This device is used to lockout the Parking Brake switch on certain Air Brake equipped Motor Coaches. The locking device houses the brake switch and guards it in the Parked position...a long shank padlock shackle serves to secure the locking device in place. It is mainly used to prevent over zealous pets, or perhaps youngsters from inadvertently releasing the parking brake system. This is not an anti-theft device... It's most practical use is when you stop for fuel...while my wife takes one of the dogs for a rest break...and I'm outside fueling the coach --- we have one puppy left unattended, inside. The air tanks are full, the transmission is in Neutral, sometimes we're on a slight slope --- it would be a bad day to have the coach start rolling away from me while standing on the off-door side...with a fuel nozzle in my hand.
Disclaimer: The designer is not responsible for the suitability of this design. It is not a substitute for wheel chocks, etc... Please refer to your Motor Coach Manufacturer's guidance for safe operation of your Recreational Vehicle.
Version 4 is the current design. I am happy with the fit and finish of this design. I am trying to add a 5th version that will not have the holes for a padlock shackle...but instead have flexible prongs inside to hold the brake control shaft. My first attempt failed due to the easy de lamination of ABS on thin walled structures. I will try again using slightly modified dimensions and nylon filament to see if I can get that model up and running.
I printed it with 4 outer layers...and 20% triangular infill. Use of raft is totally optional. I had it check when I sliced the model.
Adjusting design for fit
Since the Brake Switch installation may vary from coach to coach...the user may need to remix the design to get the proper fit.