I want to move puzzle pieces with a Lynxmotion AL5D 4DOF Robotic Arm. Goal is not to fit the pieces together, but just to sort them using some camera and machine learning. I saw the Vacuum Gripper Kit with Wrist Rotate. I was hopping for an option with continous suction, but it doesn’t seem to exist.
So I have 3 questions here.
Given that for the smallest pieces, the “inside” part of the piece (the flat part were suction can be done) is only 0.5cm x 0.5cm, can the suction cup attached to such a small area?
Is the arm precise enough to be able to center on that small section?
If one of the 2 questions above is a no, is there any “continuous suction” option for that arm?
@jmspaggi Welcome to the community! Although the default vacuum pump for the AL5 series is not continuous (uses a syringe), you can quickly create one using:
To turn this on and off via the SSC-32U, you need an RC controlled relay, ex:
We have not tried this setup to know if it work,s but seems like it might be an interesting option. Would need to calculate how much suction pressure it could provide, and you’d need to ensure the motor does not get too hot if used for an extended period of time.
Last, not sure why you need the suction to be continuous if you have to drop the pieces eventually?
Given that for the smallest pieces, the “inside” part of the piece (the flat part were suction can be done) is only 0.5cm x 0.5cm, can the suction cup attached to such a small area?
Negative - the dimensions of the suction cup can be found here:
Is the arm precise enough to be able to center on that small section?
At a distance, not sure, closer to the base it best.
If one of the 2 questions above is a no, is there any “continuous suction” option for that arm?
All of that looks like super good new to me! 99% chances that I will take a chance and try it! The puzzle pieces are very light, so I’m pretty sure almost any constant suction can work. I might take the suction cup and cut the extra diameter. Will run some tests. If it doesn’t work I will find a way to adapt my installation.
The vacuum pump will run for less than 50% of the time. So hopefully fine. Worse case I will add some pauses to make sure it cools down. And finding the right size pipe should not be a big challenge.
Regarding the precision, having all the pieces arriving straight at the feet of the arm is definitely not an issue. And if the suction is good enough it give me a buffer regarding where I “hit” on the piece.
So one last question then. My goal is to plug all of that in a laptop. I will have probably 2 cameras and the SSC-32U USB board.
Where do I plug the Pololu RC Switch w/ Relay ? Is that on the SSC-32U board? On the Analog IO Pins?
Just in case - note that the standard Lynxmotion vacuum system effectively sucks the air out between the cup and the object, so you don’t need to apply continuous suction to keep the part held by the suction cup. If you cut the suction cup with any imperfection, it won’t be able to create a vacuum seal, so you might need to order a spare or two.
Since the Pololu relay is operated like a normal RC servo, you choose which I/O pin on the SSC-32U to connect it to. Note that you need to read through the documentation to know if the center (voltage) pin needs to be connected as well, or if it’s powered from the external power supply which is powering the vacuum pump.
Happy to see you’re back at it. If stopping the pump doesn’t release the suction and the object falls under its own weight, it sounds like the object is quite lightweight. The ideal would be to reverse the pump, but the Pololu relay is one way. Something like this includes two relays from one RC input:
Alternatively a DC motor controller with RC input would not only allow you to control the pump motor in both directions, but also vary the speed.
Some examples:
Be very careful as some of these provide 5V via the red wire and will damage the other circuit (which is also providing power).
The normal Lynxmotion vacuum upgrade is intended for lighter weight objects and the servo motor which pushes and pulls the tube creates the suction but also a pressure to release the object. It would be “continuous” in that once a vacuum is made between the load and the cup, provided it’s not too heavy, it should not release the load.
Oh! Does it mean that if I invert the polarity on the motor, it will invert the flow of air too??? If that’s the case the first option might definitely be a very easy one!
I’m moving playing cards… Indeed VERY light. Planning to move puzzle pieces too. Here again on the light side…
BTW, nice to see that you are still here! And thanks for the support!
My apologies! I didn’t catch that the motor suggested is a diaphragm pump as oppose to peristaltic. That negates my previous reply since reversing a diaphragm pump does NOT reverse the flow. Again, my apologies.
Also, does it work for air? Or do I need to have an intermediate chamber with a liquid that will be pump to another chamber and will create the suction of the air?
I also like the silent aspect of it as the diaphragm one is super noisy and is a bit deforming the cards.
Oh, wow, that will be just perfect! And I can even set the speed that way! Just ordered it! Thanks again for your help. Can’t wait to try it! (and I’m pretty sure it will be way more quiet!)
Just providing a feedback on this thread in case others are reading it. The suction with the RB-DFR-855 is indeed way more controllable. I’m now able to grab a card without damaging it and release it when needed! It’s also way more quiet than the diaphragm option. Suction is definitely way lower, but enough for my needs! Thanks fo your help @cbenson !
After picking up the card there is a bid delay to let cards to “detach”. In many cases there is 5 or 6 cards lifted. Waiting and moving makes them detach. Above the desk there is a 48MP camera taking pictures, and I have a OCR script to extract the cards numbers.
Next step will be to have many buckets installed all around the robot and have it sorting the cards. I have already implement the algorithm, so I might be close to be able to do that!
I had to abandon my project (lack of time), but I’m back at it!