MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.

Download Now


Fully 3D-printable wind-up car gift card

by Bribro12 Dec 23, 2018
Download All Files

Thing Apps Enabled

Please Login to Comment

Can’t for the life of me seem to get my tolerances right. The spring and axles are way too tight. Setting are .40 nozzle, .20 layer height, 100% Infill, .40 line width and 100% first layer height. Doesn’t seem to be any elephants foot and my extruder is calibrated. I have to scale the frames up to 106% to get parts to fit but then the transmission gears won’t mesh. These are all parts from the gift card files.

Comments deleted.

I like the idea of a small gift card construction. I was trying to do that with my laser engraver, and make a small castle kit.

Hi Bribro12, Your projects been chosen by my university as a mechanical engineering design project. Would it be possible to upload the .step files so we can produce some CAD drawings of it?

Awesome design, thanks for all the work put into this! I had troubles printing the first layer (Anycubic I3 mega) but after a lot of frustration, eventually lowering the temp and speed worked fine. My printer sometimes has trouble with the spring but seems to be working just fine now!
I needed a bit of superglue to keep the back wheels on, but my son loves it and I'm just printing another for my friend.
Thanks Bribro12!

I'm glad you and your son like it ;-)

Excuse me, you used PLA or ABS , Which should I use?

I used PLA to print all the parts. I don't know what the result with ABS will be.

Very good job.

  • Posted with 3D Geeks Thingiverse Browser App

Thanks ichavesss ;-)

can you all stop making so many awesome things my printer needs a break :D
thanks a lot it looks so awesome. can't wait to gift this to myself xD

Fantastic easy printing and works fine, thanks for sharing your creation.

Looks very nice ;-)

Back wheels are super loose. I could not figure out the spacers even after reading the above, the instructions sheet is of no help because it must be for the "pre-spacer" model.

I have it working, but I think every part needed a sanding to just knock down 'hairs or burrs's some printers might make. I think My Prusa printed the spring or escapement (both?) a bit too "dummy thicc" because the spring does not tighten enough for a long ride.

So my advice for all is fix the tires in CAD, then print it cut the parts off, and then lightly sand EVERYTHING before assembly - even if you printer did it perfect from inspection.

The kit works fine for me and most other people right of the printer without the need for post-processing. In fact it's the first time I hear someone using sandpaper on the kit. As I mentioned more then once in the past, the kit will never be perfect for everyone. The difference in quallity on a lot of 3D printers is just to big to compensate for all of them.

it says non commercial. but it's a gift card.
how is that going to work?

or does giving it away not count?

Hello EstaWorks3D. I don't see how giving these gift cards to your friends and family would be commercial. As long as you don't get paid there isn't a problem. Definition of commercial according to the Cambridge Dictionary: "intended to make money, or relating to a business intended to make money".
Source: https://dictionary.cambridge.org/dictionary/english/commercial

Congrats! Great design. Perfect print at first try. Worked flawlessly.

I'm glad you like it magmunoz2000 ;-)

Thanks for the great "educational kit"! Please, could we use it to present our school MAKERS club at Maker Faire 2019 Prague event? Visitors to our site could build this "puzzle" and then compete with it. Will we get your permission?

Hello ToFe, yeah of course, no problem at all, as long as you give me credit everything is fine. you can print out a thing tag wich you can find under the tab thing details, then on the left "Give a Shout Out" ;-)

I know what I'm gonna get my friend to his Birthday!

Good choice JJesseBorn ;-)

has anyone tried scaling it down. What are the chances it will still work at 75% or 50%?

I'm printing at 82% right now (max size for my snapmaker). I'll let you know when its done.

So What do you say ? It's can be possible to scale the model ?

The spring_V2 wasn't printed right at 82%. I'm testing the optional springs and the spring_v2 at 100% (it could be a problem of my own optmization here).

Hello Bribro12! I love this design and was thinking about giving away a few to my brothers children.

