Made it to RMRRF 2025 and was able to see the LR4 in person and that was the last straw to upgrading my LR3. It has been working fine for me but was only a 2’x4’ cutting space, well just under 4’ actually, will be an issue later unfortunately. It has been my goal to upgrade it to a full 4’x8’ sheet build so I can do cabinet cutouts. Seeing the LR4 and knowing that I was going to have to redo the main beam, rail and belt systems already I decided to just go all in and move up to the LR4, so the adventure begins.
As I don’t have a space to host a full sheet build just yet I am starting with the table to sit it on. I am going to do the ~$200 non-cnc table the Ryan put together here - LR4 easy Table
This table is a bit more than $200 with the current market where I am, but still not an issue. I had some OSB and MDF sheets in the stock, so that helped. At this point I have built the center of the table with the torsion grid.
Maybe a bit of over kill, but we were using some corner clamping braces to make sure that the center braces between each to the main ribs was straight up and down. Just glue and brad nails at this point so far. We ended the day with the full torsion box built and the bottom layer of OSB glued and brad nailed in as well.
What it is sitting on in that last photo is going to be the base of the table. I have been using the LR3 to cut some cabinets and they are setup on a metal frame with wheels. I have 4 more cabinets to get done to fill the last spaces on either side of the table. With those done I will be able to have support on the main ‘bessel’ points of the table. I should be able to move it around my shop as well if needed, hopefully. Might have put too small of weight capacity wheels on it, but will see how it works out.
Was hoping to start the built at this point, parts are almost all printed.
The keen eye will notice some missing YZ min and max plates and beam braces. Had some issues with a filament order and wrong colors. So correcting that and will come back at that later. But this is a good start I think.
In parallel to the table setup and waiting for parts to print I have also been working on the XZ plates and the struts that are needed for the beam. I was hoping to use my LR3 for both of these items, sadly that wasn’t possible.
For the two strut plates on my beam they needed to be 1389mm in length. Sadly my current LR3 setup maxes out at just under 1300mm length on the Y axis. So I will be printing temp struts and having my LR4 cut its own parts. Same thing I did with the 3, so not worried about that.
The XZ plates is where I have had a lot of fun lately. This is my first steps into cutting aluminum on my machine and I have learned a lot, as well as being totally impressed with what these machines can do. I used this great write up to help me get started -
It got me a starting point, and I went from there. Did some sample cuts testing feeds and speeds. Lot of new items were learned around material hold down as well. I was able to get the V1 logo cut after a couple tries.
Got some settings I was happy with and started cutting the XZ plates. First one went well, but was a little short in regards to depth and didn’t fully cut it out. I was able to manually get the piece out and then a bit of sanding on the edges go me a final part I could use. Adjusted the depth of cut and tried to get the second one as well. Adding that extra 1mm of depth really messed up the cut and I ended up with some missed steps in the process, trashing the part. Had to slow the speed of cut down and was able to get the second one finished. I now have two XZ plates that are ready for a machine build I think.
I used Trochoidal milling with cut paths worked out in Estlcam. There were 2 tools used for this, a 1/16th bit and a 1/8th bit. Links are to the V1 shop, which is where I got these bits. It was a bit more expensive than I would have liked, as I bought two of the 1/8th" bits and due to errors on my side, ended up breaking them both. First one broke as I did a pause to try and get some screws in for hold down, wrongly it turned out. The second one broke right as the second XZ plate was finishing. Part moved due to bad hold down right at the end of the cut, bye bye bit.
The following speeds and feeds are for each bit but I did full depth cuts of 7mm on both of them. I had to slow them both down for that depth though. At a 6mm depth I was able to go a bit faster. I am using the Makita router and the speed dial is a bit under the 3 setting on the dial currently. It moved around between 2 and 3 during testing. As I list these I would say use them with a bit of ‘salt’, your mileage will vary based on your machine and bits and material and current barometric pressure, etc. etc. You get the idea.
For the 1/8 bit I am running at a feedrate of 6.7mm/s. Trochoidal stepover is 5% and width was 35%. I think I might bump the width a bit more on future cuts here as chips seemed to pack the cut curf a lot. This then packed in behind the bit I felt and sort of impacted the whole trochoidal side of things as the space for the bit to moved was now filled with packed chips. Think more space here might help.
For the 1/16th bit I am running at only 4mm/s feedrate. Trochoidal stepover is 3% and width is 50%. I didn’t have the same chip packing issue here and they cleared well. Granted I didn’t do as much cutting with this bit, more just drilling the smaller holes.
Both bits were plunged into the material at 90 degrees at 3mm/s. Still learning so I might have missed some items, but messing with these settings is what has allowed me to get the cuts I am getting. Hope it can help someone else, but the post linked above is probably a better place to start if your new over my minor notes here.
Another quick update and also asking for advice with an issue here.
Was able to get the rest of the parts printed and started the process of tearing down the LR3 for the pieces to build the LR4. Was able to get the table for it flipped over and the top piece anchored down. Nice and rigid now at this point, and a great working surface for the build.
Have started the side rails for the machine to ride on, but they are just loose still so far. I couldn’t get 10’ MDF strips, so we are doing a scarf joint across two of the braces to extend two pieces the needed length.
The area I am having issues with is the Z height motor, coupler and threaded rod. If I put on the coupler via the directions and the gauge on the YZ plate there is only ~6mm of space left for the threaded rod in the coupler. When I go to tighten the set screws on the rod it gets push up and out of the hole by a small bevel at the end of my rods.
My steppers were purchased via the V1 Amazon affiliate link but not sure where I go the coupler or threaded rod from. Not sure if this was from a friend or if from V1 affiliate link again, to long to remember directly. These worked fine on the LR3. Am I going to be ok to adjust the spacing of this coupler different than the directions? From what I can see the only issue is going to be that the bottom set screws can’t be accessed from the small access port on the back side of the YZ plates. Am I missing something else with this adjustment?
I should be able to move it around my shop as well if needed, hopefully. Might have put too small of weight capacity wheels on it, but will see how it works out.
