I am definitely very excited about the release of AR3 and thinking about a conversion to encoders for Julian's build. @Chris Annin have you heard of anyone printing an AR2 out of continuous carbon fiber strand / or fiber chop? Also now that things have moved over to ARM I am wondering about the possibility of raspberry pi 4 as a full stack controller (dreams of single board TMC driven channels as well). Do you have any interesting level shifting complications when utilizing the teensy 3.5? I'll check out @Zach Allen 's work again on the github for the control software at the OS level, but very curious if the Teensy sketch could work combined with an OS like raspbian or possibly RTOS. Can't wait to see the AR3 folder appear on the github page. Thank you so much for versioning up! Super pumped!

Thank you @Alessandro Chitè! Your build has been inspiring; what and incredible feat of machining :)

Me too. I'll be looking to try this single piece design out for the next upgrade.

A few days later we all went to see Julian present the final project to his school class. I have never seen so many young kids swarm over a project quite like this. He certainly deserved every second as the center of attention for all of the hard work that he put into this project. Additionally I’d like to thank Julian’s parents for really investing in his education and for really pushing him through some of the hardest parts of the project. You guys are doing it right!

Around the beginning of May, after much toiling, continuity troubleshooting, and youtube watching, Julian had finally put the whole system together in perfect working condition. It truly is a thing of wonder to watch the AR2’s movements for the very first time in person after drooling over Chris's youtube videos for many years. Very exciting!

In Early April Julian had completed nearly all of the 3d printing and did nearly all of the wire harnessing while waiting for the last few parts. It was really impressive to see how fast everything was moving at this point, however I can’t say that we did not come up with a few major challenges. One of the first issues that presented itself was that the rail stock for J5 did not quite fit into the mating linear guide. Upon forcing it the first time Julian's dad had accidentally destroyed one of the linear guides. We also noticed that when putting the J3 axis together that the ABS arm at J3 tends to bend just a little bit. This did get a little straighter when mounting the chain covers. Being that the AR2 is really designed to be made in aluminum you may find that this particular arm part in 3d printing is a bit wobbly when whipping around the J1 axis. Upon tackling the wiring harness Julian had mentioned that it was a bit difficult to solder the wire terminals to the aviation connectors. It requires a little bit of finesse in order to pull it off well. I would recommend having a decent soldering iron that has a larger tip on it to heat sync faster and hotter. Also really spend some time making good soldered joints on these aircraft connectors (watch a youtube video) as it will save you a lot of headache in the long run if they fall apart or break. I would also recommend getting a deeper (generally slightly larger) project box, rather than the hammond project box, as this was the most challenging point to squash all of the soldered wire connections into. Aside from this one thing I would say that the wiring harness documentation is really great and straight forward. Also if you have the ability to spend a little more on the limit switch wire I would suggest going with something that has shielding (especially If you plan to use the AR2 around applications that have big electromagnetics IE: welding, contactors, 35HP motors). This is my favorite shielded wire spec for limits here.

Hi Annin Robotics community! It’s been quite a while since I’ve provided an update on @Julian Holcroft ‘s progress and successes with the project. So I am going to have to do a couple of back track posts here. Lets Just pretend for recording sake that this post covers the end of March and then into early April. Near the end of march Julian myself and his dad all took a trip over to the Generator Maker space in an effort to drill and tap the J3 chain sprockets. This required a bit of old school machining trickery in which we clamped the sprocket into a vice and then lowered the drill bit right up to the highest point of the barrel that we could and move the vice back and forth until the tip of the drill bit scraped a line into the part indicating (very roughly) where the apex of the barrel was. From there it was easy to use a caliper to mark the distance from the end of the barrel where the set screw should be placed. Drilling was easy tapping was a little nerve racking and deburring was a little challenging. While we were there we also cut and drilled the tubing for the J4 axis using a pretty heavy duty metal lathe.

@Zach Allen makes sense to me. I have the oportunity to learn KI CAD shortly through a makerspace in town. we’ll see what happens. Are you farmilliar with CAElinux?

