Loosing steps

[jkarpy]

I am running the Light Object Anywels AWC-608 Laser controller. It is doing very well cutting but seems to loose steps when engraving.

My first guess is that I am dividing my steps too much. I am currently running 20,000 micro steps per revolution. Before I spend the time testing my theory, I was hopping for some insight from someone with more experience. I have already checked my Amps to the motors.

[Tech_Marco]

Set it to 3200 or 5000 as it is good enough for a laser machine. No need to go over 5000.

Marco

[jkarpy]

Set it to 3200 or 5000 as it is good enough for a laser machine. No need to go over 5000.

Marco

Do you think that will be my problem?

[jkarpy]

Still same problem after reducing step multiplier to 10 and adjusting my belts. So here is my entire configuration:

Light Object Anywels AWC-608
Drives: KL-4042D (automation technologies)
X: 2 amps, 2000 steps (10X) Auto configured
Y: 3.5 amps, 2000 steps (10X) Auto configured
Motors:
X: Automation Direct Sure step STP-MTR-17048
Nema 17, 83 oz torque, 2 amps
Y: KL23H2100-35-4BM (automation technologies)
Nema 22, 570 oz torque, 3.5 amps
Belts:
X: MXL
Y: XL
Pulleys:
X: MXL 20 pitch
Y: XL 10 pitch
No gear reduction on X and Y

My DSP setting can be found in the attached PDFs.

Machine settings.pdf

(168.53 KiB) Downloaded 125 times

[wctx1977]

Hi jkarpy,

Would you mind taking and posting a video of the machine while working and missing steps? I would like to see and hear how smooth the machine works while this happens.

[waltfl]

hi there
your x axis max speed is way to high with 7000 set it down to 700 and the acc jerk to less then 8000
greetings
waltfl

Still same problem after reducing step multiplier to 10 and adjusting my belts. So here is my entire configuration:

Light Object Anywels AWC-608
Drives: KL-4042D (automation technologies)
X: 2 amps, 2000 steps (10X) Auto configured
Y: 3.5 amps, 2000 steps (10X) Auto configured
Motors:
X: Automation Direct Sure step STP-MTR-17048
Nema 17, 83 oz torque, 2 amps
Y: KL23H2100-35-4BM (automation technologies)
Nema 22, 570 oz torque, 3.5 amps
Belts:
X: MXL
Y: XL
Pulleys:
X: MXL 20 pitch
Y: XL 10 pitch
No gear reduction on X and Y

My DSP setting can be found in the attached PDFs.

Machine settings.pdf

[Rad Racer]

Although this may not be your stepping problem, it is very important you use the proper voltage / current and setup for the axis stepper motors. I have attached a "stepper motor calculation" worksheet that explains the formulas and motor information needed to insure your motor drive system is correct and operating at optimum performance.

The first calculation is for max voltage...it goes like this:
Max voltage=SqRt motor inductance (mH) x32

Let's look at my example....I am using powermax II motors that have 2.8mH in series wiring.
Max voltage = SqRt 2.8 * 32 = 53.5V
Only use 90% this value for operating voltage. 53.5 * .9 = 48V (look familiar )

This same motor in a parallel configuration has an inductance of .7mH so the proper voltage for this wiring method is: SqRt .7 * 32 = 26V 26V * .9 = 24V

The other important calculation is the corner speed or optimal RPM for the motor.
RPM = (.191 * VS) / L x Is
VS = voltage supply
L = inductance in Henries
Is = phase current in amps

Here's an example for a motor with inductance of 2.8mH, operating at 2.8A at 48V. (This information comes from the motor data sheet.)
RPM = (.191 * 48) / .0028H * 2.8A = 1169 RPM

See the attachment for other information. The work sheet contains the calculations and information used for my MechMate CNC router build from a few years ago.

Hope this is useful,
Wayne

Stepper motor calculations.doc

(33 KiB) Downloaded 164 times