Category: Robot Arm

Robot Arm

Sixi Robot developments 2019-07-16

2019-07-16 Dan

New OSHPark PCBs arrived

With this we can finally finish the hardware preparation for shipping units, after which we can also get a final bill of materials and start to package DIY kits.  There will be two flavors:

  • DIY kits with all the non-printable parts.
  • DIY kits with everything, including the printed parts.

Collision detection

The software only lets each joint of the robot move within a safe range to prevent wire twisting or other potential damage.  That piece of code does not consider the angle of joint A in relation to the value of some other joint B.  So it was still possible to make the arm hit itself.

This new collision detection code prevents each bone of the arm from colliding with other bones of the arm.  At present it is a crude collision detection system, using only the box around each joint.

Also now that these boxes have been calculated, the center of each box is known.  the mass of each bone can be pulled from the Fusion360 model, and then a point-mass physics model can be created to simulate forces like gravity.  This gets us closer to dynamics like push-to-teach and telling the arm “please push on this item with a force of N newtons”

Next

Next we’ll be assembling the new shoulder design with the PCBs that should allow us to unplug the umbilical from the arm and the control box.  I’m thinking Twitch stream?  Maybe just a Youtube Live, given the recent Amazon protests.  Choice of evil companies… hmm…

Opinion Robot Arm

Robot Arms and the Recycling Problem

2019-03-25 Dan

Recycling in the US is collapsing and low cost robot arms like Sixi can help prevent disaster. The buyers of recyclables demand pre-sorted material with almost nothing mixed in. The suppliers are finding the cost to sort is astronomical. While much of the sorting is done by machines already, the job could be done even better with tireless robots.

How recycling works

Typically when you drop recyclable material in the blue bin it goes to a facility where it is crushed, packaged in bulk, and sold to a buyer that can repurpose the material. The largest buyer for canadian and american recyclables is China.

Recycling buyers have tightened standards

“As of Jan. 1, 2018, China, which buys approximately two-thirds of North America’s recyclables, requires that contamination levels – newspaper smeared with ketchup, plastics mixed with broken glass – can’t exceed 0.5 per cent as part of its National Sword initiative.” — The Globe and Mail

Humans sorting is too expensive

” A study by Rob Taylor with the State Recycling Program in the North Carolina Department of Environmental Quality estimated that the average market value of a ton of mixed recyclable material arriving at a recovery facility in the state dropped from just over $180 in early 2011 to less than $80 at the end of 2015. That value has since rebounded a bit, Taylor found, to a little over $100, but it still leaves the industry struggling to extract profit from the millions of tons of recyclable material Americans throw away every year. ” — USA Today

New solutions in High Tech

There are still buyers! The cost to prepare the has gone up, which lowers the return on investment for anyone trying to do business with recycling. Any technology that can lower the cost of recycling is a worthwhile purchase for these businesses. Let’s consider a typical recycling scenario and apply some new technology to the challenge. Suppose a pile of mixed recycled material being fed onto a conveyor belt.

The first problem is to identify the material so that it can be sorted. Computer vision and AI has been making major strides in recent years. Have you seen the Tesla’s object identification? Or VACnet, Valve’s anti-cheat system? Pattern recognition is something Deep Learning does really really well – in many cases, better than humans. In the early days it starts by having a Deep Learning system watch humans sort recycling while it learns what goes where. Soon enough, it knows enough that it should be able to spot things humans missed. Best of all, the Deep Learning doesn’t need to be retrained – it’s an employee that works forever and only gains experience.

The second problem is to physically separate the material that has been identified. This is where robot arms come into play. They don’t even have to be fast – if the arms are too slow, throw more arms at the problem!

Why aren’t robots recycling today?

The 2019 price of low end industrial robot arms is north of $10k USD each. Lowering the cost of robot arms will speed adoption. It is a worthwhile goal for a company that looks to the future and cares about the fate of the world.

There is no question that we have to do it. By lowering the cost of robotics we can raise the profitability of recycling and encourage less landfill. Until the world learns to stop making garbage, Marginally Clever Robots hopes to fill the gap and provide the low cost robots to help prolong the human experiment. Our customer base should be 7 billion strong.

