Powderbed Machine

Some time ago I Spent some time working through the various aspects of building a powderbed printer, I got to the stage where I think I had solved most of the tool chain, software and hardware, then came across Fogassa's work, so I decided not to persue it, as he had done such a good job, but recently someone asked me for help building a powder printer, this has revived the old project, it would be good to do what Fogassa has done but under the Reprap umbrella.

When I first wrote the software it used parallel port, no printers use this anymore, so the first step is to update the software,
1..slice
2..recoat
3..print

The old version used Pic mu, but Arduino will be used for the interface board

Find a simple printer that is as dumb as possible with cartridges that are fillable

Time is always a problem so progress may be slow, but from what I have found a number of people have worked on
powder printers, but there does not seem to be a site similar to reprap that documents the whole process of building one.

I intend to post software (although not finished) to start the project.

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Here is a screen shot of the software so far



Working from left to right
Image process, ...is intended to allow printing shells and reducing the amount of ink on the infill
Paulo's slicer,... is a front end to his slicer, to make life easier, I may add the freesteel slicer at a later date.
Serial port,... to select the port the arduino is using.
Printer,... select the image files to print, simulate simply puts them on screen one after the other with a one second gap.
3DPrint, instructs the arduino to do a recoat then print the layer, communication in serial between pc and arduino
should manage the process.


The next step is to search for a simple printer, that is in production, and with refillable cartridges, the HP1000 looks
like it may fit the bill, but need to keep looking, when I have the printer, I can see what paper sensors need defeating etc.

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I decided on a HP1000 printer, but having gone to various places to get one with no success, I bought a HP2050, which seems to be a HP1000 with a scanner on top, and it was only £5 more.

It seems to be OK so far, done some simple tests to see how fast it prints, (seems fast) and how much messing about it does
before each print ( none so far), I have also done some printing from the software, and all seems well at this point, I was concerned that the print dialogue would come up on each page, but its not turned out to be a problem, so far so good.

I shall do some more testing before the painful bit, of dismantling a brand new printer.


The Cartridges are 301, refilling is a must, youtube video showing it done.

Edited 1 time(s). Last edit at 01/29/2011 11:22AM by johnrpm.

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I have been giving some thought to the slides that the recoat and print heads run on, the first thoughts were to use 10mm
tube and make nylon or ptfe bushes, I want others to be able to make this thing so went to B&Q to see what was available,
they do have an area with lengths of metal, tube, angle, flat, in steel and alluminium, so this should be a good resource
for the future, but around the corner they had draw runners, I compared the cost of the runners £10, against stock materials and getting bushes etc, and decided on the draw runners, they have very low friction and next to no play.

Edited 1 time(s). Last edit at 02/09/2011 03:09AM by johnrpm.

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Bought some tooth belt and pulleys for the recoater, from rapid electronics, I have decided that a full A4 bed plus
another A4 bin would make the machine to big for the space I have, so my machine will be A5, but it should not be to difficult to increase the design to A4 if needed.

The machine will use powder recipe available at places like open3dp,
and other places initially, but with an eye to the future, using the reverse inhibitor method with polymer powders, this means the machine will get hot, something I wished I had remembered when I cut some old machine guard, lexan, I think, to make the bins, Lexan is shatter proof and would be ideal for a cold process, so would MDF, but I may as well bite the bullet and get some tufnol for the bins, or better still metal sheet, this would make manufacture more difficult for a lot of people though.

With the hot process in mind, I am using the draw slides separately, one for the print heads, powered by the original printer motor, and the other for the roller and heat unit, the roller motor and slide will pick up the printhead rail and position it, then
go to a park position, this will keep the inertia to a minimum and put the printhead out of the way when the heat is applied,
this means a electromagnetic clutch to disengage the paper feed motor and an electromagnet to pick up and piggyback
the printhead rail.

I have a few bits now, but things are still fuzzy, I shall give it another coat of looking at, and post some specifics when the
design is a little more firm.

P.S, the hot process involves printing black ink onto white polymer powder, and due to the black absorbing more heat than the white powder, fuses the part but not the surrounding polymer.

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Yo Johnrpm (Random Precision?)

Thought this link might be usefull....

[www.instructables.com]

A dude planning on building a powder printer. Maybe you have already connected, maybe you don't want to connect, maybe 'you is him'. anyway - there it is

Thanks AgeingHippy for the link, I had not seen it, from a quick read he seems to be hacking the printhead, which is a coincidence, because I have a few printheads in my bag right now so that I can try to fire them from a simple circuit this weekend, in order that they can be attached to a reprap maybe for pcb stuff.

I had not intended hacking the printheads for the powderbed machine, but use the printer drivers that came with the printer, the software just calls a print command when it gets a serial signal that the recoater has finished doing its thing, but it would be good if we could do bit banging eventually, beyond me I think.

In order to keep the cost down, I pondered on using just one stepper drive board, as it does not need to move more than one axis at a time, and have a way of switching the board outputs to different motors, but the only way I can think of, relays or transistors seem to be to much trouble or maybe not save much cost,..... any ideas.

