CoG: The Balanced CoreXY 3D Printer

CoreXY design with belts pulling thru the center of gravity of the X axis carriage. This should stop any twisting motion of the carriage and result in less wear of the bearings.
Thingiverse: www.thingiverse.com/thing:633...
Have fun! Steve

[@MakerViking]

Good video and interesting project. I always enjoy watching other peoples 3D printer designs and builds, after being stuck with my head in my own designs for a while. Lol

[@videoviewer2008]

I thought balanced was going to mean "counterbalanced". Looks nice.

[@fastslash25]

looks good, probably capable of much higher accel and double the speed with input shaping.

[@robotadventures]

wow looks like a lot of fun. really like that green filament. i have a flying bear p902, a tronxy x5sa, a neptune 4 pro and a resin printer. i really like tinkering. ive been thinking about building my own for years... its like a puzzle trying to figure out how to design stuff. its fun but only if you like puzzles.

[@willofthemaker]

Nice design. I like the 360 blower for cooling.
But that is ine chonky thick build plate. Going to take a lot of energy to heat it up, i guess it can act as a heated chamber around the print surface though.

[@capthowdy126]

i thought about this on the screws not being a perfect fit inside the bearing an was looking at trying to make a sleeve that went of the bearing but what little i messed with it it looked like id have to drop the screw size to a m4 to get a shaft on the screw that would fit the id of the bearing an the od of the screw, i even considered a couple wrapped of electrical tape around the m5 bolt to see if that helps but ive never took the time to test either. im waiting on some parts to come in the mail an im going to start a corexy build to keep on my desktop. not sure how its going to turn out, just seen a few post of ppl taking the little kingroon kp3s printers an converting them into corexy an ive got a couple for $50 each and a pro an im going to use those 3 printers to try to put one together but im going to try to use a builder bed than the 180x180 so its going to be based on the conversion i guess but i'll be dealing with getting it to work in a bigger format, or thats the hopes. i got a bunch of other machine i can use so its more going to be a learning experience an i wanna try klipper, its been out plenty long enough an ive still not tried it, but i just got a bambu lab p1s machine an its a monster compared to what ive gotten used to from my older machines so im hoping i can get the little corexy to at least print at half the speed as my p1s, if i can manage that i'll be happy, if i can do more or match id convert all my older machines.

[@bamacadam]

very nice design !
the only thing I would say is that there is a big moment force created with the unsupported pulley on the stepper motor because of the belt tension. I've seen designs that support the end of the stepper motor shaft with another bearing to avoid the twitsing motion of the belt tension to be applied to the internal components of the stepper motor only... so less wear and tear of the stepper motor bearings and prolonged durability ?

[@claws61821]

If I understand what you're describing correctly that's a very common design element for exactly that reason in other industries that make heavy use of timing belts. The last thing you want is for your machine to be down for an extended period because a motor was destructively misaligned by off-axial torque from an unbalanced belt. Another common solution is manufacturers will design in additional pulleys and idlers to redistribute or counterbalance those forces using the same or additional belts. Often this is as simple as adding a second belt and pulley to the same shaft and it's reciprocal mate exactly opposite the pull direction of your primary belt. These balancing belts don't even need to be toothed since they're simply providing tension, so for an application like these sorts of printers you could save money by using inexpensive office style rubber bands of appropriate resistance (layering them helps with that).

[@1943vermork]

Thanks for sharing.

[@RaphaelRema]

Nice video. Thanks for sharing the info. Did you ever get the carbon f rods working? I'm about to use it on my own design and I was wondering if there is any pitfall...

[@steveturner1447]

Couldn't find a good source. Good luck with your build. Steve

[@NeoIsrafil]

Smart idea, though usually you can simply go for linear rails to mostly fix the problem. If you used 2 opposed linear rails in your design with a gantry in place of the rails you could probably do it the way you did it and have damn near no twist or slop ever...
Im sure its unnecessary but i love overkill for stability...

[@derfelix052]

First of all, great work! Would it be bossible to make a video where you show the electronic parts, the wiring and how you set it up? I'm thinking of building a similar 3d printer but a little bit bigger and now the only thing im wondering is how the electric side works. Thanks in advance

[@steveturner1447]

Thanks Felix. Unfortunately, I don't think a video on my electronics would be much help. I am using a unique setup that most won't use: 2 separate controller boards with laptop running Klipper (no Raspberry Pi). There should be plenty of other videos online that show this. Steve

[@derfelix052]

@@steveturner1447 alright thanks anyways

[@derfelix052]

Hello, how much % infill did you use for the 3d printed parts?

[@steveturner1447]

Good question. I need to make a list. I used PLA on all parts with gyroid infill. 20-25% on the idler brackets and z motor mounts. 100% on the heat sink and bearing clamps. 40% on everything else. Steve

[@derfelix052]

@@steveturner1447 thanks man