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I do not have a problem with someone setting up an enterprise to make and sell electronics or mechanical stuff, it can help those who want an of the shelf solution, I do have a problem with big companies buying in, we will have to see how things go, but it would not be the first time a big company bought a small company to smother it. I am not sure why, but this really makes me feel uneasy.
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johnrpm
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General
Things now get interesting as the gap between commercial and open source gets fuzzy, 3dsystems were one of the quickest companies to litigate to defend their patents.
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johnrpm
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General
That looks realy good, will have a go with it, thanks.
Edit, I have installed and ran it, took me a while to figure out the file manager bit, but it really looks good, ran
the gcode through Mach3 and all seems well with no edits needed, I will keep playing and cut a board when time permits.
Thanks again for posting this.
P.S Designspark looks good, its by RS componants, not open source, I wo
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johnrpm
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General
Did I mention that I'm mechanically inept?
Your setup is a darn sight tidier than mine, and clean, is the Delrin less ridgid than the other materials?, or is it because it offers less friction that makes it better?, also water is one of the most problematic fluids, other fluids may be easier to jet perhaps,
I just want to say a big thank you on behalf of the community for your work, I know how
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johnrpm
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Powder Printing and Selective Laser Sintering
I have made the following determination: In order to get the piezo on the device you sent me to push the center of the brass disk into the chamber in response to a positive pulse, the red wire must be negative and the black wire must be positive.
I agree that it makes sense that the drop is ejected when the disc centre moves towards the nozzle, one way to check this could be to stick some shiny
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johnrpm
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Powder Printing and Selective Laser Sintering
Madscifi, you are doing a fantastic job, thanks for shareing your work, it looks like the parameters are tight for a particular
setup but once established should be consistant, do you think?, I don't want to stick my nose into your plan, but it would be interesting to see if the drop forms in the same manner with the polarity reversed.
David, I think I understand what you want to do, but am mak
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johnrpm
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Powder Printing and Selective Laser Sintering
davidgoodenough
Not sure if this would work, could you have a bath of one of the liquids and dispense the other material through a needle, sort of submerged reprap?would the layers bond?, I know you do not want the filament approach, but worth a thought.
sdedalus2000
Years ago we had a Arcout, I think it was called, for removing broken taps, a very crude EDM, but it did the job, so yes I think
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johnrpm
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Powder Printing and Selective Laser Sintering
David,
Now I see what you are doing, apart from the mist test, would it be worth having two syringes with the needles
intersecting?, or one needle inside the other some how.
edit, airbrushes?.
Please keep us informed of your progress.
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johnrpm
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Powder Printing and Selective Laser Sintering
Davidgoodenough,
Thats an interesting concept, I have only seen vidio's of it pulled out of a beaker like string and
have no feeling for the material, could a pinch wheel do the pulling?, does it harden over time or can it stay soft?,
could it be a support material?, could it be post processed to change its properties?.
would you take it up as a project, maybe star
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johnrpm
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Powder Printing and Selective Laser Sintering
I know its difficult to see, but is the crack through the ceramic as well as the conductive paint layer?, I would love to know how these discs are polled, to visualize how they bend, it may be that they do not bend in a uniform manner but along lines???.
Could you solder the wire on in a different place?, I hope it was not cracked when I sent it, if so sorry.
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johnrpm
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Powder Printing and Selective Laser Sintering
Here are the sizes I have to hand of the piezo bimorphs
20 dia, .17mm thick, 6 Kh
25 dia, .1mm thick , 1.8Kh
25 dia, .3mm thick , 4.2Kh
41 dia, .1mm thick , 2.8Kh
50 dia, .2mm thick , 2.8Kh
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johnrpm
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Powder Printing and Selective Laser Sintering
I did not know you could get Doctor who in the USA, I have not watched many since john pertwee, prefer lord of the rings, sad aren't we.
Could you remind me, what nozzle diameter are you using, it may be that air is being sucked back on each "stroke"
so when it is facing upwards it draws fluid from the wet face but air when it is facing down ???????.
I did measure the discs diameter and thickne
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johnrpm
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Powder Printing and Selective Laser Sintering
Extrude some of this stuff for low voltage lighting.
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johnrpm
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General
Not far from you, large machine
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johnrpm
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General
The cables are all on the most ridged side, and I shall copy the Uprint idea
for fillament hadling, so very little drag.
took me 8 attempts to get inline images, thanks Jim.