Also thought of using ratchet and pawl instead of steppers for the bins, as the movement values may never change, but steppers would make it more adaptable, maybe 2 versions ?.

Lastly, I intend to use 6mm MDF for the bins, sprayed with stove paint to reduce friction, should stand some heat and is available to many.

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Here is a drawing for the bins, they are A5 plus 10mm all round, to make part removal easier, got the 6mm MDF from B&Q for £10, enough for the bins and plenty left over, they also cut out all the pieces on a wall saw, which keeps everything square, the 10mm slot is for the overflow.

Please bear in mind that this is development, and things can change, if you are building an a4 size, the 9mm may be better.

Edited 2 time(s). Last edit at 02/18/2011 03:25PM by johnrpm.

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Work has started on the powderbed printer Here, making the powder bins, the pistons are next, my initial thoughts were to have rods from the pistons running down through bushes to quide them, but after spending some time trying to find of the shelf items that are easy to get, I decided to use draw slides again, they really are cost effective, I have machinery to make parts, but am trying to do as much as possible without them, so others can make this thing, but it may be that at some point machinery must be deployed.

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It's fun watching the machine take shape in the wiki.

Two thoughts: You may want to look at melamine-coated mdf. That's the slippery coating they use for generic white cabinets.

And as folk evolve versions, I'm sure we'll see one based on inkjet cartridges like the HP 51604A. (A popularly hacked inkjet cartridge.)

Thanks Sebastion, I will mention it in the Wiki, I looked up and down the racks of sheet material in the DIY depot, and did not see any melamine coated 6mm, but I may have missed it, I am hoping that others will add to the wiki, different ideas and materials as it progresses. ( I agonized for ages trying to choose between 6mm and 9mm mdf, but 6mm seems good)

I'm sure we'll see one based on inkjet cartridges like the HP 51604A
Yes, I hope to build it sort of modular, with a common powder bin setup, but be able to bolt on different axis to put down
ink, solvent etc.

I have a bag of old HP11 cartridges, and tried to fire nozzles, from 5volts to 30 volts, to no avail, Madscifi suggested
that it could be the chip needs defeating, any ideas?.

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I have a bag of old HP11 cartridges, and tried to fire nozzles, from 5volts to 30 volts, to no avail, Madscifi suggested
that it could be the chip needs defeating, any ideas?.

Yes. Purchase a HP 51604A cartridge.

And a kit from:
http://www.fullspectrumengineering.com/hp51604a.html

So that you'll have this circuit here:
http://www.fullspectrumengineering.com/images/hp-schematic.gif

Or use the circuit buried in:
http://reprap.org/wiki/InkJet

I believe the 51604A does not have a chip to defeat, and is basically designed to be hacked up and used as part of a production line labeling boxes, etc. The electrodes on it go direct to the resistors in the thermal-type inkjet head. I am not sure how you make electrical contact to the 51604A's electrodes;. you may need to buy spring-type pins from digikey, and print up a holder for them.

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

After getting over the trauma of the thought of spending money, Yes the 51604a cartridges do look very hackable, has anyone bolted one to a reprap?.

Here is a poor pic of the hp11, the chip looks isolated from the nozzle connections????????????.

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Yup.

And then buried the details in a pdf.
http://reprap.org/wiki/InkJet
probably using the venerable gen 3 (or gen 2!) electronics.

I'd use RAMPS, mind.

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

I am looking at the stepper motors for the powder printer, they do not need to be high performance as the motions are mainly
incremental, although I have a lot of salvaged motors I could use, it would be better to have a solution for others to follow,
I like the all in one solution [cgi.ebay.co.uk]
I have used them before and they perform well, it would also eliminate a lot of issues that people have with electronics judging by the forums. although this solution may not be around in the future,

But RAMPS seems to be the reprap way, if so where is the best place to get the motors and drive boards etc, I would like some input on this to simplify the electronics side for potential builders.

Your input would be appreciated.

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Perhaps
http://ultimachine.com/?

Johhnyr is the fellow who did up the boards, and he has lots of satisfied customers.

I've been thinking: if your MDF box doesn't meet your needs, you may want to bing Rhys Jones in Bath and see if you can borrow time on Bath's laser cutter to do up acrylic boxes and pistons.

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

Thanks again Sebastien,
Is it OK to put links to ultimachine etc on the Wiki?, I am fortunate to have access to laser cutters at work, but really want to make it doable for as many folk as possible, with basic tools, but there may come a point when something will need a lathe etc, I think you are right, If When this gets to the hello world stage, creative people will adapt and modify it.

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Is it OK to put links to ultimachine etc on the Wiki?,
Only if you're happy with what he ships ya.

... RepRap does evolve marketplace-like aspects. At some point, passers-by will add other board-suppliers to the page, and it will start to look like a Sunday Newspaper Advertising Supplement.

At which point, we'll take that part of the page and make it a dedicated A5-Powder-Printer-Buyer's-Guide.

