http://www.instructables.com/id/Desktop-Ornithopter/

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Desktop Ornithopterby Jezza Bear on March 4, 2007

Table of Contents

Desktop Ornithopter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Intro:   Desktop Ornithopter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Step 1:   Items used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Step 2:   The upper mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Step 3:   Lower mechanism . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Step 4:   End Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Related Instructables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

http://www.instructables.com/id/Desktop-Ornithopter/

Author:Jezza Bear    author's websiteI work in IT as a manager of a team responsible for server based applications.

I am also a lecturer in Database Design, XHTML and CSS at the University of London, England

Intro:  Desktop OrnithopterTo create a flying machine that simulated bird wing movement ( an ornithopter) but was able to have smooth movement.

The difficulty in creating an ornithopter is the issue of having smooth and consistant wing movement. Many people have tried building these and never quite get themovement right with the wings flapping unevenly.

This little project started about 18 months ago whilst pondering how to do it... this little instructable hopefully explains how I got around the problem.

Image Notes1. Not part of this Instructable but was a flying example...maybe at a later date.

Step 1: Items used1. Coffee Stirrers2. 4mm MDF3. Motor from redundant 1990's video camera4. Various cogs and clips from video camera5. 2mm thick dowels from PC cleaning equipment6. SupaGlue7. Twine

Build Time

6 hours

http://www.instructables.com/id/Desktop-Ornithopter/

Image Notes1. Joints made by drilling a small hole and then placing a small 2mm rod through it. Great care is needed so as not to split the stirrer2. Wire to motor. As I say in the notes, the motor is not too important but it gives a nice touch3. This is a small guide built using coffee stirrers. They are the width of a coffee stirrer apart and glued to the T-bar. The ones perpendicular to them are also glued toretain the main cam rod. A small amount of vaseline was placed on it to lubricate.

Step 2: The upper mechanismThe main difficulty that presented itself from the beginning was the issue of the smooth motion required to get the wing blades to move smoothly. This diagram shows aschematic overlay of the wing coupling on the ornithopter. The upper wing joints forming a triangle are fixed and the lower (in the current shot) is fixed to the cam. You willnote that the distance between the couplings at the low stroke and high stroke is 36mm but at mid point the distance between the central coupling and each out joint is30mm.

Due to this issue I saw fit to cut a slit in the wing blade (circled in blue on the left) with a length of 6mm, the difference between the maximum coupling distance and thethe shortset coupling distance. The couplings were made by drilling a 2mm dowel into MDF and then feeding the blades onto them. The blades were kept in place myminute aluminium washers found in the video camera.

http://www.instructables.com/id/Desktop-Ornithopter/

Step 3: Lower mechanismThis is where a simple cam mechanism worked an absolute treat. This part required a bit of trial and error but it was finally worked our using some graph paper, acompass and my trusty metal ruler. The trick is to ensure that the three arms creating the cam are cut to specific lengths so that the upthrust and down thrust do notcreate a jam at the lowest and highest points. The measurements I used are:

Arm A - 20mmArm B - 52mmArm C - 73mm

Note that there is no real need for the white polythene cog behind arm A but it was a good support. Behind the system shown is a small cog which inturn is attached to asmall 6 Volt motor. This motor was absolutely fantastic, it was taken from an old video camera in the lens housing. It appears the motor was used focus the lens. Not afast motor but had a very, very strong torque.

Step 4: End NotesYou will note that ornithopter appears to be held together with twine. The reason for this was that the motor that was used was so powerful and with such a high torquethat it had a habit of grinding over the gears. The twine was introduced to increase the tension on the cogs connecting the motor to armature A's axle.

Before I get some silly comment from someone, I do have this published on my website (non-commercial) and I have a few photographs and a few concept designs andmpg of the ornithopter. Please enjoy it for what it is, thank you.

Ornithopter library

The whole idea was just a method to see the best way to get linear motion from circular

http://www.instructables.com/id/Desktop-Ornithopter/

Image Notes1. Not part of this Instructable but was a flying example...maybe at a later date.

