3 dimensions gantry robot with gripper

[Mr Jos]

I added 4 wheels to my 2D gantry to make it able to cover a larger area, after some testing I came to this current design (where wheels don't go flying within 30seconds).

--- Video got removed ---

As the first 2 axis moved fast already, I wanted the driving to be fast aswell, and I think it works great. All movements work pretty accurate as every startup all motors are being homed.

Only problem now is that this EV3 brick has no motor slots left to power a conveyor for feeding pins to be sorted, so there's again a reason to get 1more (if I see one cheap somewhere).

This video is just when testing maximal speed with 3600°/second acceleration, but I will tune it down to prevent it from pulling wheelies like in this video.

EDIT:

 

Edited August 9, 2022 by Mr Jos
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[Mr Jos]

Added upgrades:

- A PF motor driven belt to feed pins and scan them on color/length as there are no more motor slots left on 1 EV3 brick to make this 3D+gripper gantry.

This means that the belt will not stop. As solution the gantry picks the pin on the fly. It drives aprox at the same speed as the belt and then lowers the gripper and takes the pin.

- A energy chain that allows the programming- and charging cable + color sensor wire to move along with the robot.

Future updates:

- If pins come to fast after another/ the previous pin had to be dropped far away, the pickup belt will need to become longer so it will be able to get the pin later and not always at this sweetspot. Then the belt will be able to run with higher speed/sorting speed.

- Putting more time in Pin detection data (now only 1minute was spend).

- Try to sort as many pins as possible with just this one color sensor.

- Have dedicated bins for each pin. (And if more EV3/PU bricks would be added; a system to empty these bins on a single large belt 1 by 1 to transport them to a pallet in the logistic warehouse. One can only dream)

[Mr Jos]

As it was requested by a teacher on facebook, I made (free) instructions for this simple but effective gripper.

LEGO MOC 3 armed gripper by Mr_Jos | Rebrickable - Build with LEGO

Still adding some pin data to sort as many as possible pins.

[Mr Jos]

And now it sorts more kind of pins, and a longer conveyor to pick up from.

 

[Mr Jos]

And another update (don't know if it gets viewed);

I added an automatic feeder, a slightly updated version from my drum feeder. Made the scanning belt longer and higher in the air. Pins can be dropped from high or low (as in the video). High works fine and faster, but this looks more nice.

 

Now I'm searching extra items to teach it to sort (after the video was made), for now it knows 2L red axles, 3L+Stud dark tan, 3L Reddish-Brown with stop, 3L white axle connector for clutches.

Longer than 3L does not work with this gripper.

The gripper has free PDF instructions on Rebrickable. LEGO MOC 3 armed gripper by Mr_Jos | Rebrickable - Build with LEGO

Edited April 7, 2022 by Mr Jos

[ord]

Nice work - it's looking better with every update (BTW, love these kinds of builds). The longer belt seems to be working well and speeding things up. 

Now just to move the filled bins to the parts warehouse with the 6-axis arm :P (I know, needs a lot of programmable bricks!).

 

[Mr Jos]

20 hours ago, ord said:

Nice work - it's looking better with every update (BTW, love these kinds of builds). The longer belt seems to be working well and speeding things up. 

Now just to move the filled bins to the parts warehouse with the 6-axis arm :P (I know, needs a lot of programmable bricks!).

 

Thanks!

That was my initial idea to make all my machines work together, having the 6DoF supply an empty pallet, and then make it fill up with 1 sort of the sorted pins (and remember the amount in the pallet ofcourse).

I'm still thinking on how to do this, I do have an idea (from real life machines I install/perform maintenance on). It's a second hand clothing sorting, each kind of fabric/gender is thrown in a bin, then at given times the flap under the bin open up, and the items fall on the belt underneath, that transports it all to the next station. Then another kind gets dropped on the belt. So that uses only 1 conveyor for transporting the sorted items to the pallets, but the problem is the flaps. I would need a motor for each kind of pin. So I need to find a way to make that better, perhaps with a slider or something that can select between 10 flaps, and open and close them 1by1.

And then indeed find more EV3 bricks. At this moment 3 in use for the warehouse, 2 in 6DoF, 1 in this bridge sorter, and 1 (without rechargeable battery) is in my swingarm sorter. That last one I can breakdown if needed or just use the brick, and try to make this transporting system.

Or if anyone has some cheap EV3 material leftover they do not use, I might buy/take it over :D

Edited April 8, 2022 by Mr Jos

[Mr Jos]

I finally made this model in Studio, first an empty basic version that is possible for everyone to make with standard pieces.

This one can move in 3 directions pretty fast and allows the gripper to be opened/closed quickly. As it has no feeding conveyor/energy chain to route cables down, it needs to be programmed with fixed points. Or an Infrared remote could be added as there are still 3 sensor slots free.

https://rebrickable.com/mocs/MOC-119580/Mr_Jos/4d-gantry-robot-superfast-basic-setup/#details

The latest video of it working (with a manual feeding conveyor and color sensor);

I changed the chain gears to 24T instead of 40T for more accurate positioning, but it's just a variable in the coding, so easy to change back (after adding a bit more chain pieces).

I made it into 3D as I'm now trying to make a storage system that fits under the gantry, that works with pneumatic cylinders to release 1 sort at a time onto a conveyor belt underneath, that will bring the sorted pins to a pallet/box. I don't have enough pneumatic cylinders to make this in real so I thought it would be better in Studio.

