This is a modified CoreXY setup I have been working on, I have to do the corner bearing holder and the motor mount yet, this is for a printer I am creating, it uses LME12UU bearings and 12mm shafts, I went bigger as this is also used in a much larger printer also, that and I like tanks, I don't like things that are flimsy and flex. It does not cross over it runs at two different levels so everything stays straight. I used 686Z bearings on the ends and the flanges I made are designed to be paused then the bearing added then printing to continue so they are encased in plastic (a blast of a heat gun before hitting resume makes a strong bond for the continuing layer.) I made it around this hotend that I got from amazon: Signswise Assembled J-head Hotend 0.4mm Nozzle Printer Head for 1.75mm Filaments http://www.amazon.com/Signswise-Assembled-J-head-Printer-Filaments/dp/B00SWLMWDM It shouldn't take much to change the clamp to fit your hotend. Things to do: Motor mounts. Corner bearing mounts. Spot for a small magnet on the Y carriage for the X carriage home and another for Y homing. Spot for a hall effect sensor on the X carriage to line up with above Spot for a Z probe. My thanks to Jayftee and Make-a-FaceI used Jay's bearing holder and part of Makes belt older. http://www.thingiverse.com/thing:195621 http://www.thingiverse.com/thing:745934 Update 9/12/2015: I had to redesign the X carriage, when I went to put it together it wasted almost 2 inches of space so I flipped the Y axises upside down to lift it up higher and to put the belts above the printer on top of the frame which solved the problem of no where to mount anything. it is functional now, I was going to put new picks but I am almost done mounting everything and running the belts I just need to print out some more bearing flanges, on those I stop at height with cura, and pop the bearing in and resume printing. I have made a motor mount that mounts to the outside on the sides with the belts passing through, I will have picks up hopefully by tomorrow as soon as I get the rest of the bearings done everything else is mounted, lines up and is ready to go. Update 9/15/2015: I finished assembling the mechanical parts, all seems to look good and moves as it should, I could have brought the corner bearings in more and use a t-nut in the slot and had them in line but I wanted more support than that offered and tapped the corner holes of the extruded aluminum and used nice long 1/4" bolts to hold it together, so it causes the belts to angle out to the corners but it shouldn't matter as it gets pulled away on one corner it gets pulled tighter on the other so there is never any slack and the other thing look at the serpentine belt on your car, it does not make a perfect square. ;-) Pictures added, I just need to wire the motors to the smoothieboard now. Update 9/25/2015: I worked out where to put the endstops, I made them separate to glue on (acetone for the win) now that I have how I want them designed and best placement for them I will put them in the design of the parts so that they are built in. I have everything hooked up but the hotends and the extruders and told it to print, told it to do a print speed of 150mm/s and a move speed of 300mm/s and it didn't blink an eye, I cranked it to 999% and it flew, I doubt it could push the plastic out that fast especially as I normally use a 0.3mm nozzle but the mechanism handled it just fine and flew, it was a glorious sight.Update 10/9/2015: This is fully operational now. Endstops were added, print and enjoy.Update 10/23/2015: Raised the bottom of the X carriage (hotend holder) by 1mm to give more space at the bottom of the hotend heatsink. Uploaded the fan shroud, it is designed to use blower fans for the plastic active cooling and a 40mm x 40mm x 20mm normal 12v pc fan to cool the hotends, a standard 10mm fan does not move enough air to cool both heads at a time but the 20mm fan works great. Uploaded a in progress fan duct, I have printed it a couple times for fit and am printing the final version of this style now for testing tomorrow. I thought about using two fans on the hotend one to push one to pull, the ones I found though blow a lot of air and with both nozzles at 220c you can barely feel a warm breeze at the bottom and quite cool at the top, but it is getting cooler now, the test will be in the middle of a hot summer.Here are the fans that I used. 2 - http://www.ebay.com/itm/321760495643 1 - http://www.amazon.com/gp/product/B006ODM76CUpdate 11/2/2015 I have decided to do a dual Z lift system with a hardened linear shaft in each corner, that should eliminate all Z wobble and issues, and I am switching from a 1/4" thick aluminum build plate to a 1/8", the 1/4" would probably be fine with the dual Z but might as well lighten the weight and help the build platform to heat up faster. I expected to have it all done last weekend but I forgot to get more M5 nuts and bolts as I ran out and in the US it costs me $1.50 for 2 bolts/screws from the hardware store since they are metric. :-(I was looking at everything and have decided to change the XY parts, right now they clamp the LME12UU bearing in place, sometimes that can throw the bearing out of alignment, I found that to be the case on the Z axis, it was bad. I decided to make a circular mount like you would get if you bought the brackets in metal, the metal ones you slide the bearing in and put a locking clip in, my new ones is completely encircled in plastic and you put two stop screws in the corners to keep the bearing from coming back out. I left the v5 clamp ones posted and included the new v6 as a separate item for those that may not like that style, I printed it out and it aligned perfectly and worked really well, I am working on the X axis part now.I used ABS but I think that really is only important for the parts around the nozzle, everything else PLA should work fine. 0.3mm nozzle. 0.2mm layer height Set your slicer to pause right before the top flange of the bearing, when the print pauses then insert the bearing and continure printing.