K-27 Gear Ratio

[StanAmes]

As you were part of the consultations that took place during the design stages of the K-27, do you agree that 30:1 was the gear ratio proposed?

Do you agree that Bachmann decided that 29:1 was appropriate for the K-27?

If so, how come the K-27 has ended up with 14.5:1 and not 29:1?

Tony

I did indeed provide recommendations on the K27 to Bachmann and continue to do so.  I am credited on the Video for the K27 for this support.  The role of a consultant is to provide ideas in certain areas.  The design team consists of many engineers and many ideas and recommendation are considered but not all make the end product.  The K was designed for DC, DCC, and RC users and RC users indicated that they desired max prototype speed at 14.4 volts.  The higher the voltage the more batteries are needed.

What do you believe the top speed should be at 14.4 volts?

If the K27 were to have a gear ratio that is double what it has now the top speed would half or be about 16mph for your users or about 35mph at 24 volts DC

This might be fine for some users but others would complain that it was to slow.

When you can get consensus on what the top speed should be at the various voltages then together we can approach the manufacturers with a recommendation that can be designed to.

Stan Ames
www.tttrains.com/largescale

[Tony Walsham]

Stanley,
I would respectfully suggest you try and understand what good gear ratios should be.
The lower the gear ratio the slower the speed at any given voltage.
The big advantage is that lugging power is increased.

Other manufacturers of 1:20.3 scale model trains use a high ratio and I hear no complaints.

You and I both know that the Bachmann design engineers agreed that 29:1 would be a good ratio.  At 14.4 volts it would provide a realistic top speed and give good low speed lugging power.
With track power this discussion is irrelevant.  You simply add more voltage to get to the speed you want
With battery power to achieve a faster top speed would indeed require more battery voltage.  Depending of course, on the type of batteries being used. In the case of the K-27 there is plenty of room to add more battery voltage to increase top speed if needed.
So saying that perhaps a battery R/C user would complain about it being too slow, is a furphy.

At a recent meeting you allegedly told the person you were meeting with, "Bachmann stuffed up the gear ratio". 
Why did you say that?

.

[glennk28]

For a prototypical pulling ability, the Cum,bres & Toltec Scenic RR rates K-27 463 at 183 tons from Chama to Cumbres, up a 4% grade.  A lopaded car weighs about 41 tons.  Therefore 4 loaded cars and a caboose shoiuld be it--If trhe loco can handle that, it is about right.  I haven't got track down yet to test it--Antonito to Cumbres is 1.4%--rated at 595 tons.  14 cars and the caboose.  gj