hI, br549,
That's a sad news, i think that really cnc controller aren't for this fasts speeds, embroidery machines has his property controllers, but we should try to see what happens. Really we are looking for increase embroidery speed using synchronization of movement and using a continuous motor (DC or Stepper), to keep thread tension as stable as possible.
First test of my embroidery machine was using an old SINGER sewing machine, above the table of my cnc router.
Hoop with fabric was bolted in Z axis router support for X and Y movements ,and Z axis stepper was coupled directly to sewing machine shaft using a water hose and clamps. First G code used is very simple in comparative
with personal and embroidery machines.
Some preliminary details
Z axis was set up for Z=1 for 1 revolution= stitch
Z initial = 0 = Needle in upper position
X an Y speed= 1500mm/min
A short lines of G code
G90
G21
G64
F 1500
(NEEDLE UP RAPID MOVE- Light bulb Off if On)
M09
(START STITCHING- Light Bulb Off if On)
M09
G00 X0 Y -1.5 ----Moving hoop to first stitch position.
G01 Z-0.8----------------Z moves at 80% of revolution ( First stitch, needle moves in to fabric,move out and stops 3 mm above sewing machine table
M786 -------------------Macro reset Z values--Now Z= 0 is when needle is 3mm above sewing machine table when is coming out of fabric
G01 X-0.1 Y-19.4 Z-0.4--Hope moves for one stitch, Z complete one revolution and do 40% or next and stops at 3 mm above sewing machine table, this its a guarantee that hoop movement finish before needle is come inside fabric.
G01 Z0.8
M786
G01 X-0.4 Y-25.5 Z0.4
cont...
This way of work gives me a 150 Stitches x minute aprox, I think that the same code in more speed movements can give 300 SPM.
Now I need to set an M7 command previous to any X and Y movements longer that i.e.7mm, for a solenoid that release thread tension and give a possibility to do long stitches without thread breakage. I think to set M7 line before X and Y line, but I need to use a rotary shutter to close solenoid circuit when needle arrives to specific rotation degrees for release tension in this moment.
Could be in this way
G00 X0 Y -1.5 ----Moving hoop to first stitch position.
G01 Z-0.8----------------Z moves at 80% of revolution ( First stitch, needle moves in to fabric,move out and stops 3 mm above sewing machine table
M786 -------------------Macro reset Z values--Now Z= 0 is when needle is 3mm above sewing machine table when is coming out of fabric
M7-----------------Activate Output signal for solenoid, but solenoid start and stop depends of electric circuit will close when rotary shutter activate or deactivate optical switch.
G01 X-0.1 Y-19.4 Z-0.4--Hope moves for one stitch, Z complete one revolution and do 40% or next and stops at 3 mm above sewing machine table, this its a guarantee that hoop movement finish before needle is come inside fabric.
M9------------------Close Output signal for solenoid.
G01 Z0.8
M786
M7
G01 X-0.4 Y-25.5 Z0.4
M9
cont...
Thanks for your help
Regards
Rene