[tdn] My new Bachmann shay has been returned twice for stripped gears, I hope that this time I can make at least one lap of my 19"R test track before they strip again.
Doea anyone make a Shay with metal gears any more. I had an HOn3 brass two truck years ago and that little thing would pull everything I had up the steepest grade I had and never once complained.[:(]
You might try contacting Northwest Short Line www.nwsl.com to see if they have any replacement gears available. Their gears should be more durable than the stock Bachmann ones. I think they would also custom-make the gears for you if they didn’t have them on the shelf. It’s probably not a trivial amount of money to have this done, but it would sure be cheaper than buying a new locomotive.
I believe part of the reason plastic gears are so common is that if there’s a problem in the drivetrain, it’s better and less expensive to replace a broken gear than a burned out motor. That, and plastic gears are obviously cheaper than metal ones [;)]
I have a Lehmann Large Scale engine that stripped all 4 plastic gears. Not much hope of finding replacement parts with the current situation. It used to be that at least one of the gears was brass so you wouldn’t have to replace them all. just another example of our “throw away society” Jerry
I think that NWSL is the answer for those stripped gears. I’ve head from several other people who have used the NWSL Shay gears–evidently they’re a stock item–and had really good luck with them.
I’m wondering about the ‘newer’ plastic gears–I’ve got a whole slew of older brass locos from about 1960 that have metal worms in the gearbox but plastic gears on the drivers, and they’ve NEVER worn out from running. Absolutely indestructable. Did the Japanese have some sort of ‘secret’ high-grade plastic that they used back then that they never told anyone else about, LOL? I keep hearing about stripped plastic gears on all kinds of locos, these days.
Makes me wonder.
Tom [:)]
Plastic Gears are the trojan horse of planned obsolesence, you accept it and you can
count on a short future.
In my experience all, of the eletronic equipment that required gearing to move a component failed because of bad gearing. (either the teeth wore or, the central axis connecting rod worked loose from the gear)
For example, Scanners (2 lost to bad gears), those Ripoff emegency crank radios (1 and never again, it lasted all of one night), garage door opener (the do last 10 years though)
As to how Some Plastic gearing mechanism seems tougher and more reliable, it comes down to design more than anything else. There are alot off the shelf gearing components and whole gearing units so that companies don’t have to re-invent the wheel.
If a company takes the time and money to have a first class gear box, then you are probably going to pay for it. How do you improve reliability?. Deeper teeth, More contact between gears, a primitive clutch to cushion a high impact start, sturdy axles, well closed gearing box.
2 Bachmann Shays, 3 years old, factory stock gears, used regularly and on steep grades…Zero problems.
[2c]
AR:
What kills gearing is fatigue and wear, but you don’t want to design gears to outlast the machine they’re going into, either…that’s needlessly expensive. Those scanners’ gears and crank radio gears aren’t expected to run continuously like a model loco’s gears do.
To make gears last longer, you use tougher materials, tighter tolerances, and more careful attention to mesh, lubrication,etc. There are lots of rules for gear design. It’s fun stuff.
But anyway, there’s nothing wrong with plastic gears, if they’re designed to suit the application. Brass worms driving nylon gears, for instance, have been used a lot in model RR applications with good service life.
Nothing magical about those Japanese gears mentioned above. They just did their homework.