Edit: This thing has been upgraded!
thingiverse.com/thing:52299


This is my humble start on an actuator that could be mostly printed on a 3d printer. Incomplete as it is, I thought I'd post it as it developed.

It is based on this:
act.sys.okayama-u.ac.jp/kouseigaku/research/okamoto_wobble_06/english.htm
Instead of air chambers, I plan on rolling my own solenoids, eventually.

It also uses hypo-epicycoidic gearing, based off this:
thingiverse.com/thing:28237

And it should move like this:
youtube.com/watch?v=UayBAHJQE_k
But instead the outer ring 'wobbles'.

The wobbleRing is 1 tooth larger than the drivenGear(51/50). This allows for 2.4 degrees between solenoid steps(360 / (50 * 3)). But that's with just one of the 3 solenoids pulling at a time.

Now why did I use cycloidic gearing? Well, I understand they wear a little slower for this application. Also I was really having a time getting the MCAD library to work. Please correct me if there is a better gear profile for this application.

I do also appreciate any constructive critism, as this is my first openscad project.

BEWARE: I have not printed this thing yet!
I really wish I could but I am still waiting for mine.

BEWARE: There be snakes in dem codes; look at the openscad code at your own risk!
I really do intend to add more paramaters too, just working out the basic form first.

Oh and for now there are no solenoids included. At this point I really don't know enough yet to design capable ones.

This is a proof-of-concept, 3-bit Jacquard-style, all-mechanical punch card reader. The design was inspired by designs in a textbook called "The Mechanism of Weaving" by T.W. Fox (it's about 100 years old, but I found a copy on Amazon), and adapted to work within the limitations of my Makerbot ToM printer. It is a single-cylinder, single-acting, positive-action device. This design could readily be adapted to a higher number of 'bits' (needles) by re-designing only a few parts. With minor modifications, it should be suitable to mounting over a miniature loom, with the bottom eyes of the hooks lifting healds or warp threads directly. This is probably as impractical as it sounds.

This is an implementation of Nikola Tesla's "Valvular Conduit" that acts as a one-way-valve without any moving parts.

blog.makezine.com/2012/01/05/the-tesla-valve-one-way-flow-with-no-moving-parts/

This implementation follows Tesla's patent diagrams, perhaps too closely. It works, but the cap is a bit leaky so I plan to re-design it in the future.

For a project that I'm working on, I needed a reference for some parts that are sold through Pololu. However, they don't want to release the 3D files, so like a good Maker, I just made what I needed with Solidworks and my good ol' calipers.

This is a screw driven peristaltic Paste Extruder. It is still experimental, so before you decide to build it please check the following videos to see it in action:

- extruding polymer blend (hair gel):
youtube.com/watch?v=1XWYLSRCcq8

- extruding viscous chocolate glazing:
youtube.com/watch?v=qIFkw5RNXqQ

- extruding polymer blend at 16mm/sec, 0.5 mm nozzle, 250 micron layer:
youtube.com/watch?v=axAP0btw4Lk

Some pictures of the printing head: picasaweb.google.com/ioan.festeu/ReprapPasteExtruder?authuser=0&authkey=Gv1sRgCJnau7ew38qs7AE&feat=directlink
You will find a 3D pdf file attached so you can easily inspect the pump.

Also I have attached a dxf file for the laser cutted acrylic mounting plate for Rapman 3D printers. Sorry... for Makerbots and Mendels you will have to find your solution :)

CAD drawing picture shows in yellow the printable parts. The rest of parts are stock M6 threaded rods, nuts and washers and two inexpensive 606 bearings. The stepper motor is a NEMA17.

For the tubing and pumping elements I used two sets of cheap perfusion kits. The pumping elements (shown in creamy colour) are elastic latex tubes you will find in the kit. Idealy you may use standard peristaltic pump tubes.

The reason I am using two elastic tubes (dual chanel) is because peristaltic pumps suffer from the so called "pulsing". That is, when the screw leaves the tubing the corresponding void (where the tube was pinched) will suck back a little bit the pumped fluid at the outlet hence pulsing. But using two chanels arranged in anti-phase pulsing is reduced to almost zero.

