Should the extruder body be perpendicular to the Z axis ?

[luiss]

Hi.
My Prusa i3 has the extruder body about 5 degrees inwards with regards to Z axis. (that is, the nozzle tip is looking inwards). Is not parallel.
Is this a factor should I worry about? Which would be the effect on prints ?

luiss.

[old man emu]

Since the tip is going to be something like 0.4mm above the previous layer, I don't see that the lateral distance from the vertical will have a large effect on your prints.

I haven't use trigonometry since I did some bathroom renovations for Archimedes, but I think what you are looking at is called a Cosine Error.

To calculate how far off perpendicular things are, the calculation is: Cos(degrees off vertical) x layer height, which in your case is Cos 5 x 0.4

I stand to be corrected.

Old Man Emu

[Roxy]

To calculate how far off perpendicular things are, the calculation is: Cos(degrees off vertical) x layer height, which in your case is Cos 5 x 0.4

Wouldn't it be Sin(5 degrees) * .4mm ? The reason I'm asking is the Cos(0 degrees) is 1 and if the nozzle was 0 degrees off the error would not be Cos(0 degrees) * .4mm which equals .4mm ???? The error would be 0, right?

I'm thinking you want to use the Sin( 5 degrees) * .4mm ????

That would be: .087 * .4mm = .035mm of error. That sounds more plausible.....

[RobH2]

Since the only thing I did was scratch some tasteless drawings in Archimedes bathroom I can't say that Cosine errors will be a problem. But, thinking about it in a simpler manner, your plastic will be extruded at an angle. It might make the part print oddly. There is nothing technically wrong with a slight angle I don't think, but the proof will be in if you get adequate prints or not. I'd say try it and if it looks like the prints are being affected by some odd angular flaw, then figure out a way to straighten it up. If they look great, why sweat it?

As a rule though, perpendicular flow trajectory is better and as close as you can get it is best. That's the way the system is designed to work. The angle of the exit orifice should be parallel to the print surface. Then you know it's not an issue when things go wrong. We are dealing in fractions of mm and slight misalignments can be problematic.