I had originally build a mega prusa i3 but being so large the bed just shakes the table and produced horrible prints. I had found the same person that designed the prusa moved onto this larger more stable version. I am taking his design and changing it so its a swap with the parts to save money as well as this will make this printer incredibly large,stable,fast and hope to have a dual extrusion installed.
As you can see with my printer it is very large but I have only tried to print one thing and the y axis had very bad resolution since the bed is moved by that tiny belt.
Once completed I hope to be able to print full helmets size object at a decent speed.
The frame is coming together nicely. I know with a extrusion rail it would be easier and maybe more accurate but I these are a great price and I have everything measured to within a millimeter. The 2 top smooth rods had to be angle grinded shorter in order to fit but the Z axis rails are a great size. The bed I am going to redo to a adjustable size since I found after I put it together it seems to bind but I came up with a great idea for a stable and adjustable bed.
I had originally tried just making a measured square but found it very hard to keep the bearings from binding so I scrapped it for the next idea.
Easier solution was to drill holes straight through and use the old y axis rods from the old printer. The bed would keep it from shifting once screwed into place and the threaded rod lets me adjust it to keep binding off the bearings. would be a lot easier with the 20x20 extrustion rails, Will probably updated it later.
Cut some 8mm rods for the axis lift and drilled and mounted the bed as well as glued my old heat bed to the bottom. The motor mounts have to hold a lot of weight so has me a bit worried.
mounted the Belt with this configuration and used some 628 bearings in the mean time untill my 624 smaller bearings arrive. Will post some pics of all the parts after they arrive.
Using the temp parts and loaded up the firmware and after frying one ramp board due to miss wired end stops had it up and moving. Still need to wire in the z prob and extruder and a stronger power supply for the heat bed.
Finally have gotten back to finishing this thing. printed corners for more stability and accuracy since drilled in angle brackets tend to shift slightly when drilling and the bed rails and mount wasn't that accurate. will be doing more upgrades later.
i hate these wires when ever I am working on a printer. Need to switch to ribbon cable one day.