Total parts cost (except the stepper motor) is less than 10 Euros.

I will come back later with a complete parts list and instructions.

NOTICE: I didn't uploaded yet the "pressing pads" (two small parts that press the elastic tube over the screw shaft) because I need to make some minor changes, but don't worry I will post them asap. UPDATED

P.S. If somebody needs the early CAD files let me know. I will gladly send it to you so you can adapt to your machine. I am working in Alibre Design PE and I can't save in other common formats so you must find a way to make the conversion.

P.S. 2 I have uploaded the file "pressing pad". You may want to put some rubbery material between the pad and elastic tube to be sure the screw shaft will completely close the pumping tube but not strangulate it. Otherwise the pump will loose the pressure.

Also I have updated the 3D pdf file.

I have attached a picture of the "perfusion set". Don't know the exact terminology in English, sorry. Some sets also have a Luerlock part connecting the needle and the latex tube. My Luerlock file supports that part. Obviously you can use any kind of support that fits you better.

UPDATE 1: watch my third video (I have listed above).
I will upload asap a new screw rotor design. I am not very happy with the current one since it seems it have some bugs: it creates some extra pressure when the rotor leaves the tube hence altering the low pulsation feature.

UPDATE 2: I have uploaded a new screw rotor design (Screw Rotor New.stl). Screw pitch was decreased from 12mm to 10mm so motor rpm will increase just a little bit. It should perform better than the previous one. Will come back with my own results.

UPDATE 3: Uploaded the file Screw_Rotor_New_Support.stl. Unfortunately this file must be printed with support (soluble PVA, PLA?). However this rotor leaves a smaller footprint on the elastic tubes hence less dead volume (less suck back). Still working for the perfect match to bring pulsation close to zero.

UPDATE 4: Check my photo album: picasaweb.google.com/lh/photo/oN2Z_e3g6u7eHZYbbXj2nQ?feat=directlink
It is printed using the part "Screw Rotor New.stl". Pulsation is so small I think is a good print. Just a little bit of adjustment is needed. The trick is to find the perfect match when the helicoid is fading (leaving the contact with the elastic tube)such as the dead volume arising is compensated by the incoming volume of the same chanel. Meantime the other chanel is pumping normaly. And so on. For the perfectionists I promise I will fix this to make it even better. Meantime I am preparing new .stl files for the final version. I need to clean up the bugs in some of the parts (there are plenty) and may be to make the pump smaller and with less nuts and bolts.

UPDATE 6
About the cheap latex tubes: very short lifetime, losing elasticity. So, go proffesional peristaltic tubing. The pressure will be perhaps around 0,7 bar with those tubing. Now I am waiting for the tubes to be delivered (2-3 weeks). Meantime I will try to cast my own tubing from RTV silicone. Keep you updated.

Laser cutter coolant flow sensor.

The concept was to have a sensor that wasn't inline with the coolant line and couldn't restrict the flow if it seized up. I'm sure that the design is scaleable within reason for other projects. It is simply tywrapped to the outlet end of the coolant pipe and dunked in the coolant reservoir/bucket.
The sensor is a simple hall effect switch.

BTW, if anyone knows how to embed a YouTube link to movie, let me know - the movie is at the bottom :-)

This moon rover is pretty simple; the real point is the treads. The idea of turning my Stretchy Bracelet into tank tracks is thanks to BenRockhold. Turns out it works really well: if you push this around on a slightly grippy surface like carpet, the tracks roll easily.

In fact, the track keys into the wheels so well, this could probably be used as a timing belt or chain.

Paste extruder based on the Moineau pump principle.

The pump geometry is based on thingiverse.com/thing:7958

Should work as a plug-in replacement for a hot plastic extruder in a 3D printer. However, I have NOT used this to actually print anything. I'm just publishing it in case someone else wants to try it out. (I think it's ready for printing a very small pizza without toppings, but beyond that I cannot say.)

Almost everything is parametrized and adjustable from the SCAD file. However, the resulting design should be evaluated to see if it is still sane after adjustment, since not all of the features are automatically calculated. Particularly the flange and driveshaft diameters must be adjusted by hand to match the other measurements.

