Is there a trick of some sort to get the x-belt belt inserted with the screw into the slot on the Ymin side of the LR4?
It seems incredibly tight and just doesn’t seem to want to slide down in there. Partly, it’s like the hole in the z-stub is too small, but the slot in the plate is also extremely tight.
(Admittedly, I tend to be paranoid about forcing things when plastic is involved…)
It is a tight fit, but that is by design so the belt cant slip once inserted.
I use a screwdriver in the screw to push down into the printed part, and at the same time some needle nose pliers from the bottom just outside of the aluminum XZ plate pulling down on the belt. Alternate force between the screwdriver and the pliers and slowly work the belt down to the bottom of the slot.
This was, by far, the hardest part of the build. The pliers idea sounds good.
@Bruce, were you able to install the x-belt?
It seems its extremely hard to slide the belt into position (the bigger slot at the end, 3.2mm). The entrance slot is 2mm and the thickness of the belt is 2.5mm ( belt teeth locked together).
Yes, I did manage to get it in. However, I literally had to hammer it down into the slot.
It seems that this slot is unnecessarily tight.
For various printers with various amounts of slight over-extrusion, it commonly makes outside dimensions slightly large, and inside diameters / dimensions slightly small. In an opening that tight, even a slight about of difference between calibration of printers, can affect the insertion process a lot.
A hole in a part can be revised after printing either by drilling or by heat, such as pressing a hot screwdriver in to slightly widen out the hole. In parts like this that are small and easy to reprint, it’s not a great loss if you mess it up and have to start over. But hopefully getting extrusion calibrated (edit the extruder motor’s “step” value) can aid with such issues in the future.
I did get the belt in but had to use a flat-head screwdriver and tap it in with a hammer. The printed part had enough clearance but the milled aluminum was tight. The belt ended up having some slight damage from this but not enough that it caused an issue in performance. If I had the patience I would have taken the aluminum plate off and filed it slightly but in the end, the machine works and I am cutting stuff.
Had to sign in here just to tell you that i was fighting for 2 hours till i got that thing in. Hope the machine didn’t suffer anywhere from the hit it got. After months of pain with a never working Maslow cnc, i already had the feeling everything goes to smoothly until here.
Yeah, it needs some force. 
Mounting X Belt to YZ Min Stub X normally goes something like this… Multiverse Content Viewer
Used belts from V1 Engineering shop, which for me, measure 2mm to 2.1mm thick when meshed together ( belt teeth locked together).
If this assembly step is a common frustration point, maybe folks using self sourced belts should verify belt thickness before printing parts, and, if their belts are thicker (e.g. 2.5mm) they should use a remixed Z Stub part with slightly wider slot?
I just had the same problem with my build 4 days ago. The Problem is not that the Slot in the stub is too small, but in the plate. Also it might not be perfectly aligned and then it is a very tight squeeze….
And after wrestling with it for 5 minutes I realized that i had put in the belt too short and couldn’t reach the other side….had to take the whole assembly apart again to take the belt out….fun times, would not recommend
Tokoloshe. in the end, it fit, but was close. I can measure my belt thickness later todaay and make some makroshots of the alignment. At the moment everything iis disassembled, because i’m installing the strut plates
I also asked Ryan during the Beta whether it should be that tight. I developed a strategy of pushing on the belt in the slot with a flat head screwdriver and at the screw with a Philip’s screwdriver. That works, but slowly. And it needs a lot of force…
I made this video a while back trying to help someone here on the forum. This is how I do it.
That video is worth linking in the docs.
If @vicious1 wants to do that I am all for it!
I will link that video.
The last couple I put together were definitely not that tight. I kinda just pushed them in with the screwdriver/screw. With a maybe a little wiggle on the other hand. I will check my plates and parts.
Its been a while since I have had a super tight one that’s for sure. But I still did the video to help others. I think we are seeing a difference in belt thickness here that’s causing the issues. And that is something that is going to be real hard to help with those overseas self sourcing the parts.
Thanks JJ, added here, LowRider CNC V4 - V1 Engineering Documentation