Portabee Portable 3D printer which can be packed into a laptop bag

hi folks,

we have this new 3d printer called portabee. just to share with those who would like to carry printers around.
[romscraj.com]

do let us know if you have any idea that may spice up this little printer. we are preparing the assembly instructions and will complete soon.

Seems pretty cool, but where do you put the filament when you have the printer stuffed in your laptop bag? And what is your heated bed made out of? Is that a huge piece of FR4??!?

I feel like it needs some kind of solid outer casing or rounded corners at least. Those bolts sticking out are going to make it very difficult to carry around in a laptop bag. I mean yea, my laptop bag has padding, but I feel like it won't be enough... With the electronics exposed like that I worry about just jamming this in my bag and shoving my way through pedestrians...

But, uh, good luck I guess.

it depends how much filament you carry.. . for the electronics, a casing can be useful for folks who are worried about pins bending. we have tried putting the unit inside a 14 inch laptop bag and it feels cosy enough to carry it.

and yes.. the FR4 is the heated bed with rounded corners. there is some insulation underneath. cork sheet basically.

Edited 1 time(s). Last edit at 05/29/2012 02:08PM by romscraj.

How do you keep it flat? The Prusa PCB bed rises in the middle when it gets hot.

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[www.hydraraptor.blogspot.com]

the prusa pcb seems to have a 100% filled copper trace on one side. we balanced out the traces on both sides by filling the non heated side with a mesh pattern. so it seemed to balanced out.

romscraj Wrote:
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> the prusa pcb seems to have a 100% filled copper
> trace on one side. we balanced out the traces on
> both sides by filling the non heated side with a
> mesh pattern. so it seemed to balanced out.

Can you release that revised design to the community?, it sounds useful, many thanks - can you point us to the files.

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[richrap.blogspot.com]

I bought one of these PCB's yesterday.
It looks roughly double the thickness of the PCB heated beds I saw before and it indeed has a copper mesh pattern on the top instead of solid copper. Will do some tests on it soon and post my findings here.

btw, have seen the portabee in action and must say that I am pretty impressed. When I saw the pictures on the website, I thought stability might be an issue. I was surprised to see how stable it is and how accurate it's printing. Very clever design.

Don't try shoving pedestrians with it I would be very carefull carrying it around, but it is portable, and rigid enough still to print.
It would be interesting though to have some sort of hard cover case/ protection for it, power tool style. That would really make it portable..

KP, you should really put some video online of the printer in action! And of the assembly/disassembly process

What license are you releasing the printer under? I think it would be great for the community if you shared the design of the printer and would definately benefit reprap.

Cheers,
Wauter

Wauter Wrote:
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> What license are you releasing the printer under?
> I think it would be great for the community if you
> shared the design of the printer and would
> definately benefit reprap.
>
> Cheers,
> Wauter

I didn't get an answer to the heated bed source files either from romscraj, any chance of a reply romscraj? We will take more interest if you state how you intend to develop products for this community and/or if you plan to release source files etc.

2.4mm PCB material is quite common now and not too expensive, I do like the idea of it also being the Y axis, something I have been meaning to do with a Printrbot for a while.

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[richrap.blogspot.com]

hi richrap,

everything is open source. GPL badayada.
the heated bed has nothing much changed from the original prusa's except some connectors moved to facilitate our own durbie.

i think we uploaded the v1 on [github.com]
and will update it if anyone is interested.

the difference is the mesh pattern on the other side (not the heating element) and we used 3mm thick PCB.

wauter
as for the printer, we shared it before.
[github.com]

for the latest released files, we will put it up at
[github.com]

i would hope to take some videos of them (portabees) working tirelessly for us, but i despised my phone's video quality. shall wait for a better camera or something. let me know if you know someone with eos 5d mark III and is nearby.. :>

KP

Thank you KP, that's great, thanks for the links and info, it's a nice design and it would be great to see some Portabees popping up.

Cheers,

Rich.

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[richrap.blogspot.com]

nophead Wrote:
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> How do you keep it flat? The Prusa PCB bed rises
> in the middle when it gets hot.

