HUGE 3D printer concept - how to get over the hurdles?

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So, I've decided to build a massive FDM printer. 1000 mm in all directions for build volume. It's also going to be an IDEX system with a remote direct drive extruder on each. And obviously a CoreXY, since anyone who tries to move that kind of heated bed quickly has no concept of momentum.
It will also be enclosed for ABS printing, with an air scrubber using 3M cartridges.

However, there are several hurdles, so I decided I'd come here for help.

First of all, which control boards and firmwares support IDEX setups? I would like a 32 bit processor if possible, preferably with 64x microstepping or greater.
And of course, the heated bed. Does anyone know where I could find a monstrosity like that? Alternately I was considering linking four CR-10S-5 heatbeds together, but it would have ridiculous PSU requirements and probably need two outlets.

Again with the heated bed, I need some sort of build surface that is 1 meter in X and Y axes. I prefer glass coated with an ultrabase coating or similar, though flexible plates are also an option.

Edit 1:
Thanks to everyone who has responded since the original post. The concept has evolved since then:
IDEX platform with dual E3D V6 Gold hotends and 5015s for cooling.
MGN12 linear rails on X and Y axes, with linear rods for the Z.
The X and Y axes will move up and down via four ball screws and four steppers synced with a belt.
A BLTouch or similar sensor will be mounted on one of the print heads for ABL, but the bed will use 3-point leveling and level itself to the nozzle.
Each hotend will have a Zesty Nimble RDD mounted on it.
The aluminum buld plate will be custom machined from AW5083 aluminum to stay flat. Alternately I've been considering steel, though I don't know how that would handle thermal expansion.
The total motors I'm looking at are:
Two leveling motors for the heatbed (I'm using 3 point leveling and the 3rd point will be the reference for the Z offset)
Four Z motors
Two X motors
One Y motor
Two extruder motors
Total is 11 motors. I'm also tempted to add an MMU to one of the hotends which would bring the count up to 13.
An Odroid XU4 will be connected to three RAMPS boards via Klipper to handle the stepper requirements. The Pi 3 or zero are also options, but I would like to have slicing built into the machine, assuming Klipper can do this. If not I'll probably have a Zero running Klipper with an XU4 connected to it and sending over the sliced files.

Update 2:
I've decided that an IDEX system is interesting but not optimal. Instead, I'm going to make a toolchanger similar to E3D's, but not using their motion system. It looks like I'm going to need another RAMPS board!

Hey: It has been a while, and I am looking into building a similar setup, with some extras. Did you have any success on the build?
I am planning to use 608 bearings on either 1inch square aluminum tubing, or on 1'' EMT conduit like the MPCNC. I plan to build the whole system on a gantry style similar to a CNC router that doesn't move the bed. Thoughts??

The thingiverse post from the guy in that video can be found here:

1200 x 1200 Large scale DIY 3D printer - Sub33D v3.07
by sschm9

awesome! good find

Just came across this guy:


If you haven't seen this, check it out. Pretty much what you're trying to do.

Thanks to eveyone who has replied so far. As I see it, it's much better to have a design like the Creality Ender 5 which uses a motor for the Y axis and another motor for the X axis. Of course, the X axis will rrquire a motor on either side and two belts.

As for the heated bed, most people have reccommended silicone heaters, which seem like a good idea. I was alternately considering getting two MeanWell PSUs and having a grid of four heated beds with two beds and a nozzle heater hooked up to each unit. I'm not sure if even MeanWell can handle that though, so the silicone heaters are probably a better idea.
Also, whatever build sheet I use will have to be attatched to a rigid surface to avoid flexing during thermal expansion.

consider a setup similar to the BigRep:

6mm aluminum plate of that size alone will weigh 16.2 kG or 35.7 pounds. Moving that weight using GT2 6 or 10 mm belts will be a challenge. Moving that size of the bed up and down and keep it straight will be another challenge. I would recommend a stationary bed design for your dream 3d printer.

a bed that only moves in a horizontal axis could work too

But then it still weighs 16KG - over 35 pounds. You'd need a huge stepper, and your acceleration settings would probably be something like 100mm/sec though I'm no scientist.

Yeah, the amount of force required to accelerate that at any rate would be huge... it can certainly be done, but it would be much cheaper to use a stationary or Z-only bed and only need a relatively light extruder head moving around at any significant speed.

Though, if you did go the Z bed route, moving the Z axis through its full 1m length for homing or whatever would take quite some time. At least it doesn't have to be done often.

8 leadscrews synced with a GT2 kevlar belt and 8 linear rods should do it. I hope. I hate deltas with a passion, so for me the only other way to do this would be to mount the Y axis on leadscrews and move that vertically instead.

