Tiny Planetary Gears Set

by aubenc, published

Tiny Planetary Gears Set by aubenc May 14, 2012

Featured Thing!


A small planetary gears system with a ratio of 4:1 per stage, as many stages as wanted, small, open enclosure to see the gears, and hardware free.

The gears are designed with a circular pitch of 2.5mm and they are also slightly beveled at the tips of the teeth to avoid the need of cleaning the excess of material from the firsts layers.

The OpenSCAD is not parametric, there's only parameters for clearance (set to 0.2), backslash (set to 0.1), pressure angle (set to 22.5), tolerances between nuts and bolts (set to 0.4) and length of the bolts, sometimes referred as rods. Any other change will not work.

To play with the OpenSCAD you will need the following libraries:

Public Domain Involute Parameterized Gears by LeemonBaird

Poor man's openscad screw library

Knurled surface finishing library

The libraries have been included in the ZIP file together with STL files for every single part, build plates for complete sets from 1 to 4 stages, just the crank and upgrade kits from 1 stage to 2, 3 or 4.

1 minute video: youtu.be/MUH0MGP7AGc

A shorter video (59") featuring a 10 stages set: youtube.com/watch?v=FyVZ31tLGCU&feature=plcp

More Pics: flickr.com/photos/aubenc/sets/72157629731990190/

Recent Comments

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Cool! thanks :D I think that you didn't understand anything what I was talking about but at least you saw my products! You have done nice job with the model!

Believe it or not... I enjoyed more the video than you the pizza! Thank you !!

https://www.youtube.com/watch?... (i made a video in finnish (language) if you wanna watch it working!

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My setup is a Makerbot Replicator with 0.4mm nozzle, ReplicatorG - 0034 and Skeinforge 47. The gears where not printing fine with the standard profile and printomatic, also, the threads like to print slowly and a little bit fat.

It is important to set Layer Height at 0.25mm (or the planets can find it hard to spin). Infill should not be set bellow 60% or the bolts will break too easyly!

(The profile I used is included in the ZIP file)

Use multiply to print 4 planets and see if you need to adjust the profile. Then print the stage to be sure that the gears are usable. If you don't clean the sides of the teeth it will be a tight fit perfectly usable. If you clean them they may be too loose.

Be very careful with the bolts, do not fasten the nuts too much (just a very little bit) and be extremely careful when using the crank

Update: Scaling this thing

I'm always afraid about the result of scaling multipart things, specially when the design is full of threads and gears.

Check out the awesome set printed by mread ( thingiverse.com/derivative:29726 )

He scaled it up by 25% and it looks terrific!

I don't know what are the specs of the printer he used but it could very well well be the case that scaling this thing up by 25% is the right thing to do when the extruder is equiped with a 0.5mm nozzle.

Let's check it out! bot1334 has a 0.6mm nozzle so I scaled it up by 50% (0.6 / 0.4), sliced at 0.4mm layer height and... I had a lot of trouble with the threads taped in the plates.

Amazingly, the issues disappeared when I lowered down the layer height to 0.38mm. Is it a coincidence that 0.38 is close to 0.25 scaled up a 50%?

In this bigger (huge) version everything fits but quite tight, the motion is not as smooth and I did had to clean every single teeth. After assembling it and a couple of minutes of operation with a powertool it works quite fine.

Difficult to say if the gears not meshing as nice as they do in the original is due to bot1334's limitations, poor profile, manual cleaning or side effect of the scaling, anyway, I'm very pleased with the result.


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Kart5a on Jun 9, 2014 said:

https://www.youtube.com/watch?... (i made a video in finnish (language) if you wanna watch it working!

aubenc on Jun 9, 2014 said:

Believe it or not... I enjoyed more the video than you the pizza! Thank you !!

thygate on Apr 18, 2014 said:

Awesome Thing(tm), really nice job !
I printed 2 on a Makerbot 2 with default makerware settings. 10% infill, 2 shells, and 200um layer height. no support, no raft. (PLA)
The pins on the bottom ring, that holds the planetary gears, kept breaking off, so I had to enlarge the diameter of the holes in the gears a little.

aubenc on Apr 18, 2014 said:

Glad you like it, thanks for making it!!!

jmaggiore on Mar 29, 2014 said:

Is there anyway you can post/email me individual parts for these models. Some of the parts broke when I tried to take them off of the makerbot platform so I need to print some more parts but I don't want to have to print an ENTIRE stage. Anyway you can post the individuals?

