Russ, may be you are right!

For the Demag ML15 I need two motors - one for driving the locomotive and a second for the constantly rotating flywheel.

The drive is constructed similar to my

Gmeinder 10-12. However, here is no toothed belt, but gears will be used.

**Demag_ML15_Montage_099** (fspg2)

**Demag_ML15_Montage_100** (fspg2)

First of all, I interviewed the data sheet for the little Faulhaber motor 1512 and calculated the three model speed levels of 5.5km/h, 9.5km/h and 13.5km/h in an Excel spreadsheet.

**Demag_ML15_Montage_101** (fspg2)

The already small space in the locomotive allows only very narrow gears and small engines.

**Demag_ML15_Montage_102** (fspg2)

The gear unit has the following dimensions: height = 27.0mm, width = 20.0mm and depth = 4.0mm.

**Demag_ML15_Montage_103** (fspg2)

**Demag_ML15_Montage_104** (fspg2)

The second gear for the flywheel now has a depth of 4.7mm available .... enough space!

**Demag_ML15_Montage_105** (fspg2)

**Demag_ML15_Montage_106** (fspg2)

**Demag_ML15_Montage_107** (fspg2)

Now a few comments on the gears:

The gear ratio is about 2: 1.

The gears will have module 0.5.

The gear on the lower drive shaft has about twice as many teeth as the drive gear on the motor shaft.

In order to fit into the given space, I decided to use the following gear arrangement: 9 theeth – 9 teeth – 19 teeth.

**Demag_ML15_Montage_108** (fspg2)

A few formulas for calculating the center distances:

**Demag_ML15_Montage_109** (fspg2)

No matter how many teeth the middle gear has, for the gear ratio of gears only the two outer gears have to be considered: 19/9 = 2,11. The middle gear only bridges the distance between the two motor and drive axles.

The gears are ordered - let's see if they fit as well as I think.