Search the Community
Showing results for tags 'techic'.
Found 2 results
-
There is a new thread detailing my latest version of the robotic arm: Update: Here is version 2 of the arm: Studio model available for free on Rebrickable: https://rebrickable.com/mocs/MOC-109607/glaysche/6-axis-robotic-arm-mk-2/#details Original post starting here: This is my first MOC and first time posting on Eurobricks. A few months ago, I got back into Technic by buying the Liebherr set (42100). I decided to design my own 6 degree of freedom robot. In doing research and experiments for this project, I was inspired by this post I found here on Eurobricks: I ended up making a lot of different choices in my model. Here is the big picture: I wanted to optimize for three things: It should work Maximum range of motion -- the wrist axes should be able to turn indefinitely and other axes should have as much range as is possible Built as compact as possible Here's the video with poor production values (and using a simple BuWizz profile to control it): https://www.flickr.com/photos/188456966@N07/49900167801/in/datetaken/ This was quite challenging to optimize it in this way. First of all, in order for the wrist joints to spin, they needed to be axle driven -- pneumatics won't work. In the example of the grabber at the end, I put an axle through the turntable to control the LA for the grabber. When the grabber turntable is spun, however, the grabber will open or close in an undesired way. To counter this, I used a differential and the correct gearing to compensate. Here's a picture of that: This is difficult to see in there. There is a new 2 piece differential (65413 / 65414) inside the turntable. The gears turn the differential at half the speed as the turntable which makes it so the grabber doesn't move when the turntable moves. The control for the turntable and grabber are axles on both sides that go through the next set of turntables seen here: The axle turns the perpendicular axle that goes through the turntable and is driven by another axle in the next stage. The stage has the same problem as the previous one where flexing the wrist will cause the grabber to turn and open or close. This is compensated with an additional two differentials and another set of gears. This one is particularly compact. Here's a picture of that stage: The lage gear there is a 28 tooth double bevel which is needed to get the correct gear ratio to the 28 tooth differentials. Pulling the side off of that, we see: There are three L motors (22169) here to control the grabber and first two degrees of freedom. I particularly like the gearing in the front of this section for the compensating differentials: As noted by Hanso in his series of posts, the end of this arm is actually quite heavy. I would have preferred to send all three functions though the next turntable but I could not find a solution that sturdy or compact enough. This weight caused trouble for the next turntable. To make this work, I used two turntables, one in compression and one in tension. There is a beam that goes through the center of the turntables that takes some of the load here. The next stage is a another stage that I would like to be able to turn forever so I don't want the wires to get twisted. In order to accomplish this, I also put the battery box on a turntable that turns with the rest of the arm. The wires go through this stage and don't get twisted. The humerus (in LBG) is very small (5x5) and it was a bit challenging to get the gears in there. The motors (XL 22172) for those next two axes very neatly attach there. The base has the last two degrees of freedom. The spin axis here uses a mechanism very similar to the Rough Terrain Crain (42082). The final axis uses worm gears to drive the turntables. There's a lot of force on this axis and I experimented with a variety of different gearing. The thing that worked best is displayed above. The center piece is driven and it gets geared down symmetrically to the axles that have the worm gears. Axle support was a bit tricky here: (Still waiting for the remaining black 7x11 frames to clean up the look here.) The 2nd battery box fits pretty nicely here: In conclusion, I think this works pretty well. I haven't explored the software at all yet -- just used BuWizz as a proof of concept. Many of the motors would work much better configured as servos. I wish Lego would release an SDK for Control+ so I could write an app similar to the Liebherr controls. My day job is actually a software developer so it would be pretty fun to build a full featured app to control this. -
Hi everyone BuWizz team has prepared another competition, more details below: PRIZES 1st PRIZE: Porsche 911 RSR + 1 BuWizz 2nd PRIZE: 2 BuWizz 3rd PRIZE: 1 BuWizz RULES -Show with your MOC the POWER of BuWizz Examples: lift a heavy object pull a car push a sofa fly a helicopter drive fast, etc... You must use BuWizz START & END Competition strats on Wednesday 20.02.2019. All entry videos will be excepeted until 23:59 h CET 20.03.2019. HOW TO APPLY Want to participate in our Competition? Apply now and we will enroll you as a contestant. After that, all you need to do is build your model and record a video of it do amazing stuff ? APPLY NOW CHOOSING A WINNER 5 independent and respected judges from AFOL community will choose the winner, and the 2nd and 3rd place runner ups. DECLARING A WINNER We will post the name of the Winner on 1st of April 2019. We will contact the winner by mail so please be careful when applying for the competition. More details on BuWizz website: https://buwizz.com/competition-the-power-of-buwizz/