aubenc on Mar 29, 2014 said:

Sure, there's a compressed file (.ZIP) in this thing's "Thing Files" which should contain all of the individual parts. Let me know if you don't find what you need. Thanks!

sofiadragon1979 on Feb 18, 2014 said:

I am in need of some help. I am working on a design for a large project & I need a planetary gear system that is on a 1:50 system basically the main rotation is a single rotation & the output is 50 rotations per single rotation @ the main, so I am wondering if this can do that sort of thing or will I need a completely different design?

aubenc on Feb 18, 2014 said:

Hmmm... (if I get it right) 50:1 it's quite an unusual approach because you need huge torque and very low speed in the input as well as gears made in a material that's up to the task, they will also need to be lubricated and cooled down, even very low friction will generate a lot of heat resulting in dimensional changes of the gears which will result in more friction, thus more heat thus... a lot of chances for failure. You may like to print a 3 stages (1:64) and try to use the output as input. Something will break very soon.

For this ratio I would consider designing a non planetary gear system, it's way easier to build a "traditional" gear train with two sets of gears (1:5 and 1:10) or, even better three (1:5, 1:5, 1:2). Hope it helps

baggers on Feb 8, 2014 said:

Hey there, awesome model! I am trying to print this on a Lulzbot TAZ 3, and am having some problems getting it to work. What happens is that the plastic seems to "slump" a little on the first layer (I print with no support), making the holes smaller than they should be, and meaning I have to trim them out to get them to work, which looks kind of ugly. I am also getting problems with the taller parts not printing, as they stop printing about an inch from the bed, with the extruder seeming to either knock them over, or the layers not sticking together. I am trying again, with the printer in a more sheltered location from drafts, but any other suggestions for either problem?

aubenc on Feb 9, 2014 said:

Glad you like it and sad to hear about the issues you're finding to print this :(
Looks like your printer needs a little bit of fine tunning (?). A sligtly fatter 1st layer (or a few of them) is normal, the excess should be easy to remove wherever it may be needed. If not, or your software is making them too fat or the nozzle is way too close to the build platform at Z0 position. This and the other problems you describe depend a lot on the material being extruded (ABS, PLA, ...) their quality and the way they are layd down (too hot/cold or fast/slow). Environment conditions may also have an impact...
Hope you get all those solved and we see soon another copy of this popping up in the "made" section!
Thank you!

DaPlague82 on Jul 14, 2013 said:

Just made one in OD green!! Scale was 125%, .5 nozzle, .25 layer height, 85% infill, on an Airwolf 3D printer. Print came out great in my opinion. I did break one of the screws and glued it back together (my fault). Everything meshed perfectly with these settings and size.

aubenc on Jul 14, 2013 said:

Very beautiful one! Thanks for posting the pic!!

I've break thousands of screws myself, until now, what it works the best to me is heating the two pieces with a thin blade attached to an old solder iron and "fuse" them back together in the right orientation.

Barnacules on May 21, 2013 said:

I scaled this up to 200% in Cuda with .1mm layer height and it printed and worked like a dream! I posted a picture in the "I made this section". A few of the parts fell over during printing but they were done enough for assembly to work. This was due to me being an idiot and turning on the AC in the room before heading to bed which lowered the room temp and caused the items to become detached form the platform and get knocked over by the print head (oops). I should have a video up on my YouTube channel tonight!

aubenc on May 22, 2013 said:

Wow! Really worth to take a look to your "made one". The combination size and quality is plain amazing!! Well done and thanks for sharing the pic!!!

Zh4x0r on Mar 22, 2013 said:

Awesome design, and proof that I really need to tune my settings! I've been printing fine for most stuff, but my Cupcake w/Gen4 electronics and ABS may not be up to the task on this without some serious tuning... the first print I did resulted in everything being too big to fit together, so I'm going to try scaling each part up to twice it's size and lowering my flow settings just a touch

aubenc on Mar 22, 2013 said:

Thank you!

I hope your Cupcake will get it. Mine just needed to scale up everything up to 150%. I need to mention that I had "some" work though. Because bot1334 is still Gen3 and MK4 style extruder (and, to make it worse, home made hot end) I had to print every single part in a separate build but for the planets which are too small, even @150%. I had to use a knife to clean the ooze between planets and the excess of material in the bottom of the parts or the teeth wouldn't mesh.