ShushEngine is super cool. I remember that you mentioned somewhere in the forum that you dev in eagle. Do I have that Correct? Would love to help work on this with you If you need / want a contributor. Please DM me at some point. Regardless I’d love to do a hangouts session with @Julian Holcroftyou and @Max Favre. Also, so glad your tackling this project; excellent contribution and very excited for this development.

Hey@Zach Allen, great to hear from you. We would love to check out the single piece printed base. Did you have any trouble getting the bearings in after fusing the the base plate and gussets to the J1 column? Could you post a screen cap section of that part? Also would love to have one of the PCBs that you made. Have you possibly group collaborate on that single board trinamics slushy fork Idea ? So curios about that. I’d love to jump in on dev if that’s a thing.

@Mitchell Lichtenberg really nice work! Love this build log and thank you for your careful notes.

@Julian Holcroft has been busy 3d printing components and making great progress on this build over the past 2 weeks. So far he’s generally halfway through printing as you can see from the Fusion model here. The base of the AR2 came out very nicely. The tolerances allowed for the main J1 bearings to be pressed in lightly. The belt is definitely tight and rigidly held by the J1 gear motor. The J2 parts are encountering a bit of sanding in order to make fit. And the J2 turret housing is on the bed now for the 3rd time as it tended to warp on the build plate Julian took the opportunity to really tackle and complete the electrical cabinet while waiting for the printing to complete. We both thought it would be best if the aircraft cables came out of the side to reduce wire length and therefore inter cabinet EMF. We have also been following @Max Favre 's single board control as well as @Zach Allen's buck conversion break out with nerd hungry anticipation. As significant reduction in the size of the control system would be a great deployment improvement from my perspective. Here you can see that 3d printing can be tedious sometimes and you should honestly plan to reprint many times on certain parts in order to dial in the results for your machine and take precautions to improve your printer if necessary . Early on Julian had improved his Lulzbot but laser cutting an enclosure and applying temperature control so that he could deal with ABS prints effectively. Even with such a big printer mod there are still moisture conditions to combat as well as part distortions that can just wreak havoc with tolerance critical parts. Kudos to Julian for preparing, tweaking and testing his printer early on before diving in. A couple of important observations that we had the chain gear specced for J3 does not have a tapped hole or keyway. This is a bit difficult as most of the build here is happening on a dining room table without the aid of a shop or in this case a drill press and a tap. Luckily Julian and I do have access to such things so we will get by but I think this might be a spec consideration for anyone in the community. We’ll see if we can find something helpful to add on that later. Additionally I would recommend looking at the connection from the based plate to the J1 column. It seems to have a bit of difficulty printing when supports are combined, as well as having a very tight fit to the base to begin with which needed some hand work. Thanks all and looking forward to the next update. So far so good and we are both very excited. Nice work Julian!

Julian has really just begun 3d printing and there's a bunch more time to go before we can have a completed set to show off. Everything is in ABS (which demands an enclosed and heated build chamber). I can't attest to the strength of the parts just yet we'll have to get back to you on that.

3/4/2019 I used to be a SW user for 12 years and I can say that I miss the work flow very much, but i am not missing the price. Over the last 2 years I’ve gotten used to Fusion 360 and although slightly feature bare I can say that the MCAD / ECAD (eagle) integration, Surfacing features and Make function / Mcmaster import are all improvements over SW. Lastly the team workflow (although tedious to merge) is amazing and makes me loathe the “Vault / PDM” experience of SW. So Julian, his father and myself all share this model with each other in order to communicate the progress of the build, view changes together and as a bonus the make function is also producing better STL’s and therefore results on Julian's Lulzbot 3d printer. @jokke had asked in the questions sections, if anyone had gone through the Fusion conversion, and I promised that I'd outline the process I went through here so that other folks can do the same after they purchase Chris’s models. First off you need to import the entire assembly into Fusion in one single shot. Don’t bother trying to piece together the entire model unless you are trying to do it for free by using the STL’s. I don’t recommend this approach because its an entire reverse engineering process that is not worth your time and provides no financial support for the AR2 project. Here are some quick tutorials that are sponsored by Autodesk ………... https://knowledge.autodesk.com/support/fusion-360/getting-started/caas/screencast/Main/Details/849e3578-f5d9-4f64-a0cf-750f9e2492f2.html https://www.youtube.com/watch?v=l7ViMKZPGKk - Lars C First off when importing the AR2 models one should ideally import every single part necessary in one single upload. You may have to go back an hit the “select files” button again to get the dependant components in any subfolders. When you have everything you need in the file selection screen you’ll then need to pick the master assembly From there I get a failed status on the main AR2 assembly and take a look at the translation report. Regardless of this error I just hit refresh on the left side panel and then waited quite a bit of time for the assembly to appear. It shows up as one giant heap of bodies in one single assembly. Now we’re in business ……….. More to come on conditioning the model later with joints, some minor references and possible mods if necessary.

