[bsm2003]

Trying to set up the x/y axis on my laser engraver. Nema 23 motors belt driven axis with a 2:1 step down ration. Motor gear has 24 teeth and the driven gear has 48 teeth. My table area is 500mm on X axis and 300mm on Y axis. Controller is AWC708C Lite. I can set range at 500 for X and 300 for Y but get either no where near that IE short by over half or it wants to try to go past that and just hammers the motor. I know my um/Pulse rate is off but I'm not sure how to figure them out. I have searched on here but nothing definitive has popped up oh actual steps to calculate the pulse rate.

Thanks in advance
Scott

[Dean448]

Calculations for that are pretty easy to find but the best method is trial and error. Just lay marks down, or a line, at a known distance. Just ratio the setting up or down based on actual length to target length. Make the target length as long as possible


Sent from my iPhone using Tapatalk

[bsm2003]

Calculations for that are pretty easy to find but the best method is trial and error. Just lay marks down, or a line, at a known distance. Just ratio the setting up or down based on actual length to target length. Make the target length as long as possible


Sent from my iPhone using Tapatalk

Everything you said was Greek to me. This is my first foray into the realm of cnc and laser engraving. It may be more helpful to me if you somewhat explained what you mean by your post.

Scott

[cinematic2]

Everything you said was Greek to me. This is my first foray into the realm of cnc and laser engraving. It may be more helpful to me if you somewhat explained what you mean by your post.

Just set anything, print 100x100mm square, measure what you get and make corrections. And again, and again ....as long as 100x100 will be 100x100

[george4657]

Um/Pulse is how far the machine moves per pulse from controller.
There are 2 ways to set Um/Pulse, trial and error as Dean suggested and calculation.
Trial and error:
Mark starting point
Send gcode commands
G92 x0 this sets x to zero
G0 x100 this sends x to 100
Measure actual distance say 75 mm
Calculate proper um/pulse = old value * 75/100 and enter and retry above.

Calculation method:
Motor has 200 steps per revolution
With belt drive == 400 steps per revolution
Need to know your microstepping for your drivers for example if set to 8 then we have 8*400 = 3200 steps per revoultion
You give no description of what you are driving so I don't know how far head moves per revolution.
If for example machine is driven by a threaded rod with 8 mm per revolution then machine moves 0.125 mm /revolution so steps/mm = 3200/8 = 400 steps per mm
1 um = 1/1000 of mm
To convert to um/pulse = 1000/steps per mm = 1000/400 = 2.5

I prefer the calculation method because I want to understand how things work

You would get better answers if you provided more information as to the machine you have. A link to a page with a decsription would be best.

[bsm2003]

Um/Pulse is how far the machine moves per pulse from controller.
There are 2 ways to set Um/Pulse, trial and error as Dean suggested and calculation.
Trial and error:
Mark starting point
Send gcode commands
G92 x0 this sets x to zero
G0 x100 this sends x to 100
Measure actual distance say 75 mm
Calculate proper um/pulse = old value * 75/100 and enter and retry above.

Calculation method:
Motor has 200 steps per revolution
With belt drive == 400 steps per revolution
Need to know your microstepping for your drivers for example if set to 8 then we have 8*400 = 3200 steps per revoultion
You give no description of what you are driving so I don't know how far head moves per revolution.
If for example machine is driven by a threaded rod with 8 mm per revolution then machine moves 0.125 mm /revolution so steps/mm = 3200/8 = 400 steps per mm
1 um = 1/1000 of mm
To convert to um/pulse = 1000/steps per mm = 1000/400 = 2.5

I prefer the calculation method because I want to understand how things work

You would get better answers if you provided more information as to the machine you have. A link to a page with a decsription would be best.

Thanks. My drivers are set to 1/16 steps I think that how it's said. The gear on the motor is 0.12 pitch so that comes out to 3.048 mm 24 teeth on the gear. For a total of 2.88 inches or 73.152 mm per revolution.X and Y axis are driven by belt with the same gearing. X axis is 500mm Y axis is 300mm table size.

The Z axis is on 3 ball screw legs. the gear on the motor is the same as the X and Y axis but the gears for the ball shafts are the same diameter so no reduction on the z axis. This is an old Brightstar B500S laser engraver. I obtained it for free and am trying to revive it for person use and doing some small odd jobs for The Masonic Lodge here and around. There is no entering G coordinates on the controller itself or in the Laser Cad software. All the adjustments I've been making are in the laser cad software on the computer then uploaded via network connection to the controller. It's a AWC708C Lite controller.

Scott

[bsm2003]

Thanks everyone. I finally got it figured out. Got the calculation done and the x axis is working great. The y a axis is another story. It seems I had a bad controller shipped to me. It will save the pulse rate setting but after homing the machine. It is going to random y axis positions. I have contacted the company for a replacement. Well see how it goes from here.

Again thanks everyone for the help.

Scott