You may like to use the OpenSCAD to increase the tolerance (however it will take some time to compile every single part) or use the annulus and 4 planets for testing the fit (the planets' dimensions are the same than the sun).

Looking forward to see your Cupcake's copy of this!

rpressley on Feb 24, 2013 said:

Printed on my Replicator 2 with yellow PLA(had stringy issue with Green), had to clean the hole sizes slightly but everything else fitted perfectly. Nice Job.

Heed on Feb 13, 2013 said:

My video of the printing: http://www.youtube.com/watch?v...

aubenc on Feb 16, 2013 said:

the PLA looks black to me... :)
Thanks a lot for sharing it

HobgoblinSteve on Jan 31, 2013 said:

Im trying to print this at 225% and everything prints and fits fine (the planets) but I need to get some parts separated. Specifically if the planets can be taken out of the crank/handle assembly.

HobgoblinSteve on Jan 31, 2013 said:

the parts Im missing right now (because they wont fit on the plate) are the crank/handle assembly, and the start and end pieces with washers.

ncbob on Jan 31, 2013 said:

I just printed mine, and I double sized it and it came out awesome. I only did two stages, and now I'm going to do the complete 6 stage one, but only going to scale it 150%.

aubenc on Jan 31, 2013 said:

Beautiful one!!
Looking forward to see that 6x, omg, 6x!!

chriswolfram on Jan 10, 2013 said:

I just tried to print this on a replicator 2 (with PLA) and the bolts didn't fit into any of the sockets. Has anyone else had this problem/is there a work-around?

rx7mike88 on Feb 18, 2013 said:

I was able to print this on my REPLICATOR 2. Just use the default settings, which are,15% infill, 3 shells, and layer height 0.1. It'll print perfectly.

aubenc on Jan 10, 2013 said:

Sorry to hear that.

Threads may be tricky to print, specially when they are in small parts like the ones in this thing.

You may like to carefully scrap out a little bit of PLA from them. For the plates use a x-acto like hobby knife or a small file and for the screws a flat file or some sanding paper.

Another thing you could do is use Makerware to scale down X and Y (leaving Z unaltered) for the screws (you can find them in the zip file).

Of course, you can also use the OpenSCAD to change the tolerance between nuts and bolts. However, this may have unwanted side-effects.

People with extremelly fine-tuned slicing profiles have reported the opposite (the fit was too loose).

Hopefully the first (and easiest) workaround (just don't remove all the threads!) will do the trick.

Greymantalker on Oct 3, 2012 said:

Not sure if possible to create... but might you be able to also post the DXF file equiv. for the different parts?  In the case of multiple gears molded into one shaft... acyrlic or wood could be glued together on the same shaft...  looking to create this gearbox using a laser cutter
thanks much, GMT

aubenc on Oct 3, 2012 said:

Glad you like it!

Good news is: This thing has been designed with OpenSCAD which allows you to export the parts as DXF.

Now the not so good news... :(

If I'm not wrong, there's not a single part that can be just ported to a 2D drawing without having to rework it, i.e. the gears have a small bevel at the tip of the teeth, all the threaded taps should be replaced by just holes sized to accommodate some (metric or imperial) standard size and the planets carrier should be redesigned to use some sort of tube or pins (this thing is very small and I don't think that stacking layers would make it).

I don't have access to a laser cutter to play a little bit and learn how to do it right, I'm afraid that I'm not able to put the time that all the changes would require. I'm very sorry for that.

That being said, if you'd like to do most of the work (derivative or new thing for laser cutter) I can help a little (very little) bit. i.e. it's very easy to me to provide the gears to your specs.

Just let me know...

sirmakesalot on Jul 23, 2012 said:

SO amazing! My Replicator arrived on Friday and I thought what better way to calibrate it than with this model; it was my first print! Your settings are right on the dot! I went through SF37 settings one by one (took me an hour or so) and what a difference! Thank you so much for saving me a ton of time! =-X =-X Two smily faces!!

aubenc on Jul 26, 2012 said:

Awesome! You've been quite busy with this thing ;) I love it, thanks for printing it!

sirmakesalot on Jun 20, 2012 said:

Way to go! When my replicator arrives this is the second print! Going to give it a go on my TOM too!

aubenc on Jun 20, 2012 said:

Can't wait for you'r Replicator to arrive... :-D

TravisNave on Jun 15, 2012 said:

After building it in basic ivory, I decided to build this at 2x size and used 5 different colors. This was built on a Fortus 250mc at 0.007" at 2x using Red, Yellow, Nectarine, Blue, and Steel Grey. Enjoy!