Anyhow i'm slicing it in Cura and it says the time will be about 4,5 hours (think it will be more like 5-6).
Have you tried printing it very fast? and with different layer heights?

Anyone else that have tried it faster maybe?

I just printed the v2 cards at 80mm/s and 0.3mm layers and printed fine. Took 2h each.

It's taking some time to wear off the residue, but I like it.

I downloaded the files however my printer won't print it. In fact I can't get it to print anything other that the sample that came with the printer. Hopefully I can print this soon.

Are you trying to send the files right to the printer? The files you download need to be opened in a slicer program like Cura or Simplify3D. The slicer program will convert the model into a file for your printer (usually .gcode). Hopefully that helps.

I was/am using Cura 4.0 and I did slice it. The issue was the gecode start and end scripts. The machine doesn't like the commented out descriptions of the code. I removed them and I was under way.

Awesome. I'm glad you figured it out. Sorry for assuming in my previous reply.

It's all good. This is my first 3D printer and have learned a ton so far. I have a print going right now that's been running for 22 hours.

A great design man! I will be printing this sometime soon

in the meantime, I have created a group for toy designers (stuff just like this) if anyone wants to join


Hey, thanks for the amazing design!!!

Is there any chance that you will be able to update the assembly instructions to the second version? I was able to assemble it without a problem, but I feel like it won't be nice if I gift an updated version with old instructions and people get confused.

How small do you think this can print at while still being stable? Can you print at 50%?

Very nice looks kek!

I have this assembled and am so close to getting it to run right but i must have assembled something wrong somewhere. My turn key never clicks and locks while winding up. Instead it winds up and on release the gears just bounce back and forth in opposite directions never pushing the car anywhere. I know this is assembly or user error but any feedback would be appreciated. Thanks in advance!

It looks like you got the last cog miss placed (the one to the right). Its small cog should bind with the large cog in the middle, and its large cog should bind with the cog on the axial

Great design! Thanks alot. I have printed 3 now, one for my boy and two for nephews.

My kid actually plays with it quite a bit and I found the wheels could use some extra grip. Also the axle to wheel fixture wears out pretty quickly. So, I have added some 'tyres' printed from flex. Also I did a redesign of the axles and wheels to give them a snap-on like fitting for a stronger join.

Again, thanks a bunch!

Could you share please?

This design is great! The car printed very well and after some assembly, the car moved great. However, an improvement would be to give the wheels more grip so they can move faster. Great design, thanks for sharing!

hi, i really want to print this gift card. It looks awesome. I only got a problem. When it starts to print (giftcard 2 on ender3 pro) it's really rapidly changing directions resulting in loose wheels. I tried several benchmarks( benchy, micro test, levelbed) with good result but the problem still remains. I also tried to decrease the first layer speed. This works i little bit. Any advise on a cura profile setting to try? Thnxs! i'm a beginner with 3d printing.

What's changing directions? You need to specify things clearly when you are trying to describe what's going on so people that aren't present can understand the situation.

I'm sorry. Let me explain it more thoroughly. When it's starting to print the first layer and starts with the wheel it tries to print the edges or teeth of the wheel. This resulting in rapidly changing (forward backward) directions for these teeth. It's ofcourse a triangle. It looks like it's overshooting himself. The PLA isn't sticking to the plate. All other parts of this giftcard are perfect. could this be the print speed of the first layer?

It can be a lot of things that can give you problems with adhesion on your first layer. You could try to configure your slicer to move at half speed on your first layer and turn off cooling until the second layer. Otherwise there are all kinds of information online to help you troubleshoot your issue like on youtube.

I had a lot of fun putting it together and learned a lot about motion too, thank you for this.

Printed 2 of the cards. Back wheels on both were very loose. Fixed this by fusing the axle and wheel connection with a soldering gun, for added strength did the same to front wheels and cross pieces (gotta love thermoplastics). Rubber bands around the wheels for grip and these things zoom. The kids love them. Nice work, Thanks.