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Bike Blender byksutherland

Comments

29 comments Add Comment

 T_T_ says:  Jul 14, 2010. 8:36 PM  REPLYlook at what this person did, it looks pretty simple http://www.youtube.com/watch?v=lhjWX9HAKmQ&feature=related

 DELETED_drewdegruyter says:  Mar 4, 2007. 5:23 PM (removed by author or community request)

 budsiskos says:  Nov 4, 2007. 5:24 PM  REPLYi also agree with el_roboto_loco because why else would instructables be called The worlds biggest show and tell?

 el_roboto_loco says:  Jun 23, 2007. 5:25 AM  REPLYActually, it's a good instructable. If he solves one problem, then it might be the missing piece of the puzzle for somebody else who is doing somethingextreme and novel, but maybe they're stuck on this one item. If somebody does some analysis, and design, and makes a model, then that is a project initself. Military contracts usually are given out as 3 phases. You submit a proposal for something they are soliciting, and if you win a contract, it's just astudy contract to do more analysis and then you do a final report. Phase 2 is to build a working prototype. Phase 3 is production. The point is that ifsomebody has done some thinking, and some tinkering, and goes to the trouble to make an instructable, then I thank them. Ph.D.s write white papers,etc., which are theories, and theories of operation, and those papers get published. Then, other people get inspired and write a paper and they referencethe work in the first paper, and similar papers, and eventually somebody builds something.

 budsiskos says:  Nov 3, 2007. 8:35 PM  REPLYyou can make it smaller by having armA side ways - arm B down at an angle \ and arm c up I OR you can completely eliminate arm c

http://www.instructables.com/id/Desktop-Ornithopter/

 Jezza Bear says:  Nov 4, 2007. 5:23 AM  REPLYThat is an interesting point. The diagram on the right of your image is worth looking at but I have a feeling (yet to be tested) that it may put a lotof stain onthe mechanism....one to test. I have been meaning to post my latest creation which has been sitting on my work bench for the past 5 months where Ihave used a "conventional" mechanism. Your idea has certainly made me think, thanks for your input.

 lightninjim says:  Apr 4, 2007. 4:59 PM  REPLYROYALESTEL WROTE:"anyone know more about this ornithopter?" posssibly lol Yusuke Takahashi built this remarkable infrared remote-controlledornithopter based on The Ornithopter Zone's Luna kit. The ornithopter uses a 0.4 gram infrared receiver desgined by Koichi Tanaka. In contrast to the flat tailof the standard Luna, Takahashi's version has separate rudder and elevator surfaces with magnetic actuators(standard indoor modelling practice). Theornithopter also has proportional throttle control. It uses a super slick orange motor.What makes these motors so special? First, they have a weight of 2.7gwhich is about 1.1g lighter than a typical M20-LV motor. They also have reasonably strong magnets and will attract objects to them. Not all coreless pagertype motors have magnets this strong. They also come with various motor windings identifiable by the colour of the motor. The power source was a 70mAhLi-po providing around 10 mins flight times

 Jezza Bear says:  Apr 4, 2007. 4:58 PM  REPLYThanks for the feedback, I have been around that site so many times that I hadn't even noticed that section. I am planning the next stage of this projectand just getting my materials together.

 rickharris says:  Mar 18, 2007. 10:24 AM  REPLYhave a look herehere

 crestind says:  Mar 4, 2007. 10:19 PM  REPLYhttp://hight3ch.com/post/gorgeous-ornithopter/#more-2382

Here's the one I saw. Amazing. Wood sticks and plastic cloth wings. It seems to be rubber band powered, because there doesn't seem to be a motor. Thedual wing design is incredible.

 Hands Without Shadows says:  Mar 10, 2007. 8:28 PM  REPLYI think that its rc. During the part of the movie where the guy holds it you can see that it is variable speed and when there is a closeup of the frontmechanism there is what looks like an outrunner brushless motor behind it. There also looks to be a small lipo battery right in front of the rudder, thatcombined with the mess of wires, flying small rc in gymns being common, and another plane in the background for parts of the movie just adds to mytheory.

 royalestel says:  Mar 9, 2007. 2:18 PM  REPLYThere seems to be a very similar model being sold here.

 Jezza Bear says:  Mar 9, 2007. 2:23 PM  REPLYrofl....I was looking at that very page last night...I am tempted to buy one and then get ideas from them...

 royalestel says:  Mar 8, 2007. 1:48 PM  REPLYAnyone know anything more about this ornithopter? It's by far the most beautiful and natural looking one I've ever seen. Love to make one, I think.

 crestind says:  Mar 10, 2007. 7:47 PM  REPLYYou can sort of see the gears around 1:04 on the video. I still can't tell what it's powered by though. I can't see a motor or anything.

