What follows is nothing more than a rant about the brake cylinders on the Proto PA trucks.
I have four Proto 2000 locomotives, two PA and two PB. Each loco has two trucks, and each truck has two sideframes, left and right, with two brake cylinders on each sidefram. So, there is a total of 8 dynamic brake parts on each locomotive.
I have attached a couple of photos. The first photo shows the truck with both brake cylinders in place. The second photo shows the truck with one brake cylinder missing.
Those brake cylinders are very large and pronounced, sticking out from the sideframes. From the factory, the brake cylinders are press fit into the sideframes, not glued. If you are not extremely careful when positioning the trucks on the rails, it is easy to knock off those cylinders, and there are very tiny pegs on the brake cylinders on which glue can be applied.
So, you have to grab the trucks with your fingers in the center of the trucks between the brake cylinders. I have lost count of how many brake cylinders have fallen off those trucks, mostly on the PA units.
Unfortunately, I have lost a couple which are capable of bouncing off the basement concrete floor 4 to 6 feet or more. I have even gone so far as to buy a pair of trucks on eBay to scavenge a total of 8 brake cylinders. I couldn’t find any PA trucks, but the Proto 2000 Erie-Built trucks have the same brake cylinders.
Couldn’t resist, Rich, but I sure do identify. I’ve lost many a teeny part to the mysterious ether of the workshop floor, never to be seen again even after searching on hands and knees with a magnifier and flashlight. -Rob
Sorry Rich, but those are simply castings representing air-operated brake cylinders. If the PAs had dynamic brakes, they would be basically resistor banks inside the locomotive, with fans, likely on the roof, to dissipate the heat.
If the cylinders are so fragile, simply remove them from the locomotive, cut off the mounting pins, and drill the spot from where the pins were removed to accept piano wire of a diameter similar to (or slightly larger) than the plastic ones. Use ca to secure the wire in the cylinders, and into the loco’s sideframes, too.
There’s a chance that the sideframes may be cast in engineering plastic - if so, use a ca designed for use with such plastic… LePage offers a"super glue for all plastics". It consists of a tube of ca, and a marker-like applicator to “prep” the plastic.
The “prep” will outlast the ca that’s included, but will work with any ordinary ca that you might have on-hand.
Thanks for the correction, Wayne. I do appreciate it. I wasn’t at all sure what that part was called so I just threw the term “dynamic brake cylinder” out there to see if it would stick. So, is the correct term simply “brake cylinders”?
I like your suggestion about using piano wire in place of the plastic pins. I need to take a closer look at that.
A trick that seems to help is to lay the flashlight on the floor - even a small part lit side on like that will cast a fairly large shadow. But so will crumbs…
Stewart F units have the same problem. The cylinders and the trucks are all slippery engineering plastic, so it’s not even easy to glue the parts in place.
Randy, that Lepage ca for engineering plastic does work as advertised, and there are similar products from others, including Loctite, who , I think, first developed it.
I’ll have to find some of that. Regular CA doesn’t work very well. I was using white glue - it doesn’t actually adhere but it more or less jams the mounting stem in the hole so it won’t fall out and if you care careful not to dislodge it, the cylinders stay put. Plus it dries clear so you don’t know it’s there.
Thanks, Sheldon, but I am good for now. I found a pair of Proto 2000 Erie-Built trucks on eBay for cheap, so I bought them to scavenge 8 brake cylinders.
Rich you made me check all my erie built cylinders. They were all there and solidly attached, I couldnt pull them off. Maybe the PAs were made different, or you got a bad run. Good luck with the repair.
They can be pulled off. When I bought those two Erie-Built trucks on eBay, I pulled off all of the brake cylinders and put them in a small storage box. But if yours are securely in place, that is good because when one falls off it is very noticeable.
Wayne, I bought LePage Super Glue along with the marker. I just glued on the first two of four brake cylinders. I will let them cure 12 hours, per instructions. If it holds, I will do the other two brake cylinders.
I was working on an Athearn Genesis GP9 last week. Had two detail parts fall off, and for the life of me the locomotive doesn’t look any different than when I started.
In many instances, that is true. But, with those brake cylinders on the PA locomotive, a missing one is easily noticed because of their size and a second brake cylinder on the same truck. It might be less noticeable if both brake cylinders on the truck were missing.
Take a look at the first photo with a missing brake cylinder. Then, look at the second photo where both brake cylinders are in place.
I checked the two brake cylinders that I glued on with LePage Super Glue and they look and feel pretty secure. So, I did the other two brake cylinders that had fallen off.
Time will tell how well the bond holds. Meanwhile, I need to be extremely careful how I grip the trucks if they need to be rerailed for any reason.
Air brake cylinders. Linkage on the ‘business end’ for slack adjustment without going under the locomotive, and that end ‘ought’ to connect to levers and rods (collectively called the 'foundation) that pull the brake shoes evenly against the wheel treads. Ed can provide views of the prototype truck that clearly show the brake rigging and the air connections to the cylinders.
Dynamic braking doesn’t use cylinders, or a linkage. It uses the electrical traction motors, reconnected and excited to serve as generators, to brake the motored wheels. On a PA that’s only the two ‘end’ axles per truck.