V2 printed perfectly and runs perfectly. Any chance of updating the instruction sheet for the V2 spacers and frame stiffener so it can be given as a gift?

Thanks for the work on this one!

Awesome! Runs great!

Thanks spikes100 ;-)

Thank You for this Great Project!
Make uploaded,

I'm glad you like it, It looks great in blue ;-)

I love the design. I was really looking forward to print this and to build this. I had great time building. And it looks ok and quite interesting. But about running? No matter what I try it always catches at one of the gears and does not want to ride. Light years from what you show on the video. My dog likes it though :) Thumbs up for the design!

Hahaha that's a pity ;-) I'm glad your dogs like it :-)

Hello, I want to thank the designer ! Very fun to print and assemble with my kid.
Only 2 little things :

  1. most parts are too loose to have a tight assembly : the wheels and the crosspieces in particular. My printer extrusion is perfectly calibrated, but I guess I would use a little bit "overextrusion" next time I'll print this
  2. The gripper part and the spring V2 have a little notche around the hexagonal axis hole to make them easier to assemble I guess. But this is a mistake because it make them too loose, at least with my filament. So I printed spring v1, and I slightly modified the gripper stl to fill this notch, and everything is perfect.

Thanks Richard90 :-)

Just printed and played with this car, and it is a slick little design! I printed Updated_gift_card_1_V2 and the second parts tray of a similar name. Once complete I trimmed all the pieces free of their sprues using a pair of scissors. While the PDF doesn't show 3 of the spacers, the author mentions them in the notes of the model. Assembly is pretty simple, with the front spacer between the spring and the gear being the hardest thing to line up.

Once together it works okay, but adding a pair of rubber bands to the drive wheels REALLY helps it perform reliably. I found it would simply spin out if you fully wound the spring on hard floors, and while it works okay on thick carpet, it won't overcome the carpet after 1/2 travel. A small groove in the drive wheels, then adding an O-ring would be great, as rubber bands were quickly knocked off by my 4 year old. But I measured that the spring crank turns approx 1 turn before the spring winds tight, then the car will propel itself about 16 feet, then due to inertia, "unwind" the spring enough that it stops and goes in reverse about 3 feet. I'm curious how well a larger spring would work, or putting larger rear wheels on the car. As it seems the spring is plenty strong enough to accelerate the car with the current gearing.

Altogether such a fun little project. Big thumbs up to the creator. Well done.

I might add the grooves to the wheels. Thanks Geostorm91 ;-)

I just printed this yesterday without the card as I didn't want to waste plastic and do extra cleanup. It took a while to figure out which files are not needed (old versions of some parts) and how many of each part is needed so I could pick all the necessary parts to the build plate in my slicer and without using old versions. Especially since some of the filenames are very inconsistent between old and new version of the same part.

It would be very helpful if there was an explicit list of the filenames and number of each part needed (like a bill of materials) of all the individual parts that are needed for printing the latest version of this thing. Or even better would be to have an STL (or AMF) that just includes all the individual parts (no card) of the latest version files (and correct number of each part needed to build one car). I printed all the parts at once on a Prusa i3 MK3 and there was a lot of extra space available on the build plate too

I also noticed that the instructions sheet and video are for an older version so it's missing e.g. the new spacers. At least the text description tells where those are supposed to go but it could still be clearer. At first I didn't even know which is the front and which is the back of the car since I wasn't sure which way it will go when wound up. So if you haven't built this yet it might be hard to know which part is "first gear shaft" and which "second gear shaft".

Otherwise everything worked out great after printing, except all the wheels seem to connect too loosely to the back shaft (back_shaft_V2) so the wheels very easily fall off. Front shaft seemed to connect a bit better, but I think that should also be a bit tighter to hold good.

I used a bit of super glue to hold the loose wheels in place, but my son (2y) already broke the back shaft by throwing it.

