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Quotedzach
a ratio at which the formulas I used start to fit closely the shape of the plastic.
That was a wrong statement, indeed. At lower ratios the filament continues to be pressed by the nozzle, which still gives it the rounded rectangle shape. Things change when W /T < 1, or when W > flat bottom of nozzle. Which, I think, puts the limits of the practical extrudate Width sizes to "no
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dzach
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Slic3r
QuoteQuackingPlums
For printing purposes I think we are more interested in the cross-section as it leaves the trailing edge of the nozzle (nozzle aperture removed to illustrate that this is the trailing edge):
At this point, the plastic is securely adhered to the plate/object below and the movement of the nozzle/bed has dragged the plastic into the squashed cylinder that Chris describes.
Yes, t
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dzach
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Slic3r
Here is my concern:
In doing the calculation of the cross section of the area of the filament outside the nozzle, I'll have to correct the graphic and make it detach earlier from the bed, assuming speed doesn't change. That is, I'll have to reduce the size of the circle to compensate for the area missing in the connection of the vertical (cylinder) rectangle with the (horizontal cylinder) circ
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dzach
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Slic3r
Quotenophead
I think your confusion is that the drawing shows a cross section of the nozzle and a cross section of the resulting extrudate together, not a section of what the extrudate would look like at the centre of the nozzle. The filament comes out the nozzle as a vertical cylinder and then bends through 90 degrees to lay down as a horizontal cylinder.
I think you are right. I'll try to corr
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dzach
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Slic3r
Needless to, but I will anyway, say that I have great respect for developers of open source software and hardware, and sincere appreciation of their work that helps me and thousands other users achieve their goals. That includes Sound, Nophead and many others. My comments were meant to show how I solved the problem of wrong hole dimentsions I had back in 2012, and forgot about it ever after.
Re
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dzach
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Slic3r
Oh, and here is the reason I did all the above with Skeinforge:
http://forums.reprap.org/read.php?263,134103,137818#msg-137818
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dzach
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Slic3r
For a picture of reality, one can extrude a length of plastic in a single layer (or better in multiple layers) and then take a knife and make a cut across it. By observing the result with a magnifying glass or with a microscope one can be persuaded 100% about the shape of the extrudate. The animation above simply shows the result of the underlying math for the calculation of 4-5 of the parameters
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dzach
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Slic3r
I've been slicing with Skeinforge for more than 2 years now, with a set of formulas based on a very similar to nophead's model, without calibrating anything on the printer itself (after the initial calibration), but only measuring some parameters of the plastic that give the upper limit in speed (needed when printing in fast "draft" mode) and a flow multiplier, depending on the plastic. Here is a
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dzach
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Slic3r
If we are talking about a wish list for filament spools, I'd very much like to second NewPerfection's input for 2+kg spools, for the very same reasons he mentions.
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dzach
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Printing
Petrus Wrote:
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> why wasting energy with a big print bed if I have to print a small object ?
Thanks Petrus. To save energy I cover most of the bed with insulation and leave exposed only what's needed for the print. It does help raise the temperature faster too.
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dzach
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General New Machines Topics
Thank you for your reply Chelsea, I really like your 'no offense' attitude to my somewhat harsh criticism.
I see the "We Will Be Releasing The Source Files When They Ship!" in the details of the new printer pages, maybe it was there and I missed it. It's a good thing to give something back to the community that trusts you, even if you do not mention open source or how you intend to license these
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dzach
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General
My apologies for the long post.
I am not selling extruders, printers, electronics or anything, so there is no money involved in what I say. But I really expect from people that make a profit out of their claims to be able to support them, as do many of those who design open source hardware or software and announce it or sell it in here. They abide by the open source rules and ethics: there is a
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dzach
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General
In the photos I can see a small heated bed etched on a PCB, is that right? Any info on that one?
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dzach
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General New Machines Topics
Traumflug Wrote:
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> Now, which extruder can keep up with these 478
> mm/s?
That's the question. Interesting achievement though if it "can keep up" as claimed, given the performance of the current QU-BD extruder design.
A video with the extruder actually extruding wouldn't harm the extruder's reputation I believe.
