I’m starting to plan a full 4x8 LR4, and would like to invest in upgrades/materials that make a meaningful difference to performance, with the eventual plan of using the gantry for both routing and plasma work. The main things I’m looking at are 1.25” OD DOM tubing, and PPF-CF Core filament for the functional printed parts (significant flex modulus improvement and temp resistance in a hot garage).
I’m concerned that the 31.75mm OD on the tubing is outside the stated ±0.2 mm described in the rail overview. If anyone has any experience with whether this is manageable with the 32mm parts, I’d appreciate the input before investing the time and materials.
Thank you in advance; I really like this design for the ability to break it down and reclaim my garage at need, compared to a more significant structure like an extrusion-based router.
Thanks for the response, I’ve gained the most confidence in the system from your videos of projects! I also saw you mention somewhere that you’ve used DOM before, but I wasn’t sure if that was on a design where the dimensions matched more closely.
Didn’t mean for my word choice to make it seem as though I have any reason to believe the tube is the most limiting factor, it’s just an element of the design that I’m familiar enough with the math and materials to assess, and an easy spot to make a change of material before starting. It does have the downside of needing to reprint many parts if DOM turns out to be unusable, which is why I asked in advance.
I know there are many folks on here who have made all sorts of tweaks. So, I’m hoping to pull from collective experience and observations, and not intending to step on toes or cast aspersions on the published design and material recommendations. It’s inspiringly optimized. I’m excited that it’s accessible enough to make changes and try to assess performance differences.
Thanks for the clarification, I’m looking to do a few different things, long term.
I’ve got a garage, shop, and house worth of cabinetry and furniture to build, eventually. I don’t think either the garage or shop has long-term room for a dedicated 4x8 machine, thus the allure of the Lowrider. I’m very concerned about creep on PLA parts, as I’ve experienced that before at garage temperatures in my climate (someday, climate control…). I’m looking at Polymaker’s HT PLA GF or the PPF CF route, and I am confident in printing either. I’d also like to be able to use the gantry as a plotter for paint/pen art at a large scale, and eventually plasma for decorative metalwork.
With regard to cost invested in the project, I’m cross-shopping against a 4x2 kit machine like a PrintNC or Altmill. The Lowrider lets me do sheets and large canvas without tiling, which would be great from management. I’m certainly not looking to spend unnecessary money, but things like closed-loop steppers for improved rapids when I’m not cutting would be fun to implement.
I am a little time-constrained on investment, as I also have the house to work on, and that’s the real pain point for things to modify during the first build, vs later or as a rebuild. I would love to start from stock and change one parameter at a time, just don’t want to take years to do it or wind up with an unusable machine on my first build due to creeping PLA.
Thanks again for clarifying your interest, I teach high school engineering and robotics and can certainly appreciate the “just get the tested, documented build running, before you mess it up” advice.
This argues VERY strongly for you following what Ryan calls “the yellow brick road.” Build it stock to start, just as you’re considering.
What printer do you have?
I don’t know what PPF CF is, do you mean the Bambo PPA-CF?
We want rigidity in the printed parts, in particular the core.
PET-CF (Not PETG-CF) is the recommended route to take where heat softening is a concern.
HT PLA of any sort I’d avoid as to do that correctly the annealing will muck up dimensional accuracy.
(Note: My garage gets to 120F in the worst of the summer, and neither LR4 nor my MPRP&P have yet to soften over the course of two summers).
If you’re in AZ or west TX or somewhere that the outside air temp is 110F plus and your garage gets into the 130F plus range, I’d advise you to consider forced air ventilation or HVAC for your shop. Aside from the machines being happier, I can tell you that I can’t work for more than about 30 minutes in my garage when it’s in that state.
Okay, I am using standard 32mm parts on 1.25" tube. Not recommended, but it will probably be fine.
My reason was that I work for a comlany that sells steel tube, and I could get the 1.25" for significantly cheaper than the 1" conduit would have cost. (I got 2 20’ lengths for about the cost of 10’ of conduit.) It seemed worth the risk.
There are some things that I notice. The Y rail is looser in the clips than the Y rail on my LR3 was. I don’t think it is badly so, but it rotates by hand easily. The X rail braces still clamp adequately, and the core tightens appropriately.
The Y rail does not have noticeable motion, so if it does allow any inaccuracy to creep in, it is less than 0.1mm, which is acceptable to me.
On the plus side the 1.25" tube should be stiffer than the conduit, and I did not have to pick through a bunch to find a straight piece.
So my experience was good with the 1.25" tube. While I have no reason to believe that yours would be different, the possibility exists, so caveat emptor.
That’s reassuring to hear that 120 F hasn’t given you trouble, that’s the range I measured in mine this summer. I don’t intend to leave it as hot as it is for subsequent summer seasons, just not placing bets on having that updating complete before next summer…
And you’re right, I did mean PPA CF, which would be printed on an enclosed and preheated Kobra S1 with an all-metal, hardened hotend.
