New build few questions

[zotiri]

hello everyone (sorry for my english)
after i got my first printer i noticed that i love building and designing more than printing
so i decided to build a printer with an independent x axis then i realized that with duet wifi and duex5 i can control 4 x axis so i decided to build a printer with 4 independent x axis and 4 independent nozzle.
it will be a cube printer and the x and y axis will travel on mgn12 rails. - i ordered the rails and cariage already
z axis motors will move sfu1204 ball screws and for support i will use 4x sbr12 rails and cariage on corners.
i will use 500w 24v meanwell power supply and heated bed will be 220v ac and controled by an independent controler
i have not ordered most of the parts because of my lack of experiance and knowladge.
1- i will use double z and double y motors wired in serial i want to use long nema17 motors for that i have two choices 0.6 amp and 1.6 amp each both produce 73nm.cm torque , which one should i buy ? which are better for duet board ?
2- which build is better ? Moving bed on Z axis or totally stable bed ( at stable bed build whole rail will be mounted to Z ball rods so all extruders will be move on Z axis)
build plate will be at least 60x60cm glass only.
3- 2 Z rods driven by 2 motors directly or 4 rods driven by 2 motors directyand 2 will driven by belt all of them by belts ?
thank you for your thoughts and answers

[strips]

Just trying to visualise all the stepper drivers needed…

• 1 - X0

• 2 - X1

• 3 - X2

• 4 - X3

• 5 - Y0 Y1

• 6 - Z1 Z1

• 7 - E0

• 8 - E1

• 9 - E2

• 10 - E3

…. that's a long list.

For point 2 I would use a movable bed (Z). Just so I do not have to think about wiring and filament feeding for 4 separate extruders moving up and down as well.

[dc42]

A few comments on your design:

• If the bed is AC mains, you don't need anything like a 500W PSU. 300W should be plenty. I guess 500W might handle power off/resume a little better by providing additional reserve power to move the head away from the print when power is lost.
• The 1.6A motors will be much more suitable than the 0.6A ones. 2A or 2.4A would be even better.
• When using multiple Z motors, it's best to connect them to separate drivers so you can do auto levelling to keep them in sync. You can do this if you use an external driver for one of the extruders.
• It's probably better to use aluminium tooling plate for the bed support, to ensure flatness. Although I normally put glass on top of the bed plate so that I can remove it, a 60x60cm piece of glass won't be easy to handle and won't fit in the fridge or freezer to help with print removal. So you may be better off using PEI or polycarbonate glued directly to the bed plate. Or use Kapton tape.

[zotiri]

@dc42:

A few comments on your design:

• If the bed is AC mains, you don't need anything like a 500W PSU. 300W should be plenty. I guess 500W might handle power off/resume a little better by providing additional reserve power to move the head away from the print when power is lost.
• The 1.6A motors will be much more suitable than the 0.6A ones. 2A or 2.4A would be even better.
• When using multiple Z motors, it's best to connect them to separate drivers so you can do auto levelling to keep them in sync. You can do this if you use an external driver for one of the extruders.
• It's probably better to use aluminium tooling plate for the bed support, to ensure flatness. Although I normally put glass on top of the bed plate so that I can remove it, a 60x60cm piece of glass won't be easy to handle and won't fit in the fridge or freezer to help with print removal. So you may be better off using PEI or polycarbonate glued directly to the bed plate. Or use Kapton tape.

At duet wifi there is two Z axis connection in serial right ? can i use them ?
i dont know how to use external driver and what about y axis should i use external driver for y axis too ?

[FrankNPrinter]

you can use the 2 z serial ports but there is an issue with them coming out of sync during power on \ off so your bed can get crooked. recommend you tie the z gears together or only use 1 z motor or as mentioned above, dont use serial port for 2nd z motor so you will be able to use dual sensor homing. tons of stuff in the forum on that

[Whitewolf]

Hi Zortiri,

Personally I am a fan of fixed build plates, there are a number of good designs where the build plate doesnt move most only use a single X. But have you checked out the multi head printer from Titan Robotics which uses 4 independant x carriages… also project Escher where the Titan concept was born. It can give you some good ideas

A company by the name of mechaduino also has a video up on youtube of a printer with a stationary build plate that i intend to build one of these days... they do not have it up on their website and charge way too much for what looks like an easy to build design on a buget (emailed them they want like $2500)

[zotiri]

@FrankNPrinter:

you can use the 2 z serial ports but there is an issue with them coming out of sync during power on \ off so your bed can get crooked. recommend you tie the z gears together or only use 1 z motor or as mentioned above, dont use serial port for 2nd z motor so you will be able to use dual sensor homing. tons of stuff in the forum on that

" recommend you tie the z gears together " does it mean 2 motors with 2 rods tied with belt or 1 motor 2 rods tied with belt ?

[FrankNPrinter]

tied = all z azis move together in direct drive. more motors on separate ports give you more power but with more than 1, can get out of sync. As it was explained to be by the Man here (props to dc42!) "when powered u,p steppers move to the closest full step. it is entirely possible for 1 motor to go up and the other down". Bigger the bed, more likely it can be tilted by this even just on power on \ off)… hence the dual z end stop solution or IMHO direct drive for all z axis (single belt to all lead screws is my plan BTW) currently running dual z motors in serial and not crazy about performance issues as mentioned above.

[zotiri]

thanks for your help.
i decided to use one motor and 2 rods for y axis i will use double shaft

[FrankNPrinter]

no problem, in truth, i think i enjoyed the building phase more myself LOL I would be curious to see what it looks like when you get it done so plz post a pic some time.