See it in action: youtu.be/OHQiKuQvuEU

Note: obviously it is impossible to build an object from material that flows on it's own - the object would not hold it's shape. So in practice the material has to either be pulled into the extruder by a negative pressure (impossible with PLA printed pump parts) or pushed into the extruder by a positive pressure. In either case the motor axle has to be sealed, or it would either relieve the negative pressure or allow the material to flow up and out from the inlet block.

This is a Bistable Fluidic Logic Element. Its operation is described in a US Patent issued in 1974: google.com/patents?id=tZAzAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f=false

The final design will be usable for fluidic logic circuits. This gate can be used as both a memory element as well as logic element in digital logic circuits. It will be possible to combine many of these fluidic logic elements into one large integrated digital logic circuit that can be printed by a 3D printer.

It is currently a work in progress and this printable version has not yet been demonstrated to work.

Anyone who can help is encouraged to check out the github repository with the OpenSCAD source code: github.com/hardtoe/Printable-Fluidics

!! New version penrose5.stl with a couple of wayward vertices fixed !!

This is a 3D-printable version of the Penrose Triangle illusion, based solely on the 1934 design painted by Swedish artist Oscar Reutersvärd. The design also appeared on Swedish postage stamps in the early 1980s.

I created this 3D design entirely from scratch using the process outlined in the "Instructions" section below. This work is based solely on Oscar Reutersvärd's design, although some elements are inspired by the Hollow-Face illusion discovered many decades (if not centuries) ago.

This model contains a number of notable improvements over previous 3D representations:

1) It is parallax-corrected for a viewing distance of 40cm, i.e. it will look exactly like Oscar Reutersvärd's design, with cubes lining up on all 3 sides simultaneously. This is a great visual improvement over previous versions, which only lined up on 2 sides simultaneously.

2) It has been resized (to 99.43 x 99.65mm) to make maximum use of the Makerbot build envelope.

3) The top edges are now tapered so as to make the most of your printer's capabilities. The better your printer, the sharper the edges will be.

4) I own the copyright to this 3D design, and hereby distribute it under the "Attribution/Non-Commercial/Share-Alike" licence for all non-profit parties to print, improve and share.

This is an extrapolation of the now infamous Penrose Triangle illusion 3D model (http://www.thingiverse.com/thing:6513). If you had trouble getting your head around that one, you're not going to find this one any easier! :)

Where the triangle used 9 cubes, this arrangement uses 31 cubes to make a larger sorta-notreally-cube.

All versions are parallax-corrected for a viewing distance of 40cm.
(the larger ones are not simply scaled up versions of the smaller ones)

So I recently saw a blog post on hypocycloid gears on the Reprap Blog ( fabricationsofthemind.com/2010/07/09/extruder-design-1-printable-1001-hypocycloidal-gearbox/ ) .

Some really good info on them can be found here:

zincland.com/hypocycloid/

Also do a search on youtube for hypocycloid reducer. Lots of vids.

They seem to be perfect for a robot arm joint. I want to make a robot arm. I started to put one together in OpenSCAD. I have way more than I'm uploading here, but this is just the arm joint. The outside layers are fixed and the inside four layers rotate as the gears turn. I wanted to cut this using ponoko bamboo, but there is no way to go from OpenSCAD to ponoko bamboo (that I know of). I don't have a makerbot yet.

Hopefully someone can pick this up and run with it. The file needs to be edited quite a bit to print it out on a Reprap or something. Drop me a message if you want to print this out and I can help you understand the file.

I got featured on Thingiverse! Also, now for sale on Shapeways!

A fairly simple sculpture of DNA, built on a stand so you can use it as a nerdy desk ornament or as a teaching aid. Or as an aspirational goal, if you're anything like me ("I will best you yet, DNA!")

The Makerbot-printed versions are not technically correct, but all told, it's a modestly accurate representation, although the real thing is more dense and complex. And constantly under assault/revision by proteins and nosy scientists. I've included a version of the molecule which roughly corresponds to the common, active form in cells, called "B-DNA".

