Hey all it’s been a long time.
So a couple kids later and I’m finally getting back to some shed time and dusting off the MPCNC.
I have a pesky core wobble I just can’t get rid of and suspect I will be either printing parts or upgrading rails/bearings (I’ve never been super happy with them).
With this in mind what is the communities thoughts on the lowrider v4 stability vs MPCNC Primo. Will there be a new version of the MPCNC soon?
Really not sure which route to go.
No, the focus is on the LR nowadays.
I personally would build the LR, it’s an incredible machine. 
Haven’t seen any movement on MPCNC development for a while. The LR4 is a very solid machine. There are a few details where I like the Primo better, but my LR4 gets far more use than the Primo nowadays.
The Primo allows a few more hold-down options, IMO. The gantry clears the work surface allowing T track or threaded inserts to use toggle clamps to hold down the work. The LR has minimal clearance, which is great for rigidity, but means that you either screw the work down to the spoilboard, or else use tape, either double-sided or painter’s tape and CA glue. This is a bit more wasteful since the tape can’t be re-used. As for use case, because the LowRider usually mounts control electronics and controls on the gantry, it is much more difficult to enclose effectively, whereas the Primo has less of that moving around.
The Primo is a bit more picky about build. The X and Y rails have to be precisely parallel or else you get issues. The LR4 is more lenient that way, because it has only the 1 Y rail and the beam/gantry is more controlled by the 3D print. That said, it also benefits from attention to build quality.
The LR4 of course has the capacity for a larger form factor. Both have about the same footprint to work area ratios. Slightly different, sure, but similar.
The only downside to the LR4, really is the MGN12H rails on the Z axis, which are a cost increase. If you’re looking at new rails anyway, the steel cost isn’t much different, and with new printed parts, not much there, either. The aluminum XZ plates can be something to source, but I 3D printed those plates, and they were enough to be able to cut aluminum replacements. The LR4 build process that way involves some iterations and rebuilding. build the machine with 3D printed XZ plates and temporary struts. Cut new struts, tear down machine, install permanent struts. Cut new XZ plates. Tear down machine and install new XZ plates.
All that said, I would lean towards an LR4 upgrade.
You can re-use several components from your Primo. The 5 motors, end stop switches (If you used them) 608 skate bearings, and some of the 5/16" or M8 nuts and bolts, and control electronics. If you used a 3 motor control board, or used something like a RAMPS board, I would upgrade to a Jackpot control board, it will make things easier for you troubleshooting on the forums. If you used an SKR Pro, or you have something else that you’re comfortable with the firmware on (I use Duet3D boards, for example) then go ahead and keep that.
You will need 4x MGN12H linear rails, 1 (or 2) TR8 lead screws and couplers depending on the length that you have for the Primo, a large number of M5 screws and nuts, and of course the printed parts. The LR4 is a much easier base. I used a sheet of plywood cut to size, and a couple of 75mm strips to raise the base to the height of the spoilboard. Super simple.
I built the primo, it was ok. I rebuilt it as a l3r, then to the 4. It’s a pretty good machine. I wouldn’t go backup to the primo. Even if you only need ptimo working size, you just shrink the lowrider, which becomes even more rigid.
Thanks guys. You have all echoed what I was thinking so I guess it’s a no brainer.
Time to start printing lowrider parts.
Are there any benefits between the 4 versions of the Jackpot board?
Jackpot V1 and V3 are good options for a new build. V1 has a removable ESP-32 so it’s the one to choose if you need an external antenna (plan to put the jackpot in a metal box), or if you are a developer/tinker who wants to be able to easily play with different ESP-32s.
Otherwise, for a new build I would recommend a Jackpot V3.
Jackpot V2 is ok if you don’t run a laser, but that board won’t be produced any longer.
Thanks for the quick response Jim. I’ve been playing around with ESP32 for a couple other projects but I may lean towards the Jackpot v3.
The MPCNC I built was printed using PLA. What shed temperatures are folks working with?
I have no AC and no insulation in Australia so the shed gets to 40 degrees C in peak summer. This happened 3 days ago.
What’s everyone’s experience with this? Worth using PETG or stick to the old reliable PLA. My favourite filament at the moment I get is Elegoo.
Also I love seeing that this community is still going strong and as helpful as always.
My garage gets to 110F in the summer, haven’t trashed PLA yet.
If you do want to upgrade, print parts in PET-CF (which is NOT PETG -or- PETG-CF). PET-CF is more rigid than PLA and much more rigid than any of the PETG, and can take higher temperature.
Thanks @MakerJim I’ll check it out.
I’ve started printing the files. Decided to go with standard PLA because well I had some unopened rolls on hand. Call it lazy or convenient I’m not sure.
Went with the standard red and black for the MPCNC when I built it so this time going something completely different.
I’m watching this thread with great interest. I built my Primo last year and honestly I’m not sure why I went for it over the LR3 at the time. After having lots of wobble issues and now facing weird upbowing issues, and not looking forward to constantly squaring my gantry, a migration to the LR4 seems kinda palatable. I don’t need something sizeable enough to cut a whole plywood sheet, just a beginner CNC machine, and I can definitely afford the parts cost to migrate.
If you end up with any pitfalls in the build/assembly please do post ‘em!