Included in the pic is a US Nickel to show scale.

aubenc on Jun 15, 2012 said:

Absolutely colorful awesome!

k1nc41d on Jun 10, 2012 said:

Don't use sclic3r 0.8.2 on this. I printed it great on 7.2b but after the upgrade to 0.8.2 the holes were too large. If using sclic3r 0.8.2 don't blame the thing, check your software. :)

Known issue that heavily affects this thing. https://github.com/alexrj/Slic...

jridley on Aug 23, 2012 said:

That has been fixed with 0.9.x Slic3r 0.9.x is the best thing since sliced bread. My prints are now better than I ever could have hoped for.

TravisNave on Jun 8, 2012 said:

This part came out great on my Fortus 250mc. Layer resolution was 0.007" and I built it at 125%. Went together great!

aubenc on Jun 8, 2012 said:

I was marvelling about the definition and the quality when I first saw it in the "made things" section. Now I understand it better ;-)

With such a printer, I guess it would also work at 75% 8-)

Thanks a lot for posting the pic and comment!!

aubenc on Jun 6, 2012 said:

At this moment I feel like I need to say something:

I was happy when I saw the "likes" rising, pleased to see it featured, surprised that it made it to the popular #1, astonished to see the blog posts talking about it, number of youtube views, comments, twitter, Google+, Facebook and the like...


what I love the most is the feedback received,
comments, tries, successful prints, people sharing the settings for the different set-ups...

Thank you.

BlueBot on Jun 5, 2012 said:

I liked it so much i had to print the extension kit. Fantastic design, thanks.

aubenc on Jun 5, 2012 said:

I'm so glad you did it!

Your copy is amazing, it's the 1st time I see so clear the smoothed surface of the knurl in the crank (I don't remember if I set it to a 50% or to 40%).

Thank you !!

mcentric on Jun 5, 2012 said:

a quick video of the 4 stage version in action: http://youtu.be/Qfuwpd945SI

Great model! :)


k1nc41d on Jun 7, 2012 said:

Awesome video. That fourth stage is insane.

aubenc on Jun 5, 2012 said:

I would rather say...

Great print!

Thanks a lot for the video too!!

k1nc41d on Jun 5, 2012 said:

I can tell a lot of work went into this. Worked perfectly first print, and bumped up the size by 25%. This was the most complex thing I've put through my Printrbot. Simply Amazing! Thanks.

MDFast1 on Aug 5, 2012 said:

Settings? Trying to run it through my Printrbot now.

LeeroyLee on May 30, 2012 said:

Even the failures are beautiful :)

aubenc on May 30, 2012 said:

:) Believe me, it's even more beautiful without failures ;)

Looks like the gears have been having hard time to get printed... I see a Replicator in the background. If not done yet, I would try with the profile I included in the ZIP. Don't forget to use Multiply to print the 3 planets in one build (one planet at a time can be hard to get it right).

Hope I'
ll soon see this set completed!!

duckythescientist on May 25, 2012 said:

I tried a few times to get the print working for me to no avail. The tolerances between things such as the nuts and bolts are too tight. I'd rather not change and export from the SCAD file, so do people have suggestions how I can get Slic3r to work? Could this be from a bad Esteps value? I can get the layer height down to where I need it, but I have had overall very poor luck figuring out calibration with my printer (Prusa, Makergear).

Sal on May 31, 2012 said:

I believe the key here is to get a perimeter width that suits the model. Slic3r's default width is inversely proportional to layer height (within limits). Try changing layer height or width over height ratio. The "wall width" calculated by slic3r is shown in the gcode header. For me, 0.49 mm worked ok, which I got with nozzle .35 and layer .20. Good luck :)

aubenc on May 25, 2012 said:

I'm sorry to hear that, unfortunatelly, I cannot be of much help because I have never used Slic3r. Hope someone will help here.

Anyway, if the tolerances are way too tight, it looks clear that too much material is being laid down from the nozzle. I would try to either decrease the flowrate or increase the feedrate (or both). Also, you may like to increase the layer height.

Good luck!

trebhill on May 25, 2012 said:

Nice work, very cool.

aubenc on May 25, 2012 said:

Just a silly comment, hope you will forgive me...

