Tower Pro micro server 9g sg90

[raphmann]

My Tower Pro micro servo 9g has stopped to work during a drawing yesterday.
The pen doesn´t move up or down anymore. Is the micro servo defect?

Of course I shut down the makelangelo 5 and started all again, but the micro servo
does not move. What do you advise?

Raphael

[Dan]

First check your cable is in ok. Then connect software, and try the pen up and pen down moves in the settings panel. I say in the settings panel because there you can also check the angle values are not both set to the same thing (never happened before, but who knows?)

If it fails all those tests, it’s probably dead. either motor has burned out or plastic gear teeth have worn off and you’ll need to replace the servo.

[raphmann]

All those tests failed. I ordered a new servo.

If it´s not the servo, but the arduino – where can I buy one in Germany?
Which one is the right model?

Raphael

[Dan]

Is this a RUMBA board on a Makelangelo 5? I don’t know local German retailers, so I would look on Aliexpress.com or Amazon.de. Of course we’d be happy to sell you a board, but I appreciate how expensive shipping can be.

[raphmann]

Dan, I need your help.

I´ve bought new Tower Pro servos. They are identical. But when I connect the new one,
the numbers on the display disappear! And the servo gets very hot and it smells a little
like electric fringing.

I suppose the old one gets damaged cause there´s something wrong with the rumba board?!

I urgently need the drawings from the robot, please could you give me a hint?

Raphael

[raphmann]

… the voltage of the board for the servo is 4,48 V. I think this should be normal?

[raphmann]

Hi Dan,

is this the right board?
https://www.amazon.de/PoPprint-Controller-DRV8825-Treiber-Stepper-K%C3%BChlk%C3%B6rper/dp/B071V9JHSG/ref=nav_signin?ie=UTF8&qid=1523954690&sr=8-2-fkmr0&keywords=BIQU+Rumba+For+3D+printer+motherboard+rumba+MPU+RUMBA+optimized+version+control+Board&#

Raphael

[Dan]

That looks like the same board, yes. notice that the cable on the original servo has the red and black wires switched. if you pug in a normal servo without switching the wires you might kill the servo.

[raphmann]

I´ve changed the board and installed the firmware. The display shows:

X 0.00 Z 90.00
Y 0.00 F 100%

But the motors are not moving when I type “Find Home”. I only hear a high sound. It´s not loud.
When I press “Stop” on the control board (display), the sound stops.

What can I do?
Also the little servo does not move 🙁

[Dan]

There’s more to the setup than just replacing the board and installing the firmware. EEPROM settings need to be updated.
For most Makelangelo 5 machines it’s enough to send a D11 once. It can be further tweaked after that with D7-D9.
I’ve only had to explain the process maybe once before because we don’t ship unfinished machines.

[raphmann]

How can I do this? I don´t know, what EEPROM or what D11 or D7-D9 is.

Do you have a short guide for me, what steps I have to do? (I´m not a coder…)

Thanks

[raphmann]

One more question:

I´ve plugged in the “old” (=Originalboard) again. But the new micro servos do not work anymore.
Do you know any reasons, why they give up work? I thought the Board has a failure (perhaps got to hot).
Thats why I replaced it.

But if you could have a short guide (EEPROM, D11, D7-D9) I will try it.

[Dan]

plug in robot
open arduino software
arduino > tools > port > [set port]
open serial window (magnifying glass, top right)
set baud=57600, drop down=”new line”.
confirm message from robot says “hello world!” etc.
type D11 and hit enter. messages appear.
type G28. robot goes home.

if pen does not stop exactly at home position,
D8 reports calibration. should look like D8 Lnnn Rnnn where nnn is a decimal close to 101.1
D7 Lnnn Rnnn changes left and right calibration. increase n to make pen home closer to that motor. use very changes of maybe 1.0 or 0.1 at a time.
after each D7, use G28 to home again and see change.
repeat until satisfied.
D9 to save changes.

[raphmann]

When I tpye G28 the robot goes not home. I only hear a sound, but the motors
do not move.

With the old board I do not have this problem. The Steppers are moving/working.
Only the little micro servo does not work. With the new board the micro servo
does alos not work.

What could be the reason for it?

[Dan]

robot does not home? what does it say when you send D8? should be L1011 R1011

[raphmann]

Yes, sending D8 is L1011 R1011.

1. Problem new board: robot does not home or move. Micro servo does not work.

2. Problem “Old” Board: Robot does home, but micro servo does not work (That´s why I bought
a new one.) Why does the servo not work? What could I do?

[raphmann]

Here you can see the sound, when homing with the new board. Motors are not moving:

[raphmann]

Home does not work/motors are not moving. Only a quiet high sound you can hear.

baud=57600, drop down=”new line”.
message from robot says “hello world!”
type D11 and hit enter: messages appear.
type G28: robot goes NOT home.

[Dan]

Well… I’m out of ideas. what messages do you see on D11? let’s confirm that part is working 100%.

[Author]

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