Model 3

JeffreyILipton - Posted on 09 November 2010

Hi everyone,

Im trying to work on Model 3 for Fab@Home. It will be a minor improvement over the model 2, kinda like snow leopard is to leopard designed to lower the cost, and allow for a wider range of vendors and parts. To that end I need to know what you think is important to improve. Please comment on what you would like to see in Model 3.

- Jeff

Hi Jeff,

Can't wait for the snow leopard to hit the road. You've got any idea how much time this might take?

The price is still the biggest challenge of the Fab@home concept. Great focus for Model 3.

Would it be possible to achieve same printing accuracy with a (not off the shelf) central steering unit and the cheaper DC motors?


Hi Jeff,

Thank you for asking.

My suggestions :

1) hardaware : plexiglass might be replaced by another stronger material especially for strategic part like belt tensioners.

2) Sofware : I would appreciate to set the parameters of the slicer myself, in Fabstudio (for example, the pitch between successive lines). Having control on the toolscript (slice height, for example) in Fabstudio could also be more convenient (rather than modyfing it in the script itself). In short, using Fabstudio to control all the parameters that drive the printer in 2D and 3D might be more convenient.

3) Could it be possible to engineer a z-motion on the bays themselves. This could be usefull to print small deposit like drops of material.

Thank you.


Thanks for the input. Is there anything about the build process you found difficult?

(_ Looks like the motor screws have been forgotten by the supplier)

The procedure : my colleague first found the videos, which were not exactly matching. I then found the procedure on wiki. I think both the video and instructions in wiki are welcome. All in all we found the mounting rather simple.

We have however some suggestions to improve clarity of instructions. We found the wiki website, workable, but improvable.
Espacially, instructions for the "basis" are lost somewhere:

while most of the instructions are here : http://www.fabathome.org/wiki/index.php/Fab@Home:_Model_2_Overview#Software

There is no need to recall the sub assemblies behind the link "final assembly", and again behind the link "Fab@Home:Model 2 Chassis". The link "basis" which is on the page "Fab@Home:Model 2 Chassis" should be placed behind the link "final assembly". All in all, I think the wiki site is a little confusing and we had to unbuild the printer several times (but obviously, it was clear enough since it works now).

I think most of your energy should be focused on the software (because the hardware is simply amazing in terms of efficiency/resolution/cost). It has been hard for us to understand the whole procedure. It is not clear that an STL file must be created to feed FabStudio. It is (still) not clear how the path is generated, unless we are familiar with the source code (we are not). If the Fab@home project is destined to be democratized, then I don't see any other way than to use software with graphical interface. I must say FabStudio is simply great. The counter part is that it does not handle the whole process. At least, suggestions of FREE softwares (sketchup + plug in ?) to create a stl file should appear on Fabathome.org or wiki.

In addition, as mentionned in previous post, why not implementing some control over the path parameters, in FabStudio itself, same for tool parameters (even if modifying the toolscript is not much a challenge, it is not convenient) ?

I don't see the rationnal of separating Fabstudio and Fabinterpreter.



Hi Bertrand. Lets start a seperate thread on improving the FabStudio software. FabStudio/Fabinterpreter are part of hte Fab@Home tool chain right now, but Model 3 is the chasis design, and noth the whole printer

The idea behind the project is modularity. FabInterpreter is specific the the Fab@home right now. We are developing code call Fab2Gcode which will allow for converting a FabFile to the G-code which can run a Reprap and Makerbot, or any other GCode based printer. In the end it will allow for projects to specialize.