Too bad this is under a no derivatives license :(. I would have wanted to make a remix with some small tweaks to make few parts fit together a bit better at least for my printer.

Thanks for the nice design anyway!

Btw also the "crosspiece" is super loose (even more so than the wheels), it doesn't stay in the slots of the V2 frame at all on it's own but thankfully the gear shafts hold the frame together so that the cross pieces don't have room to fall off.

This is amazing, Thank you =) =) =) I can't wait

Thanks Alinecab1001 ;-)

I also note that the spring with the slot in it, is not available as standalone, only in the card. The other two experimental springs also have no slot. given one is called spring_v2 and some parts you need v2 and others not, it's a little hard to tell which files you need. It would be helpful if there was a list, like "these are the files for v1", "there are the files for v2". However it looks like a nice little build and look forward to giving the parts to the kids!

I'll add the spring with the slot. I'm sorry I'm not going to make a list for every update with all the parts. It seems logical to me and most people to print the most recent version. That's the reason I put V2, V3, V4,... after all my part names.

I didn't want to criticize, cos it's a nice print. However it was a little bit of faff to figure it all out. For example, which is right? completed_gift_card_1_V4.stl or Updated_gift_card_1_V2.stl? cos card2 has only v2, no v4, there's no v3, and I thought from your description you'd just released v2... V4 doesn't have the extra front brace support, so in this case, I think going by version numbers would be wrong.

You can always take a look at the 'last updated' date displayed under the file. This way you can be sure you have the latest version.

Well, when I unzip them, they all have the same date. I am sure there are ways for everyone to figure this out, however you did state that you have a versioning convention, which I then found was not consistently used, and therefore it's not as easy as it could be, and I thought that since you seemed to have made a super effort to make everything as easy as possible, that you would appreciate it. Of course you are free to ignore it, and I won't think the worse of you, and I thank you again for providing this nice print free to the world.

I changed the names of the optional springs to 'Optional spring 1' and 'Optional spring 2' and added the spring from the updated cards under the name 'Spring V2'

I just arranged all the files from the most recent on top to outdated on the bottom.

What rotation does one need to do on the back connector? It's not at 45 deg, nor 45+22.5

Have now spent 20 minutes fiddling with it, and can't get it flat...

Normally most slicers have a 'lay flat' option to possition parts. The angle is -66 degrees.

Thanks, you're very responsive ;-)

I am using Slic3r PE, and can't see a "lay flat" anywhere, however that could just be me...

Latest version of Slic3r PE does have a "place on face" option which lets you easily select a face of an object to lay flat on the build plate. I think it's still only in the alpha version though. I'm using the Slic3r PE 1.42.0-alpha5 atm. and it works good. The "place on face" feature is one of the icons on the left side of the screen. Here's a video showing how to use it: https://youtu.be/Cg4VjasRyOo?t=216

I'll upload the crosspiece in the right orientation as I experienced other people have the same problem.

Thanks, you're very responsive ;-)

I am using Slic3r PE, and can't see a "lay flat" anywhere, however that could just be me...

Comments deleted.

Just printed it out last night in copper! Can't wait to assemble it. It's nice to see something 100% printable.

I'm glad you like my design :-)

Wow, that is one heck of a V2 update. Thank you for listening to those that have built this. It is very nice to see the ideas be integrated into the new version.

I could picture a core car set of 2 cards and then various smaller 'upgrade' cards. I have some more research to do, but a floating pinion on the rear axel would be pretty cool.

This design does have a lot in common with another wind up car (with a floating pinion). https://www.thingiverse.com/thing:2025760. Was your design inspired by this guy's work? He has a few car designs and has some cool demonstrator modules.