I am fortunate to have access to laser cutters at work,
I'd say, use the tooling you've got. And then watch it evolve. Mendel has diffracted into milled aluminum, lasercut plywood, sawed oak, and cast resin versions. The sooner you get your (lasercut/tablesawn) version out the door, the sooner someone else does a (tablesawn/lasercut) version.

But yes, I suspect there may be a market for lasercut reprap-flavored printers out there.

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

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But RAMPS seems to be the reprap way

That, and Gen3, Gen4, Gen6, Gen7, "Adrians Pololu". For driving three steppers, RepRap has plenty of solutions. Perhaps a link to Alternative Electronics suits better than a link to a single vendor, in your case.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Yes, I will avoid links to vendors and put the alternative electronics link, but it must be daunting for a newbie to be confronted with all the variations, I would like this thing to work out of the box so to speak, like the up printer, to be as inclusive as possible, so that they say What if I try..... .and not... how do I get this thing to work.

Another question, I am posting images for drawings, is this format OK, if not what is the preferred format?, I suppose it would be better to get it right now rather than later.

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it must be daunting for a newbie to be confronted with all the variations

It perhaps is, but having a good chance to get into some sort of business around RepRap is a major motivation factor for many developers. So, keeping the RepRap Wiki as neutral as possible is a good idea.

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like the up printer

The UP! Printer doesn't spark any derivative development ...

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Another question, I am posting images for drawings, is this format OK, if not what is the preferred format?

PNG for the web preview (smaller than JPEGs for drawings), along with a downloadable PDF (crisp sharp) and native format (for modification) is ideal. Some people provide just a big ZIP and others try to motivate participation by moving the file stuff to GitHub.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

Up to now, all the parts for the powder bins are available from a diy store (B&Q) , but I am using 10mm studding as lead screws and need a coupling to fit leadscrew to motor (.250 shaft), and leadscrew nut, I shall make them in a lathe but in the spirit of making it doable by as many as possible, does anyone have suggestions for off the shelf parts that could be adapted.

I shall do a PDF or DOC file at the end of each stage, describing what happened, not what is intended to happen, this will make it more accurate hopefully.

Edited 1 time(s). Last edit at 03/06/2011 06:26PM by johnrpm.

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It should be possible to print a reasonable coupler, especially since the speeds and forces should not be too great (or so I would imagine). See here.

Edited 1 time(s). Last edit at 03/07/2011 12:54AM by madscifi.

I now have the powder bins more or less done, I hooked up a stepper driver and had the pistons moving up and down, also tried with a little powder in the bins, as yet do not have a seal but surprised at how little powder escaped past the piston, I looked at the door seals for the pistons in the local DIY store, they were £25, the thought of spending that much made me feel all woozy, so will give some thought to the seal problem.

I opted for 8mm leadscrews, my steppers (salvaged) are 200 steps per rev, and the pitch of the 8mm is 1.25mm, this works well for layer thickness's of .1, .15, .2 etc, 1,25/200= .00625 so ,1 = 16 steps, .15= 24 steps, .2 = 32 steps. unless my sums are wrong, the motor shafts are .250 and the tapping drill for 8mm is 6.8 so that makes the coupling simpler.

will get up to date with the documentation and put it on the wiki page, I use open office so will post odt, and pdf for each section.

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.025 mm = 4 steps
.05 mm = 8 steps

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Bob Morrison
Wörth am Rhein, Germany
"Luke, use the source!"
BLOG - PHOTOS - Thingiverse

rhmorrison Wrote:
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> .025 mm = 4 steps
> .05 mm = 8 steps

Indeed, but I do not know if the powder will go that thin at this time so am thinking in terms of .1- .2, originally the plan was to use 10mm studding, I got some for the purpose as bigger is always better, but the pitch of 1.5mm does not divide so well,

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I think I have a solution to the seals, silicone baking paper, I had some in the workshop, by having it 4 or 5mm bigger and 90 degrees upwards around the edges, it seems to work well, but will need a plate to trap it, maybe something similar to veroboard?, as glueing may not last long, especially if heat is involved.

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Hi Johnrpm, it's great to see that you are taking this project on. A while ago I started collecting all the powder and binder liquid formulations that I could find so I would have them when I (eventually) build my own powderbed printer. Most of them are from Mark Ganter and his students at UofW. I have put them all into a single document and posted it on googledocs. You can take a look at it or download it at the following link:

[docs.google.com]

It may be useful when you start experimenting with formulas.

Cheers

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Kevin

Always use the right tool for the job, and the right tool for every job is a hammer.
Note - the above is not true but some days it feels like it's true.

[kevins3dprinter.blogspot.com]

thanks kevin
would you consider putting it on the wiki,

I am working on the recoater at present, the roller had me scratching my head
For a while, but a laser toner cartridge came to the rescue, and they are obtainable.

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thanks kevin
would you consider putting it on the wiki,

I've pasted the wiki-formatted text in here:
http://reprap.org/wiki/Powder_Printer_Recipes
and added it to the Powder Category.

http://reprap.org/wiki/Powder

It still needs the photos.

Thanks for working on this stuff, Kevin.

Edited 1 time(s). Last edit at 03/23/2011 12:45AM by SebastienBailard.

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!