I'm in the middle of assembling my Prusa i3 and I have some doubts,

3D Printing
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1

I’m in the middle of assembling my Prusa i3 and I have some doubts, hope you guys can help me, thanks in advance.

How big must the power supply be? A 200W PC power supply would be enough?

I don’t seam to find anywhere the specification for the termistor needed for the heated bad. I went to the electronics store nearby and they had none matching the pictures I found for it.

Also, I’m 90% sure the step motor cables are too short. What’s the best way to make an extension without creating signal noise in the cable later?

2

I’ve built a prusa i3 recently and used a 360W transformer, although I opted for this high to be able to handle the heated be without trouble. If you want a heated bed I would definitely go higher than 200W.

I’m not sure what thermistor I used but if you go into marlin firmware settings there’s a list of about 11 preconfigured to work with marlin.

Just last week it started to change the length of my stepper cables and just soldered ends together and hand many successful prints and no noise with the signal.

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Thanks Brandon, I’ll check it out.

4

For the stepper extensions, as long as you’re soldering you should be OK noise-wise.

I like to cut each wire about a half-inch shorter, so that you have 4 wires of gradually increasing length - that way, when you solder none of the exposed sections will be able to touch even without heatshrink around each connection.

I also twist my stepper cables to try and cancel out the noise they make - it seems to help.