Ok so to continue on an older thread, I’m finally using this thing and love it. However, I still have the problem where the left y axis motor drops (by gravity) when machine is first powered on or not but doesn’t I it after I manually move any axis through the screen. Also not sure If this is connected it if I choose to move z axis first before anything else it bottoms out neverending grinding the belt. The workaround I found was to go into movement move x one click, back out the go back to movement and no issue. Anyhow that’s off subject. My big concern is the nema 17 is way too weak for the x axis in my opinion. I have the typical build with skr pro 1.2 with tmc2209 v1.3 drivers. Can I upgrade to nema 26 and if so do I need to change the x axis driver and or flash a change to firmware. Power supply larger or anything else?
Why do you think the NEMA17 is too weak for the X axis? Is there some specific thing that has led you to that conclusion?
Plenty of people seem to be able to lean pretty heavily on their routers using just that single NEMA17 and fundamentally the machine has rigidity limits that more power won’t overcome.
Looking at the ones sold on the store, they’re rated at 60N.cm holding torque at 1.7A and I believe most people are running them at around half that so 30N.cm. That torque will increase slightly with a little bit of RPM and then drop off starting around 500rpm which is 270mm/s, way beyond anything we’d be cutting at.
With a 16T GT2 pulley, that’s 32mm circumference or ~5mm radius, so 30N.cm is 60N or ~6kg. That’s a pretty decent chunk of force to be pushing on a trim router with…
So I am working on a bartop which is a live edge type wood piece covered in epoxy resin. Unfortunately as I am not a wood worker ai used osb rather than particle board for the mold. This led to the piece being twisted and the bottom having 1/2" of useless resin and waste of money. So i flipped the unit upside on the lowrider and shaved down the excess. with a 1/2" cutting bit using estlcam, i routed off the bottom 1/4" layer. the x axis motor struggled at passes even at 7mm/s with a brand new bit. You could hear what sounded like belt jump or maybe it was motor lockups idk. i dropped it to 35% speed and i still had to help push the unit by hand to keep cutting. Maybe I could crank up driver idk?
Small wonder the motor was locking up and the belt was “slipping” (skipping steps). Trying to cut epoxy resin with a 1/2" bit at 6mm DOC is WAY beyond what anyone should expect from the Lowrider. With a 1/2" bit in a soft material like MDF or Plywood, a 2-3mm DOC might be expected to work (given proper feeds and router RPM), but tripling that depth in a solid material like epoxy is not something that most people would expect to have a successful outcome (IMO)
Possibly idk, thus the reason I am here. Resin really wasnt even that hard. When touching the actual wood it bogged more. Maybe the reason I asked if I could upgrade to a nema 26 idk…? 
My understanding is that the problem is that it’s not just upgrading the motor, it’s then the rigidity of the whole system that needs to be upgraded to suit.
You either need a different approach or to take lighter cuts. I would be running passes with everything moving quicker and either less depth or a smaller overlap.
Slower speeds don’t always help cutting tools. The right speed is important. This is counter-intuitive, but moving the router slower increases friction on the tool. The tool needs to cut chips from the material, thisnks the most efficient way to use it and requires less power.
A slower RPM might help. Faster speed (lower acceleration) might work better. A shallower cut will most certainly help. Multiple passes are good.
I agree that a quarter inch deep with that large mill is asking a lot. Maybe not for a $30,000 machine, but as good as the LR4 is, it’s still dependent on printed plastic parts, and you will have rigidity issues pushing too hard.
There is always a trade-off. Project speed js a combination of tool path speed, and depth of cut. Often, a deeper cut that can eliminate a pass is a greater improvement in project time, to a point. Looks to me that you’ve passed that point.
Too high RPM or too slow a feed rate in Epoxy can start to melt it and cause all sorts of grief.
7mm/s (420mm/minute) is a lot slower than I use my router. At that low a speed, my Makita on speed “3” can start burning bits. I usually cut about 1800 mm/min (30mm/sec) at a shallow 3-4mm DOC. With a 1/4" single flute but that results in a fairly good cut in hardwoods. Recently I have started even faster passes with the LR4, and have played with some deeper cuts at the same speed.
Speeds and feeds are a lot more forgiving with shallow depth of cut. You can look at the generated debris and listen to the tool to tune the router speed and feed rate.
I would not want to be learning the speeds and feeds on an expensive live-edge piece, I’d likely pour some resin on a scrap piece and experiment with it. I’ll bet you can do better.
Thanks Dan. This information is exactly what I have read in the past and didn’t want to hurt the others feeling about their thought. Doing a shallow dive only utilizes a small fraction of the bit and simply wears it out and the machine faster. Not to mention the more angle/force it has on the router when pulling into the media. So the cuts were great, good sized chips no burning. I think part of why the machine was struggling was my vacuum wasnt functioning well as I was waiting on my skirt to arrive today. I designed my own head and quick release for multiple tools to be used along with a vacuum base to help clean up. This stuff was a mess, like I can’t even describe. With that said media was getting into rails and making it tough to move like a brake. Anyhow, I bring up nema 26 as I saw someone else a attempted this mod. Common sense tells me that the y has two motors and z I irrelevant to a certain degree so why not put some more beef into the x axis? Makes sense to me. There is room for clearance so just need to know what I would need to swap it. Also as far as someone’s comment on rigidity of the chassis I built my horizontal plates out of 1/8" aluminum. It’s not bending.
Also I suppose it doesn’t have to be nema 23 if it’s not an easy swap.i could do a nema 17 but instead of 84oz/in upgrade to 107oz/in. Can this be don’t in as easy as a simple motor swap?
Yes, unless they are too long.