There are more than 20 models of LEGO®'s Dune Buggy type car, even more than the models in LEGO® Race Car category.
Dune Buggy is usually four wheels drive off road vehicle,  which would not be used on the road.

Now that I got excited on the "dune buggy", and was also inspired by 1998 LEGO®'s Turbo Command 8428/8432 (See picture 6 and 7), I designed my own buggy, "The Bull" Buggy

"The Bull" Buggy is larger, and more complicate car to build than my two other LEGO cars, R/C Lego Car (or R/C Lego Car Redux) and Wireless Lego Car. It needed bigger or more power (torque) to drive the car. So I decided to use round 24mm. diameter with 9V input power. That made me to design another version of 3D printed motor housing (See details in Step 1.)

This 3D printed motor housing was designed to be used with the Lego's parts, and compatible with Lego Modular System just like my smaller version of the motor housing for 130-type DC motor (See Step 1 of my R/C LEGO Car Redux.) 

After I built the first "Bull" Buggy, I realized that when I want to access the Palm Arduino and motor controller PCB, I had to tear apart the rear frame to get to PCBs. So I altered the design by adding the hinges to the rear frame so I can just flip the rear roll cage up instead of tear them apart (picture 2 and 3.)

The "Bull" Buggy's  features:
  • Shock absorbers.
  • The chassis is not all paralleled to ground.
  • Can be constructed without shock absorbers as an alternative, so the chassis is all paralleled to ground level. With this alteration, the motor could be mounted using the side holes on the motor housing to and connectors to mount to the LEGO bricks (photo 5, or see Step 11 for details installation)
  • Rotatable rear roll cage.
  • Switchable steering wheel. (Can be switched between the left side and the right side of the vehicle.)

Lego Bricks or parts are already reusable/recyclable products. And it could be passed on to the next generation just like all the Lego parts do. I would say this is the right way to solve the problem and more "green" than hacking toy R/C Motor housing, like I did earlier with R/C Lego Car and Wireless Lego Car projects.

For the wireless control, I used XBee module as an alternative) for controlling the car wirelessly, similar to my previous cars, R/C Lego Car, Wireless Lego Car, Ford Mustang Arduino Controlled R/C Car. (Picture 8)

More photos and video in Step 13.

LEGO®, TECHNIC, are property of The LEGO Group of Companies (http://www.lego.com), which does not sponsor, own, authorize or endorse this creation.

Step 1: 3D Printed Motor Housing

Why 3D Printed Motor Housing?

As I mentioned in R/C LEGO Car Redux, I was not very happy and was tired of using hacked motor and motor housing from toy car or toy R/C car, because each time I want to build a different design Lego Cars. Most of the time the new design Lego car that I plan to make was not able to use the previous hacked motor and motor housing.

This 3D Printed motor housing is the second version of the 3D printed motor housing. The design and 3D modeling processes were also done in 123D Design.

This 3D Printed motor housing fits most of 24mm. diameter DC motors with 2mm shaft diameter.

The motor housing was designed to have studs that compatibles with Lego modular system. (4x6 studs.)

This version has better advantage than the first version since we could secure the motor housing with the Technic Brick by using the holes on the sides of the motor housing (See Photo 20, 21, 22)

This 24mm. motor housing is a lot sleaker than the 130-type DC motor housing, and it used less material than the 130-type motor housing.

Attached is the STL file, you download below. Or in case if you do not have a 3D printer, you can view the model or have it made at Shapeways, here.

It is a good value for the long run. My motor housing for Lego car design can be used over and over, and I do not have to buy toy R/C car to hack for motor housing from it and mod it to fit with my new design Lego car anymore.

Design Processes and 3D Modeling

Photo 1 Shows finished  3D model of motor housing with the 1:1 scale 3D model of 24mm. diameter motor. 

Photo 2 I created 1:1 scale 3D model using 123D Design from the manufacturer datasheet. Then saved to my models library.

Photo 3 I inserted the 4-stud LEGO Technic Brick (1:1 scale) that I have in my 3D models library. (Note: I hid the motor for clarity.)

Photo 4 I used The Patterns Tool in 123D Design to create the second Technic 1x4 stud brick.

Photo 5, 6, 7 I created the housing for the motor, using Primitives Tool in 123D Design and the Modify Tool to create the housing for motor.

Photo 8 I added opening by using Combine-Substract tool to the surface for fingers to push in or pull out the motor.

Photo 9 The final 3D model before combining the LEGO Bricks and the housing together.

Photo 10 The final 3D model after combining the LEGO Bricks and the housing together.

Photo 11 The finished 3D model of the motor housing with the motor. Then checked to see if the motor fit into the void area.

Photo 12 I rotated 3D Printed Motor Housing 90 degree to make the model have more strength while the model get print.

Photo 13 I hid the motor model before export to stl format before send the model for printing.

Photo 14 Different view angle (from the bottom) of the 3D model.

Photo 15, 16 The real 3D Printed Motor Housing.

Photo 17 Assembled motor housing ready to use. See details installation in Step 11.

Photo 18 3D Printed Motor Housing in used.

<p>I really like this model and the instructions are great. I would love a copy of the .stl for the motor housing. Autodesk is not letting me sign in with my usual account info! can you attach the .stl file?</p>
<p>Where can I purchase the lego parts easily and quickly in sets perhaps because buying each part is frustrating and time consuming, thank you!</p>
You are a genius you've just gave me a awesome idea thanks bro
Wow I always build Legos and I never thought of that
Thanks. <br>
I like the back suspension!
I like them too!
Really nice ! <br>I like your ideas !
Thanks for the kind words.
Outstanding. I just finished building a techniques model and am using some of the designs for my Arduino robot schematic. Your motor housing is awesome. What do you use to secure the motor in the housing. I see where you can secure it with screws through the holes, but I can't see them in the final design. And have you had any problems with the heat from the motor melting the 3D material? <br> <br>Thanks, <br>
Thanks and looking forward to see your robot post on instructables. <br>Yes, it needs M2.3 (about 4mm long) screws to secure the motor to the housing. The screws did not come with the motor, because I got it as used motors from eBay. <br>The 24mm motor housing as used in this instructable was a first prototype, it still has round mounting holes, t he latest version has two pill shape mounting holes. So it could accommodate the different distance of the mounting holes. <br>I did the test run eight times (for video shooting, the last one shown in Step 13). I looked at the motor, as I aware of the mounting screw as well. The motor shifted (rotated) away a little bit. For the heat and the 3D material question, I can removed the motor out and did not see any sign of melting 3D material on the motor or on the motor housing itself. I will try to do more heavier test run than what I had don before, may be doing it outside! <br>Thanks for your good question and observation! :)
That's so awesome. Is the mount model public on the 123D site?
Thanks. <br>Yes, it is public on 123D site, here is the link, <br>http://www.123dapp.com/FullPreview/Index.cfm/ID/1540902

About This Instructable




Bio: I am Electronic Visualization Artist. I look at things through the Looking Glasses.
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