High Power Propeller Launcher

Hello everyone.

Kids have asked me about a flying toy, so I have decided to make something special. I did some discovery and found nothing suitable. I decided to create something from the scratch, so have sit to the computer and spent some time with 3D modeling software, testing and etc. After a few days of research, they received a propeller launcher and propellers to it with amazing flying characteristics. I also decided to publish this project as part of "Make it Fly" contest. This propeller launcher can launch the propeller up to the 30 meters (10 floors) in height and about the 40 meters in horizontal distance (see promo video).

Some words about it. Because it's easy to lose the propellers on the street, loans, forest, they have to bring less plastic waste to the environment. That is why whole launched and propellers were designed to be made with PLA plastic, including gears, because it's bio degradable. Launcher assembled using small bearings, to get more performance and reduce the wear for axis, housing and make it last longer. Another one requirement was - get rid of rewinding the cord after the launch with hands, it takes a lot of time and that is exhausting. That is why this launcher has rubber powered mechanism that rewind the fishing line back to spool after the launch. Propellers are absolutely fine to fall to the asphalt from the heigh ≈30m, because of the large surface and small weight.

Important Notice: This launcher has gearbox with ratio 1:4 and propeller can spin more than 4000 RPM, so kids have to be warned about fast moving blades and other safety rules, if you decided to make a copy of this. If propellers has cracks, chips - throws it away and do not use!

8 x 693ZZ bearings, you can buy them e.g. here on AliExpress

2 x M3x45 screws

2 x M3x25 screws

2 x M3x12 screws

1 x M3*14 screw

1 x M3x8 screw

8 x M3x2 nuts

2 x M3 locking nuts

1 x M3 shim

≈ 75 cm of the fishing line with 0,8-1mm diameter

2 x mid sized rubber bands

1 x piece of the filament ≈3cm

1 x shim (with 12mm inner diameter and 16 for the outer) that made of sheet material, e.g. PVC (aluminum works better)

1 x drop of the Super glue

Some of silicone lubricant (if you decide to use plastic shim on the starter gear, as I)

3D printer with PLA filament

Flat file, pliers, screw driver, to assemble all of these and remove the supports

Here you can find the parts for 3D printing and some pictures with hints how to print them. As perviously mentioned, even gears were designed are could be printed from PLA and there is to visible wear after 300+ launches. Total printing time is about 10 hours with 0.2 mm Layer height. Almost all models are printed with supports from the build plate. Housing was printed with "supports everywhere" mode enabled. Rubber holder for the spool axis, propeller and starter handle are printed with no supports. There is a trick in printing handle that can save you some time with removing supports, see attached images to this step.

There is attached "PropellerBase.STL" file, it's a base of the propeller, so you can use it to make own propeller designs.

Assembling the handle on this step has no tricks. You have to remove the supports and make sure that surface that was touched with support material is flat, if not, use a flat file/piece os sand paper and get it looks right. Make sure that groove around the handle printed well and has constant thickness.

Once previous step is done - insert 2 nuts in the bottom part of the handle, then 2 nuts in the top part. Insert 2 bearings. Insert and screw tightly the mid gear axis.

Take a rubber holder, insert a nut in it and screw it tightly with the second long screw.

Take a spool gear, remove the supports and make sure that fishing line could be inserted with no problems through the hole on the spool.

Take a spool axis and handle, that we assemble in the previous steps, M3 nut, shim, M3 locking nut and super glue. Insert a spool axis, from the bottom, through the bearings in the handle. Insert the M3 nut in the bottom of the gear and screw it on its place. Put the shim and screw the locking nut on the screw. Adjust the tighten moment in the axis. Spin the gear with hand, it have to spin smoothly with no friction and no gaps between gear and bearings, tight the locking nut and fix it with the drop of the Super Glue.

Take a started gear, insert 2 bearings in it, one by one, be careful to do not damage the propeller locking mechanism. Repeat the same with Mid gear and insert 2 bearings in it, one from each side. Because the spool axis is heavily loaded with forces, we have to addd another bearing on it. Put the Mid Gear on its axis, put another one bearing on the spool axis and put the starter gear. See attached images for the reference.

Make sure that all gears are moving smoothly and there is no friction or extra resistance. If there is any, check that all support material removed.

Once this done, please remove the gears and bearing from the axis and put aside.

This step is tricky one, because no sharp tools could be used when you works with rubber bands.

Take a fishing line and insert it through the 2 rubber bands. Insert the fishing line through the handle cap rubber holder and pull until the holder appear in the middle of the rubber loops. Now we have to insert 4 rubber loops through the handle and lock in the spool axis rubber holder. repeat the same thick with the fishing line and thread through the spool axis holder (see attached images). Insert the piece of the filament, or other stick inside the rubber loop and remove the fishing line. Lock the rubber loops in the holder and pull the rubber bands. Remove the extra ends of the filament (stick) with the wire cutters. Put the handle cover into the groove on the top side of the handle. Insert 2 x M3x25 screws and tighten the screws.

Put all gears on their places + put the plastic shim to the top of the starter gear.

Take the the housing part (side with nuts) and insert 2 x M3 nuts in it. Put any part of the housing to the previously assembled parts (handle with gears) and fix it with the screw on the handle. Put the second half of the housing, tighten all screws and check that housing "sits" properly in the groove and gears are spinning smoothly. If not, check that supports are removed and there is no other issues.

When no problems with gears spinning found, remove one half the housing. Take a fishing line, and make a knot on the one end, take the other end and thread it through spool (outside in) bearing and starter handle. Once done - measure about 75 cm, cut and make another one knot. Put the bearing on its place in the housing, apply some silicone lubricant or machine oil to the plastic shim, put 2 parts of the housing and tighten all screws.

Now we need the "rubber power" work for our purposes :)

Take a launcher, pull the handle cap for about 3 mm out, twist it CCW and slowly release, repeat this several times and you'll see that fishing line will be winded on the spool. When you'll be doing this - pay an attention that there is not resistance in gears, everything have to spin smoothly. Once done, check that it works fine, see the video from this step.

If you have followed steps from above, I'm sure that everything works fine for you and you're ready to take just printed propellers and go outside. Enjoy!

Now, my little one, has asked to make a propellers for the night mode with LED lights. There is an idea for this solution, so I'm sure that some update will happen here.

If you like it, please vote!

If you have something to say - write a comment!

Thank you for reading.

As a bonus to this toy I've decided to publish an extra performance upgrade, which gives a possibility to launch propellers much higher.

Be careful and remember, safety first.

This upgrade gives more rotating speed to the propellers, gearbox has gear ratio 1:4.924

Let's do some math.

* Adult person is able to unwind the spool with the fishing line in ≈1.5 seconds or less.

* Spool has ≈25 turns

* after some calculations we have … 25*4.924*(60/1.5)=4924 RPM

If you decided to upgrade this launcher - all that you need is to download 3 new gear models, print them and replace old version with these. There is no need to print other new parts. New gears works much silent, smoother. Using silicone lubricant is recommended. It still works for PLA plastic really well.

Kind regards and have fun!

After some thoughts I've decided to add a very last step, not a separate instructable. Hope that some you had some fun with this Launched and enjoyed it. Here is LED upgrade for this launcher that is detachable and fully compatible with existing propellers.

To get it done you'll need:

• SMD LEDs

• thin transformer wire

• 2032 battery socket, that could be purchased e.g. from here

• CR2032 Button Cell Battery

• Soldering tools, knife, cutters and so on

• printed model

If you an owner of the SLA/DLP printer or printing with 0.2 nozzle you can print very detailed model with tiny groves.

Not sure that there is much to add, just look at the step by step photos and if you have hands not that clumsy that mine, the LED upgrade will be looking much better. :)

NOTE: Model is fully balanced, so there is no vibration and other problems.

Do not forget to vote for this one, if you like it.

Kind regards