If you've only ever seen those pictures of DNA that look like a ladder twisted along its virtual axis, welcome to the slightly quirkier reality! If you like this kinda stuff, check out DIYbio.org. If you live on the West Coast and want a Bio-Hackerspace to play in, support "Biocurious" on Kickstarter!

I have put this model on Shapeways for those who might want a premium model in acrylic, glass, steel or plated gold!
shapeways.com/model/134213/dna_sculpture.html

Have you ever wanted a Gothic Cathedral of your very own?

Are you intimidated by the centuries long construction schedule, and the punishing job requirements of being a European Bishop during the Dark Ages?

Then We Have a Thing For YOU!

The Gothic Cathedral Play Set!

This is my first attempt at a Sarrus linkage suitable for a Z axis. It has room for a skate bearing, 10-32 threaded rod, and 10-32 nut to drive it. In practice, this mechanism is not quite stiff enough for good printing, but it might be useful for other things.

The total range of movement is just over 100 mm.

This is the next step in my attempt to make a Sarrus linkage based 3D printer. The idea is to have a cartesian mechanism without those long rods and bearings.

I built three of the Mark III and mounted them in a x-y arrangement as shown. They can move over a square about 105 mm wide, and someday may carry an extruder. They are driven by DC motors taken from inkjet printers. These motors are driven in a servo arrangement using quadrature optical encoders and optical strips removed from the same printers.

This is a Peristaltic Pump designed in Sketchup. I have tried to design it with an eye towards printing on a MakerBot, but do not own one so I cannot test at this time.

It should accept 3/4 inch hose with a 1/8 inch wall thickness.

For those whole like to ban things, this is a printed speldge hammer with the word BAN reversed out of the face.
Post about it on my blog: eagleapex.com/2009/11/01/ban-hammer-3d-printed/
Made at hive76.org

This is the final episode of a three-part mini-series on making things with low-melting-temperature-alloy. The collection of things here form a hot material transfer system that can be used to extrude (sort of) molten metal or wax. This is inspired by earlier work done by Dr. Sells and Prof. Bowyer reprap.org/bin/view/Main/AutomaticDepositionOfMoltenAlloyInt oACastingChannelToCreateAVerySimple Electro-mechanicalComponent .

As usual, remember that low-melt alloys are toxic and hot enough to cause burns and fires, so only use this material if you are experienced in a lab environment. On the plus side, this system can also be used to make things out of wax, which is much safer to use, although you still have to watch out for burns and fires! Possible uses for a wax-handling system include: 1) automated wax casting; 2) use of wax as a support material.

If you omit the heaters, you can probably use the nozzle and syringe pump to deposit slurries or liquids.

The idea of operation is that a standard RepRap prints a layer of plastic (HDPE, ABS, etc). Then the toolheads are switched, and the metal/wax toolhead deposits molten material in the channels or cavities formed by the plastic. If necessary, the process can be repeated for constructing thicker and more complex parts.

We have had good success using the nozzle as a hand-held tool for transferring metal. For example, we used it to make this thing: thingiverse.com/thing:802 .

We have had somewhat less success using it when mounted to a RepRap, as seen in the pictures. The main problem is poor control of flow-rate (see photo of pattern on hot plate). With some modification (such as a smaller nozzle hole diameter) and tuning of parameters (feed rate, height of nozzle above plate, etc) it might work much better. We RepRapped a simple test piece, manually filled it with metal while it was still on the hotplate, then let it cool (see photo of widget with 25-cent piece). This yielded fairly good results, indicating that an automated system may be able to produce usable parts.

The main components of the system are

1) Heated cup - this is a heated reservoir that contains the molten work material.

2) Heated copper nozzle - the nozzle slurps up material from the cup, then moves to a desired location and deposits the material.

3) Syringe pump - a motor-driven syringe controls air flow in and out of the nozzle, which in turn causes the nozzle to slurp or deposit material.

4) Heated plate - this keeps the work hot to improve the flow of the heated material. It also melts the base of the deposited part, creating a good seal between part and plate, so that molten material does not leak under the part. In general, the heated plate seems to help avoid warping, but the downside is that the bottom of the part starts to ooze outwards after a while.