Those upgrade cards are a really cool idea! I was thinking about a card with upgrade pieces to make the car look like a dragster. The original idea to make a 3D-printable gift card came from the christmas reindeer model that I saw on thingiverse. I thought it would be very nice to design a gift card with some mechanical pieces so you could show people what is possible with 3D-printing (combination of gears, springs, clickers). When I came up with the idea to make a wind-up car gift card, I searched on thingiverse to see if other people might of had already made it. Then I also saw the wind-up car models of Gzumwalt. I have to admit I was intrigued by his design and thought it was really well designed! This might of have influenced the final design of my model, but everything is build up from scratch. Mainly because all the parts had to be relatively flat in order for it to become a card.

I can definitely see some similarities, but it is clear that your design is your own, and is a novel approach to the windup car problem. That is prints flat and can be in cards is a huge plus that gives the project a whole other level of charm.

Nice design, one little tip, you have one ring in the design to keep the small gear in place. In my case it didn't ride that great so I looked more closely and on a slomotion cam I could see the larger gears shifting and the spring gear go out of line a bit.

I created the rings again to fit on the shafts which prevents this from happening.

The spacers are in order from spring gear to the small gear from left to right. The spacer for the spring gear is made to be between the spring and the gear.

It runs smooth and fast now. My kid is very happy with it. Thank you!

Hello Mariusvw, Thanks, please see the updated thing details and comments. I uploaded an updated version of the car this weekend where the extra spacers are included. I'm glad your kid likes it :-)

I absolutely love this design. Thank you so much for sharing it. It's one of my most favorite designs on thingiverse.

The V2 is another great improvement. I do wish that the tolerance was a slightly less tight, I have to reduce my flow rate significantly(leaving gaps in the surfaces) to get everything to fit and I still need to apply quite a lot of force (most notably on the windup shaft, and pressing in the gear shafts into the frame, and the crosspieces).

A tip for other builders: applying some silicone oil to the gears makes it run much smoother.

I've started to stack up on these gift cards to give away. Such a perfect gift. Thanks again!

If your slicer has a horizontal size compensation setting, then you might try putting a small value in there (0.02mm).

Good call on greasing the gears. Just did that. Now my problem is that it doesn't coast at the end. I saw another design that does this, but it's more heavy duty than the card design.

If your slicer has a horizontal size compensation setting, then you might try putting a small value in there (0.02mm).

Good call on greasing the gears. Just did that. Now my problem is that it doesn't coast at the end. I saw another design that does this, but it's more heavy duty than the card design.

I have been trying to print this a few times but each time on one of the gears it skipped teeth when the printer went back those missing teeth messed it up. I don't know if it was Slic3r or the model. Now I will try again with the update models thanks. :)

Printed with white, black and wood PLA in an Ender 3! I did add a 7.7mm spacer to the shaft between the rail and gear of the rear most “middle” gear to keep everything a bit more aligned and now it works perfectly. Thanks you for sharing this pretty cool model!

You're welcome Gtjoshua, I already uploaded an upgraded version of the car wich includes all the spacers to keep the parts in place.

Hands down the coolest thing on thingiverse!

Thank you very much Ephex!

I just uploaded the updated gift cards, to see all the changes, see the thing details. The spacers have bumps on the side. The amount of bumps determins it's place from front to back. Spacer 1 (1 bump) goes between the spring and the gripper ring. Spacer 2 (2 bumps) goes on the first gear shaft. Spacer 3 (3 bumps) goes on the second gear shaft. Spacer 4 (4 bumps) goes between the small gear and the frame on the rear axel.


Thanks BOTWFAN ;-)

I was unable to get the turn key to fit into the spring hole. Either the spring hole is too small, or the turn key is too large. Does anyone else have this problem or know what I need to do to make it print the proper size? I printed as per instructions with support on the key. Thanks.

I was just about to upload the updated cards when I saw your comment. I added a slot cut out to the spring for better fitment around the shaft.

Great - thanks! I'll give it another go. Also thanks for eliminating supports. I didn't notice originally it required them and printed without on first try. The key ended up warping upwards and broke my fan shield off and made a big mess.