Makelangelo News Robot Arm

Weekly summary ending 2018-02-22

2019-02-22 Dan

Hey, gang! Here is what we worked on in the last week, where we are heading next, and how you can join us.

Makelangelo Update Released!

Makelangelo Software v7.20.1 and Makelangelo firmware v9.0.0 are out now. This is a major change to the firmware which rewrites all the logic for planning movement, especially with acceleration and deceleration. If you upgrade one then you must upgrade both. We have written a guide to help you with updating the Makelangelo firmware that should make this easy for you.

One of the side effects is that the old and busted steps/min values have been replaced with new hotness mm/s and mm/s/s. I am getting good drawing results with top speed=90mm/s, drawing speed=60mm/s, and acceleration=300mm/s/s. See for yourself.

Makelangelo 5 at Science World Vancouver, Feb 20, 2019

Wednesday the power was out for a scheduled electrical upgrade and we used the time at Vancouver’s Telus World of Science to take some better photographs and video. I hope that with this I can finally make a presentation pitch video that does the machine sweet vengeful justice.

Fun fact: A large sheet of acrylic has enough static cling and surface tension to hold an A0 sheet of paper without tape.

Makelangelo on a white board

I find that the Makelangelo suction cups work great on glass …and not so great on a class room white board. I tasked Jacob with designing a new system and he went through several rapid prototype iterations.

In house we’ve moved on a few versions from what you just saw and have an even better design. When it’s ready we’ll offer it in the store and on Thingiverse.

I should also mention Scott has been doing a great job of manufacturing Makelangelos and documenting process. I don’t mention enough how good he’s doing (very!) at a job some people would look down on. Documentation is hard, yo! He’s even inventing better ways to make the machines faster with less futzing.

Sixi motors arrived

Jin was taking some much earned time off this week, during which time the motors and the power supply we ordered finally arrived. As I write this he’s doing electrical tests and torque tests and making sure that everything is to spec.

Meanwhile, on the other side of town,

In anticipation of our new CNC machine arriving in ~6 weeks I’ve been taking night classes to learn how to be a better machinist. Here’s a funny from my last session:

Manners really seal the deal.

Next

The next week is Jacob & Scott’s last week of internship. Pizza party? Pizza party. If everything goes well with the testing we should be installing the new motors into Sixi this week. I can wait, but I don’t want to… 😭

Join Us

Get the latest Sixi Master Assembly for Fusion360 on Patreon
OR
Buy anything in our store and mention ‘The Fusion link’ in the notes field to get a link by email.

You can use this file to build your own copy of the robot arm.  Put that 3D printer you bought to use – Make it your own! Share your creation with others!  That’s what open source is about.  If you build one we would love to share it with others.  I am actively seeking talent… show me what you got.

As always, follow our daily progress on our Instagram or see our older stuff on Youtube.

You can do us a huge favor by watching just 2 minutes of video on our Youtube channel. We have 44k subscribers on IG and we need 100k minutes watched to monetize our channel. If you all watch 2 minutes of video that’s 88k minutes done, finito, in the bank, sayanora. So Like, Share, Subscribe! We thank you.

Lastly, thank you for your likes, subscribes, comments, and purchases. You keep the lights on and the mood high so we can keep working on awesome things that will help the planet.

3D Printing Makelangelo Robot Arm

Weekly summary ending 2018-02-15

2019-02-15 Dan

Hey, gang! Here is what we worked on in the last week, where we are heading next, and how you can join us.

Welcome Jacob & Scott

We have new interns! Our factory grows! Mwhahahahaha~! I get these two bright young men for three whole weeks and I am working them tirelessly to breaking beneath the unforgiving whip of industry on every project that we’ve been saving as “great if we had more unfiltered evil time”.

