getting resolution into the microns

I was wondering if it is only filament size that dictates resolution?

IF someone was able to create a low cost print head that extruded powder or anything in the microns, would there be anything else holding the mendel back from say 3 to 5 microns resolution?

not that i have any ideas

i recently got in a taxi with a driver who during the week is a mechatronics engineer, he is interested in reprap but his work requires resolution of +/-5 microns. (we are email friends now).

... it's the stiffness of the frame, torque and resolution of the motors, accuracy of the ref-switches and some other mechanical issues too ...

I have some linear stages with 2Nm-steppers and high precision spindles, which have a stepping resolution of 0.5 microns and inductive sensors for a 'reference-switch' with 1micron acuracy - but this will normally cost some ten thousand bucks

So you can estimate, for enhancing the resolution by 1/10-th you can calculate rising the price of the neede mechanics by 10x too

Another question is the fabbing speed - if you'll fab with let's say 10 microns resolution (when extruding with the same speed as with 0,1mm resolution) you'll need 10x10x10 = 1000-fold time for the same volume!

So you need controllers and drivers capable of this speed, what's a massive cost issue too!

I have two sorts of highres/highspeed-drivers - one with 10000 steps per rev and 200kHz, another with 51200 steps per rev and 10MHz clocking speed, but actually Arduino lacks of this timing resolution

Edited 1 time(s). Last edit at 10/11/2010 03:28AM by VDX.

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

Ok that opens my eyes to the massive cost of commercial printers a bit...

would it be possibly to use belts and nema17 steppers but add a bit of a gearbox so 1step equates much less distance? But i guess you would still need the expensive sensors.

... referencing with common microswitches or cheap inductive sensors should be accurate to +/- 10 microns, tweaking opto-sensors with a thin slit and isolating against ambient light would do even better ...

When reducing the stepwidth by gear-ratio you can run the motor with higher clocking speed too, so this could be a way in the right direction - but then you have the highsphed-clocking-issues too, so it's a bit of testing, whats possible with your cost-limits ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

i'm pretty much broke. plus i have no real ideas.. except what i've read elsewhere like putting ABS to a discsander for powder, or putting things in blenders. Then i guess hacking an epson printhead... or designing a tiny nozzle that can open by solenoid. Then lazer sintering as a seperate toolhead. (after every layer?)

you mentioned you have the stages and sensors, is finer resolution a path you are going down?

... it's a bit more complex - essentially i'm going two roads synchronously ...

With the finer/stiffer stages i'm building a machine with 1 micron accuracy and a moving range of 180x180x180mm.

Aditionally i'm adopting some nanostages with 0,1micron accuracy and 25mm travelling range and another type with sub-nano accuracy and 50 microns travelling range into a hybride structure, where i'll have a selectable positioning accuracy from 1micron to some nanometers over a 'macroscopic' area of 180mm in XYZ ... some high precision tilting and rotating stages are there too.

Actually i'll be happy with 5 microns accuracy (my smallest laserspot is 10 microns wide), but with time i'm searching some linear encoders with 10 nanometers accuracy for adopting the nano-stages in the system, then i'll try with some more pecise stuff.

My goal is nano-fabbing for DIY-electronics and micromechanics ...

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

using a microscope as your toolhead, and using stop motion photography, you could get some really beautiful camera moves over tiny tiny environments. I.e, take a photo, move camera a bit, repeat a billion times then put the photos together as an image sequence. Something i've tried semi successfully (a tiny linear axis for a camera move over one of my eye lashes).

resolution like that sounds appropriate for not only nanotech but maybe even biotech! God speed.

Really? +/- 0.01 millimeters from something like this? Repeatable?

[www.grainger.com]

Why is anyone using end-stops, besides the fact that they're specified?

(here I'm glad I've not made progress on my Digikey.com order)


VDX Wrote:
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> ... referencing with common microswitches or cheap
> inductive sensors should be accurate to +/- 10
> microns, tweaking opto-sensors with a thin slit
> and isolating against ambient light would do even
> better ...

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My blog's Reprap feed: [blog.markbova.com]
I'm currently working on a stock Mendel build with a Seeeduino Mega and four Pololu A4983 stepper controllers.

... in my Isel-CNC-mill are microswitches as reference- and endstops and when i measured some inductive sensors/switches from Pepperl&Fuchs i found in my scrap, i measured one (rectangular) type with 50 microns hysteresis and 2 microns repeatability ... the other (cylindrical) type with 120microns hysteresis but with 2-3microns repeatability too.

My inductive sensors from Omron have sensing accuracy better than 1 micron in measuring range of 2 millimeters ...

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Viktor
--------
Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

VDX Wrote:
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> ... i measured some
> inductive sensors/switches from Pepperl&Fuchs i
> found in my scrap, i measured one (rectangular)
> type with 50 microns hysteresis and 2 microns
> repeatability ...

Ah, I just searched for "inductive sensor|switch" and found some examples. While they may work great, they're not in the price range of the simple mechanical electronic switches that I linked to.

Th one I linked to is the type that's typically used in microwaves to ensure that the door is closed, among other things.