Projects + Forums

A Home Built capable CNC built on 3D printing. The MPCNC is an open-source, mostly-printed, DIY CNC platform. The design was built by V1 Engineering, but mainly by a guy named Ryan Zellar who came up with the idea. The designs, code, parts lists, all of it was his idea to be able to share opensource with the community. Wanting a large platform capable CNC of my own, but not having thousands of dollars to spend on one, this was a good option for me and greatly exceeded my expectations. While my build was mostly just a verbatim build based off of the documentation of the MPCNC, I still wanted to share it here as a testament of how printers just in PLA can create real stressed parts like the ones on this CNC. Furthermore, I had a great time pushing the limits of this machine. The original footprint that I had chosen for this machine was a working area of 300mm x 300mm, as I was determined to have a machine capable of cutting aluminum, which comes down to a factor of rigidity. The smaller your footprint, the more rigid your machine. However, some time after I had initially built it this way, I changed it to approximately 12” by 36”, a much bigger footprint. Interestingly, I didn’t see a huge change in the rigidity of the machine – it could still cut aluminum just fine. With this machine I cut everything from foam to soft wood to hard wood to delrin (or any plastic really) as well as aluminum sheet. I didn’t have any aluminum thicker than .25” sheet, but it seemed to still work fine for me, provided you went slow enough. I won’t go into all of the details of the machine here, as you can see those over at V1 Engineering’s page, but just to showcase a cool project with some pictures. Enjoy. :)

Using 3D printing to manufacture end-use high quality robotic tires. ADDRESSING THE NEED This project started as a pursuit of a manufacturing a better tire for our robotic swerve drive. While I was on the FRC team 33 Killer Bees, we had built a custom swerve drive for the 2021 at home challenges. Because this platform was powered by Falcon motors on 3in wheels, we really started struggling with traction, as the tires couldn’t keep up with the power of the motors, despite having a very light frame to help agility. At the time, the two commercial solutions consisted of riveting blue nitrile tread onto wheels, which created an inconsistent contact patch because of the rivet heads, or adapting colson tires to work with the swerve design. DESIGN CREATION I started off toying with the idea of using my recently built dual extrusion 3D printer to print both the wheel and tire as a whole, as shown in Fig. 2 below. This is actually a replacement tire for a common rc car, something much easier to test. These tires were a great point to start, but we quickly realized their drawbacks. Firstly, printing them as a single piece not only took too long but was too specialized. Ideally we would be able to swap tires independent of the rim, so the dual extrusion wasn’t the right application here. Secondly, the flexible TPU that we used was way too hard, we needed a softer compound for more grip. Finally, while the airless “fin” design was cool, it didn’t leave much for the practicality of tread wear, so that was out the window. Therefore, from here we moved on to the second iteration, shown in Fig. 3 below. This was our first tested design. It consisted of a two-piece clamped wheel which was printed in blue nylon here, as well as a 90A studded TPU design for the tread, both originating from my mentor at the time Nick Coussens. This worked pretty well, and was definitely a step in the right direction, but the Nylon was not rigid enough and the TPU still needed to be softer. Then, I took the two piece clamped idea for the wheel, but changed up the tread design as shown in Fig 4. on the right. This tread design would allow for a larger contact patch for the tire, allowing for more tread. This tread idea was quite promising, and we tested this extensively, but we still thought that a softer TPU would give us a better performance. While there was a bit more testing and a few different tweaks from here, this idea moved us to the final design shown in Fig. 5 below. For this design, we wanted to get the softest TPE compound that we could find. After doing some research, I found a company out of Spain called Recreus who made a 60A shore hardness TPE that was more grippy than any substance that I have ever printed. And surprisingly, it wasn’t that hard to print at all, with a little bit of tuning on my machines, it was easily manageable with no stringing at all. The tires that resulted from this are still in use and continue to supply superior traction for robotic tires.

An Ongoing development of an inexpensive, custom desktop dual extrusion printer. This is a passion project that had a great role in allowing me to push the possibilities of desktop 3D printing and showcase the capability that can be had in a low-cost 3D printer. This printer has been through many many different iterations and is a project that is never fully finished, rather a working platform to test advancements in low cost custom 3D printing. THE BUILD I started this build almost four years ago now, where I wanted to have a more capable machine that would be able to do a lot of different types of 3D printing housed in a budget frame. Therefore I started with the frame of the most popular budget printer, the Ender 3. From here came a plethora of upgrades to allow for dual extrusion printing. Upgrades: • New Mainboard: SKR 1.4 Turbo • New Hotend: Triangle Lab’s Chimera Clone (2 in 2 out) • BLTouch (genuine) • New fan shroud • New mounts for extra extruder steppers • New Firmware • These parts built the first generation of my dual axis machine as seen below: Notice how this printer doesn’t have a purge block or prime tower, two aspects of normal dual extrusion that make it very resource consuming, on both time and materials. The goal for this machine was for a setup that was so dialed in that neither of those things was needed. Here I am using a Petsfang style mount for the hotend with a remixed fan mount to have enough cooling capacity to cover both extruders. Coupled with a long bowden tube that had the extruders mounted at the top of the frame, this setup worked pretty well: it was an all metal hotend so it could easily handle higher temp materials, and it had very few problems with oozing and retraction, even with the bowden setup. However, I wanted to print flexibles, specifically, I wanted to print 85A TPE, something not possible with a bowden setup. Therefore a direct drive extrusion, where the stepper motor is as close to the hotend as possible, was necessary. Yet this created quite a large packaging problem – I had to fit two 5015 blower fans, two full size extruders, a BLTouch, and the hotend, all with the determination of not losing any buildspace. Furthermore, I came to a weight problem. All of this was heavy. From there, I realized that not only did I need to redesign the whole entire hotend, but also upgrade yet again with a dual z-axis setup that would be able to handle the weight. I looked to see if anyone had done this sort of setup online, and while I found some inspiration, I couldn’t find anything that perfectly fit my needs, so I set out designing it by myself. I came up with the design you see below. It is definitely very cramped, and admittedly a bit of a hassle to disassemble, but it worked surprisingly well. After reworking the code on the new 2.0.x branch of Marlin, I was off to the races again… until there was a third iteration. While the dual direct drive extrusion was a fun journey, and honestly the version of this printer that I liked that best, it seemed that it was time for a practical change. I found, as the printer got older, that I wasn’t really using that extra temperature of the all-metal hotend as often as I thought I would, and having heat creep made it difficult to tune retraction sometimes. So, although this might sound a bit counterintuitive, for the sake of reliability, I changed it to a PTFE setup. even with PTFE, I find that I can still print PLA, PETG, TPU, and ASA very well, which is more than suitable for me, while I can let my printer that specializes in exotics handle the rest. I found that this made the printer much easier to tune as far as retraction and oozing went, and overall, surprisingly, a better machine to use. If you are interested in building a custom dual extrusion 3D printer, feel free to reach out to me, I would love to talk to you about it!