Drop table for some ability to handle thicker projects or for accessories like a rotary axis.
Use MPCNC to mill parts before disassembly.
Recycle parts from MPCNC to control costs.
Questions
What do I lose in this conversion? Rigidity? Is there something the MPCNC does far better?
Is EMT sufficient, or is it important to source the larger diameter tubes? (MPCNC is EMT)
I’ll probably order the metal XZ plates. Are there any other modifications I might need to consider?
Typical uses: Cutting boxes/parts from BB ply, MDF, or acrylic. Would like enough accuracy for cutting gears for wooden clocks/kinetic sculptures. Laser cutting/engraving. Never thought I’d consider aluminum, now I’m considering aluminum. Nothing high volume, so can afford to cut slowly.
I know I could probably accomplish most of the goals by tearing down the MPCNC and rebuilding it. But with my little bit of experience, I’m thinking a LR3 might be worth the effort. I’d certainly go into it with a more “mature” plan.
Maybe a little bit of downward force in Z, some flexibility with material clamping. I have many more options with material hold-downs on my Primo than with my LR3. The LR3 is better than the LR2 was though. I think it is possible to adapt though.
Although I use 1" steel for the X rails, I believe the 3/4" EMT is adequate, and I use 1/2" conduit for the Y rail. On the beta build, the X rails were also 1/2" conduit, and it was almost enough. Probably would be enough for a shorter span. The smaller Y rail is nice as it doesn’t hold chips on the table.
The printed XZ plates are good, but I have metal X Plates too. I increased the Z travel on mine by 50mm. I have never actually needed this, but I have used it when I didn’t want to take something apart to work on a top surface. A drop table would have allowed the same thing.
The MPCNC will provide control electronics, 608 skate bearings, M8(5/16") bolts, locknuts and motors. Another Z screw set will be needed as well as the MGN12H rails, and you will need a bunch of M5×30mm screws and locknuts. Add in the printed parts, and make sure that you cut your flat parts on the MPCNC firts. The YZ plates should be all you need, you cut the struts for the LR on the LR after initial assembly.
I chose to keep my Primo, but I also had a LR2, which got converted to the LR3.
I have the same exact setup as Dan… re. practically everything he mentioned. On this (see bold):
And on this (again see bold):
I called the taller YZ plates “Dan’s Extra Tall” — not sure if I got that naming from somewhere on the forum or what. I love being able to raise my LowRider up higher for getting under it for changing bits, and in case I have something thick, like a box or something, to work on.
And this:
Same for me. However, after I upgraded my LR2 to LR3, I built another LR3 for plasma. That was where I used printed XZ plates for a while. I eventually upgraded to metal XZ plates on that one too.
There’s a couple of mods that take the belt on side without the rail and move it off to the side of the table. That means if your Y tube rail is against the wall you have the use of the other long side as a workbench without disconnecting any belts.
Mine works flawlessly, and I have been using it for many cut jobs. I delayed posting it on Printables and by the time I did, it had a great track record for me. I’m sure Fabien’s design works as flawlessly.
Basic difference is mine is for hiding belt inside superstrut while his works without superstrut.
I switched from a Primo to a LR3 and do not regret it. There are some things that are different, mainly that X only has one motor now, needed to learn that the hard way. I also miss the captured rails of the Primo and that I was able to touch the spoilboard with the collet. Had to learn that as well that the endmills have to stick out a little more for thin pieces of wood. Besides that the LR is awesome in every way.
You can check my Youtube: From large things like a tongue drum to teeny tiny inlays in earrings the LR can do everything.
For clamping I have been using bluetape and ca glue\activator every since i learnt about it. I hit a clamp with mpcnc and from there I found the blue tape method!! In fact that is how i attached my (crap cant think of the name). My sacrificial board for the cnc! It holds so well!! And you dont need tabs most of the time!!
Thank you guys for the input. Still happy to hear more opinions. I did run around my garage/shop this morning with a measuring tape. Sad news, I just don’t have room for a full sheet. (Maybe one day!)
