Hi! I finally mostly finished my 4x4 Lowrider V4.
I really like the changes in the new version. The parts all fit together great and have a more “complete” feel when built. My partner said, “Wow, it looks like a real machine instead of a toy.” I think the cable routing and the changes in the y carriages made a big difference.
I went from the SKR board to the jackpot this time. I had experience using SKR style boards with 3D printing and I even did some pin management on my LR3 as some of the pins seemed to fail over time on the board. The Jackpot feels a lot more like using a duet board or interfacing with the raspberry pi with octoprint. It was initially confusing learning some changes in GRBL compared to Marlin, but it wasn’t as scary as I thought.
I was having a lot of trouble trying to get the keyboard jog commands to work, until I realized I had to upgrade to the v3 interface. I did that, and I like it much better.
My one big wish for the FluidNC interface is to be able to sort my files by created by/modified instead of only by filename. I will probably have to start naming my files with the date code so I can get what I want that way.
I added the RSJ45 connector on the jackpot to talk to my HY VFD and I am very impressed with how that works. It didn’t work for a day, but I finally figured out I was calling the wrong pins in my config.
I slightly miss my 2.2kw 80mm spindle I had on my LR3, but I followed Ryan’s advice and went with a 65mm spindle on this build. I miss being able to chuck up 1/2 bits, but watching the amp draw, it rarely even goes above 2 amps so far with a ceiling of 7. The 80mm is a lot heavier than the 65, and I think less stress on the frame is a good call.
Comments on assembly and some places I got stuck:
I didn’t see a spot where I was supposed to screw in the little hats on the top of the Z screws. I eventually just did it at the end, but I wasn’t sure if there was a particular point to do that.
I had an issue with the calculator when referencing my struts relative to the tube lengths. It looks like the struts are supposed to be about 2-3mm longer than the tubes. In the calculator on the Imperial setting, I noticed it has the same length. I found a forum post describing a potential issue so I recalculated using the Metric version, and it correctly added 2mm. However, then the strut generator will remove .5mm from the total length you input. So I had to increase by 2.5mm to get the increase of 2mm that I wanted. It reminded me of ordering and replacing windows. You add an offset and the company adds an offset… I digress.
This did result me in cutting my struts twice. Though I used some pretty flimsy plywood the first time and wasn’t very happy with them anyway. I bought some 1/4 Baltic birch ply for them and am happy with how they turned out.
The first time I cut my struts I cut each one in two pieces because my edge length was 49 inches and the strut length was 59 in. In the directions it says to cut your struts near the sides to avoid out of square issues. I tried joining them up straight and I don’t think it went that well. The second set I cut diagonally with the first set of struts on to give me some extra rigidity.
Water Cooling:
I wanted to use a water cooled spindle even though it is a little silly. I had some old water-cooling pieces from a pc build that was given to me. I repurposed the heater block with some fans and used the fountain pump that came with the spindle. I have them turn on using one of those auto dust collection relays intended for sanders and miter saws. As soon as more than (I think) 40 watts is pulled from the VFD, it turns on the outlets for the pump and radiator fans.
Extendable to 8x4?
I had this idea to use a giant set of drawer slides on the back of the table to make it temporarily extendable to a full size CNC when I had a job or idea that needed the full sheets. I haven’t tried it out yet, but my idea is to extend the drawer slides, build a lightweight platform, make some swing down legs, and move out the y stops to 8 feet. The regular y side should be easy, but the EMT side might be trickier. I think I will try making an internal coupler for the tube so I can extend it without having a “bump” for the wheels. We will see if I end up using it or trying it out.
So far, very impressed with the rigidity, travel speeds, Jackpot board, and the dust collection.
Let me know if you have any questions!