I've tested the heated bed for the durbee yesterday, which is actually bigger than the one for the portabee and it is square, but i understand the principle is the same. Here are the results:

Mounted and levelled the bed on 4 screws and hooked it up to my prusa's Ramp 1.4 electronics.
The resistive side of the bed is at the bottom.

Setup

I used a ruler, a bit of string and calyphers to measure the flatness, so don't except this to be too accurate.

As far as I can tell, in rest, the bed is flat.

About 20 seconds after turning on the heat (12-13V over a 1R resistance) the middle of the bed sunk a bit.
Using a bit of rope, stuffing a bit of paper underneath and measuring that with calyphers, I gathered that the depression should be about 0.3mm.

About 10 seconds after taking off the heat the bed goes back to being really flat. This does not appear to be affected by the overall temperature of the bed. The depression is the same at room temperature as at 110 degrees. Also, at that temperature, after turning of the heater, the bed is flat.

not heating the bed
heating the bed

Also repeated the test with insulation below the bed (kitchen hood filter) and kapton tape on top, but this doesn't seem to make much of a difference.

With a simple on-off temperature control, it seems that with this durbee bed, it would be better to print on glass, as 0.3 mm movement every time the heater is turned on or off is quite a bit.

Perhaps with pid control of the heated bed and good insulation, this effect will be less of an issue.

It would be interesting if someone could test the actual portabee bed as well.

It seems a step backwards because the with solid copper on the top it presses against the glass. Without the solid layer the bottom will expand more than the the top because it is hotter, so it domes downwards away from the glass giving a poor thermal contact.

Perhaps you can mount it upside down under glass.

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[www.hydraraptor.blogspot.com]

Have already mounted it with the heater at the bottom, but might try to mount it upside down later.

Hello All,
This is my first post here, I am a design engineer and have been involved in high tech mechanical product design for many years, the simple way of preventing warpage in this kind of heated bed is to put the element in the centre of the board not on one side.

So assuming you are using standard copper faced glass fibre reinforced pcb material, simply make two boards mirror reversed, and bond them together, with a sheet of heat conductive but electrically non conductive material between them, this material will be able to withstand the highest heat anticipated, link the two elements together so that they both add heat, by having the copper protected from the atmosphere the element life will be extended, the element "runs" should be placed diagonally on the element and the runs on the top sheet should be at 90 degrees to those on the bottom sheet,
In this way the expansion forces will be exactly countered by the compression stresses in each reinforced fibreglass sheet, preventing warpage.

Best Regards
Rick

All my printers now just use the Prusa V2, I use the middle hole (usually where you place the thermistor) as another mechanical connection to keep the board flat. IT works really well, you just need to countersink with middle hole a little (be careful of the tracking) and use a countersunk M3 screw.

Use M3 metal PCB stand-off's in all corners and the middle, and you have a nice and flat PCB ready for your glass printing surface.

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[richrap.blogspot.com]

You should post it on thingiverse and link to your site where folks can buy it

Cool design! Perhaps the electronics could be encased in a printed case (not attached to the printer) and with some cleaver wire work, a single plug could be the interface between the electronics and the printer

Amazing work on this build manual! You are under selling what a great job you have done!

This printer is not just portable, it's really well designed! A Bowden derivative of your x-axis should be applied to the Huxley Pro and then made official!

[cloud.github.com]

Build manual link

What is the actual hot end on there, and what is the Bill of Materials for the extruder and hot-end

What a cool design for a printer!,

It looks so simple, yet so effective!

Does she ever act like she is going to fall down? Maybe some feet or legs could fold out to give support n the Y axis to stop her from toppling over?

I like what I see very Much! It makes me think of all the good features in a Huxley and Printr Bot plus some great ideas to make it portable.

Have you considered adding two printed brackets and a bar at the top to make the Z bars ridgid? Granted the machine is pretty small and might not need it; but maybe it could act as a handle and add strength at the same time. Besides, I think you design could be used to make a LARGE AND PORTABLE RepRap... Which is unheard of!

