OK, I'm still trying to configure and optimize the MakerBot Cupcake I have;

OK, I’m still trying to configure and optimize the MakerBot Cupcake I have; it’s a basic version, DC extruder controlled by PWM, I choose usually a 0.4 mm layer, I set 220 PWM for extruder, I need enough precision with enough speed, so I decreased feed rate to 28 mm/sec; now I have a problem about measures : if I build a rectangular cave box, to do a piece of square tube, I can see the external measures are right enough (1/10 mm about) but not the internal, I have about 9.2 instead of 10.0 mm, I cant understand why and what O might do to fix it.Please send me any suggestion.Regards

I’m surprised you are getting that close to 10mm. Cupcake is antique. The design is just awful. If you need sub-mm precision you should get a new printer.

Oh yes, I’m going to build a prusa with a my friend, but I need to investigate more deeply on all Skeinforge (or other slicing engine) settings…

yeah, you need to get up to date :slight_smile: No one is using Skeinforge anymore. Look at Slic3r or Cura.

You need to move to a stepper extruder. Those old DC extruders are crap and don’t work reliably at a reduced duty cycle (255 or nothing). Other than old versions of skeinforge, you’re not likely to find slicer support for them either.

@Dario_Marrini There are still some of us out here printing on our , often heavily modified, Cupcakes. I agree that you really need a stepper extruder and go ahead and upgrade your electronics to something modern ( like a Printrboard ) and your printing life will be MUCH easier, and much more precise, not to mention quieter.

I am printing at speeds up to ~150mm/sec (usually only around 45-60 in reality) and can print down to 0.15mm layer thickness, on my cupcake.

If you are planning on using it for a while, I would also recommend upgrading the Z-axis with a Cantilever style, it will take care of any wobble you may be having.

many thanks for your helpes, at this point I need more knowledge about stepper extruder, that cantilever style and so on; about electronics, I wish to use real Arduino board + dedicated shields, I’ve bought a set for the birthing Prusa, Arduino Mega 2560 + RAMPS1.4 + stepper drivers; I hope this will be a correct way; if you wish to give me additional and deeper infos, I’ll appreciate that very much.

A Ramps 1.4 is a fine board. It’s hard to give you additional info without knowing what kind of info you need.

You’re right, I’ll make my mind a little clear, and then I’ll proceed for asking… no doubt about :slight_smile: