Making a Reusable Rocket Fin Can for a BT 50 Body Tube

Welcome. I within the past year I have been tasked with development of BT-50 Body Tube Fin Cans for a STEM class. This design is completely reusable. This design was 3D printed for testing and it held up to the immense forces exerted by the rocket motor.

Also if it says hole it doesn't mean "whole", it means a component that will make a hole in a space.

Sorry that most images do not have the dimensions on them, Tinkercad did not want to cooperate with me taking pictures.

Sadly, I do not have videos of this because all of my rocketry supplies are stuck at the school due to quarantine.

Supplies

1. Tinkercad Account

2. WiFi access

3. A computer

4. (OPTIONAL) A 3D Printer

5. (OPTIONAL) A BT-50 Paper Rocket Body Tube

Step 1. Open Tinkercad

This one is a very simple step, but if you don't do this, you cannot make this. You will want to enter into your account. Then, click the Create New Design button. You will then want to change your size settings to 0.1mm.

Step 2: Starting Cylinders

Now you will place a cylinder with the dimensions of 28.5mm x 28.5mm x 70mm. Now place another cylinder with the dimensions of 25.45mm x 25.45mm x 70mm, this cylinder will be a hole cylinder. Place that cylinder 8mm off the ground, then center it inside the other cylinder and group them together.

Step 3: Interior Cylinders

Now you will make a hole cylinder that has the dimensions of 18.7mm x 18.7mm x 76.2mm. Then make another cylinder that has the dimensions of 24mm x 24mm x 76.2mm. Align them, BUT DO NOT GROUP YET. Then drag the two over to the other cylinders and align them all together. Then group.

Step 4: Creating the Top Lock

This is a smaller step, BUT if you do not do this the fin can will NOT work at all, because the rocket motor will go out the top of the fin can. Create a cylinder that has the dimensions of 24mm x 24mm x 4mm. Then place it at a height of 76.2mm. Then create another cylinder that is a hole, this cylinder will have the dimensions of 14mm x 14mm x 20mm. Place it at a height of 76.2mm. Then align and group the two cylinders. The align and group the top lock with the main tube.

Step 5: Creating the Bottom Locking Zone

This is where you must be careful, this keeps the rocket motor in the rocket instead of falling out of the bottom. First take a cylinder it will be a solid, it will have the dimensions of 20mm x 20mm x 3mm. Raise it off the ground by 3.3mm. Then you will make a solid cube with the dimensions of 3mm x 2mm x 6.2mm. Copy that cube and paste it. Then make another solid cube with the dimensions of 3mm x 3mm x 2mm. Raise it to a height of 1.6mm, then copy and paste. Then arrange them similarly to image 4. Then select all, and group them. Now turn them into a hole object. Now drag them over to the fin can and align. Then group.

Image 5 is what the underside of your fin can should look like after following this step.

NOTE: You may want to adjust the locking mechanism, it is different and will be different for almost anybody, these measurements are accurate BUT adjust positioning while you are creating.

Step 6: the Locking Mechanism

This mechanism will slide into the bottom lock, then it will be used to hold the motor in place. First, create a solid cylinder with the dimensions of 18mm x 18mm x 3mm. Then make a hole cylinder with the dimensions of 14mm x 14mm x 3mm. Then align them and group. Now make a solid cube with the dimensions of 2mm x 2mm x 3mm. Copy it, then arrange them similarly to picture 4. Then group.

Step 7: You Are Somewhat Done.

You can now customize the fin can. You will want to add some fins. Though, once you are done all you have to do it 3D print it, and glue the body tube on. Then you are done. Congratulations!