https://www.amazon.com/Monoprice-Commercial-24AWG-Speed-Jacket/dp/B005CAPIDW

@Max Favre I'm so glad that your thinking of using Trinamics. I was also thinking the same when I first saw your design. Do you follow Marco Reps on youtube? https://www.youtube.com/watch?v=ZzO9skEYqwY I wonder if limit switches are necessary with the trinamics current sense back shown in his video here. Do you think an HDMI cable could work? OR DVI? I have been reading that in premium HDMI cables that the strands are paired and sub wrapped by AL as pairs then externally wrapped by braided steel or AL. Furthermore premiums can have 26 or 28 AWG which might be able to handle the current. 2 amps roughly at 26 awg. https://www.powerstream.com/Wire_Size.htm I haven't dived into the typical current draw for this arm design using the motors from the stepper online kit, so take that with a grain of salt. Also I am a big fan of raspberry pi. Any interest in model 3b+?

@Max Favre I really want to port these files over to Eagle. I know its bad taste to not use OS software for OS builds, but I like the ECAD/MCAD cross. I use eagle and fusion 360 together as part of a team operation and have gotten used to the workflow. The subscription is cheap and I have a decent relationship with Autodesk. I'm rather new to ECAD in general though, and really should just know Ki as well. Very interesting direction choice on the VGA cables though, even though you are not using them now. In the past I have used Cat6e directly to drive steppers and also route limits (not in the same cable bundles though). It made for a very deployable cnc machine. I've also tried DB9 and also USB's to route power as well. I can honestly say my favorite "cheap cable" choice is USB. Although you only get 4 pins per the current ceiling is fairly high - often rated up to 3 amps - is always double shielded, barrel terminated, with pre-crimped chokes, and did I mention "cheap"? The only thing to watch for are cables that reduce the RX/TX gauge relative to the power lines. As I have begun to build with current draws higher than 3 amps I am finding that aircraft cables are the only cheapish and safe choice. Still looking for a source for pre-terminated, shielded options and sources. Being that you have this single board solution going already, have you thought about incorporating your own stepper drivers on the single board? Something like the Synthios grbl shield or Tiny G? Perhaps that is a little beyond the scope of this project but I am just curious about your vision for this controller upgrade (and excited!!!). Seems like a great way to crack the price per driver on the AR2 build in general while also shrinking the control system. Have you also taken a look at @Zach Allen 's mega shield that bucks down to 12v and 5v? I saw in the "jan 16th" post above that it looks like a 24v supply from meanwell (excellent, love the SDR series) and a cheapo 5v. I might be wrong about that but just curious. Would love to see the both of you combine your super brains on a single board solution and contribute where I can.

I'm also interested in checking out how to integrate the AR2 with ROS. @Chris Annin We're you able to get the URDF to work in Move it? I saw that you still have a Q open on answers.ROS.org from almost a year ago https://answers.ros.org/question/292331/ar2-robot-import-into-ros/.

Max, This is a very intensive piece of work. Thank you for contributing back, I would love to try this board out when I start my build/s. Are you planning to continue to develop this? ;and what ECAD / CAD platform do you work with?

Max is that a Mooshimeter?