I had the same issue. Everything fit fine except the key into the spring. I solved it with some judicious filing on both the key and the spring. Once I did that, it assembled and ran fine.

Hi. I printed this and everything came out too tight. I had to whittle almost every piece down to get them to fit. After doing so, I put it together but the gears would bind and not turn. Also I had to reprint the rear shaft (the smallest wheel with teeth) since the piece seemed to be too big and push against the other gears, creating too much friction to turn. Please help me out as I printed this and was really looking forward to building it. Thanks and have a great day

Also the gears are not straight. They are all tilted some way or another

I'm sorry to hear that oc162960, But to me it apears you have a printer issue. I think one of you axes is tilted (z-axis). I would suggest to callibrate your printer and make sure all you axes are perpendicular to each other.

I don’t know what happens if my z axis is not perpendicular but everything seems to print flat and straight. Maybe my flow rate is too much. Anyways I hope you did well on your finals. Thanks

I had the same problem on my first 3D-printer. I also noticed this offset while printing gears, they were wobbling around the shaft. The problem was my z-axis wich wasn't perpendicular to the other axes. Flow rate however could be the reason for everything being to tight. And thank you, I hope you did well on your finals to! :-)

I will look into your tips. Thank you for your help and I will update you once I have time to investigate. This was my first complex moving-parts print so there was bound to be problems.

Would not the trun shaft be modified for printing without support? The whole could then be printed without support.

Hello Maxinoha, Please see other comments. I just finished my last exam and I'll try to post an updated version by this weekend. :-)

I just finished my last exam today as well. Nice

Very nice oc162960 ;-)

In addition to printing the key vertically and reducing the gripper by 3%, I added some spacers to reduce gear slop/binding.

Added spacers for less gear slop/binding. The rear axel spacer was a little loose, so I replaced that with a slightly longer one. If you are experiencing gear binding, then I highly recommend printing these.

Rear axel- 4.0mm
Rear gear- 7.5mm
Middle gear- 3.25mm
Front gear- 4.25mm

Sadly all the spacers are different, which makes assembly a bit trickier. I suppose they could be labeled with marks or something to avoid confusion...

I also had some old bike inner-tube laying around and cut a couple pieces to make rubber grips for the rear tires.

The more I play with this thing, the more I like the design. With a few tweaks, I could see this as something that could be sold at one of those stores that feature the art of design school students like ShopSCAD (http://www.shopscad.com/).

Hi! would love to print however I'm just wondering before i download and make it, will this work made out of PLA? I have not printed a circular spring like this out of PLA and am a little worried it would be too stiff and break. Thanks!

The spring actually works quite well with PLA, no worries there.

What LabsOfCognitiveNeuroscience says ☝

How well would this work on hard wood floors?

I used a hot glue gun and spread the glue with the tip of the nozzle until it was relatively flat. Worked great.

I Think it'd work ok. If the wheels turn out to slipping you could try to put some rubber bands around it. Some glues work as well.

Thank you for such a fun model.

I've been struggling with the turnkey for a bit now and it is driving me nuts even with various support settings tested. An easier to print card version would be nice. Since I printed everything out in individual parts, I will just print vertically as Goebish suggests. I am also going to print out more spacers as things are binding a bit.

For those of us that opt to not print the cards, could you rotate the parts before uploading them so that we don't have to do all the rotation in the slicer? I know it doesn't take that long to do, but it would be nice to not have to do it.

An option for a bigger spring would be nice as well. The current frame might handle one more revolution, but changing the frame so that the front wheels were more below the spring would create a lot more space, it would look much different, but it would travel much further.

I would like to print a set of cards for my brother, but I'd have to print a separate turnkey and probably have to crop the turnkey out of the card version that I print.

Hello LabsofCognitiveNeuroscience, Just finished my last exam and i'll try to post an updated version by this weekend. ;-)

Live this, Looking forward to the update, and am going to give one to my Nephew. (Hopefully in early Feb. for his birthday.)

