Originally shared by Nicholas Seward Brandon Heller  got me thinking about making a backpack

Originally shared by Nicholas Seward

@Brandon_Heller got me thinking about making a backpack printer. The foldable printers are neat but I thought it would be better if the printer just WAS thin. I got a little carried away with the mock up. It is nearly complete. The shortest collapsed dimension is 72mm. The other dimensions are similar to a fullsized laptop and will most definitely fit in my backpack.

The Z is the main attraction. There are 4 scissor lifts that are coordinated by a loop of string and are actuated by a NEMA14 with TR5*2 lead screw. I did the math and even in the worst position there is still 5lbf on tap for pushing the XY stage up. Assuming I can get the hot end to zero out when the printer is fully collapsed there shouldn’t be a problem with the firmware.

The XY is a CoreXY arrangement.

The bowden tube and the string for the XY aren’t pictured.

I would like some ideas on…

How to make the exterior smoother and slimmer?
How to deal with the bowden tube during transport? (I have thought about allowing the hot end to fold down or allowing the tube to be removed.)
How to level the bed/top?
How to zero the Z?

For a design like this that is basically Cartesian and supported by common firmware would auto leveling work? I would imagine if you get things close so your not chasing a 20° angle it wouldn’t be bad. I like the idea of aluminum plate and homing through the nozzle with a firmware based offset. Otherwise a simple plate with thumb screws would be easiest I would think.

Want people to built it?

I agree with the auto-leveling, as long as there isnt much slack/ stretch in the z axis. BTW, I love your designs and you continue to impress me. Do you have any sugestions on how to get started writing the kinematics for these amazing designs?

This is clearly a much better thought out design than this gem was… https://www.kickstarter.com/projects/japica/japicain-revolution-changing-the-way-you-print-in?ref=users

Very cool design! Automatic bed compensation (I refuse to call it “leveling”! :-)) won’t work unless the scissor action is perfectly consistent, but I guess that would be critical no matter how you slice it.

hahahahaha slice it

Nice thinking!!!