How long to you think the bars could be extended before they start to bend? You are using m8 rods on the X-axis (like prusa) , so I would think ithe x-axis could be extended as wide as a Prusa?

How hard is it to change rod sizes on your design? Will you be releasing a scad version with changeable rod diameters?

You made a vertical x-carriage; you made a rare breed My Huxley Pro has a vertical x-carriage. Huxley uses a 6mm smooth rod for its x carriage; but a modified Huxley carriage, or moddified Printerbee (6mm x bars) would mean you could mount Adrian Bowyer's current Hexley Bowden carriage which requires a Vert X-Axis... I am probably going to attempt something likie this in a derivative of your design.

Do you think that the current Y motor setup would have the strength to push around a Prusa MK2 heated bed with glass on top? If not, I will have to redesign the motor carriages to hold bigger badder stepper motors.

Thanks for the Great Design and nifty instructions! Looking forward to seeing your instructions finished!

Idolcrasher Wrote:
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> What is the actual hot end on there, and what is
> the Bill of Materials for the extruder and hot-end

We're in the midst of updating the newer files for the hot end, but it is very similar to the older one that can be found in this assembly manual (with BOM list an part drawings - refer to Part 1 in the manual).

(High Res 7MB ) [github.com]
(Low Res 2.4MB ) [github.com]

Other hot ends may be used, and shouldn't be too difficult to be integrated into the extruder-block. Aside from modifying the extruder-block part itself, a bracket that replaces the 'slidemount plate' can be designed and printed to hold other hot ends (eg a PTFE barrel based design). There is a gap under the 'arch' of the extruder-block that allows different couplings and holders to be incorporated if desired.

Other extruders however may not fit onto the Portabee unless modifications are done to the Portabee's x-plate (or the extruder itself).

Which Wades extruder in particular does the Porabee carry? There are so many derivatives. Could I bother you for a thingiverse link?

Idolcrasher Wrote:
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> Which Wades extruder in particular does the
> Porabee carry? There are so many derivatives.
> Could I bother you for a thingiverse link?

The files are here, including the sketchup .skp design files [github.com]

We named the older version 'Wade V2', but the extruder block design had to be modified a little to incorporate into the portabee carriage (raising the motor and at the same time making the rear extruder mounting bolt accessible without having to remove the motor). The idler uses an M4x15 set screw and zipties to do away with the glue but can easily be hacked to use the older design M4x20 bolt with some minor filing / Dremel work. In all it's mostly the same, but we decided to name it 'romscraj extruder' as the design is already quite far off from the original wade (while crediting Wade and Adrian as design inspirations for the work).

Fantastic. Can't wait to try mine.

What are the folded dimensions?

jason.fisher Wrote:
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> What are the folded dimensions?

Including all protrusions (of the bolts and rods) the maximum dimensions are:
365mm W x 290mm H x 103mm D

In practice it will fit into a padded laptop bag, as the bag will accommodate the 'protrusions' so to speak. We have tried it before using a 14" laptop bag (a 'free gift' bundled kind that came with a 14" Acer brand laptop) and it can be zipped up, though it was with a little squeeze with the z smooth rods. The width and depth was alright.

The bag has to be the 'regular' fabric type (with padding of course), and a larger size would be better, we think a 17" bag should be a more comfortable fit. Additional internal padding eg silicone sponge or a suitable thickness polyethylene foam sheet will provide shock protection. If using the hardshell/hardcase kind, the max dimensions have to be taken into consideration as these cases have no 'give'.

For those who have been waiting, we have completed the assembly instructions for the Portabee and Romscraj Extruder.

Builders can access them here:

Portabee: [github.com]
Assembly Instructions in High Res, PDF (25.5MB )
Assembly Instructions in Medium Res, PDF (16.9MB )
Assembly Instructions in Low Res, PDF (6.5MB )

Romscraj Extruder: [github.com]
Assembly Instructions in High Res, PDF (6.2MB )
Assembly Instructions in Low Res, PDF (1.9MB )

Idolcrasher Wrote:
-------------------------------------------------------
> What a cool design for a printer!,
>
> It looks so simple, yet so effective!
>
> Does she ever act like she is going to fall down?
> Maybe some feet or legs could fold out to give
> support n the Y axis to stop her from toppling
> over?

