~1/4 Scale ACA Penetrator 10/15/Third Gen Allertor

It's here!!

After such a long wait, the files for these 1/4 Scale mini sirens are on Printables :)

I'm super happy with how they turned out and they should be a very simple and easy build for you all! Way easier than my Thunderbolt that's for sure

SOME THINGS TO NOTE:

• The siren is perfectly outdoor safe if printed in the correct filament!

• The Penetrator horn and the Allertor horn are 100% interchangeable

• Shaft couplers allow the rotor to be removed and put back in infinitely without needing a tolerance tool or a press-fit rotor

• The siren should take around 2 rolls of filament total to complete (if there aren't any print fails)

ALL PARTS FOR THE SIREN COST JUST AROUND $50-70 TOTAL

PARTS LIST:

MOTOR: https://www.amazon.com/CHANCS-Electric-555-8000RPM-Accessory/dp/B0CW61NGF4/ref

SHAFT COUPLER(S): https://www.amazon.com/12Pcs-3-17mm-Coupling-Connector-Airplane/dp/B0DKT5T64L/ref

ALAN WRENCH:

Any LONG 1.5mm alan wrench will work but the ones that come with the coupler are not long enough. Here's one you can use although feel free to search for another one or style you prefer!

https://www.amazon.com/Dynamite-DYN2814-Hex-Driver-1-5mm/dp/B000BQ1SFE/ref

SLIP RING: https://www.amazon.com/Comidox-CIRCUITSx2A-Capsule-Electrical-Equipment/dp/B07H2SRMXP/ref

BEARINGS: https://a.co/d/45fWKgO

GEARBOX: https://www.amazon.com/SparkFun-Hobby-Gearmotor-140-Pair/dp/B07JX7MHSL/ref

THREADED INSERTS: https://www.amazon.com/dp/B08BCRZZS3?ref

HARDWARE KIT: https://www.amazon.com/Machine-Assorted-Assortment-Stainless-Threaded/dp/B0DFWYBJJJ/

SMALL RUBBER BAND (Get from anywhere)

POWER:

POWER SUPPLY: https://www.amazon.com/Adapter-100-240V-50-60Hz-Converter-Transformer/dp/B0D7GGGM6Q/ref

SPEED CONTROLLER:  https://www.amazon.com/RioRandTM-Upgraded-6V-90V-Motor-Controller/dp/B00F839VNQ/ref

INSTRUCTIONS!!

I'd start with printing the core (rotor, stator) first. The motor fits into the bottom of the stator and is secured in place by two short M3 bolts. For the rotor, take a shaft coupler and press it gently into the hole (so it stays upright) You need to make sure that the holes for the setscrews on the coupler are facing exactly towards where the holes come out of the side of the rotor. Making a sharpie mark can help you line it up! Then, take a hammer and tap your coupler STRAIGHT down into the rotor. Then, you can put your setscrews through with the 1.5 alan wrench through the side of the rotor and stator to secure the rotor to the motor.

The next step is printing the Motor Cover (Has been updated since these pictures). This piece goes directly on the bottom of the stator (where the motor is located) and is welded on. Make sure you know which rotation will allow the mounting holes on the stator (that go to the intake) to line up and be squared. Once you orient the piece correctly, you can super glue it on and then weld it in place with a soldering iron. Now your core should be complete!

The next step is building the main frame of the siren. Once you have the main frame printed and decked out with threaded inserts, take the Outer rotator tube as well as the teardrop rotator cover piece. The teardrop piece should go underneath the frame and four bolts will attach it to the frame up from the bottom. Once the bolts you put in reach the top inner surface of the frame, put your outer rotator tube inside and thread the bolts all the way through. Then secure it with nuts at the top. Your outer rotator tube/frame sandwich is done!

For finishing the rotator, once you have your inner rotator tube piece printed, you'll want to sand the outside of it as well as the inside of the outer rotator tube that's attached to the frame (you should have just built that)

The sanding may take quite a while but you want to get it super nice and smooth to where the pieces can fit together and slide around with minimal friction! Make sure to sand the print seam lines extra to avoid having a bumpy spot in the rotation as well. This should take around 20 minutes although with experience, sometimes 5-10 minutes to complete if you're careful and you sand it enough. Just be cautious when putting the two threaded inserts into the top of the inner rotator tube. If you misalign them even slightly, they can bulge out the plastic on the tube and you'll have to sand it more. 

