Model L wrote: ↑Fri Oct 22, 2021 4:24 pm
my friend Sam is currently working on a locked up STH-10. you will probably need to get the chopper off using a torch of some sort. as for the motor itself the rotor has likely rusted a small amount and has locked itself in the motor. I am not entirely certain but i would think that tapping it out with a sledge hammer may work.
The STH-10 is one of the easier ones to get apart because of the rotor design. Once you remove the three bolts from the center take the plate that sits across them and put a socket that is slightly smaller than the shaft on it and then run the two bolts in the outside holes. Put nuts on those bolts before putting them in and then start tightening those nuts pushing that socket against the shaft. Set the siren upside down and spray PB Blaster in there until the shaft hole is full up. Then let it sit overnight. Next day tighten the nuts 1/4 turn. Spray more PB Blaster and let it sit. It could take a week or more but once the shaft starts to move out of the rotor, it will go easy. Stack sockets to get the distance right to keep pushing it apart but that is what I did.
The bearings are press fit in the housings so once the rotor is off. You can take (most likely SNAP) the 4 long bolts that hold the motor together.
Get a couple 2X4's and drill them through on the 2 inch side and bolt them to the holes that hold the chopper housing on that you removed after getting the rotor off the shaft.
Shore up the 2X4's so the top of the motor is hanging above the work bench. The motor would be shaft up at this point.
With a piece of 2X4 to protect the shaft of the motor put against the top of the shaft smack the 2X4 with a dead blow hammer several time and the motor should begin to separate.
DO NOT get all crazy and beat the hell out of it. You will only break things. This again is a slow and steady sort of thing. Once you get the motor apart you will have access to pull the rotor out of the other end of the housing. DO NOT PRY on ANY OF THIS.
Flip the motor over and support the housing with stacks of 4X4's or some other thick wood. Bolt a piece of 2X4 to the shaft and hit the 2X4 down to dislodge the bearing from teh top housing.
At this point the motor should be ready to be inspected. PUT NEW BEARINGS IN IT. IF they were locked up and came free they are still bad.
The bearings will have a part number on them you can google that number and the manufacture name and find the proper bearing size. DO THIS BEFORE any attempt is made to remove the bearings.