What do you think about a PETG spring?

Comments deleted.

Hello Lunar. Thanks , I haven't tried printing the spring with PETG material. I really wouldn't know if it'd be better or worse. Did you already try it? How did it turn out? Would love to know :-)

Comments deleted.

Can I scale down to 85% due to print bed size issue ?

Hello Vctiktik, I wouldn't know. I haven't tried it yet. I think most parts would be fine when scaled down to 85% .Although you might find some issues with fitment and thin parts that becoming to thin to print properly. Like the gripper it's arms for example. There might be no issues at all. Feel free to try for yourself ;-)

ThankS alot for this nice design!

No problem Sebastiaan ;-)

Thank you for this amazing gift it looks very fun to print and to put together. I just finished tuning and modding my CR-10 in lots of ways. So this should be a good test of my adaptations, I also have someone who will be very excited to put one of these together.

Thank you again

You're welcome Remowyliams ;-)

Nice design, printed fine, just a few notes:

  • printed the turn shaft verticaly (upright), thus printed perfectly without supports (only a brim)
  • printed 2 extra spacers to press the middle gears against the left frame
  • printed the gripper 3% smaller (X & Y) or the hole was too large, probably because I printed the turn shaft vertically

I agree with you.
The whole thing was pretty shaky wthout the additional spacers. I printed three spacers, each for every gear. Now it works great :)

Unfortunately, Bribro12 doesn't allow any remixes, otherwise I would've uploaded a version 2 of card 2 which includes the additional spacers.

Thor171 Yeah you're right, I don't. No worries, I will upload the files when I finish my exams (end of januari). But for now the original design will do. The car works fine as designed.

Thanks goebish. printing the turn shaft verticaly is a great idea for when you print all the parts seperatly, but unfortunatly not for when printing the cards. Dekmaker also suggested an extra spacer on the gear shaft which is a great idea. I will see if I can find some extra space on the cards so I can add some upgraded parts to them.
Thanks for the feedback ;-)

Ah OK, I didn't realize that, I had to print parts separately as the cards didn't fit on my smallish bed.

Thanks a lot for the design, that's exactly the kind of things I got a printer for :-)

hahaha you're welcome. I'm glad you like it :-)

Comments deleted.

very cool project im gonna try this on my custom tronxy p802 :) thanks a lot!!

Thanks Weldingboy73, you're welcome ;-)

Argh, this "thing" drives me crazy. It's such a cool little project, and it could be awesome. However, it feels like something designed to be injection moulded, and not 3d printed. This can be spotted in a couple of places.

First, the wind-up handle. It would be quite easy to design this so that it had a "flat" side on the build plate, and didn't require any support, even for the handle section.

Second, the spring isn't optimized for 3D printing. It works, but there's a significant amount of bulk at the beginning of the coil that could be used to store more energy by tapering the gap, instead of making it just a round end.

Additionally, the design could be a lot easier to assemble, with some break-away pieces to guide things together, and the cards could be easier to take apart, again with tapered shear points.

Now, these wouldn't bother me half as much, but this thing is a proprietary design. If I make changes to fix these, or to make one that can print on a smaller printer, I can't share that with anybody.

Your complaints have been noted and (some) will be taken into account in the updated version.

You don't have to worry about "changing or fixing" anything. I'll do that for you in the updated version :-)

Just made one. I used the cards / sprue trees. Very nice tolerances on my Prusa MK3; all parts press fit without glue.

3D printing a sprue tree is kind of strange, isn't it? I'm used to seeing them in model kits, of course, but they are part of the injection mold process. So we are copying a manufacturing byproduct that doesn't exist in 3D printing. This didn't occur to me until it was printed and I was removing the extra bits with a razor and pliers. It's unnecessary and adds post-processing work.

But that's what caught my eye about this thing in the first place, the cards... makes the kit feel nostalgic, like something you'd see in a gift shop at the museum or science center. So if you're going to use them, do for nostalgia's sake. Otherwise print the individual parts.

