Finally got to expanding my Dollo printer in X and Y axes (sorry about the bad quality, Jolla C doesn't have very good camera...). Needed to print lot of extension parts and ties, also some of the older extensions needed to be replaced as they were printed badly (bad printer, bad settings...)
The axis dimensions are 240mm x 210mm x 435mm (x y z) currently.
https://dl.dropboxusercontent.com/u/...2021.48.22.jpg

I use PETG for the ties, they are bit more flexible than PLA and seem to make tighter joints. Also it helps when joining parts that are printed on different printers and don't have 100% same dimensions.
https://dl.dropboxusercontent.com/u/...2015.51.02.jpg


I also did bit better cable management and designed these clips that attach to the bow tie grooves on the frame. It helps, but there's still room for improvement , especially around the RAMPS box. Z motor wires needed to be extended too.
https://dl.dropboxusercontent.com/u/...2018.25.57.jpg
https://dl.dropboxusercontent.com/u/...2021.48.57.jpg

The bed looks quite small now and is bit too small compared to the X axis. Also the bolt heads stick out and care needs to be taken so that nozzle doesn't hit them. The current bed carriage setup is too flimsy due to the extra lenght, but works for the time being. Need to design much beefier parts and maybe move the rails inside the frame.
https://dl.dropboxusercontent.com/u/...2017.14.46.jpg
https://dl.dropboxusercontent.com/u/...2021.49.27.jpg

The X and Y racks were also updated as more length was needed. For X rack, I did some redesignin of the motor mount and the rack. For Y, I used the leftover X rack (it was two 9cm rack parts joined) on both sides. Also finally found out why I had some artifacts in prints:
1. the bolts that fastens the gears to the motor shafts were bit too long and would hit the rack once in revolution and cause a bump
2. the rack joints weren't completely smooth, so I took some time to sand them properly
Now they move quite smoothly, without extra bumps.
https://github.com/spegelius/Dollo/b...L/rackv4_4.stl
https://github.com/spegelius/Dollo/b...t_small_v4.stl
https://dl.dropboxusercontent.com/u/...2017.15.05.jpg

Currently printing Benchy (scaled to 200%):
https://dl.dropboxusercontent.com/u/...2015.51.35.jpg

Current problems I need to address:
- frame isn't that rigid, as I've already mentioned. Especially the corners give way too much. So far doesn't seem to affect quality much, when printing moderately slowly, but then again I haven't done too many prints yet. This'll need some experimenting about how to fix. Maybe some corner pieces to make it more stiff
- related to the above, the angles aren't straight. So calibration is needed.
- bed carriage too flimsy.
- X and Y motor gears will probably start slipping after a while. I've seen it happen. Current design use M3 bolts to fasten them to the motor shaft, but the gears are plastic and they start to give after a while, causing backlash. X and Y axes put quite a strain on them as the racks have bit of friction. I've been contemplating about changing the M3 bolts to M4 and also annealing the gears: https://www.youtube.com/watch?v=CZX8eHC7fws. Maybe even drill a hole through the motor shaft for the bolt
- no part cooling fan. Need to design one.
- bed bolt heads.
- other stuff I forget...