If only a 10% of the stages that have been downloaded to date where printed and stacked together and the input stage was rotating at 250RPM, in ideal conditions where nothing never breaks or wears, it would take 1.29x10^235 years to the output stage to give only one turn. The whole thing should fi
t inside a 40mm id tube/pipe with a total length of 4.6655 meters.

00,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 years

Sal on May 21, 2012 said:

Totally awesome!

Definitely needed some tuning to get slic3r and my .35 nozzle to print working versions of this... Latest git version (0.7.3-dev?), one perimeter and .20 layer height was the key to success! I left infill at 25% but slic3r produced mostly solid infill anyway. Two more stages tomorrow...

aubenc on May 21, 2012 said:

Agreed! To-ta-lly awesome!! I'm talking about the print ;)

Can't wait to see the remaining 2 stages. Thank you!

g_uenk on May 20, 2012 said:

Wow, beautifull prints !

I wanted to see if my 3dprinter was also able to make these tiny parts.
It is, but far from beautifull.
I used my own adapted profile and the one (PLA) from the planetaryAssembly.zip but my skeinforge makes it with hardly no infill as can be seen in the pictures. This is also how my prints look.

May I ask how you get those awesome prints with infill?
Thanks ! :)

aubenc on May 20, 2012 said:

Hmmm... hard to tell. I'm not really good at fine tunning, the number of parameters involved and their naming it's quite a difficult thing to me to get it right.

I'm affraid that the profile included in the ZIP will not be of much help for other printers than the Replicator or at least printers with an MK8 (may be MK7 too ?) + 0.4mm nozzle and using 1.75mm filament.

In Fill preferences I was setting all the Extra Shells to zero and infill Solidity to 60%.

In Carve I was adjusting Witdth over Thickness accordingly to nozzle size and Layer Height (set to 0.25) : 0.4/0.25=1.6

I did some changes in Dimension which I'm not able to explain, just to get the plastic extruded at the right point when changing from one part to the next one.

And the last thi
ng I did is adjust Feedrate and Flowrate.

This beeing said...

Looking at the images you posted, it looks like you have more shells than just the outer perimeters, the parts are too thin and there's no place for the extra shells but, because there are extra shells in your profile (just an assumptio
n) then there's no place for infill neither resulting in an empty space between the outer perimeters.

It could also happen that the combination of speeds (Feed and Flow rates) and Width over Thickness is not allowing room enough for any infill (just gessing here because it looks like there's space
for some infill in the teeth)

I would 1st check that there's no extra shells, infill is set to something different than zero and Width over Thickness is set at the right value. If there's still no infill showing up then, then I would try to decrease Flowrate and increase Feedrate. If that is not he
lping neither then I would try to increase the layer height and set Width over Thickness accordingly.

It could also help to check if your printer is in the menu: Machine -
gt; Machine Type -
gt; Other Bots (I don't know if versions previous to 0034 also have this implemented) and then use Print-O-Matic with the adequate parameters, filament diameter, number of shells =0, nozzle size... and like.

Sorry for the long answer, I just feel myself a little bit lost when I have to tweak the profile. I really like to read how it went and if that info was of some use ???

Hope to see your Tiny Planetary System soon, good luck!!

chriscrewdson on May 18, 2012 said:

I used your profile on my replicator which definitely helped with the quality. Still took a few tries to to get all the parts I needed for a functional model, but now I have a 4-stage set which is an awesome example of what can be done with a Replicator.

aubenc on May 18, 2012 said:

I'm sorry for the tries, I admire the spirit of not giving up. I must admit that it also took me
a href="http://www.thingiverse.com/der..."
quite a few tries

Glad to hear that the profile helped and happy as one can be to see that 4 stage looking so good!!!

Thanks a lot for the feedback!

Rasle500 on May 16, 2012 said:

So cool, great design 8-)

aubenc on May 16, 2012 said:

Thank you :-D

Hobie on May 16, 2012 said:

Awesome print! I enjoy prints without a raft or support and this gear set is awesome to play with. Thanks!

aubenc on May 16, 2012 said:

Wow! Thank you and also thank you for the print
amp;pic !!

rustedrobot on May 15, 2012 said:

Awesome! Beveled tiny teeth!

aubenc on May 16, 2012 said:

:-D even if it's only the tip of the teeth, it really makes a difference.

sirmakesalot on May 15, 2012 said:

Very nice!

aubenc on May 15, 2012 said: