Z motor works when x is 0 but not when x = 2640

Goanna7007 · October 9, 2019, 3:35am

Z motor works when x is 0 but moves real slow when x = 2640

here’s a video: https://youtu.be/O8qhnchm-cE

Sequence used in the video:

additional information:

y axis seems to have no affect.
going up when x = 2640 works fine
values from x = 1000 to x = 3000 seem to have the same problem.

I’d guess this is a software problem.

jsimmonds · October 9, 2019, 7:15am

[@Goanna7007, Just trying to speed up diagnosis and solution for you]
The Farmbot developers will need to know your versions ( Bot Kit, FarmbotOS and MCU/Farmduino )

Goanna7007 · October 9, 2019, 8:45am

ah yep,

Farmduino v1.3
Fambot os: Version 8.0.4

cris · October 10, 2019, 2:33am

It could be binding somehow - turn off the power, move the x to home, twist z by hand; Move x to max, twist z by hand, and compare the drag. If equal, keep going on software. The coil-joint at the top seemed to be compressed - same at both ends?

Also, the silent drivers will rock your world. . .cd

Goanna7007 · October 15, 2019, 5:07am

Thank you Cris,

The drag seems equal.
What do you mean by the coil joint at both ends?
We’ll have a look at the silent drivers.

Update: the Z only freaks out if the location it’s moving to has a combined vector value of over 10 characters (CHAR).

tests:
2640, 99, -100 works. CHAR length: 10
2640, 100, -100 fails. CHAR length: 11
2640, 100, -99 works. CHAR length: 10
2640, 100, -100 fails. CHAR length: 11
999, 100, -100 works. CHAR length: 10
999, 1000, -100 fails. CHAR length: 11

This leads me to believe it is a software problem with the G code.

cris · October 15, 2019, 10:40pm

The coil joint thingy has a better name - it’s attached to the top of the Z lead screw and connects the stepper motor to the shaft - presumably to reduce any shock in the mechanicals. Anyway, given the testing, it truly seems like a software problem. I’ll let Rory and team address this - squarely out of my league. . .cd

farmbotFr · October 18, 2019, 12:56pm

Hello,
I think I found the solution to the problem. The farmduino buffer has a max fixed side of 50.
It’s defined in th config.h file of the farmduino “const int INCOMING_CMD_BUF_SIZE = 50”;
However if you request a move with x>999 or y>999, the size of the request is more than 50.
Exemple : G00 X1050.60 Y999.00 Z-200.04 A400.00 B400.00 C250.00 Q42 (57 char).

Goanna7007 · October 19, 2019, 8:52am

Thank you farmbotFr!

I have downloaded a copy of the Arduino software and changed the config from 50 to 60.

I should be able to test it out on the 22nd of October.

To flash the Arduino, can I just plug the Arduino into my laptop and press “upload” in the IDE?

Edit:
I think I’ve got it:

https://genesis.farm.bot/v0.8/docs/arduino-firmware

Download and install the Arduino IDE onto your computer

Download and unzip the latest FarmBot Arduino Firmware

In the firmware folder you just unzipped, go to the src sub-folder and open up src with the Arduino IDE. Note: this file is blank, but there are many other file tabs that should be automatically opened as well.

Connect your Arduino to your computer with a USB cable

From the IDE, click Tools > Board, and then select Arduino Mega 2560

Now click File > Upload. This will flash the firmware onto your Arduino

jsimmonds · October 21, 2019, 7:43am

That may or may not be the best fix.
The code in https://github.com/FarmBot/farmbot-arduino-firmware/blob/master/src/farmbot_arduino_controller.cpp at lines 382:388 appears to be trying to deal with command lines longer than INCOMING_CMD_BUF_SIZE (?)
I’ll try to desk-check that code myself soon.

roryaronson · October 22, 2019, 10:08pm

Thanks everyone for helping troubleshoot here. The fix has been merged into master and was deployed today in the latest version of FBOS (v8.1.0)

Goanna7007 · October 23, 2019, 5:47am

Huge thanks!

Update fixed it!