It’s time for Part 3 of the 3 part series on the Rat Rig V-Core 3 review. In Part 1 we discussed the build process and Part 2 completed the build and shared some first impressions of the printer. Part 3 is sharing my experience after some more use.
For the purposes of this review series, Rat Rig provided the mechanical portion of the V-Core 3 300mm kit and I acquired all the electronics, motors, extruder, hot end, heatpad, and wiring components locally. I built the V-Core 3 300mm using a Dragon hot end, Orbiter V1.5 extruder, and a SKR Pro V1.2 control board running Klipper with a Raspberry Pi 4.
The printer in not enclosed, and the parts were printed with Sparta3D PETG filament with the only exception being the duct which I used some spare ASA I had sitting around. The build process was fairly smooth with the exception of some bad idler bearings that Rat Rig replaced. The V-Core OS setup was a fantastic experience to commission the firmware on the printer. Initial prints were good quality as well.
Getting down to it
During my time with the Rat Rig V-Core 3 I used SuperSlicer with a base profile I had setup for my various Voron 3D printers. The profile worked quite well for the Rat Rig for both PLA and ABS (Yes, I did enclose it and test ABS 🙂 )
My prints for the most part were good, which we’ll showcase a little lower. However, while only a couple, I do have some concerns with the Rat Rig that revolve just around the quality control of the mechanical parts.
Upon commissioning the printer and starting using it more often the bed mesh was a concern. I felt that I took the time to carefully assemble the frame, but from the mesh, it would appear that the frame is a touch twisted. I believe one side of the Y rails slants down and the opposite side slants up from front to back.
This could be from the cuts of the extrusions. During initial build, I did my best to make sure all extrusions were butted up to each other and I also use a method that involves using spare aluminum corner plates along top and side faces of the extrusions to bring them all flush. I have used this method on 7 other builds (using LDO or Misumi extrusions) this year and it has always worked out well for me, so I had expected it to be sufficient for this frame build as well. The assumed frame issue is preventing me from assessing the quality of the flatness of the heatbed at the moment.
The other portion of the printer I’m not 100% happy with at the moment is the motion. As described earlier I did receive a batch of bad idlers. The bearings were swapped during the build but after use, however the motion just doesn’t feel exceptionally smooth yet. There is also some minor Z Axis banding that is more noticeable on the front right side of prints.
To mitigate the above concerns I would look to maybe add some precision shims to the frame and attempt to align the Y axis closer to where it would be ideally. I’d rebuild the motion system, cleaning and greasing up the linear bearings and replacing all the idlers.
Now that I’ve explained a couple of the issues I have had, let’s talk about print quality. Even with the issues, the Rat Rig V-Core 3 is a robust printer that can print nicely.
The triple lead screw levelling combined with the BL Touch sensor has worked well. As I’ve mentioned before, I love the 3030 extrusions with MGN12 rails and 9mm belt system. It makes for a really beefy printer setup. I did use an ADXL sensor and ran input shaper. My initial run of prints was done with 6k accelerations and typical print speeds of ~100mm/s. Not crazy fast, but speedy. See below gallery for a variety of PLA prints I ran throughout the last couple months.
The EVA setup with the Orbiter and Dragon hot end, seemed plenty adequate for typical printing and it’s a system I’d certainly consider adopting on some of my custom 3D printers I build. Spiderman’s chin had a touch of droopy lines but I could snip those easily.
I tested the Mini Godzilla from Wekster Patreon and the supports works great. The peeled off with ease.
I also wanted to see if I could print ABS on the Rat Rig V-Core 3. I have a large Creality pop-up enclosure and it fit the Rat Rig 300mm size with plenty of space. I printed some Voron drive plates and a spool holder with some red Sparta3D ABS. The V-Core 3 handled the prints just fine. The cooling took care of the bridges or overhang perimeters quite nicely. If I were to enclose it permanently I would definitely replace all the printed PETG parts with ABS.
My Z-offset was a touch high on the spool holder, however this a great opportunity to commend the Rat Rig team on their choice of flexible build plate. It held PLA and ABS extremely well during my testing period. The magnetic hold felt quite strong which surprised me the first time I attached the plate. The texture surface was not too aggressive for me and just worked extremely well. I was very impressed. I’ve used a large variety of build plates and this easily ranks quite high on my list of good plates.
Working with the Rat Rig V-Core 3 was a good experience. The build was fun with nicely laid out instructions. The wiring and firmware process was one of the easiest ones for this type of DIY build where the details necessary to get to the finish line were extremely clear and I didn’t need any outside help or additional resources to figure it out.
Using the printer has been a genuinely fun experience. There is still a couple of things I’d like to do as mentioned above to make it perform smoother, however without doing those things the results have still been good. I like how robust the printer is and how I was able to enclose and print ABS+ easily.
At roughly $1700 CAD for the setup I built I think it’s priced reasonably for what you get. The community surrounding Rat Rig seems to be quite active with nearly 8,000 members in their Facebook group at the time of this post and another active unofficial Discord server. The Rat Rig V-Core 3 300mm should certainly be a contender if your looking for a coreXY printer in the 300mm size or more and I truly think that it will be further refined as time goes on and improved.