Thanks for the neat design!

you're very welcome jmbcool! The car looks awsome in white ;-)

I printed and it assembled and its really cool. What a great idea. One wheel was nice and tight but three were loose so I wedged a small piece of paper in the small rectangle hole and it works great. Those circle cutouts on the main body are great for making a tight fight I wonder why not use those circle cutouts for the wheels to mount instead of the rectangles. Thank you.

Hello Extruded, Thank you very much. I double checked the tolerances on all 4 wheels and they should all be exactly the same. The slots in the wheels actually do exactly the same as the circle cutouts on the main body. They also allow for some play with the fitment. The wheels are also more prone to movement then the shafts that hold the gears in place. I experienced that the flexible holes tend to lose there tension and become loose when moved to much. I tried to make the design as 3D-printer friendly for different kind of 3D-printers (flexible holes in body, slots in the wheels, larger holes and smaller shafts for moving parts...) but even then it's hard to get the tollerances right for every single printer that exist out there (experienced the same problem with my bearing model). I printed every part about 5 to 10 times on 2 different 3D-printers to see what works best and what doesn't. I'm glad you like the overal design. Be sure to post a make ;-)

I also tried to use the flexible holes on the gripper and the small gear but they were to small and fused together. So I ended up just using a slot for gripper and made the hole for the small gear bigger so it can move freely over the shaft. The spacer keeps the small gear in place.

Thank you for designing and sharing this excellent learning project.


You're welcome Dadmezz

I've printed and assembled this. It mostly works but I see a number of issues: the last reduction gear before the geared axle is "loose" and could probably be constrained using a bushing on its axle. When the balance spring is wound tightly, it pushes its retaining pin out of position and bulges, pushing the first reduction gear against the side (more friction). This may be because I overwound the spring.
The rear (driven) wheel should also probably have a crosspiece like the front, I find the long front-to-back pieces assemble around the rear axle loosely.

n general, pretty good design (such as giving holes a small flexible cut so they parts can be inserted easily). Are you a mechanical engineer/designer of parts?

Dekmaker, Thanks for the feedback.

  1. The bushing on the 3d reduction axle is a good idea and would help the gear to stay in place. Now the gear is held in place by the other gear and the axle itself. I didn't have any problems with mis aligning of the gears however this could be possible. The problem is that I had to keep the number of parts limited otherwise they wouldn't fit inside the card (I already have 2). I could add the part seperatly for people who print the parts individually.
  2. Just don't overwind the spring ;-)
  3. You probably mean that the front needs a crosspiece like the rear (The crosspiece is at the rear driven wheel) This would indeed make the frame more ridgid. But again I had to limit the amount of parts and the size of the 2 large frame pieces.

Thanks for the compliment :-), but I'm not a mechanical engineer/designer of parts. Everything I do is for a hobby and is self-taught.
I currently am a student electromechanics (bachelor second year) but you don't learn things like this there.
(you can thank MakersMuse for the flexible holes ;-) )

may need support for the windup tool

Ben27p Thanks for pointing that out. I forgot to mention that. I'll edit the details now. ;-)

Guess you didn't get around to editing the details yet.
The windup tool definitely needs support.
I printed that card and that portion of the print failed due to no support.
(Guess I should of read the comments first before printing.)

Hello Abinder3, as a matter of fact I did edit the thing details. You can find all the print settings under the tab 'print settings' ;-)

Print Settings
Printer Brand:












Filament: Esun PLA Grey

I edited the summary to so it is more noticeable.

Actually, now that I think about it, why not modify the windup key so that it's printed with a side against the print surface instead of an edge? Just make a portion of the key that you hold a little thicker so it wouldn't need supports when printed.
(Just a thought though.)

Hello Abinder3, yes I thought of that to but then you still need support for the larger overhanging area of the turn shaft. I might upload an updated turn shaft wich is easier to print in the future.