[Angel LM]

Hi Mohamed!

Your Thor looks great! I hope you will tell us more in the future about the control software in matlab 🙂

Now it is registered in the Worldwide Section as the number #25!

Welcome to Thor family 😉

[Angel LM]

Hello necaettin,

I don´t know what part are you referring to. If you are looking for the gripper STL files you can find them all in Thor’s github repository

Hope it helps!

[Angel LM]

Thanks for the contribution! 😉

[Angel LM]

That’s what I was thinking…

Could I ask you for that design as well? I would like to include it in the modifications section of the github repository along with the design of your end-effector!
In fact, if you have a github account and want to make a pull request with your designs to Thor’s repository, I’ll be happy to accept it 🙂

[Angel LM]

Some time ago I also thought about developing my own firmware. Actually, with GRBL, Thor’s movements are not like those of a normal robot, since the movement of all motors starts and ends at the same time, making linear movements not possible. Or at least I think so.
If you decide to design your own firmware, please keep me updated!

[Angel LM]

Hi Mendy!

You can see the configuration files of GRBL I modified in order to make it work for Thor: https://github.com/angellm/grbl

However, these are the most relevant ones:

Steppers ENABLE/DISABLE signal

#define STEPPERS_DISABLE_BIT 1 // MEGA2560 Digital Pin 40

Steppers STEP signals

#define A_STEP_BIT    6 // MEGA2560 Digital Pin 28
#define B_STEP_BIT    4 // MEGA2560 Digital Pin 26
#define C_STEP_BIT    2 // MEGA2560 Digital Pin 24
#define D_STEP_BIT    0 // MEGA2560 Digital Pin 22
#define E_STEP_BIT    1 // MEGA2560 Digital Pin 23
#define F_STEP_BIT    3 // MEGA2560 Digital Pin 25
#define G_STEP_BIT    5 // MEGA2560 Digital Pin 27

Steppers DIR signals

#define A_DIRECTION_BIT   1 // MEGA2560 Digital Pin 36
#define B_DIRECTION_BIT   3 // MEGA2560 Digital Pin 34
#define C_DIRECTION_BIT   5 // MEGA2560 Digital Pin 32
#define D_DIRECTION_BIT   7 // MEGA2560 Digital Pin 30
#define E_DIRECTION_BIT   6 // MEGA2560 Digital Pin 31
#define F_DIRECTION_BIT   4 // MEGA2560 Digital Pin 33
#define G_DIRECTION_BIT   2 // MEGA2560 Digital Pin 35

Endstop signals

#define A_LIMIT_BIT     7 // MEGA2560 Digital Pin 42
#define B_LIMIT_BIT     5 // MEGA2560 Digital Pin 44
#define C_LIMIT_BIT     5 // MEGA2560 Digital Pin 44 //3 // MEGA2560 Digital Pin 46
#define D_LIMIT_BIT     1 // MEGA2560 Digital Pin 48
#define E_LIMIT_BIT     0 // MEGA2560 Digital Pin 49
#define F_LIMIT_BIT     2 // MEGA2560 Digital Pin 47
#define G_LIMIT_BIT     2 // MEGA2560 Digital Pin 47//4 // MEGA2560 Digital Pin 45

Tool signal:

#define SPINDLE_ENABLE_BIT 4 // MEGA2560 Digital Pin 7

[Angel LM]

As soon as I have some time I’ll add it to the mods folder at Thor’s repository and I’ll note it down to incorporate it for future versions! 🙂

Thank you very much for contributing to the project! 🙂

[Angel LM]

Impressive job! Thanks for sharing the design! 🙂

I noticed that your robot has bearing supports under the second joint. It seems to me a great solution to release the load that falls on the axis. Have you noticed improvement in the movement?

[Angel LM]

Woah! Very clever!
Do you designed it in FreeCAD? If so, can you share the .fcstd file too? I would love to incorporate your design for future versions of Thor!

Thanks for sharing 🙂

[Angel LM]

Hi Mohamed!

Sorry, I have been busy these weeks and I just read your question.

I think that the problem could be related with the homing process. As you don’t have sensors to home the motors, GRBL doesn’t have a reference to start the motion. I think you can do a manual homing by placing the robot in the fully stretched upward position and sending the “Kill alarm lock” command ($X).

Here you have the documentation of GRBL commands in case you need it: https://github.com/gnea/grbl/blob/master/doc/markdown/commands.md

[Angel LM]

Hi Mendy!

The 0.4A is the current drawn by each phase of the stepper. As we are using bipolar (2 poles) stepper motors, there are 2 phases. So the total current drawn by the stepper should be around 0.8A at 12V.

Let me know if it helps!

[Angel LM]

Hi Mendy! Thanks for noticing it!

The 3D viewer on angellm.github.io/ThorAssembly was an early version of Thor v2 and I think is now deprecated, but I’ll check it anyway!

I’ll review every point you mentioned.

Thanks for the help 🙂

[Angel LM]

Yes, that’s it!

I wanted the Shield to be easy to plug, but I screwed it up with the design of the PCB, assigning the pin 41 for the tool servo before realizing that the port 41 is not PWM… So, as a hotfix, a jumper wire should be connected to a free PWM pin and I used the number 7.

[Angel LM]

I will post the video so the rest of the community can see it too!

Great job!

[Angel LM]

Woah, Thor manipulating a 3D scanner looks impressive!

I’m glad you got articulation 2 to work well. Sometimes printing tolerances are a bit tricky 🙂

[Author]

Posts