Hey doug any plans for something like this for the v4? I would love to upgrade my x and y to nema 23 motors, linear rails and possibly rack and pinion but that kind of mod is way over my pay .grade.
Well, the upgrades shown in this thread were done by @WalterUA — and of those, the hidden belt mod is the only one based on my work. That mod, as shown, does not translate easily to the LR4 design. There’s been some interest but nothing concrete accomplished on it thus far. WalterUA might chime in and offer advice about the other stuff.
Hi Miguel! The NEMA 23 motors with TMC2209s have been running great, even during 2-3 hour sessions—no overheating, no skipping. I’m really happy with this mod!
The modifications showcased in this post have transformed the LR3 into an exceptionally capable machine—perhaps even deserving the title “LR3 Pro”. In many respects, it matches or even surpasses the LR4, and for the vast majority of users in this community, this build will meet all their needs.
Through extensive testing and pushing the machine to its limits, I’ve found that the next logical area for improvement would be enhancing X-axis rigidity. If someone were looking to take this design even further, I would recommend modifying the X gantry by replacing the current braces and pipes with 2x4 square tubing, similar to the approach used in PrintNC.
As Doug mentioned, the LR4’s design differs significantly from the LR3, making it challenging to integrate the modifications presented here.
Personally, this LR3 build exceeds my requirements, and I don’t foresee needing further upgrades in the near future. However, if I were to pursue additional improvements, I would likely transition to building a PrintNC instead.
Statements like this are not really useful because it’s been proven that mods with motors on the side have major drawbacks.
The NEMA 17 are also more than enough to reach speeds where the machine gets to its limit, even the LR4, so peddling this as a “pro” version is more than misleading.
The LR4 is also a major improvement in stiffness of the gantry which the LR3 can’t match, so there is a better version already, no reason to bother with a further LR3 upgrade.
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I get where you’re coming from, and I definitely respect the improvements made in the LR4 design. I never said this is a “Pro” version—I simply said “maybe it deserves” that title based on the upgrades. Also, keep in mind that these mods were developed before the LR4 was released, so the goal was to push the LR3 platform as far as possible for those who already had one.
For me, the upgrades—NEMA 23 motors, linear rails, and a more rigid structure—made a huge difference in accuracy and performance, especially at higher speeds and with deeper cuts. I’ve tested this setup extensively, and it’s handling faster feed rates and more aggressive cuts than a stock LR3 ever could.
The LR4 is absolutely a great machine, but if someone already has an LR3 and wants to maximize its potential without rebuilding from scratch, these mods offer a solid path forward.
This is nitpicking, the basic message still stands. You consider it an essential upgrade that makes the LR a lot better and you are labeling it as such.
This is now again one of the times where ask for DOC, feeds etc. Because I know what my LR3 was able to do and that brought it over the limits of the construction at times so I had to dial it back. So it’s pretty hard to convince me that the 23s are going to change anything at all.
Where I agree with you though is that the next logical step might (!) be the PrintNC, but I dislike how they portray the different CNCs on their Wiki though it’s been disproven. I’d be lying if I said I’d never thought about a non-printed CNC with steel beams and bigger motors just to see how far I can push it with a homemade CNC.
