5 ten thousandths isnt that bad for tolerances.  Heck some of my hydraulic motors are tighter than that as they are metal sealed by the fit.  Blowby occurs when it wears off one thousandth.

Yup, Interference Fits are fun... but doesn't mean using thousands of an inch makes it more accurate... thats all I'm saying.. there is nothing magical or special about a Mil vs a Micron - except one is an International Standard, understood and accepted and utilised all over the world, and the other is from a bygone era and is used formally in only 3 nations in the world.. Burma, Liberia and the US.

Not sure how that makes mils more accurate for tolerances than a micron (which is what you stated above....)

I only think in 0.000" (+/- 0.0005) as I like to build things that have tolerances.

Sorry if you dont appreciate it.

Yes, because you can't possibly design a tolerance with a mere Micron

Quick - Call the world wide scientific industry - Their measurements are out, particularly at the molecular level !!!

(I regularly do PCB design work.. I am *very* versed in Mils and live in the sub-20 mils zone. Doesn't mean its magically more accurate than a Base 10 derived international standard )

Sorry if you dont appreciate it.

elmoret wrote:

No, a clog from debris. The nozzle is 0.35mm in diameter. That's not much bigger than a human hair, so it doesn't take much of a particle to clog it.

Actually?  A human hair is around 0.004" thick.  .35mm comes to around 0.0137" more than three hairs.  But I suppose I am splitting hairs now.

I was going to give you kudos.. but then you ruined it by using Non-SI units.... And more so by 'converting' an SI unit in the same sentence... What is it with Burma, Liberia and the US insisting on having discussions in Non-SI Units...

And a human hair in research can be observed to range between 17 µm to 181 µm ... or 0.017mm to 0.181mm ... So only two human hairs if you've got thick hair

SI Units for the win... as used by 193 other nations in the world

No, a clog from debris. The nozzle is 0.35mm in diameter. That's not much bigger than a human hair, so it doesn't take much of a particle to clog it.

Actually?  A human hair is around 0.004" thick.  .35mm comes to around 0.0137" more than three hairs.  But I suppose I am splitting hairs now.

Does this mean that the drive is too close to the hot end?

I would think a clog would be that the nozzle cooled.  If it got too warm it should flow more easily.

No, a clog from debris. The nozzle is 0.35mm in diameter. That's not much bigger than a human hair, so it doesn't take much of a particle to clog it.

I really don't think those will work. When shavings are made, it's because the steel teeth are pushing so hard the plastic is disintegrating. I don't think you can approach the same tangental force that steel teeth make on plastic using rubber.

Usually shredding occurs because something is wrong, like the nozzle is clogged or the filament is getting too warm while feeding.

Can some one tell me the OD of the drive wheel?

What I am wondering is what if the drive wheel were to have a rubber surface? 
Or is it more a matter of torque that only a metal wheel can exert?