360

M30 ; End of program

Actually I asked ChatGPT to help rewrite it. When i put the complete line in the bottom of control It will move the chuck maybe 1 mm. I have also tried to execute each step one by one and i still do not get the expected results, very little movement. steps/mm is set to around 1500 not the linear ~198.

Also I am not sure if this is the problem but continuous jog seems to be intermittent. Is there any way to fix this, maybe a reload of Control would help.

Your help with the grbl program would be nice. I am also wondering if there needs to be a pause in the program but that doesn't make much sense.

Thanks

John

 

In addition I have placed the GRBL program in a file and tried to Run Program in Control but nothing reasonable happened.

 

The chuck is 100:1, no pully, so we get 160,000 and then divide by 360 we get 444.44. So given that number I would want to check to see if it is correct using the GRBL program. Do you think the program makes sense?

John

 

Thanks MisterG and Peter. I am out of the house right now hopefully will get to jog it this evening.

john

 

Processing of the variables did not work, at least not for now. I am in the process of walking into the correct steps/mm with a mark on my chuck. The variables said it should be ~444. We will see what the number is when I put the 444 in and jog to the correct value. At the doc all day today so hopefully tomorrow will give the answer. I will also say there have been some approach problems along the way. J

 

Hi in setting my rotary steps/mm, my chuck is 319.18 mm circumference. I took a guess and set the steps/mm in the profile to 500, set the x axis which drives my rotary to 0.0 mm. I put a tape mark on the chuck and ran the chuck 360 deg that is from tape mark to tape mark. The readout was 319.149. I think that was a fantastic first guess and a keeper.

In a different subject I tried to update control to the new version and it updated to the same version xx.371. Upon further inspection it might be the first line, top line, that hasn’t changed from 371.

I will go to gadget now a see if I can create a rounding tool path.

thanks for your help

 

Hi

my rotary chuck had a diameter of 4 inches. It converts to 319.18 mm circumference. When I run this cumference with a steps/mm of 500 I get a rotation of 360 deg.

when I run the same 500 steps/mm on the create rounding gadget with a radial selection the chuck only seems to rotate ~1/4 of the way around. Radial indicates that it should rotate 360.

I am stumped, should I change the steps/mm. Peter you indicated the steps per mm should be really in degrees. So does 360 divided by 319.18 = steps per
?? Make sense? It doesn’t seem to.

Advice is surely desired

thanks

john

 

I ran the creat rounding toolpath using the radial approach (around cylinder) with the suggested 444 steps/in. The x axis turned back and forth not around about a quarter turn. I changed 444 to 888 and 222 and still no movement larger than about a 1/4 turn.
So I thought maybe I should run the gadget and run the program for 444 steps per inch. Since I was confused as to which post processor I was dealing with I ran the openbuilds post processor for mm and then inches. Neither gave a result that was much greater than ~1/4.

As I said I am using the openbuilds post processor. Is there an openbuilds pp for rotary jobs that I am missing.

Reviewing math

Result, Are we looking for steps/mm or steps/degree? so let’s do both.

nema 17 = 200 steps per rotation x 8 micro stepping at the stepper =1600 or 160,000 per rotation at output of gear box or chuck

gear box has an input to output ratio of 100:1

chuck diameter 4”

Therefore chuck circumference 4 x pi = 12.5663 inches
In mm, 319.18 mm circumference

160,000/319.18 = 500 steps per mm

or 444 steps/ degree, I think this is used in the profile steps per/mm line 100

Doesn’t this indicate that 500 or 444 should be the profile line 100 number?

When changing steps/mm do I need to change anything else in the profile?

since the only time I was able to get an agreeable rotation was jogging 318.18 mm with a profile 100# equal to 500 and a chuck rotation of 360 deg. Not using the gadget. There must be something more the gadget needs to work properly.

I think when running the gadget for different values of steps/mm profile line 100# has a problem in my process. Ie. change line 100 then run program again with no program change may be a problem but I did run the gadget with line 100 change but no real difference.

Thanks in advance for your comments

john

 

No I am not using the Rotary Demon post processor. I was not aware of it. Since I didn’t see an openbuilds rotary I figured openbuilds inches or mm was what I should use. I will give it a try today. I assume I should use your number, I have to look up, something like 56970/diameter for steps per mm. I assume that is always finish diameter as I think you implied. So for running around my chuck it would be 4 in dia and for the gadget the finished diameter is 1.5 inches converted to mm. Please correct my thoughts if necessary.

thanks

John

 

Just read your previous note again. The steps/mm =50929/ diameter applied at the circumference of the FiINISHED ( my word but implied by you) object you are machining for a wrapped toolpath. So the profile line 100 would be in mm.

 

I see your recent edit but I am not sure what the edit means “ for some reason, it is plugging the Vcarve to the axis”

 

I found the rotary demon but all jobs are along the X and Wrap Y. I am along the Y and wrap X. I chose this augmentation since I wanted to make longer objects like canes. I am tempted to make the stand alone machine but not now.