General

Hi
I am in the planning stages of a potential large format 3D Printer build, and want some input. I am considering what the best budget option for the linear slides/ rails is. Currently, here are my options, and the pros/cons:

Aluminum t slot with v bearings: more expensive, possibly higher accuracy
Aluminum square tubing with 3d printed bearing blocks that clamp 608 skateboard bearings to all sides
EMT conduit with 608 bearings like the MPCNC
12mm metal rods with linear bearings
Supported linear rail with bearings

What are your thoughts?

I plan to build the machine in a gantry style that takes design aspects from cnc machines that have a stationary bed. I hope to eventually equip it with a E3D Volcano or Supervolcano hotend, and a diy Pellet extruder for recycling old prints, and printing with cheap pellets. As for a heated bed, I will likely be using multiple smaller heated beds tied together and powered through some relays. I am also considering having dual control boards with a multiplexer/ demultiplexer circuit to switch the stepper and endstop wiring between control boards. This would enable me to run a 32 bit control board for 3d printing, and have the option to switch control over to an arduino uno with a GRBL shield for cnc milling and laser cutting. I have never seen anyone do a dual control board setup before. This is the best way I know of to achieve the dual function, other than building a custom PCB, or switching firmware for different uses. Please let me know if you are aware of a better way of doing this. For now, I am working with a budget of $500 USD to get a working printer with the volcano hodtnd, and adding on features as I go.

Any ideas are appreciated as always

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!

The robot that i want to configure it this one: https://www.thingiverse.com/thing:4010129
But in scara orientation, where the linear axis is vertical and both arms move horizontally.

My questions are as follows:

Is it possible to:

-configure a robot other than MPScara or Morgan-Scara with marlins default config files?
-use a scara with non equal arm lengths?
-having both arm segments home in a position where they are parallel/180° towards each other?
-set up everything in the config, scara.h and scara.cpp files without the need for Gcode commands?

And are all settings related to scara dimensions and kinematics contained only in scara.cpp?

I would be glad if someone can help me.

Has anyone used the TMC2209 Stepper drivers in UART mode on an MKS 1.4? I want to upgrade my drivers but I'm looking for a little help using the UART mode on the driver. The firmware part I can handle no problem, I just want make sure they're wired correctly for UART.

I have set up Marlin, plugged in a stepper motor into the 'X' slot, plugged in the 'X' endstop, and yet when I run Pronterface I am getting no movement. I am not sure what is wrong. Thanks in advance for your help!

P.S.: I am using 28BYJ-48 motors

Hi. My thermistor was showing wrong temperature about 20-25 degree less compared to the new one. They are basic glass 100k thermistors in J-head v5 clone with standard 40W 12V 4ohm ceramic heater Cartridge. I thought that would be great to change the heating Cartridge too bcs i used it maybe 500-700 hours :v. Swapped both of them and now extruder can't even reach 220C.. The old one heated perfectly to 230C while printer was self leveling. The new one is heating about 5 minutes to unstable 200C... I did PID tuning in pronterface the first one with 230C and 10 Cycles ended up with timeout error. The second one with 180C and 8 Cycles ended with 5 Times higher PID values compared to the old heater. On new PID settings and after restart printer still can't reach 230C. Running on the newest marlin and arduino. Its my own custom 3d printer. Fan is blowing on fins exactly one fin above Heat Block. Never needed any silicon sock or other stuff. Cartridge and thermistor is secured with screw and Red titanium high temperature silicone. Cables are tight and undamaged. Any ideas?

I am plugging the pi in to the type B USB port and i keep getting the following error:

Error: Failed to autodetect serial port, please set it manually.

The pi is fine, it worked onthe previous melzi board, but now it wont connect to the MKS board. Is there some setting I am missing here? Any help appreciated.

Just wanted to throw a thread here that made it apparent using the Simplifi3d - LulzbotTaz 3 settings for older model Lulzbot printers works well. The only things I had to do was set the platform dimension to the smaller size of the AO 101 and add a script to make sure the fan is running. I had been messing with these settings for awhile and finally broke down and bought Simplify3d. Man am glad I did because even though this is an old ass machine it works like a dream.

Has anyone ever worked with this expansion board?

https://everything-pi.myshopify.com/collections/3d-printing/products/3d-printer-a4988-drv8825-stepper-motor-control-extension-board-ramps-1-4

If so, can you share a picture of how you connected it to Ramps?