December 17, 2025
Description
This model is the first 2001 SRNB model on Printables! It's a bit bigger than what I usually do, but a user requested this model, so here it is! The stator, chopper, and part of the horn shouldn't be too difficult to assemble, as they are all based on the same principles as my other models. However, the two collector rings can be complicated and require a lot of dexterity.
First, I would start with the chopper. It's the easiest. I have divided the two parts so as not to confuse them. You can also start with the rotator.
First, attach the motor to the stator. Then attach the chopper to the motor shaft. Make sure that the chopper does not rub against the edge of the stator. This greatly affects the sound. If the stator rubs against the edge the whole time, it is best to simply print a new chopper. Now attach the cables to the motor. Once this is done, you can glue the motor cover to the stator. If
you have already printed the Federal Signal logo, you can now stick it on. Now comes the horn base. Stick the horn onto it and then insert the entire stator-chopper construction into the horn. Now stick the two intake nozzles under the horn base. You can see how to do this in the pictures. Don't attach the cover to the horn base yet; that comes at the end!
Rotator
Be careful with the rotator, as it can be a little complicated. Take an empty beverage can and sand off the print. I used an empty cola can. After sanding, the can should no longer have any printing on it. Now use scissors to cut two strips that fit into the slots of the main shaft. Solder a cable to each strip and pull the cable through the holes. Then glue the strips into the slots. The cable should be long enough! Now you have the collector rings. Now place the main shaft in the large hole in the rotator base. Now attach the main gear to the main shaft and glue it in place. Now attach the motor to the rotator base and the gear to the motor. Finally, glue the cable to the brush holder and glue it to the rotator base. Make sure that the motor wires touch the collector rings. Glue it so that it touches the collector rings well!
Now all that remains is to glue the horn onto the main shaft and connect the cables to the motor. Finally, place the two covers onto the rotator and the horn, and the model is complete!
Operating the Siren
To operate the siren, you can connect two different cables for the rotator and the chopper so that you can run the rotator and chopper separately. However, if you prefer a simpler solution, simply solder the rotator motor to the wires of the brushes to operate it with a battery.
If you have a problem, you can write to me and I will help you. There may be errors with the collector rings, so make sure the metal is smooth. If the motor on the chopper is too heavy, you can place weights in the rotator. If you want a different siren, be sure to write it in the comments! Have fun! :D
License:
Creative Commons — Attribution — Noncommercial — NoDerivatives
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JNPrinting
