NEW!!! 1/3 Scale Federal Signal STH-10

This is a ⅓ scale working model of a Federal Signal STH-10.  This siren uses a Samsung DE31-00029H microwave blower motor.  It is also compatible with the 29K and 29J and any other 2.9/2.95" length Samsung motor.

Models come already in their intended print orientation.  

Please print the stator in 99 percent infill.  This will make sure the back of the stator will be decently stiff, so it wont be too easy to make it flex and cause rotor rub.

Hardware:

18x M4x10 machine screws (stand assembly and motor covers to the motor)

You need to re-tap the motor threads to M4x0.70.  To do that, take your M4 screw and force it in and out a bunch of times until the threads get smooth.  You must use a head that can take high torque, like socket cap or hex head.  Philips and flathead will not work for this.  

You can speed this process up a ton using a drill or impact driver.  Be very careful when doing this.  Do not let the screw stab into the motor windings, and do not let it bottom out in the threads either.

12x M4 nuts

7x M3x8 machine screws (stator to motor and motor back cap to wire side cover)

10x M3x6 machine screws (joining intake to stator and junction box to motor) 

24x M2x10 machine screws (mounting horns)

4x M2x6 machine screws (junction box lid)

24x M2 nuts

19x M3x5.7mm heat set threaded inserts.

https://www.amazon.com/gp/product/B08BCRZZS3 (I used these)

You need two of these capacitors and wire them in parallel for a total of 8uf.

https://www.ebay.com/itm/285415751960

If you for some reason still want to print the old shitty model, you can download it as a .zip file in the “Other Files” section.