An Experiment with Face Book

[Jay Criswell]

Thank Jon!

Butch, sure. Whatever is desired.

Jay

[Roy]

The gearboxes...have...1:1 helical gears. This is a photo [of] an early version, made of injection molded Delrin, or something similar. We use brass castings now.




Jay

So, the entirety of the reduction is in the gear head. Do those ball bearings on the drive shaft and axle also take up the thrust? The gear design would give as much axial thrust, as force acting on the axle gear to provide a drive moment.

[Jay Criswell]

Roy,

That may, or may not be the case. I can still raise or lower the overall ratio with various pulleys installed in the motor or truck tower(s). Might help to look at the photos.

Jay

[Roy]

Roy,

That may, or may not be the case. I can still raise or lower the overall ratio with various pulleys installed in the motor or truck tower(s). Might help to look at the photos.

Jay

Jay, I presume you're referring to my comment about the reduction being strictly in the gear head. That comes from observing the belt stage, which is greater than 1:1, and the helical gear final drive, which is 1:1. That only leaves the gear head, for reduction.

And yes, by adding belt or gear stages, you can change the overall drive ratio. Perhaps, Faulhaber makes other gear heads for your motor, with different ratios?

[Jay Criswell]

Roy,

Yes, all of the manufacturers do. The little Faulhaber 2619s, shown in the photos, come with numerous ratios. The only two applicable to our needs are the 8:! (a little fast and 22:1 (usually a little slow). I've used both and like the 8:1 but settled on the 22:1. The 2230s I use are 9.7:1, the 2840s are 14:1. Most of the Pittmans 8724s are 19.5.1. There are others but those are the primary gear heads I use.

Jay

[Jay Criswell]

Roy,

As an example of the extremes. Shown in these photos are the little 2619 and the 2840 Faulhabers along with the 8000 series Pittman. All gear heads with various reduction. As you can see, sometimes I like to use big flywheels.




Jay

[Roy]

I know those are very expensive power components. They remind me of an old HO diesel advertising campaign, where they'd time how long it took for an engine to go from one track tie to the next. That may have been for Kato.

[Jay Criswell]

Roy,

Ya know, it's kinda funny, we do that sometimes and, I suppose, it's almost like a competition. A couple of buddies of mine, that actually were engineers, tell me the real ones don't run that slow. Shoot, what do those 12" to the foot guys know anyway.

Jay

[Roy]

The only two [gear head ratios] applicable to our needs are the 8:! (a little fast) and 22:1 (usually a little slow).

Jay, what's your ideal drive ratio?

[Jay Criswell]

Roy,

Too many variables to say a particular ratio is ideal. Things like wheel diameter, customer desires. These would be things like, hi speed mainline operation, slow speed switching, pulling long trains, or maybe just 1/2 a dozen. Also depends on the motor. Some have maybe 4000 RPM output while others are closer to 10,000.

I'm not trying to evade your question but, as I said earlier, too many variable. For diesels 14:1 is a good starting point. Steam would be more like 23:1. Others mileage will vary, to be sure.

Jay

[Jay Criswell]

Roy,

BTW, when I said the two ratios available on the Faulhaber gear head motor were 8:1 & 22:1, I was talking specifically about the 2619 (motor is 26mm in diameter and 19mm long).

Jay