Among their first tasks has been converting some of the STL files we use into Fusion 360 versions so that we can tweak them; testing parts they designed;

practicing their maniacal laughter; and repairing a 3D printer that has an unfortunate accident…

New Dozuki Process Control

Scott & Jacob have also been building new documentation for our team, DIYers, and new users. Documenting our process means more control and better quality. I love Dozuki ever since I saw it used by Prusa Printers. Check out the start of our documentation.

Sixi Robot Arm Anchor and Shoulder First Look

Yes! The first version of the anchor and the shoulder have been birthed from the primordial ooze printed. As soon as omc-stepperonline.com come back from Lunar New Years and ship our parts (we expect delivery ~the 20th) then we’ll be putting it together and finally conquering the planet making it move.

Get Educated

I’m back in school to up my game!

First off, Mandarin. I keep ordering fancy parts from China and I hear all the best deals are on chinese-only sites like Taobao. It is easier to convince people that robots are the future if I speak their language. One in six people understands Mandarin so it’s the obvious choice.

Second off, professional Machinist courses. I’ve signed up to take CNC lathe work at BCIT and their classroom is a machine porn wet dream.

Next

Next week we have a scheduled power outage for another electrical upgrade to the super ray. I plan to spend the time at Vancouver’s Science World wreaking havoc filming footage for a new Makelangelo video. We don’t plan to be there more than once for this, so I’m drawing schemes storyboards for the first time. Nice!

Join Us

Get the latest Sixi Master Assembly for Fusion360 on Patreon
OR
Buy anything in our store and mention ‘The Fusion link’ in the notes field to get a link by email.

You can use this file to build your own copy of the robot arm.  Put that 3D printer you bought to use – Make it your own! Share your creation with others!  That’s what open source is about.  If you build one we would love to share it with others.  I am actively seeking talent… show me what you got.

As always, follow our daily progress on our Instagram or see our older stuff on Youtube.

Lastly, thank you for your likes, subscribes, comments, and purchases. You keep the lights on and the mood high so we can keep working on awesome things that will help the planet.

Special thanks to Bernie at Coast Precision CNC that saw my broken printer Instagram post and offered me one of his spare thermistors. We were back up and running the same day! Excellent.

News Robot Arm

Weekly summary ending 2018-02-01

2019-02-08 Dan

Hey, friends! Here is what we worked on in the last week, where we are heading next, and how you can join us.

Last week I mentioned that I’m trying to sell a vending machine to make room for a CNC metal cutting machine. The CNC quote came back at >$40k CAD.

As you probably know by now, we’ve been working on a robot arm. Last week we ended off with a new cycloidal gearbox. Well this week we printed two more and installed them.

We’ve had many challenges dealing with friction in our power transmission. Bevel gears have been a real problem – There’s no perfect solution to make bevel gears and some of the tutorials we found online were flat out wrong… which we figured out only after following the tutorials.

There are, in fact, three popular ways to make bevel gears.

Once we had a better understanding of how to make bevel gears correctly, it only took three tries to get the gears perfectly tuned on our printers. With that out of the way we can finally show our three motors working together to move the first three joints of the robot arm.

Fun fact! The joints and motors work as a differential: one motor is needed to move the hand, but it takes two working together to turn the wrist, and three working together to turn the ulna.

Next

I am currently deep into the Makelangelo firmware, trying to solve a mystery that should improve speed across all our robots.

Jin is working on the math for our motors. There is an ideal speed (in RPM) to get best torque, and from that ideal we can calculate what Sixi’s actual speed will be. We didn’t know earlier because the priority was strength and accuracy. Fast, Strong, Precise: pick two!

How you can join us

Get the latest Sixi Master Assembly for Fusion360 on Patreon
OR
Buy anything in our store and mention ‘The Fusion link’ in the notes field to get a link by email.

You can use this file to build your own copy of the robot arm.  Put that 3D printer you bought to use – Make it your own! Share your creation with others!  That’s what open source is about.  If you build one we would love to share it with others.  I am actively seeking talent… show me what you got.

As always, follow our daily progress on our Instagram or see our older stuff on Youtube.

Lastly, thank you for your likes, subscribes, comments, and purchases. You keep the lights on and the mood high so we can keep working on awesome things for you.