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BUY HERE: https://source-robotics.com

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BUILD YOUR OWN!

Project log reading order: PAROL6 control board, mechanical design, Software design

Github repo with PAROL6 Files and building instructions: Link

Github repo with PAROL commander GUI: Link

Documentation: Link

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Join forum: https://discourse.source-robotics.com

Problem

I first saw a need for robots such as this in my high school days where 30 students were working on one robot. At colleges, it was nothing better. I did some research and that was the situation in most colleges. My first attempt to change that and make it one robot per student was with Faze4. That project was financed by the college but was not a big hit because of its large size, imprecision, and lack of easy-to-use intuitive software. The second time I saw the need for a robot such as PAROL6 was when working as an RnD engineer on electric vehicles. Building a prototype is one thing but building a production is another much harder thing. I saw many ways robots such as PAROL6 could help companies that need to go from RnD to small production, or at least try to accelerate their RnD processes. Tasks such as adding thru-hole components, placing PCBs to test jigs, handling PCB, gluing, inserting brass bushings, and many more could be in some part automated with robots such as PAROL6.
Solution

Solution

With now a large amount of problems that I saw in education and industry I decided to try to tackle them with PAROL6. Just the idea of this kind of robot is nothing new and there are many robotic arm businesses that try to fill this gap but they either fail in terms of price, usability, or lack of support / being open. PAROL6 aims to be a low-price solution, be usable, and be as open source as possible.

PAROL6 is a desktop robotic arm. Its reach is 400mm and has 6 axes of freedom. Its capabilities are on par with industrial robots in terms of repeatability, speed, and usability. It is equipped with stepper motors and precision planetary reducers/belt drives. Its mechanical parts can be 3D printed on any desktop 3D printer and its full weight is only 5.5 kilograms! In terms of connectivity, it has pneumatic tubes running thru the robot and the ability to connect a force-sensitive gripper that is being developed.

The design is minimalistic and because of that can be easily modified. Stepper drivers can be upgraded to a closed loop for almost all axes without any major design changes. For that purpose closed loop stepper drivers running FOC have been developed.

Previous robots

Faze4 - Project link

Faze4 was my bachelor's degree project and was financed by my college with the goal to make a robot arm for education. This is where my realization came that robotic education is very underdeveloped. It is mostly done on simulations or with 10+ students working on one robot. Faze4 was supposed to change that. It is a fully 3D-printed behemoth of a robot with a reach of 580 mm, a weight of 15 kg, and fully 3D printed.

Problems of Faze4 were many:

Too large a robot for students to manipulate safely
Printed gearboxes flex and make precision and repeatability terrible
Underdeveloped electronics and software
Because of all of the above, it was hard to work on and develop software

Nevertheless, Faze4 is still one of the most popular DIY robotic arms and is being used by multiple collages, as part of masters' and bachelor's theses, and by the maker community in general. Even 2 accelerator stage startups are using Faze4!

CM6 -Project link

CM6 was my master's degree project. It is using gimbal BLDC motors and printed planetary gearboxes paired with custom BLDC drivers called S-drive. This robot was of the experimental type where the goal was to make a robot...

Programming guide for PAROL6
Petar Crnjak • 6 days ago • 0 comments
PAROL6 setup video
Petar Crnjak • 04/14/2024 at 09:05 • 0 comments
Video assembly guides
Petar Crnjak • 04/06/2024 at 17:02 • 0 comments

https://youtube.com/playlist?list=PLSueoDrBt5MMTL9O8qAWZiJrNIf8-29Qz&si=Zca3UZKENje9ifow
Vacuum gripper for PAROL6
Petar Crnjak • 03/30/2024 at 13:04 • 0 comments
Official forum for PAROL6
Petar Crnjak • 03/23/2024 at 11:30 • 0 comments

Join forum: https://discourse.source-robotics.com
Happy holidays from PAROL6!
Petar Crnjak • 12/24/2023 at 10:56 • 0 comments
Beta batch of PAROL6 PCBS
Petar Crnjak • 10/09/2023 at 14:19 • 0 comments

If you are interested in the beta batch of PCBS sign up here:
https://forms.gle/sZqHVLPoMJxuVAyJ9
If you are interested in buying PAROL6 as a kit, fully assembled robot, or just a gripper sign up here:
https://forms.gle/XkSvStwnQxw1f8xL8
30 more PAROL6 robots coming soon!
Petar Crnjak • 09/28/2023 at 10:57 • 0 comments
Robot testing code!
Petar Crnjak • 09/27/2023 at 07:32 • 0 comments

To test PAROL6 control board connection to your robot you can use stock software or use testing software. Testing software is more safe and interactive for users. It can be found at github. Once you flash your PAROL6 control board testing will start.
Stepper drivers test

The code will try to communicate with stepper drivers. Output1 and Output will go from high to low every 1s and LED1 and LED2 will flasg. If everything is okay you will get output like this on serial:
If the stepper driver is faulty or not connected you will get:
If stepper drivers are good your stepper motors should spin at a low speed using moderate current of 200-300 mA.

Flash memory test

In the serial terminal write # FLASH and press enter. You should get an output like this for a successful test.
LIMIT test

In serial terminal write # LIMIT and press enter. You should get a output like this if you activate the switch.
IO

In serial terminal write # IO and press enter. You should get an output like this:
If you change the state of ESTOP, INPUT1 or INPUT2 you will see states changing. You will also be able to see the voltage of your power supply in mV!
Trajectory follow and script language RBTscript
Petar Crnjak • 09/16/2023 at 21:01 • 0 comments

PAROL6 commander software allows you to write simple robot arm scripts. The scripting language is called RBTscript. It allows you to move the robot in joint space or cartesian space, use delay functions, control outputs, grippers, read inputs, and much more!
How are trajectories tracked?
Once the program starts it needs to generate and track commanded trajectories.
There are 2 ways we can command robots' trajectory here:
For example, we want joint 6 to move from 260 deg to 180 degrees. We want to follow trap velocity profile and get to 260 position in 2 seconds. We generated speed and position curves.
Now if we command only the speed curve robot will follow it perfectly but if the move is too long or too fast it will miss the demanded position. Why? We are sending commands every 10 ms. but it is not always exactly 10 ms since pc is not a real-time machine that time fluctuates. another thing is that steppers execute some really small speed moves from the beginning and the ends of the speed curve. Because of that position is missed usually. How to compensate for that? Use position curve. Use your current position and commanded position and calculate how fast you need to go. After that take that speed and add commanded speed and average that.