A 3 or 6 wide belt will then be running under these flaps to bring all the pins to the end of the conveyor and drop into a box. Flaps setup will be 2x10 in row or something.

These small pneumatic cylinders need very little air, and move quick, just need to find a way to actuate 20 levers with just 2motors max. (I want 20 or more bins) So before I buy all these 'expensive' pneumatic pieces I'ld like to make a 3D model as I don't have enough system parts to make the bins either.

Edited August 9, 2022 by Mr Jos
Typo

[Mr Jos]

The 'real' machine this is made after is a clothing sorting installation. The usage of the flaps can be seen here.

Still needs to expand a whole lot to be the 'same'!

[Mr Jos]

First free extension for the set is ready, the energy chain that can hold all the cables needed for; Programming / Charging the battery for a whole day running without changing the batteries / Sensor cables for sensors on the baseplate (as in my model).

https://rebrickable.com/mocs/MOC-119640/Mr_Jos/4d-gantry-robot-free-extension-1-energy-chain/#details

Anyone ever in need for an energy chain, have fun with this design, it's working perfect for me in my warehouse that has been running for 100+hours already.

Next upgrade will be a simple feeding conveyor belt.

Edited August 9, 2022 by Mr Jos

[Mr Jos]

And the last, free extension 2, the scanning conveyor belt is done.

https://rebrickable.com/mocs/MOC-119698/Mr_Jos/4d-gantry-robot-free-extension-2-scan-conveyor/#details

Now my whole current setup can be rebuild from scratch. (Also allows me to break it completely down now, if I'm bored of testing the pneumatic release system to free up an EV3). But I need to have my Logistics center setup ready for the event in 3weeks.

 

[Mr Jos]

I've been testing some setups, and seems a 6x6 tile is a good storage bin, the gripper hand can fit inside to drop a pin. And each storage place can hold a lot of pins.

I tested some real setup to see the forces on the hinges if the pneumatic cylinder is opened/closed many times with 2-3bar.

The test was good, but I now need to find a way to make 20+ individual trapdoors that can be opened on request.

I tried to find a good and strong design in Studio, but due to the 1stud thickness allround and the middle being shared, it's an odd number of studs. Hard to make a bin with system bricks only, so I used Technic stacked for the 13L. What's your opinion for this system/studless mix, or any idea how to get it better?

Later a 3 or 6wide conveyor will run under all these trapdoors to bring the dropped items into a pallet/bag/whatever as they were sorted.

Another still to do issue is how to operate 20 pneumatic valves with max 2 motors (or 3 at the limit). The pneumatic pumps will just be run by a power functions motor at constant 12V with an over pressure valve I'll build, so no worries for air pressure. Just how to get a motor to actuate 20 valves. Interval times can be like 20seconds or more.

Edited August 11, 2022 by Mr Jos

[Mr Jos]

I've been modelling the full size 20 storage spaces in build order steps. I did finally find a way to render faster, but it looks really bad with the shadowing on. Will need to turn that off next time.

This is the real basic needed structure to make it strong enough to withstand any forces on it. Now need to find a way to route the 20 pneumatic air lines from the back to the front, and then all 40 to a remote place where all the valves are to be operated.

 

Now need to test and see what walls I want to put on top of this structure.. If anyone got ideas.. don't hold back and let me know. Would like it if it's semi transparant so you can actually see the sorted pins in the storage bins.

 

EDIT: Added a missile wall setup:

The height is the same as the original design, around 4,5studs. But the problem is the walls in the middle, they are 6studs wide, so the liftarm setup will not work there. (So nothing in the middle yet)

Edit2: Just realised that 3+3 = 6.

On to legs and conveyor belt underneath design.

Edited August 12, 2022 by Mr Jos
Added the missile wall design

[Mr Jos]

Pneumatics are something hard to design in 3D.. It's difficult to know how the air lines will behave.

The conveyor underneath needs to be high enough so stuff dropped from one side, does not flow over the wall at the other side. But as can be seen in the next render, the air line connected to the cylinder has to pass this wall.

The full open cylinder (left one at front) can be in that position easy. The closed ones as well. But the right front, somewhere in the middle of the movement, will go very close to the wall.

[pleegwat]

Could you cheat by only connecting a hose to the port at the base of the cylinder, and simply releasing pressure to let the hatch drop?

[Mr Jos]

51 minutes ago, pleegwat said:

Could you cheat by only connecting a hose to the port at the base of the cylinder, and simply releasing pressure to let the hatch drop?

I tried that, the weigth is not enough. But right now, I'm rethinking about an older idea, of adding a rubber band to open the latch. If they would help pull it open.. And then the cylinder pushes it to a closed position again. mhmm worth trying.

I already tried many setups, using springs etc, but they have a short range. Only 1 stud for the normal ones, and the large ones 2studs, but they are so big.. The pneumatic cylinder is just 5studs long and has 2studs range, so fits perfectly under a 6stud tile.

For another TODO, the operation of multiple valves I already tried adding shocks to the valve to push it back closed, so I just need to push or pull the lever in 1 direction. Problem here; It's huge and 1 hard shock is not enough to move the valve (there is a lot of resistance in these).

Conveyor is already finished, and fits under the gantry with the bins on top. Might have to put it a bit more up to fit another belt under it.