GIANT Core-xy build

Hello! First post here.
I've always wanted to design a printer so here is my take on a giant core-xy 3d printer.
I'm mainly looking for any opinions/suggestions on the build so far (especially the z-axis movement platform)
Printer is almost complete, and will test print as soon as I can.

400 x 400 x 550 mm build volume
500 x 620 x 840 mm printer volume

I took inspiration from the D-bot printer on thingiverse: D-Bot Core XY
I designed everything from scratch on Solidworks except the LCD housing.
LCD housing here: LCD Housing

I decided to make it a huge build volume because I was tired of printing things in parts.
I also tried to use as much of the printer volume as possible in order to save material as well as make use of the wasted space many other printers have.

WIll update with more pictures/files as this project progresses.

450mm MGN 12 linear rails and block (much more reliable + similar price. $63 on ebay for all 3)
-Openbuilds 20x20mm V-slot extrusions
-8x Openbuilds V-wheels for Z-axis (yet to be tested. seems to move very smoothly though)
-8mm lead screw
-GT2560 board-marlin
-Inductive auto levelling
-600W heated bed
-Compact tool head (hot end is higher in relation to the carriage, giving more space in Z direction)
-Optical endstops
-SSR for heated bed

Would like to add swappable tool heads and bed plates, and out of filament sensors in the future and more.
































Edited 3 time(s). Last edit at 08/05/2016 01:39PM by NightCrispyy.

Have you published the project some where?
you have screwed the X endstop directly on the linear rail block?

I'm certainly no expert, so take what I say with a grain of salt. But here is what I am noticing based on spending time here and my own intuition

-Have you considered using a belt and 1 motor to drive your Z-axis? This way they never get out of sync.

-The x and y axis. I'm no expert on rails again, I know they are supposed to be a great solution, but should they not be mounted on a more rigid surface? Atleast 1 axis?. Even if they can take the load, seems like there would be deflection in the middle of the span. And at the very center of the plate, you would add the deflection of the x and y axis. Might not be tremendous, but it adds up in a precision machine (I assume you want to build a very robust large machine). I would think about adding two extrusions, or something (perhaps machined piece) below two of the rails so overall deflection in the center of the build plate is reduced.

-Is the 8mm lead screw thick enough? Should it be secured at both ends?(Don't know, but a question for the experts on here)

-Have you considered a Flex3drive extruder? Based on my sleuthing, seems to be the best (perhaps maybe tied with the new E3D Titan)

-How many points is the bed leveled with? 3 point manual leveling is the best method. (my own experience with a very high precision polishing machine)

Looks like a good concept though. The frame seems strong and rigid. I like that the bed is well supported. Might even take one of those heavy but very cool basalt beds.

Look forward to your progression and the comments of the people who really know what's going on. I'm really looking for a very good, bulletproof design with a larger build space. 9"x9" is just too small.

A very nice looking build you have so far, but will the bed be stable enough with only 2 wheels per extrusion?
The normal set up (3 / 4 wheels per piece of extrusion) works well as the wheels can 'clamp' on to the rigid extrusion, and I assume that you are trying to do the opposite by torquing the wheels outwards on to each piece of extrusion, but when the bed reaches the center of the extrusion, it will be able to flex it more, and you may see movement in the bed.

Quote
Origamib
A very nice looking build you have so far, but will the bed be stable enough with only 2 wheels per extrusion?
The normal set up (3 / 4 wheels per piece of extrusion) works well as the wheels can 'clamp' on to the rigid extrusion, and I assume that you are trying to do the opposite by torquing the wheels outwards on to each piece of extrusion, but when the bed reaches the center of the extrusion, it will be able to flex it more, and you may see movement in the bed.

Yes the plan is to push the wheels outwards. The reason I didn't clamp them is because I wanted to add plexiglass/acrylic panels to the sides in the future, and the wheels on the outside would interfere. I'll probably find a way around it if this setup doesn't end up working well. There was some flexing, but it was reduced drastically when I used a spreader to push the wheels against the frame.

Quote
filipeCampos
Have you published the project some where?
you have screwed the X endstop directly on the linear rail block?

Currently only on this forum.
Sorry, that was an older design. The X endstop is not directly screwed onto the rail block.
I updated the picture.

Quote
wbwing
I'm certainly no expert, so take what I say with a grain of salt. But here is what I am noticing based on spending time here and my own intuition

-Have you considered using a belt and 1 motor to drive your Z-axis? This way they never get out of sync.

-The x and y axis. I'm no expert on rails again, I know they are supposed to be a great solution, but should they not be mounted on a more rigid surface? Atleast 1 axis?. Even if they can take the load, seems like there would be deflection in the middle of the span. And at the very center of the plate, you would add the deflection of the x and y axis. Might not be tremendous, but it adds up in a precision machine (I assume you want to build a very robust large machine). I would think about adding two extrusions, or something (perhaps machined piece) below two of the rails so overall deflection in the center of the build plate is reduced.

-Is the 8mm lead screw thick enough? Should it be secured at both ends?(Don't know, but a question for the experts on here)

-Have you considered a Flex3drive extruder? Based on my sleuthing, seems to be the best (perhaps maybe tied with the new E3D Titan)

-How many points is the bed leveled with? 3 point manual leveling is the best method. (my own experience with a very high precision polishing machine)

Looks like a good concept though. The frame seems strong and rigid. I like that the bed is well supported. Might even take one of those heavy but very cool basalt beds.

Look forward to your progression and the comments of the people who really know what's going on. I'm really looking for a very good, bulletproof design with a larger build space. 9"x9" is just too small.

Thank you for your thoughts. Yes I think the rails may be need to be attached on some machined parts. I'm probably going to get that done soon.
For the 8mm screw, i couldn't find a 10 or 12 mm one long enough (600mm) for some strange reason. They only went up to 400mm. I'll have to check with the flex3drive extruder. It does look like a pretty robust and reliable system. As for the bed, I was going to do 3 point leveling until i noticed that my bed was not 100% flat. But i can go from 4 point to 3 point leveling very easily.