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Showing results for tags 'Spirograph'.
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Idiosyncratic gear ratios
Peter Nolan posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
A little while ago I became interested in some slightly unusual gear ratios (for a few reasons covered below). More recently though, I gained access to a laser cutter, and hence the ability to make custom lego gears. With this in mind, I decided to work out all the possible custom gear combinations that will fit on a standard technic beam (ie all the combinations where the centre-to-centre axle distance is a whole number of studs). I found the website https://www.cailliau.org/en/Alphabetical/L/Lego/Gears/Dimensions/ handy for figuring out the meshing. I'm not sure if this is of interest to anyone else, but here is what I found: One custom gear with one standard gear (Standard gear, Custom gear, Ratio) 12 52 3/13 16 32 1/2 16 48 1/3 20 44 5/11 20 60 1/3 28 52 7/13 36 44 9/11 36 60 3/5 Two custom gears where both have a prime number of teeth (Custom gear, Custom gear, Ratio) 11 53 11/53 11 37 11/37 17 47 17/47 17 31 17/31 23 41 23/41 37 59 37/59 19 29 19/29 13 19 13/19 43 53 43/53 37 43 37/43 53 59 53/59 There are also plenty of 'loose running' combinations where the centre-to-centre distance between axles is only 0.5 mm off an integral number of studs. I tried one of these, and it seemed to work fine. Loose-running combos (standard gears in bold) (Gear 1, Gear 2, Ratio) 8 23 8/23 8 39 8/39 8 55 8/55 11 20 11/20 11 36 11/36 12 19 12/19 12 35 12/35 12 51 4/17 15 16 15/16 16 31 16/31 16 47 16/47 19 28 19/28 20 27 20/27 20 43 20/43 20 59 20/59 23 24 23/24 23 40 23/40 23 56 23/56 24 39 8/13 24 55 24/55 27 36 3/4 28 35 4/5 28 51 28/51 36 43 36/43 36 59 36/59 39 40 39/40 39 56 39/56 40 55 8/11 55 56 55/56 SO the big question is, why would I be interested in such things? The first is that a while back I built a 'phase revival' machine (video below). In this situation I wanted a ratio close to, but not exactly 1:1. In the video I used 20:24, which means that the first cog has to rotate 7776 times before all the parts line up again. If I used a custom ratio of 39:40, and had 11 modules instead of 5, it would take 10 billion years (rotating the left-most gear at 1 revolution/second) before all the pieces realigned! I'm not quite sure why, but the idea of a machine that takes the entire lifetime of our sun to reset is appealing! And now for the prime numbers... I've been interested in making lego spirographs recently, and the key to interesting patterns is the lowest common multiple of the two gears. If you have a gear with a prime number of teeth, you are pretty much guaranteed of getting lots of 'knots' in the design. In the second video below, I used a 43 tooth gear meshed with a 36 tooth gear. To actually make the gear profile, I used https://www.festi.info/boxes.py/Gears?language=en with a modulus setting of Pi (3.14) to make lego compatible gears. You also need to tweak the burn correction depending on the cutter and material. I also set 'profile_shift' to zero. I suspect that a little more fine-tuning would be required to get the best result, but this is a good starting point. I hope that someone else finds this interesting! Ahhhrrgh. I can't delete the table below! Please ignore.... -
[MOC] Inverted spirograph
Peter Nolan posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hello! I'm a first time poster in the Technic forum, but thought that my inverted spirograph might be of interest. Rather than move the pen, I used a planetary gear setup to move the paper. Different gear combinations give different results, as does the pen position. The pen-holding frame is made up from a lot of 2 x 4 bricks, but the guts of the machine is a hard plastic wheel with internal gear teeth (I'm not sure of the correct name, but this is the part I used: http://www.bricklink.com/v2/catalog/catalogitem.page?id=83393&idColor=11#T=C&C=11). Sadly the spirograph has now been dismantled--my son needed the parts for a Chima vehicle... Enjoy! -
[MOC] 42110 B Model - 'Defendergraph'
Nalyd997 posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hey everyone, As soon as I saw the defender set and heard about its ambitious gearbox I knew I was gonna get it! Loved the set but felt that it didn't show off its engineering enough so I set off on building a B model for it. It has two speed gearboxes for each arm and a four speed gearbox for the turntable. Still has a few tweaks needed but for the most part all major mechanisms are in place. It's based off the design of my V2 spirograph which makes use of the sets differentials. I was worried about the stability of it as it is hand cranked, however I was pleasantly surprised with the results. The finished prints almost hide imperfections when viewed as a whole. I love this set, looking forward to see what others come up with. Once I am happy with everything I will make some intsructions and a full video of it, just wanted to share it with you all. Peace:) -
Adjustable Spirograph V9 by PG52
GBC Master posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hi all! At the end of June I've visited Fana'Briques, where I saw version 9 of PG52's adjustable spirograph. Based on some pictures I've taken, and some help of PG52 (merci beaucoup! :-) ), I have finally finished a replica of the model: It's very stable and runs very fluently (only requires one M-motor to turn all the gears!). I used a simulator in JavaScript to check if my model did the same as the one at Fana'Briques did. The gearbox of the model also has been created already in Ldraw. Those files can be found here: https://drive.google.com/drive/folders/0B6rVwJJ-wpyRRDNINkdJeUlnTDQ?resourcekey=0-nAIq3XumlLtvCi2NPbZLHg&usp=sharing Happy drawing! Kind regards, Joris -
[MOC] Spirograph V2
Nalyd997 posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hey everyone! Finally found some time to shoot a video for my second spirograph. I actually had this finished over a year ago but you know how life works sometimes:) Thanks to PG5200 for describing to me how his V5 works which largely inspired this one. To address the question I get asked all the time at exhibitions "Can you get two going at once?" I came up with this: These are drawn simultaneously, which you can see in the video here: Thanks everyone:) I'll have an LDD file on the way shortly -
[MOC] PsyCloid Drawing Machine
SevenStuds posted a topic in LEGO Technic, Mindstorms, Model Team and Scale Modeling
Hello! This time I'd like to share my latest project: a drawing machine that is inspired by Joe Freedman's Wooden Cycloid. The LEGO version uses freestanding boxes that can be moved around the turntable. A slight change in position creates a different pattern. Further adjustment is possible by placing the drawing arm onto the different pins on either drive box or changing the position and distance of the pen. Placing one end of the arms further from the center can create a pattern up to 20cm in diameter. The variation possible with this setup makes it almost impossible to repeat exactly the same pattern. Now since I'm a huge fan of psychedelic music and digital art, I wanted to make the video resemble some of the artwork we always see at the outdoor parties. Without giving too much away, I'll let you grab a drink, turn the volume up and enjoy the video! Full write up with more images here. Thanks, Mik -
After seeing PG5200's spirographs a couple of years ago and being completely blown away I knew I had to make my own. It was not until some months ago where I realised how it worked and set about making my own. Mine has 6 speed gearboxes on each arm to increase the variations in patterns. Whilst the exterior looks similar internally mine is very different. You could say that it is 'upside down' compared to Pg's as his outputs for the gearboxes are where my inputs are if that makes sense. I did two videos for it, one describing the functions and the other with it looking cool! As seen in the video I have made various attachments for it, one to turn it into A5 size, and the other to create significantly different patterns. Thanks for watching!