Compact printer ideas?

I am interested in exploring the idea of making a reprap with compact overall dimensions - that is capable of making builds that are a large proportion of the printer volume (or even larger than the printer volume). My Prusa i2 is about twice the size in all dimensions as the models it can make. Deltas are good for a small footprint but are very tall. Folding repraps are a reasonable idea for portability. GUS Simpson looks promising and could probably be modified to give a more compact parked position.

What I am considering is something that starts out short (vertically) and grows in height as the print progresses. When parked - I'd like the printer to be tiny. Of course I don't want to compromise on all the usual performance metrics - cost, speed, accuracy, reliability, reprapability(?).

Any pearls of wisdom?

This design has a huge working volume compared to its footprint. Traditional designs will always be limited to shorter motion than the length of the rails. We have to think outside the box for this one. Unfortunately out of the box thinking usually comes at an initial cost. Compromises will have to be made until you can refine these experimental designs.

BTW, GUS can fit in a 450mm circle and can print larger than a 225mm circle. (I think some of the deltas can do better for sure. The plus here is that it isn't crazy tall.)

Is there any reason in particular that you'd need this? I could maybe see it coming in handy for travel or something like that, but other than that it's not like there is a regular difficulty finding a place to store something only a few cubic feet in volume. It's like how although I would hate having on old 20" thick tube TV, I really don't care whether or not my TV is 3" thick or 1/2" thick, as long as the screen (analagous to build volume?) is an okay size.

Although even if it's not practical, I'm very intrigued. Portability would be very cool. I think finding a way to drive linear axis from motors under the bed would be cool, rather than the three arm printers. Just an opinion...let me know if you find anything more!

The printable version of Tantillus by default has a build area of 100x100mm and the case is 200x200mm. That means the mechanics only take up 100mm and since the case is expandable it can have a build area of 200x200mm but the outside would only be 300x300mm. Have a look at Goopyplastic's T-slot variant or Ingentis which are both based on Tantillus and can be made any size.

Edited 1 time(s). Last edit at 01/11/2014 12:38AM by Sublime.

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The Scara looks awesome but it would certainly be a challenge to make with printed parts.

I like the Tantillus concept. Having the build bed moving vertically makes a lot more sense to me than moving it horizontally. If the bed moves in the Y direction the printer will always be at least twice as long in that direction than the Y print length.

There are two main reasons I am interested in a compact machine - 1 for portability and 2 for more options on where to put it when using it. Another good feature for portability would be having a machine that is well protected within a frame or case so it doesn't get damaged in transit.

As far as compactness for home use goes a 300 x 300 printer that can build 200 x 200 would sit on a bookshelf rather than needing to sit on a workbench. I doubt that I am alone with the problem of having too much stuff and not enough space. Even if I were to shift my printer from the house out to the workshop, it would still be a plus to have it compact, because my workshop is a real multi-purpose space and the only way I could keep a 3D printer there was inside a sealed cabinet to protect it from swarf, grinding, welding, wood shavings and sawdust. A compact printer = smaller sealed cabinet requried + less shelf/bench area occupied.

I have also been thinking of a way to eliminate Z axis steppers by using X or Y axis travel to drive a simple ratchet to increment Z axes travel each layer (either using X or Y travel beyond normal limits to actuate it or using a solenoid to clamp Z axis actuation linkage onto the X or Y). Setting Z layer thickness would be a manual process and it would be necessary to devise some way to more quickly zero the Z axis. It has always seemed inefficient to me to have 2 stepper motors driving a Z axis when there are ways it could be done with one or none.

A polar printer like PiMaker is another interesting idea for a compact printer, although I'd be tempted to make it with just one tower - cantilevering the X-axis (or should that be the radial axis?). I can see no reason for the radial axis to need to extend beyond the centre of the turntable. It might be tricky to print things fast near the centre but with careful design it should be possible to fit all hardware within a square of sides equal to the turntable diameter.

Depends how far "out there" you'd like to go for compactness.
If you know coaxially drivan Scara layouts, like the Reprap Morgan, the head can reach everywhere in a 360 degree area except near/over the origin. Sort of doughnut shaped. This limits the useful area to one side of the scara. (unless you happen to be building doughnuts ). However, the sketch below shows a mod that removes that restriction

Scara360 mechanism
This is still coaxially driven through the origin, but it can move the head over the pivot axis to get full coverage.
The idea here is that it would print on the underside of a box lid, and raise the box as the layers progress.
The box would also provide some protection in your workshop.

Apologies for the crude sketch - you'd want finger hinges or something much stiffer than what I've drawn, and proper clearances etc.
I don't know offhand that anyone has attempted a build quite like this, so there's a chance you'd be breaking new ground.

Seen this?
[blog.polarworks.no]
It's a bit difficulte to se the whole printer, but I have seen it live. :-)
Really tiny footprint compared to build envelop....

Cant really think of a good way to do it but when I was a kid I ran a CNC punch press. The X axis was limitless because it would reposition the holding fingers on the sheet so maybe some way of repositioning the print????Of course it would need to be supported as it moved away from the work envelope