"I hate deltas with a passion" Have you seen Piper 2 or Voron 2 designs? They are not IDEX, but they are coreXY designs with moving gantry and stationary bed. Both use 4 Z motors and run on Klipper. BTW Klipper has support for IDEX. [Edit] I should say 4 independent Z motors and have mechanical gantry leveling.

I like that idea. With a more or less stationary bed that should even allow for true ABL where the bed is leveled to the nozzle. Of course, that needs an expansion board.
I like the idea of multiple motors but they'd have to be synced with a belt to avoid slight discrepancies during homing unless each motor had an endstop.
So, looking at it this way, the board requirements now are:
Dual X, a Y, a Z, three leveling motors and two extruders = 9 stepper ports. That means that a Duex 5 or similar is needed.


"That means that a Duex 5 or similar is needed." not true. Klipper is running on Raspberry Pi and may control multiple 8 bit boards. So my setup for 4 Z motors is: Rapsberry Pi +2 Ramps 1.4 boards what gives access to 10 stepper drivers without any expansion boards. Klipper itself is 32 bit application so all calculations of motor movements are 32 bit. It sends simple 8bit commands to MCUs (Ramps 1.4 or similar) to drive stepper drivers. So no need for 32 bit boards, even so, it can work with 32 bit boards. ABL is already implemented in Klipper and also dual or quad Z endstop configurations. So you will get this out of the box. If 10 steppers are not enough, connect one more Ramps 1.4 and you will have 15 steppers. Also instead of running Klipper on Raspberry Pi, you may run it on any computer/laptop with compatible Linux and USB ports.

Like that a lot. Theoretically by using 2 ramps boards connected to an Odroid XU4 you could have slicing built into the machine, though it would be slow.
And, of course, it's about half the price.

I like that idea. With a more or less stationary bed that should even allow for true ABL where the bed is leveled to the nozzle. Of course, that needs an expansion board.
I like the idea of multiple motors but they'd have to be synced with a belt to avoid slight discrepancies during homing unless each motor had an endstop.
So, looking at it this way, the board requirements now are:
Dual X, a Y, a Z, three leveling motors and two extruders = 9 stepper ports. That means that a Duex 5 or similar is needed.


getting all of that square is going to be a challenge. You may be better off with only 4 beefy leadscrews. Stratasys uses two NEMA 34 steppers and 4 leadscrews on their (very heavy) build platforms.

You'll need a pretty powerful stepper motor to handle that, but, they are available, so it could work.

Heated bed with a PT100 sensor and a LERDGE "K" control board would be a good start. LERDGE supports TP100 as a standard plug and play including auto calibrating the PT100.
I use a mirror glass of 3 mm (with real metal coating) on an aluminum bed 310x310x4, with no need for auto leveling. The build is within 0.05mm flat and leveled and stays that way.
A large bed of 1000x1000 mm would ask for quite some thickness. To keep such a plate flat please think about quality type AW 5083 (or similar for North America), it comes milled or grinded with flatness <0.05mm. Just regular warm/cold rolled aluminum will keep on deforming a LOT when heated up and cooled down again. (will not work)
I have designed heated bed plates of 1200mm in diameter, with sandwiched in between two long hot runners imbedded with copper paste for contact purposes. (my application 120 dgr Celsius) The AW 5083 material stays flat under all conditions if well isolated and enclosed. (For even cooling down and heating up)
If you like to go cheap on this huge heated bed design, and think all flatness problems will be solved with auto-leveling, ….. a disaster is guaranteed.
The XYZ movements/mechanic design is simple and quite standard. (THK linear guides (or similar quality) with "Caged balls" are recommended)
I added a 1200 mm sandwiched hotplate design from 2011 I believe it was.
Good luck

Your bed will need mains power. No way you'll want to try to find a PSU for that. Going to be very tricky to get any reliable thermistor readings from that bed. Once you get that big, RepRap style heated beds might not be the way to go.

You can buy glass in any size. Mirrored glass will be stronger than regular glass. You may be able to find x-strength glass which is also typically thicker.

Going to be nearly impossible to do CoreXY with IDEX. But if you have that all figured out, would be cool to hear your solution.

Both Smoothie and Duet controllers can handle IDEX and CoreXY. Not sure about both.

For a heated bed that large, you might want to get a big plate and stick 4 of the 120/240VAC silicone heaters to the bottom, with a solid state relay to control them.
No matter what you're going to be using a ton of power, since energy in = energy out, but at least that way you don't have to worry about converting that amount of wall power to 12/24VDC before it gets spent.

If you're going with a glass surface, it might not be a terrible idea to have an aluminium (or copper) plate sandwiched in the middle to help keep the heat spread evenly, too, though you'd have to be careful the different thermal expansion doesn't crack the glass if it's attached too tightly.

Another thing to consider, stepper drivers do have a maximum step frequency. If your microstepping is too high it might take a long time for the print head to move that distance, regardless of what the motors can handle.