I was considering a 2ft by 4 ft size, but I realized that one of my more common materials is baltic birch plywood sold in 60" x 60" squares. To minimize waste within my constraints, I’m considering 30" x 60" half-sheet size. This would also allow slightly more than quarter sheets of my big box store sheet goods.
New questions for my planning phase:
Is the plan for a 30" length a problem? It looks like 24" and 48" are the common sizes. Am I likely to create any large difficulties going with 30" working area?
Because some of my work is laser, I am considering the increase 50mm z-height mods. I probably wouldn’t use it for the router. But it might allow me to engrave slightly thicker things without reconfiguring to the dropped portion of the table. What is the latest version of this mod? (Bonus: Is there any drawback to those cool looking acrylic plates?)
Many folks are advocating 1/2" EMT as sufficient for the Y-rail. I see the smaller clamps. It’s unclear to me what other modifications are needed? Do I need to do anything on the carriage?
I printed my MPCNC out of HTPET (285ºC print temp) because it lives in a garage in Arizona (188.6ºF heat deflection temp). In looking at the build instructions, I’m curious if anyone has printed in PETG (176ºF heat deflection temp) and has an opinion on whether it is acceptable. Or whether someone has a bad experience and can warn me off (the filament isn’t cheap.) Or if anyone has a strong feeling on a better filament to withstand a hot summer garage. (For reference, PLA is listed as 131ºF heat deflection temp.)
Make it whatever size you want. I decided to use 47.5" for the beam length, which gives me about 37" working width. 24" and 48" are the sizes thst Ryan provides the strut dimensions for explicitly, but any width works as per the calculator.
I use some of that 60" material as well.
No idea if anyone has done a more recent one than me, but mine is close. I don’t have the slight arc for the bottom of the Y drive on my parts, but my latest DXF has them.
I like the acrylic parts. If there is a downside, it is that you can’t just ad-hoc screw parts into them. My parts have a couple of holes marked or my LCD holder, but they aren’t cut on one side, only on the side where the LCD is.
Nope. The clamps hold the smaller rail so thst the bearings work in the exact same position.
I do the vast majority of my printing in PETg, but did make the LR3 in PLA.
Ryan does say PETg is a better high temperature substitute than ABS, because of its dimensuonal stability, but it is more flexible than PLA. I believe that it should be acceptable, with the sole exception of the XZ plates. These carry the most stress and are have greater effect on accuracy if they flex. If you are going to print in PETg, I would strongly advise milled MDF or metal XZ plates.
I would make sure you can at least place a 30"x60" piece. But I doubt you will have that many projects that will cut the whole thing in one go. Something like 30"x50" work area is a great size. Enough to cut a hat rack or a 2 piece bookshelf.
Do you have the latest DXF posted anywhere or would you be willing to share? I have the version with the flat Y, which I’m sure I can make work, but I can’t find a version with the arc.
I made the decision to go with MDF first, and come back to acrylic later. I can mill 6mm acrylic on the current machine, but I think the LR may do a better job at 12mm once it’s up and running. Would make a fun gee-whiz project if nothing else.
Do you think the superstrut could but just on the front belt, with the standard belt near the rail? Would that create any asymmetry in the forces? It seems like it would work. When I look at the cost of the superstrut, I’m wondering if I could save the rail-side for later.
Also, do you think it works with a different brand as long as its the same 1 5/8" profile? I’m not sure the stores near me have genuine superstrut.
My setup for the hidden belt has a printed stepper drive mount that its business end is 20mm tall, and the opening in the metal strut varies between 21 and 22mm. The crucial thing is that the opening of the strut be no narrower than that. There must be clearance. The brand should not matter. Mine is not the superstrut brand.
I often use the word superstrut because (my perception is) their brand name is associated with this like Kleenex is associated with facial tissue.
My current build will be around 30" x 48" and I had to squeeze to fit that, but in the limited time I had for the LR2, pretty much everything was less than 18" in it’s largest dimension.
This time I have left enough cable in the loom to extend to 48" if a project turns up and I’ll set up temporarily in that case just for that project.
