acorn board fusion 360 and smooth circle

[usinart]

ShawnM thank to look into the manuel for the informations .
I also place into the PN (parameter edit mode 3.2) some as PN001=9 ... THE one that I want to have your advice on is the PN 098 ,099 ,100 , 101 as nominator as in fraction x/y and the PN 102 as denominator .
X at PN098 as 10 the other have 7 at PN098 (numerator ) and at PN102 all have 1. so it 10/1,7/1,7/1.
should I put it back to the default value =1
thanks

[usinart]

After changing in the wizard the number at 2500 . No modification as been made yet to the drive motor on the Pn098/Pn102 .But I have to reduce the maximum and the high speed in to the wizard because it was to much.

Ok now the DRO is a 0 and I move all axe of .010 in .
at the dial indicator that is something else .
x = +/-0.033
y = +/- 0.025
z = +/- 0.033
and all have some amount of backlash at the first move at changing direction.

[suntravel]

How to set up the axis is described here:

https://www.centroidcnc.com/dealersuppo ... ads/36.pdf

Encodercounts in Acorn must match to the setup of drives.

Uwe

[ShawnM]

Post a link to your actual servo drive manual and we can all work through it to find the proper settings. I was just suggesting 2500 as I saw that in a manual that was very similar to your drive. We need to see your exact manual to know for sure. Then it’s 4 times that number. Oddly the sticker on the top of your drive in your photo is a part number for a motor not a drive.

Once you change the steps per revolution you will need to adjust your overall turns ratio for each axis also. Uwe posted a link to those instruction in his post.

Please post a link to your drive manual here.

[usinart]

I just add my manual in one previous message but it one of the manual the chinese compagny send me . the other one was chinise /english very hard to understand.

[usinart]

Hi suntravel I know that procedure for adjusting the axes , thanks .Now is in the motor drive and the cnc12 that I have to find the match.
And what about the ratio that one person told me to adjust to find my drive setup.
Pn 098/pn102 .

[suntravel]

Hi suntravel I know that procedure for adjusting the axes , thanks .Now is in the motor drive and the cnc12 that I have to find the match.
And what about the ratio that one person told me to adjust to find my drive setup.
Pn 098/pn102 .

Look at the manual of yous servos, the pulse per revolution ( PPR ) is set up by the factory, most times 2500 with cheap chinese servos.

Dial this in the Acorn Wizard and the pitch of your ballscrews.

Done this, even without finetunning, the machine will move almost precise.

Even cheap CL7 ballscrews are most times better than 0,05mm / 300mm travel

Measure backlash and dial it also in the Wizard. If backlash is more than 0,04mm better get the hardware fixed.

Uwe

[ShawnM]

I was just pointing out that you have a 2500 line encoder, not to set your steps per rev to 2500. Bad choice of words on my part.

I always start with the default settings and don’t change ANYTHING unless the drive doesn’t work. Then I read through the parameters and change one at a time and test.

This is how I interpret your servo drive manual and how I’d start if it were mine.

Pn001 should be 9 for your motors just like you have it.
Is Pn080 set to 0? If so that’s the 2500 line encoder or 10,000 pulses per rev. for a quadrature encoder.
Is Pn016 and Pn017 still set to 1?
I would leave Pn098 thru Pn102 alone and not change them, leave them at 1 which is the default.

The settings you want to change are for Pn016 and Pn017 for this “ratio” you mention. The example in your manual shows you how to get it to 800 lines and then you would set your pulses per revolution in the wizard to 3200. Then adjust your overall turns ratio with these new settings.

The example in your manual suggest these settings:

Set Pn016 to 25
Set Pn017 to 8

This will now take your 2500 line encoder to 800 lines. 2500 / (25/8) = 800 lines. A quadrature encoder counts 4 times that in a revolution so your new steps per rev is 3200 in the wizard.

Make these settings and recalculate your overall turns ratio and report back.

As for your backlash, you’ll have to calculate what it is for each axis and enter that into the wizard as well.

[usinart]

Ok I calculate the overall turn ratio ( distance ask / distance move ) x the overall turn ratio number in the wizard = the new overall turn ratio to inscribe in the wizard .
Correct me if I'm wrong.

Question
for the more precision the distance ask should it be the longest on possible ?
Because all of the distance are made with a dial .1 by turn.
Is it possible that if I'm asking 48 in that it's giving more or less.

[ShawnM]

Yes, you should travel farther than .1” for accuracy. I mentioned that earlier. Most dial indicators will travel 1”. Start there. Do you have some precision 123 blocks? You can use those for even further travel. I’ve heard of other people chucking up a sharp, pointy object and using a ruler over a longer distance. That might be ok for my plasma cutter but it’s not accurate enough for my router.

What is the pitch on your ball screws?

What other changes have you made in your servo drive?

Did you set Pn098 thru Pn102 back to 1?