I wanted a rigid motorized bed for my laser so after looking at options i decided to make my own.

inspired by:
https://www.thingiverse.com/thing:2299337
https://www.thingiverse.com/thing:3073708
https://www.thingiverse.com/thing:1906231
https://www.holgamods.com/holgamods/Lasers.html

https://youtu.be/Bznpt6CiLvE

the corners are on their 5th revision and while things might change this is about as good as i can get.

the idea is there is 2 bearings and a collar in each corner designed to preload the bearing and reduce the wobble.To this end push the bearing in so that it sticks out a hair on the top cap. you can use a bigger stepper but there isn't much height in the laser.

i designed this to have very tight fitting bearings so i used a G clamp to insert the bearings.

Sizes below were for my machine, please verify yours before cutting.

alu tubing lengths 2x 200mm and 2x 300mm for the sides

12ga steel sheet cut to 350mm x 250mm

Bill of materials with links (yes some are affiliate links, don't hate, its like a free tip for me)

Cost from Amazon is about 135usd not including shipping just in parts
Cost from Banggood is about 104usd not including shipping just in parts

Ebay:
Belt 1220mm - 2GT 610 Teeth 7.99usd
https://www.ebay.com/itm/GT2-Timing-Belt-Fiberglass-Reinforced-Width-6mm-Pitch-2mm-for-3D-Printer-CNC/152834326397

Metals:
12ga steel sheet 15.4usd
https://www.onlinemetals.com/en/buy/cold-roll-steel/0-105-mild-steel-sheet-a366-1008-cold-roll/pid/20183

Alu tube 1in 0.065" wall 14.5usd
https://www.onlinemetals.com/merchant.cfm?pid=20737&step=4&showunits=inches&id=1270&top_cat=60

Amazon Links:
608 bearings 8x - 9.14 :https://amzn.to/2CoNh4T
100mm lead screws with nuts 4x - 4.79 :https://amzn.to/2CoMCQX
gt2 pulley 3mm inside 2x - 8.98 :https://amzn.to/2CTRZbQ
34mm hight nema 17 stepper - 11.69 :https://amzn.to/2RSeguO
20t gt2 pulley 5mm bore 1x - 7.84 :https://amzn.to/2q5suvX
5mm x2mm magnets - 6.99 :https://amzn.to/2CN83vS
8mm collar - 9.98 :https://amzn.to/2yNsNiz
Spikes - 6.95 :https://amzn.to/2CnZjvh
20t gt2 pulley 8mm bore 4x - 7.84 :https://amzn.to/2CkxmEJ
m3 screw set - 12.95 :https://amzn.to/2Cnzsn2

Banggood Links:
608 bearings 8x - 7.02 :https://goo.gl/SKsbEf
100mm lead screws with nuts 4x - 11.96 :https://goo.gl/C8wNUj
gt2 pulley 3mm inside 2x - 3.38 :https://goo.gl/CsGxun
34mm hight nema 17 stepper - 10.95 :https://goo.gl/dLqAAR
20t gt2 pulley 5mm bore 1x - 1.55 :https://goo.gl/4LC6c2
5mm x2mm magnets - 3.99 :https://goo.gl/37iX2s
8mm collar - 6.76 :https://goo.gl/QqGQFr
Spikes - 5.49 :https://goo.gl/uZwCBp
20t gt2 pulley 8mm bore 4x - 6.2 :https://goo.gl/vwPBYz
m3 screw set - 8.39 :https://goo.gl/dDvF8C