Rotary Attachment -need Guidance

[Greg Holt]

Amos

I did a quick search and the motor is a 1.8 degree stepper motor (200 steps/rev) This is quite normal.

Now you need to know something of the stepper driver. Look for a model number. 16 micro steps is common with the Chinese drives. Sometimes the number of microsteps can be set with dip switches.

Count the teeth on both the pulleys. This is the simplest way to get the reduction ratio. Say the small one was 12 teeth and the large 72 teeth - 72/12 = 6 to 1 reduction

In the above example I said mine was 10 to 1. Actually I have 14 tooth and 120 tooth. 120/14 = 8.571428571 to 1 reduction. Not such a nice round number but perfectly OK.

Greolt

[Amos De Pasquale]

Dip Switches (Medium).jpg Ok, Greg I have 72 to 24=3 to 1 reduction, and a 200 step motor, the model of my stepper driver is Leadshire M542-05, the dip switch is set to 6400 (unless I am reading the dip switch incorrectly, which would then change the figure to 4000) I cannot see the markings on the dip switch to see which setting is "on" and which setting is "off", so experience tells me that the "off" position is usually the straight positioning and the click down position is the "on" position)
going with the 6400 setting; and my MAGIC number for my machine is 3*6400=19200,
So for 13mm diameter 13*3.14159/19200=0.0001636
If my dip switch reading was the opposite way my magic number would be 12000!
This is a quick sketch of my dip switches

[Kim Vellore]

I think it would be easier if you calculate backwards.
1) Draw a line on a spare cylinder so your laser gets a complete circle (from trial and error), you can use a slightly slanted line so you will know when they cross
2) Now you have the correct length for your cylinder, just divide the length by the perimeter of your cylinder, that will be your multiplication factor for different cylinders.

Kim

[Greg Holt]

Amos

Couldn't be easier.

If driver is set to 6400 steps per rev then;
D*pi/19200 = Distance per step in mm to enter.
Same equation simplified is D*0.000163625 = Distance per step in mm to enter.

Or

If driver is set to 4000 steps per rev then;
D*pi/12000 = Distance per step in mm to enter.
Same equation simplified is D*0.000261799 = Distance per step in mm to enter.

I think the second one is correct.

Check it by real example like Kim said above.

Greolt

[Amos De Pasquale]

Ok, thanks Kim and Greg, will check out and let you know results ,probably next 24 hours. Amos

[Greg Holt]

For anyone else who reads this thread;

The example above is for LaserCut 5.1
Pulse Unit is the distance moved per step in MM.


My controller, which is a AWC608 with LaserCad 6.27, the pulse unit is the distance moved per step in uM

Some other controllers the setting is in steps per MM(inch), like Mach3 for example.

Greolt

[Amos De Pasquale]

OK, tried it out tonight, my "magic" number is definitely 19200, worked like a charm. tried the 12000 but definitely not the right figure. Thanks Greg for the preserverance and help on this issue, certainly a great learning curve. Amos

[Greg Holt]

Ok that's great, now you can forget all that and just remember........ Diameter of the material multiplied by 0.000163625 is the appropriate step value.

Write it down somewhere that you will always have it handy.

Greolt

[Amos De Pasquale]

Greg, that is Pi/the magic number, in my case the number is 19200 so 3.14159/19200=0.000163625, thanks, Amos

[Gerhard Koekemoer]

I have build my own rotary system that can handle up to 200mm dia objects but is having a problem with the return speed. When engraving glasses the return speed is too high and the glasses jumps off the rollers. I am running RDCAM6.0.25 from CorelDraw X6 on a Astroware laser machine I have tried RDCAM5 before with the same problem. I also tried adjusting the Home speed to 5mm/s and also tried to adjusting the line shift from 150 to 10 with no luck. Can anybody help please.

[Rodne Gold]

Where are you adjusting ? on the machine lcd panel or in software?

[Gerhard Koekemoer]

Sorry Rodney, I should have opened up the machine tab to explain better on the previous image.
I was adjusting on the software, in the user settings.
RDCAM6_1.jpg

[Rodne Gold]

Gerhard, Try set the non engraving speed and steps (jog steps) in the Vendors settings , password rd8888 (read it , change it and don't forget to write it and save it and a copy of the original config) and if that doesnt work , try it on the machine lcd panel.

[Gerhard Koekemoer]

I have tried that before but will go through the settings again next week. I am going to Pinetown tomorrow to replace a 130Watt tube and will only be back on Saturday.
Thank you for all the help.

[Robbie Kent]

Amos,
Here is the correct answer for my Rabbit Laser running Lasercut 5.3. This is for the Chuck Style Rotary. D(Diameter of Cylinder) / 3277.647. I can't tell you why, or the specific math reasons, but I know it works, and is correct for my machine. I have attached the link for you, as well. I hope this helps.http://www.rabbitlaserusa.com/Manual...uctions_RL.pdf

Robbie Kent Jr
Rabbit Laser HX 4060SE
Rabbit Laser HX 1290SE