You are correct, one of the design compromises we made in order to make the Portabee easily flat-packable (to an extent) and do so repeatably with as little hassle as possible was that the entire Y axis had to sit on the base rods, and as a result the stability is fully dependent on the stiffness of those rods. We opted for M6 for the base rods just so that there will be only one threaded rod requirement for the printer (z 'leadscrews' are M6 as well). With larger diameter rods the stability will improve.

Stability wise during use, we find that it is not a big problem unless the printer gets bumped or knocked over. Maybe much like a vase sitting there doing just fine until something bad happens (baseball, jumping cat, nunchuck etc). The base is heavier than the x axis (3 motors on the base vs 2 on the x axis) but yes, more stability is always a good thing.

We have tested a 'Y-brace' mod and it works pretty well. Basically this mod allows two printed removable braces to be attached to the (modified) y bearing holders, supporting them directly. The printer can still be taken apart fairly easily for packing if this is not made permanent - there is an option to permanently bolt the braces if the printer is not intended to be moved around, at least in its 'flat-packed' form.

I've attached a photo, and the files can be found here (look in the 'y-brace-mod' folder). Two parts need to be changed (both y bearing holders) and 2x y-brace parts need to be printed for this mod. Oh and some M3 bolts, nuts and washers for the adjustable feet and if you want it to be bolted permanently.

> I like what I see very Much! It makes me think of
> all the good features in a Huxley and Printr Bot
> plus some great ideas to make it portable.
>
> Have you considered adding two printed brackets
> and a bar at the top to make the Z bars ridgid?
> Granted the machine is pretty small and might not
> need it; but maybe it could act as a handle and
> add strength at the same time. Besides, I think
> you design could be used to make a LARGE AND
> PORTABLE RepRap... Which is unheard of!
>
> How long to you think the bars could be extended
> before they start to bend? You are using m8 rods
> on the X-axis (like prusa) , so I would think ithe
> x-axis could be extended as wide as a Prusa?

The M6 rods on the base are already stretching the limits of 'stiffness' of the y axis. We designed the Portabee with one main goal: a conveniently portable 3D printer. Not to say that it cannot be expanded, but that wasn't part of the design process, and as such we went ahead with the M6 base rods. With the y brace mod this may be improved, but overall stability might be affected. Not all is lost however, the holes on the base parts can be modified to take M8 or better still M10 or M12 rods. The y axis parts need to be modified as well, but this shouldn't be too difficult. We will work on this in the near future and give more options to the Portabee design. Open source hardware means that others can do this mod themselves, and it wouldn't be surprised if someone could come up with better design changes than us, given the large number of smart and ingenious designs the RepRap community has come up with!

> How hard is it to change rod sizes on your design?
> Will you be releasing a scad version with
> changeable rod diameters?

Design files are in sketchup .skp format. Our 'designer' is very comfortable designing in sketchup, so that's what he sticks with. He finds OpenSCAD painfully non-intuitive and gives him more headaches, which is a very sad thing, as this appears to be the CAD platform of choice in the RepRap community. Maybe he can change his mind in future. To someone who is familiar with sketchup, this should not be too difficult, but still needs work. Definitely not as straightforward as compared to changing parameters in a parametric OpenSCAD design. Maybe the OpenSCAD experts could redo/(import?) the design and make a parametric version, that would really be awesome!

Edited 1 time(s). Last edit at 07/11/2012 06:41AM by romscraj.

Love the "optional" support feet

Thanks so much for releasing the support foot mod.

I definitely want to try build a large one of these with a full Prusa Bed.

I love the idea of the base supporting 10mm rods to accommodate a bigger printer. I might have to give google skethchup a crack after all

Hopping you guys beat me to the punch, and release a version with larger holes