pros and cons of 1.75mm vs. 3mm filament.

pros and cons of 1.75mm vs. 3mm filament. It seems everything used to be 3, now there is just as much 1.75

I guess 1.75 melts faster. Is the 3 just around because of all the parts out there that have been made for it?

This maybe should be a different post, but also I need to know what is the reasons for all the different nozzle sizes. What is best? Why?

You will be seeing a lot more posts from me as I am just wrapping up some things in the design stage and will be starting to purchase and build this weekend hopefully.

The different nozzle sizes produce different sizes of extrusion, so narrower lines in each layer of print. In theory the smaller the nozzle the finer the surface detail you can print. But the smaller the nozzle the greater the back pressure and the easier it is to clog (at least, to judge by people’s account of using them).

So it’s a balancing act between detail and clogging. But the performance of the nozzle is also dependent on what it’s made out of, some swell more than others making them perform more like a larger nozzle.

back in the early days of hobbyist 3d printing you could barely find any 3mm filament (used as plastic welding rod) so 1.75 wasn’t available.

technically 1.75 is better as you said because it melts faster (less melted plastic at any one time), but also you have finer control of how much plastic is pushed through for each step of the extruder motor.

my printers are still 3mm. but if i was starting from scratch i would definitely go with 1.75.

how about pros and cons about the hot end with the block vs the wire wrapped version.

At this time I think I narrowed my choice to either
http://printrbot.com/shop/ubis-hot-end/
or
http://store.qu-bd.com/product.php?id_product=22

If I went with the block, should I spend the extra money to get the heater vs. the resistor?

.05 of a mm is pretty small, do you really notice that kind of difference in a nozzle?

Is .4 mm a good size?

Ok that’s what I figured. Thanks @Andres_Huertas

I could write another 2000 word article in response to this… Don’t have time now, but I’ll wait and see what others post, then add anything I think is important that hasn’t been said when I have more time.

We’ve been trying to print small-feature-size objects and just can’t do it with a 0.5mm nozzle, so I machined a 0.3mm one the other day. You have to buy good filament or it’ll block constantly. (Or put mesh in there to strain out debris in the filament.) We got some PLA at about $8/lb and it was debris city: it could only run in a 1mm nozzle. In contrast, some translucent stuff at $50/lb seems to work fine with the 0.3mm.

@John_Bump Does anyone actually use a mesh? Seems like it would be a built-in debris infrastructure.

to extrude 3mm --> 0.3mm takes more pressure than 1.75mm --> 0.3mm.

3mm --> 0.5mm has been a happy setup for many but if you plan on extruding 0.3mm or less it would be wise to start with 1.75mm

Compared to 3mm, 1.75mm is more sensitive to filament diameter error. Nearly 2 times more according to http://www.protoparadigm.com/blog/2011/11/filament-tolerances-and-print-quality/

My printing quality went up dramatically when i switched from 3mm to 1.75 with the same nozzle.(0.35mm) And I’ve put at least 50 pounds of filament through my makergear Brutstruder with only cleaning every few months or so. You have better control over filament flow with 1.75 mm.

I care more about precision than speed. I like things to be consistent…

Smaller nozzle is better for precision, but I hear the .25 ones are more jam-prone. I have no complaints about .35

I can only speak from my own experience, but I’ve used 1.75 PLA filament and a .35 nozzle for over a year and the only jamming issues I’ve had were related to hot-end design issues (Makergear) and filament drive design flaws (QU-BD). Once I coupled the Makergear filament drive with a J-Head it’s been smooth-sailing in the extruder department!

There certainly may be something to the quality of filament argument. FWIW I’ve used whatever it is that Makergear sells, Faberdashery and Ultimachine filament without issue.

Another issue is that 3mm has more spring to it, so careful feeding works best. there’s less spring to 1.75 so bowdens work better without causing inacuracy.