I have been attempting to build a Bowser Manufacturing Pennsy M1a Loco. I love the kit full of details and easy to understand instructions, but every time I add the drawbar to the drive wheels they bind and will not roll properly. All the wheels roll easily without the drawbar connected but once I connect all four drivers I have the problem. Any suggestions no how to trouble shoot this problem?
Hello “ejackson,”
I guess when you say “drawbar” you really mean “side rod,” since the drawbar connects the engine to the tender. The problem you’re having is called side-rod bind, and it indicates that the quartering of the drivers – the 90-degree offset of the crankpins in each driver wheelset – isn’t consistent or the side-rod spacing isn’t correct, or some combination of both.
To fix your engine, try the side rods connected to just two pairs of drivers and see if it will still roll smoothly. If not, look slosely at the side rods as you pu***he engine frame back and forth and you should be able to see where the bind is occuring. Use a rattail file or a tapered reamer to slightly enlarge the hole where the side rod is binding, then try it again. When you get the first two sets of drivers to work correctly, then connect the third set and continue until the whole engine is rolling smoothly.
I’ve built a Bowser M1 kit myself, and when you get everything right it does make a good-running, powerful engine.
Good luck,
Andy
Thanks for advice. I don’t know why I had drawbar stuck in my head…
Andy makes a great suggestion in just connecting two driving wheels at a time. Start with the outside drivers and work symetrically. That means that you must connect the siderods on both sides of the drivers. Once the outside drivers start working, then start adding the interior drivers. It is crutial that you get the mechanism running smooth at this point, or it will always run rough or bind in the future.
As for filing the siderods, a lot of scratch builders consider this taboo or cheating and will only do this as a last resort. If you do decide to go this route, remember that less is more - take only what you need off, because any extra material that you file off will introduce slop in the mechanism.
The M1 is a really nice kit - good luck…
I thank you both. By connecting the side rods to both sides of the front and rear wheel sets and then securing one of the four remaining screws at a time I found three problems. Once corrected the engine tested great, for about 3 hours I might add. Then it was time for the kids to get some sleep, as well as my 3 year old.
Well I have learned something here. I have a Rex 2-6-0 kit that has the same problem. I put it aside because I wasn’t sure how to fix it. Now I know what to do. Thanks Andy.
Enjoy
Paul
I have built several Bowser locomotive kits, the latest is a USRA Pacific 4 6 2 , nice kit, a lot of work but worth it. If you really want something super, contact NWSL and install one of their gearboxes and can motor, you wont beleve the differance. It is also a lot of work fitting it in to the locomotive.