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johnrpm
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Mechanics
I think it would make a good reprap, it needs some bevel gears for the
Z axis and some sheet material to hold the shafts for the X axis but the part count is very low.
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johnrpm
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Mechanics
Here are some rubbish images of a machine I dismantled a while ago, the design is
very economical and could easily be a reprap, maybe it will be when I have time.
3 geard motors mounted on a plate, "could be swapped for steppers"
linear bearings but could be bushes
http://forums.reprap.org/file.php?14,file=2982,filename=3+axis+002.jpg
http://forums.reprap.org/file.php?14,file=2983,filenam
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johnrpm
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Mechanics
Sorry I know what I mean to say but have a habit of not explaining very well,
the front is the paper face, the nozzle holes, I can not look from the rear side as there is a bar covering the nozzles
but by getting the light in the correct place and due to the translucent foil, I can see what appears to be the chamfer.
Imagine if you looked at a piece of clear acrylic with a chamfered hole, althou
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johnrpm
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Powder Printing and Selective Laser Sintering
I suppose a small stepper, like the tiny one's in some cd drives could be used as a crude encoder by reading the pulses, but not so good at slow speed perhaps.
I did mess about with the mouse thingy a while back, the result was pretty good but I did not do any tests for "slippage" it would make an interesting project one day.
I know someone who has been working on "in process feedback using ca
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johnrpm
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General
Would optical mouse cameras have a high enough resolution, (arduino playground) to act as a linear encoder???,
referencing on every layer, by going to limit swithes may help reduce loss of steps accumalating, but add some time to the
build, roborealm is very good at video processing, it was free but costs about $85 now, for heavy collisions could the current be monitored.
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johnrpm
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General
Looking through a microscope it appears there is a chamfer on the rear face, 3 times the diameter of the nozzle, and as the foil is approx .3 thick is a steep angle, the microscope is not able to measure but will try to get images and sizes if possible
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johnrpm
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Powder Printing and Selective Laser Sintering
I can not promise, but I shall try to get some microscope images from a HP cartridge foil, front and back, this should give us a benchmark to aim for, although they are bubblejet and not piezo it should give us a clue.
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johnrpm
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Powder Printing and Selective Laser Sintering
I looked on wikipedia for AcoustoOpticalModulator, I am familiar with the jeffree cell, used in the 1930's for early television,
the strange thing is that less than an hour after reading about them I was given one by a friend.
or I think its one.
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johnrpm
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Powder Printing and Selective Laser Sintering
Looking at a HP cartridge, the "foil" with the nozzles in appears to be a substrate of translucent polymer, with copper tracks
for electrical connections, the foil is .3mm thick and similar to OHP sheet.
Looks like they use eximer lasers for drilling the nozzle plate.
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johnrpm
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Powder Printing and Selective Laser Sintering
That is fantastic stuff, you are really getting to the heart of the matter, by having the image capture setup, you will be able to
quantify many different parameters, or at least see the result of various factors.
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johnrpm
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Powder Printing and Selective Laser Sintering
Madscifi, I am having trouble visualising what you describe, is it a sort of U bend.
I buggered up my pipette, but had some tubes from way back when I played with glass blowing and managed to make a crude
pipette, but not as slim as the commercial one, the nozzle was small enough to only allow a drip to form slowly, it works but not as well, because it is thicker the heating takes longer, but st
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johnrpm
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Powder Printing and Selective Laser Sintering
To understand some fundementals of bubblejets, I tried an experiment with this glass pipette, the coin is 20mm.
the nozzle is approx 1mm diameter, refill ink flowed through the nozzle, a finger on the top stopped the flow, a small antex soldering iron, 15watt, was brought into contact with the glass approx 10 mm from the tip.
the reaction was instant, I expected a small delay, the ink was ejec
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johnrpm
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Powder Printing and Selective Laser Sintering
Yes,I can make out the jet in the image, what if we could get some small disks of a similar material to the brass
bimorph backing, say 6mm/10mm diameter, shim perhaps, or a small blanking tool could punch some out,
the clearance would have to be good not to produce burr's.
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johnrpm
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Powder Printing and Selective Laser Sintering
An inverter for a laptop backlight, the black oblong to the right is maked pzt1,
which I think is a piezo transformer, it has 3 connections, in out and common groung I assume, the yellow squares are tiny transformers.
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johnrpm
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Powder Printing and Selective Laser Sintering
