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Sorry for the late reply, I was on my vacations hehe
When I started to build it, I had issues with the Art4 which was moving a lot due to slack but I found this and it fixed it perfectly. I would recommend to add it to the mod folder to be easier to find 😉
Yeah, I forgot to add them to the mod folder. I’ll try to add it ASAP. Thanks for the reminder!
Regarding my issue, I have randoms homing failure. Is there any way to know more about the failure?
I’m not very sure what is happening. To discard some common issues, please check that your $$ settings match with the ones listed in the Firmware Documentation.
Don’t you think it’s weird to have only 3A drawn?
Do your motors skip steps or not move at all when they should? In my experience when the robot is holding the maximum load it can handle, the current drawn is something between 7A and 8A.
The Art1OptoFix piece is no longer needed if you printed de latest version of the BaseBot piece (which I think you have printed) and you are going to use the commercial Optical Endstops listed in the BOM.
I’ll note it to remove the piece from the repository ASAP.
The Art4BearingPlug piece is used to prevent the bearing balls to escape the ring. In the assembly animation it should be inserted in the same hole used to insert the bearing balls after inserting them. This video of Sr Ferrete shows how he inserted the balls and the Art4BearingPlug piece.
The Art56Interface is only needed if you want to use other tool than the Thor Gripper. This piece provides 3 screw anchor points, and can be used as a base to design your own tool holder.
In this image you can see a Thor using this piece to attatch a different gripper.
Hope it helps!
First of all, congratulations on the submission! I’m sure it was a challenge and a lot of work on your part, I hope you got a good mark! 🙂
Of course I’m interested in that report you mentioned, has the work been published somewhere online? I say this because I would love to include it in the Worldwide section, in the “Academic Presence” to make your work visible and that what you have done can be used by more people.
A big hug for you from across the pond!
Primero de todo, ¡enhorabuena por la entrega del trabajo! Estoy seguro que ha sido todo un reto y mucho trabajo por vuestra parte, ¡espero que hayáis obtenido una buena puntuación! 🙂
Por supuesto estoy interesado en ese informe que comentas. ¿El trabajo ha sido publicado en algún sitio online? Lo digo porque me encantaría incluirlo en la sección Worldwide, en el apartado de “Academic Presence” para visibilizar vuestro trabajo y que lo que habéis hecho pueda servir a más personas.
¡Un abrazo para vosotros también desde el otro lado del charco!
Welcome to the Thor community 🙂
I’m glad you liked the project and decided to build one with your boys!
Do not hesitate to share your progress with us or ask any question you have 😉
Thank you very much for noticing this, I’ll add the fans and the magnets to the Bill Of Materials 🙂
About the pulleys, the 3 units of GT2 Pulley 20 teeth are correct. But as the geared motor shaft is 6mm, you have to drill half of the hole in the pulley with a 6mm drill bit. If not, you should replace the 625ZZ bearing and the 5mm diameter rod of that side with a 6mm diameter rod and a bearing with 6mm bore.
I placed the fans in order to intake air, but I think both ways are ok as long as the air flows through the robot.
I am sorry that the previous reply has been deleted, the anti-spam system has deleted the message and I am not able to recover it.
Regarding your question, currently with ABS printed gears, the limit of the robot load is due to the maximum torque provided by the motors.
First of all, thanks for your interest in this project! I am very happy that after years, this robot is still being studied 🙂
To answer your question, indeed, in terms of load support, joint 2 is the one that has to support the most, followed by joint 3.
In terms of mechanical failures, the most sensitive parts and the ones that have ever broken are the gears that attach directly to the motor shaft. They are sensitive for two reasons, the first being temperature: Motors get hot during robot operation, and as the printed parts are in direct contact with the motor, they can reach temperatures high enough that they become malleable and deform due to the combination of stress and heat. That is why for all small parts that are in direct contact with the motors it is recommended to print them in ABS.
The second reason is the force that the gear teeth have to withstand. As they are small parts and are printed, due to the force they are supporting, if the layers are not well bonded to each other, they can break.
In the rest of the structure of the robot I have not observed mechanical failures of this type, but there is another that occurs in many axes and has to do with the flexibility of the assembly of the parts and their clearance. For example, the body of joint 2 (the one formed by the 8-shaped pieces and their intermediate connection) can be seen as an H if you look at it from the side. Because the connection of this body is only in the middle, when it is subjected to a lot of load the ends (especially the lower ones) tend to open up a bit. If this opening is large enough, the gears of the motors may not make good contact with the inside crown of the second joint, which can cause anything from a loss of steps of the motors to gear breakage.
Regarding the mechanics, these are the faults that I have detected the most, I hope it is of help!
Ouch, I’m sorry about that! Maybe you can ask Tolga about where did he get the motors for his Thor? I think that he’s from Turkey also.
If that’s not possible, I guess that a motor with a similar torque and dimensions may do the job, but it will probably require a redesign of some printed pieces…
I’m glad the problem has been fixed!
I will modify the documentation to make it clear how to make that connection and avoid more confusion in the future 😉
Oh, my bad, my mistake. I forgot the most common problem in these cases. As you can see in the wiring diagram, the servomotor signal pin has to be connected to pin 7 of the Arduino (it is marked in another color).
When I designed the board, I made the mistake of thinking that pin 41 of the Arduino Mega could be used as PWM and it is not, so the solution is to unsolder from the Control PCB the pin that would be connected to pin 41 of the Arduino and instead solder a jumper wire to connect it to pin 7 of the Arduino.
I hope this solves the problem!
Ok, it’s the same one I use. I assume you have already tried connecting the wires by turning the connector 180 degrees.
Check, just in case, that the motor connector pins correspond to SIG, VCC, GND in that order. By the way, check also the state of the connector pins, to discard that it could be due to a bad contact.
Is the servo motor powered? There is 5V between the center pin of the PT1 pin set and the one closest to the edge of the board?
What Gcode are you using? These are the ones that I use to check the functionality:
M3 S900– Open gripper
M3 S0– Close gripper
What model of servomotor are you using? How it is connected to the PCB?
You are trying to attach an image located in a private Google Drive folder, so we can’t see it!
You can use an image upload free service (like this one) and then attach the image again