Standard mendel Feed/Flow rate?

Hello! I finished my Mendel build and made my first print! The quality is crappy but they look like something! Now I tuned skeinforge like I could but I have a hard time to choose what feed rate and flow rate I should use. Could you tell me if there is a ''standard value''? Or if someone with the same equipment could tell me what is the value he/she use, I would appreciate it! Right now, my settings are feed/flow = 12/12

My equipment is :
-1,75mm PLA filament
-0,32mm Nozzle
-Wade's extruder

Thank you!

In my experience, the answer depends on your firmware, electronics, and extruder/nozzle. With Sprinter, to get high quality parts with smooth sides, I had to print at or below 20 mm/s (feed and flow set equal in Skeinforge). With Marlin, I can go as high as 30 mm/s. Above these values, I start to see jagged edges around circles and curves. I print using a uSD card on RAMPS 1.2 with a 0.5 mm nozzle Budaschnozzle hot end.

Hehe, "as high as" 30 mm/sec. Marlin really frees you from this speed constraint and makes the game all about your machine's rigidity. On my Prusa with Marlin, I can print perimeters at 40-50mm/sec and Infill at 80-100 mm/sec. See [techpaladin.com] for examples.

With my techzone remix Im going a constant 50mm/s perimeter and infill prints are nice though take a tad longer.

EDIT: electronics set ramps 1.2 with marlin

Edited 1 time(s). Last edit at 12/08/2011 03:50PM by ECSuyu.

With Gen6 I regularly print at 40mm/s and often 50-60mm/s with no real problems

---

__________________________________________________________________________
Experimenting in 3D in New Zealand

So the flow rate value always match the feed rate value?? Thanks for your answer!

in SF41+ yes as long as e_steps_per_mm is input properly in the firmware

ECSuyu Wrote:
-------------------------------------------------------
> in SF41+ yes as long as e_steps_per_mm is input
> properly in the firmware

Yes it is correct for SF41 not sure about the newer Sfact versions as I don't use them

---

__________________________________________________________________________
Experimenting in 3D in New Zealand

Question for those printing at 40 mm/s and faster: What is your nozzle size? I'm printing with a 0.5mm nozzle.

With my Mendel, I'm still convinced that my quality suffer above 30 mm/s not because of frame vibrations but because the extruder is not keeping up with the head/bed movement. I'm wondering if this problem is more pronounced with a larger nozzle (fatter extruded filament) than a smaller one.

brnrd Wrote:
-------------------------------------------------------
> Question for those printing at 40 mm/s and faster:
> What is your nozzle size? I'm printing with a
> 0.5mm nozzle.
>
> With my Mendel, I'm still convinced that my
> quality suffer above 30 mm/s not because of frame
> vibrations but because the extruder is not keeping
> up with the head/bed movement. I'm wondering if
> this problem is more pronounced with a larger
> nozzle (fatter extruded filament) than a smaller
> one.

Im printing with 0.35mm nozzle Jhead at the moment.

I personally havent found much issue with printing about 30mm/s, for me its when I get to 80mm/s that things start to go crazy mostly because the previous layer gets almost no time to cool before the next is applied and thats when I start to see vibration on the frame start to amplify. I can see the 0.5mm nozzle needing pressure to keep up with the print speed...but even then it should only be marginal and SF should be able to put the difference into the calculation of the gcode

Edited 1 time(s). Last edit at 12/09/2011 04:10AM by ECSuyu.

I wouldn't have though nozzle size played much of a part. Isn't the max speed you can print at mainly governed by your layer thickness, your extrusion width, the power of the heater and the material being printed, with a decrease in layer thickness, decrease in extrusion width, an increase in heater power (e.g smaller resistor) and using PLA rather than ABS all allowing you to go faster.

CeeThreeEs Wrote:
-------------------------------------------------------
> [...] with a decrease in layer
> thickness, decrease in extrusion width [...]

I've been led to believe those 2 are inversely proportionals. So they might not actually change the maximum achievable speed ?

1) firmware limits
The extruder is somewhat of a 4th axis, and i think most firmwares would have its extruder settings and top, at least one i use. Even if not explicitly, there is a generic bandwidth limit of the clocks outputs hz for step lines, which might come in narrower for 16x step setting, as a sort of ultimate limit.

2) agregting to lowest
In practice as commands are received, the firmware will have to adjust the effective cartesian movements to the limits of the extruder, so they are in sync. I could put 1 million km / sec in gcode and in firmware as xyz speeds, it wouldnt make any difference to what printer ends up doing. The speed is given by extruder, and after a point machine should do the same no matter how much cartesian settings are increased. Only the smaller of the agregated speeds should matter.

3) print settings / layer height, w/t ~nozzle
Also the constraint of extruder over cartesian movement decreases at smaller layer heights. Clearly 0.2 layer height will need proportional less plastic than a 0.5 layer. So with a small nozzle and a very thin layer height, speeds of machine can increase slightly. So perhaps one guy speed of 25mm/s & 0.4 layer is basically same of next guy 50mm/s & 0.2 layer. Actually to think about it, 25mm/sec<->0.4layer is more "effort" for the machine because it needs to lay out that plastic in a single pass. Therefore sometimes 26mm/s > 50mm/s, at least if we refer to speed of build.

Conclusion
Tbh for me, generally speaking, the thought of these speed settings not being actually realistically executed on machine feels pretty probable than otherwise. And 100mm/sec in terms of extruder capability feels pretty much like my hot end exploding :-)

I run 20mm/s at 0.4 layer height with 3mm filament and a 0.6 welding nozzle hammered down to around .5 or lower.

This is a tad on the slow side for most, but it's reliable. I was running 30mm/s but that's when I ruptured my PTFE on my old hot end.

I use a 0.5 Jhead and at 30-40mm/s its fine above that things just get a bit stringy and a bit rougher but the actual print is still usable until I get to around 70mm/s then it turns to custard

---

__________________________________________________________________________
Experimenting in 3D in New Zealand