Building a Prusa(Questions)

I am wanting to order Steppers from pololu
should i get these
[www.pololu.com]
or these
[www.pololu.com]

I'd go for the higher torque for the few extra $$ you'll end up not using the yellow and white wires.

thanks i appreciate the response, i have borrowed a friends makerbot and am almost done printing all the parts to make my prusa mendel i am really excited about building one.

In addition, the lower torque ones are NEMA14 and the others are NEMA17.

The RP parts are designed to take NEMA17 steppers so if you wanted to mount NEMA14s you would need to drill holes etc and generally muck about unneccesarily.

Don't know if the 2.7 voltage rating of the NEMA14s would also be a problem or not.

A few quick tips for your new Prusa build... if you are using printed bushings they need to be printed in PLA, when you assemble the machine,

either slide them on before installing the smooth bars or you may need to warm them up with a hair dryer so they don't break when you pop them on the bar.

I think the zip tie coupling are more forgiving and better than the default coupling, you'll need a zip tie gun to get a good amount of pressure on them though.

after you glue everything together, if there seems to be some play in the bushings, or they have too much friction, you can wanr them up with a hair dryer and move them back and forth or hold them to the bar to re-adjust.

Actually i bought Brass Bushings to use in my Prusa Build i just need to put them in the Holders
i got the STLS from here [www.thingiverse.com]
but the bushings do not slide into those holders well at all.
i do not know if i need to make the holes a little bigger to fit my bushings or are you supposed to put them in the holders
with a vise

i do have a blog i update occasionally now about the build bit i apologize in advance about my writing ,spelling and grammar skills as they are lacking in the greatest.
here is a link to the blog [electronicsbeginner.blogspot.com]

Edited 1 time(s). Last edit at 02/17/2011 08:47AM by ostamo2.

The brass bushing parts are designed to be reamed/drilled out so that you get a good fit (printers don't make the best holes)

funny thing about that, i made a .scad file of the bushings and printed them until i could get my bushings ina bit , then i pressed them in with a bench vise and they fit very well.
here is the code for the file , it needs to be cleaned up though.

InsideDiameter =(11.6/2);
OutsideDiameter =8.5;
BushingHeighth = 12;
//////////////////////////////////
// Outside Diameter
//////////////////////////////////
union()
{
union(){
difference(){
color([128/255,128/255,128/255]) 
cylinder(h=BushingHeighth,r1=OutsideDiameter,r2 = OutsideDiameter,center = true);
//////////////////////////////////
// Inside Diameter
//////////////////////////////////
color([128/255,1/255,128/255]) 
cylinder(h=15,r1=InsideDiameter,r2 = InsideDiameter,center = true);
}
}
union()
{
difference()
{
//////////////////////////////////
// Insert
//////////////////////////////////
translate(v=[0,4.5,0]){
color([128/255,128/255,1/255]) 
cube(size = [16.9,9,BushingHeighth],center = true);
// 7/16" = 11.1125mm
// 1/2" length = 12.7mm
}
//////////////////////////////////
// Inside Diameter
//////////////////////////////////
color([128/255,1/255,128/255]) 
cylinder(h=15,r1=InsideDiameter,r2 = InsideDiameter,center = true);
}}}