One more thing to note, if you're building an Allertor, you NEED to put silicone grease at the base of the inner rotator tube (where the whole weight of the siren sits on) or else the weight of the front of the horn will rub the plastic against itself so hard the plastic will start eating itself alive. You can get away with not using any grease on a penetrator but I'd still recommend it as it keeps things running nice and smoothly!

As for the slip ring, COMBINE THREE AND THREE WIRES INTO ONLY ONE PAIR OF WIRES!!! This is super important since that motor is way too big for only one of those wires to handle. On the bottom of your slip ring, there should be two sides of wires. You'll want to solder both pairs of three together (near the top). Then, find out which colors you merged on the bottom and merge the same colors on the top. Now you've converted your 6 wire slip ring into a 2 wire that can handle that motor! Now, you can stick the bottom wires through that little hole on the retainer and use some super glue to lock it into place! Thread the bottom wires through the inner rotator tube (with the outer frame on as well) and they should either come out the bottom, or the side of the mounting plate (it's your choice) The last step is to fasten the slip ring onto the inner rotator with two M3 bolts that go through the holes on the retainer into the two inserts on the top of the inner rotator tube. Now you can spin it freely while also not being able to lift it off it's base. You'll also now actually have power to your motor!

Since you now have the two main parts of the siren complete, it's time to combine them! the main core attaches to the top of the frame with four M3 bolts that go into inserts. This step is pretty self explanatory but I'll still put an image example so you can make sure you know what you're doing!

 Please refrain from wiring the motor right away!! The rotator system will still need some space and you want to wait until that's done in case the wires are in the way of your pulley. As for the rotator system, that small hole in the bottom of the frame that goes through the teardrop piece is for your bearing. You'll want to drop the bearing into the little hole with the flange facing up. Secure the sides with a tiny bit of super glue. Just make sure not to get any glue inside the bearing!

Now, print the rotator shaft and the small rotator drive gear. You'll want to sand the bottom (the small circular end) of the rotator shaft and test fit the small gear onto it a couple times to make sure it'll fit snug. Don't worry about it being too loose since you can always secure it with some super glue or hot glue. You could even weld it if you'd like. 

As for your gearbox, you shouldn't have to even mess with it at all. Just remove the zip tie and cut off the wires. You won't be needing those anymore as the motor just serves as a bearing! Take your rotator shaft and just slip it through the bearing hole at the bottom of the frame with the fat side inside of the siren. Now your gearbox should be bolted to the top of the frame (there's a little indent with two holes for the bolts to come through on the top. As for the orientation of the gearbox, you'll want to put the side with the little circular nub on the top of the gearbox facing downwards towards the bottom of the siren so it rotates the correct way.

Now that your gearbox is in place and your shaft is in the right area, push the end of your rotator shaft up into the gearbox shaft. If the fit is too tight, sand your gear motor shaft. The fit should be pretty tight though so don't be alarmed if it takes a bit of force to push on. Now you just need to push your drive gear onto the shaft underneath the siren! 

All that's left from here is to print the two rotator pulleys. The smaller one goes on the back of the chopper motor and the bigger one goes onto the small motor shaft of the gearbox motor. You'll want to make sure both of them are aligned with each other. Now just find a small rubber band (doesn't have to be super tight) and stretch it across both pulleys. Now you can solder your wires together and test the siren! It should run up and also rotate. As for the rest of the siren, all that's left is the intake, the horn, and the motor cover which are all literally self explanatory as they just go on and get bolted. If you have some small eyebolts, can thread them into the small hole at the top of the motor cover. The eyebolt just being in the motor cover is plenty strong enough to lift the whole siren up. 

Although I wasn't able to do a tutorial video for this siren, I hope these instructions will still clearly explain how to assemble the model. I've also tried out adding images to the instructions to give some visual aid that should hopefully help out the building process! If you have any other questions, I rarely check Printables comments and there's a chance I'll miss a YouTube comment. My Discord server is the best way to get in contact with me. If you have any questions, don't be afraid to ping me. I'll always be there to help :)