 Jezza Bear says:  Mar 8, 2007. 1:56 PM  REPLYI have just had a look at the video and paused it at the various points and reckon the cam model is pretty straight forward. I think I may have have ago and make a concept. It appears they are using very light weight material for the wings, possibly fine silk.. I shall have a go tonight and publish amock up

 crestind says:  Mar 10, 2007. 7:47 PM  REPLYPlease post if you have any working ornithopters! Knex seems to be too big for ornithopter joints and such :( Maybe barbecue skewers will workwell.

 el_roboto_loco says:  Jun 23, 2007. 5:07 AM  REPLYI'm using BBQ skewers. They work great. And I have a very cool linkage for the vertical motion at the crank that I just tested for proof-of-concept, and it works. And, it's frictionless! Also, you don't need to bend any wire as with the typical cranks. Whether it'll fly remains to beseen, but I'll know in a day or two. I just came up with this novel linkage yesterday. As soon as I have something that almost flies I'll do aninstructable. I've already started taking pics as I go. I'm also making a hybrid ornithopter, which has a propeller, and I'll put that in theinstructable, too.

http://www.instructables.com/id/Desktop-Ornithopter/

 royalestel says:  Mar 8, 2007. 5:45 PM  REPLYI was thinking it was a wal-mart shopping bag or something even thinner like a thin paint tarp.

 el_roboto_loco says:  Jun 23, 2007. 4:50 AM  REPLYwhat works well as material for the wings is "plastic" basket wrap tissue, or the same thing in the form of party bags. I got a big roll of the clearstuff (which I had to splash paint on it because I could never find my clear pieces) but it also comes in colors and festive patterns. It's verylight weight, and crinkly, but it doesn't wrinkle. It's seems very similar to mylar. I got some from a crafts store, and the party bags at dollarstore right next to the first store. It's cheap, too. Also, unlike the normal tissue people use, it's easy to handle, and doesn't stick to your fingerswhen you glue it. I'll put some pics up later.

 royalestel says:  Jun 23, 2007. 8:39 AM  REPLYcool.

 el_roboto_loco says:  Jun 24, 2007. 12:20 PM  REPLYhere's a pic picwww.pneumagic.com/instructables/ornithopters

 jtobako says:  Mar 5, 2007. 8:34 AM  REPLYin step 2, the upper mechinism, you would get better strength with a guide that goes around the spar rather than cutting a slot in the spar. something like astaple or eye hook, even if it had to be able to turn in the suport because of tight tolerances. when you start worrying about weight, i've seen where balsawood is impregnated with super glue to harden some surfaces without adding much weight.

 Jezza Bear says:  Mar 5, 2007. 2:01 PM  REPLYHi There Funnily enough I tried that as an option and whilst agreeing, I decided not (for this model and probably others) only because "it was anotherbleeding part ready to go wrong" :-) In the smaller model I actually built a flexible rod that did work. Thanks for the idea, it would certainly be an option forthe future. The super glue idea is very good, I have hardened pegs with this idea before but good to share.

 crestind says:  Mar 4, 2007. 9:50 PM  REPLYAwesome! I've been wanting to build one ever since I learned about these (last month lol)! I understand the basic concepts, and I'm probably going to useKnex for movement parts. A few questions- -Wing angles. So I'm sure the front tip should be up to generate forward movement. But what angle would be thebest? -Horizontal wing movement piece that runs through both grooves. That also serves to ensure both wings move in unison? -Even though it's balsawood (I think), it looks really heavy even without the base. So how fast does it go? (layman terms please - walking speed, light jog :P) -Is there an "optimal"wing width per weight? Can you post a few side views please? I want to see if you had any rear fins and such and width of wings. Sorry for all the questions,but this is really cool! Since I have no motor, I'm going to try and make a lightweight rubber band powered version.

 Jezza Bear says:  Mar 5, 2007. 4:18 AM  REPLYHi There Thanks for the comments. This one was purely a concept model and just a desktop version, it was way to heavy for it to fly properly. Thesmaller one in the first image was designed "on the fly" (pardon the pun) and actually flew and then shattered. When I get home tonight I will certainlyphotograph a side view for you to look at he rig.

 Williz says:  Mar 4, 2007. 3:58 PM  REPLYBe easier if you used a step by steap guide on how to MAKE it. Not just photo's of it done and instructions. Makes it hard for some people.

 trebuchet03 says:  Mar 4, 2007. 10:27 PM  REPLYYou need to read the intro to realize this is not how to make it, just how to fix a common problem ;)

Many people have tried building these and never quite get the movement right with the wings flapping unevenly.... this little instructable hopefullyexplains how I got around the problem.

;)

 Jezza Bear says:  Mar 4, 2007. 4:21 PM  REPLYI hope you note the very last sentence of Step 4 I have made: "...the best way to get linear motion from circular" I thought Step 2 and Step 3 of myInstructable showed the steps to create linear motion using calculations.