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dzach
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General
To be able to print properly one needs to match the virtual printer model that exists in the firmware and the slicing program to the actual physical object, the printer itself. Here is how I do it:
First thing to do is make sure the physical dimensions/parameters in the firmware are set correctly. The reprap wiki has detailed descriptions of the calibration procedures for the 4 axes.
Next thin
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dzach
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General
Happy New Year!
Hoping to aid in understanding how some basic parameters influence 3d printing, triggered by Nopehead's wish to device a set of formulas for setting these parameters, here are two animated gifs from a program I've written to automatically calculate and adjust Skeinforge's parameters for my prints. They show how variation of layer thickness and width/thickess (W/T) influence the s
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dzach
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Printing
nophead Wrote:
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> The 1.5 ratio and the die swell area maths I use
> gives me the upper limits of the extrusion size.
> I.e. the absolute maximum layer height is sqrt((pi
> * d^2))/6).
There is one extra parenthesis in the above. Should the '/6' term be inside the sqrt() ?
I regularly print with layer height between 0.2 and 0.6
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dzach
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Printing
nophead Wrote:
> I have started using Car Plan fire putty exhaust
> assembly paste from Halfords in the UK.
I don't seem to be able to find any details on this putty, other than it can withstand 1000+C° and that it stays elastic while applying.
Do they have any other technical data on the box or on the back of the tube? Like thermal and electrical conductivity?
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dzach
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Australia, Sydney RUG
Interesting reading about conductive :
A Simple, Low-Cost Conductive Composite Material for 3D Printing of Electronic Sensors.
Quotefrom the paper
This advance in low-cost 3D printing with offer a new paradigm in the 3D printing field with printed sensors and electronics embedded inside 3D printed objects in a single build process without requiring complex or expensive materials incorporating a
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dzach
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General
This is very interesting. What was the Width / Thickness ratio for the prints?
Is it possible to provide some close up pictures showing details of the laid threads?
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dzach
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Plastic Extruder Working Group
It looks significantly better. No visible warping. Is it ABS?
Any more details on the printing conditions?
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dzach
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General
I tried to do it but did not succeed.
One problem was how to secure the bag on the X plate, so that the extruder fan would help inflate it. The fan is 50mm and I doubt it didn't seem powerful enough to keep it inflated.
The other problem was the bag limiting XY motion of the Hadron OrdBot bed. Maybe the bag was not big enough. I'll try to find a bigger one made of some heat resistant plastic
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dzach
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General
I've noticed that the wiki started getting tons of spam since spring this year. This might explain some of the loss of responsiveness that is evident there. Could that be a reason for the same here?
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dzach
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General
DGC PartWorks Wrote:
> Based on my calculations it would go like this for
> a .35 mm orifice:
>
>
> Layer Height Bead Width
> 0.3 0.385
> 0.2 0.524
> 0.1 0.984
>
>
> These are theoretical values, of course, and your
> mileage may vary, but it gives some idea of what
> changing the layer height will
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dzach
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General
I like this idea.
I have a rather weak nichrome heater which cannot raise the bed temperature higher than 80°C and this might be what is needed for it to reach 100°C.
Will give it a try and report back.
Thanks for the post!
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dzach
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General
What didn't make sense was the "turn the pot fully CCW" that did not explain the need a 30kΩ pot. Your explanations here remedy that.
Good to see the schematic and Gerber files published under a CC license.
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dzach
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For Sale
If all one has to do is turn the 30KΩ pot fully CCW then why isn't that a fixed 30kΩ or 0Ω resistor?
It doesn't make sense.
Nophead has published a number of articles on this issue, I think, the essence of which is to replace R4 on a Pololu/Stepstick with a short or a 0Ω resistor. Is this what you are doing with the 30kΩ pot?
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dzach
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For Sale
How are these extruders coming out?
Any reports on their performance? Back in June - July there were some requests for a video showing one printing. Has anyone received the extruder and printed with it successfully?
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dzach
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General
QuotedzachThe community's reaction is not at all insignificant, it is the ecosystem where this Darwinian game takes place. A sterile machine in such an environment has no future.
Quoteorcinus
The problem with the sterility argument is that it assumes a lot.
You are right, even what I said above assumes that the ecosystem where a self replicating machine lives is "a community", maybe this RepRa
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dzach
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General
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