Bemo V51/V52 improvement

Coreless motor, belt drive, DCC and sound

The Bemo V51 (H0e) and V52 (H0m) are not bad for their looks, but inside it’s all very crude. The worse is the sprocket on sprocket connection, which causes a whining noise that can only be solved in two ways: digging a deep hole in the metal to install a motor that will directly power the worms, or replace the gearing with a belt drive. These are popularised and sold by Nigel Lawton, so I had a little play to see what works best. And because the noise was very much reduced, I upped the noise with noise that is more desirable from a model train.


4x 4 mm pulley 

2x Brass adapter 1.0 to 1.5 mm L3 (art AD1015 L3)

2x 6.5 mm belt

DCC: Train-O-Matic Lokommander II Micro W (art 02010223)

Sound: Doehler & Haass SH10A SUSI sound module

Important CV settings when using the Train-O-Matic and Doehler & Haass decoders

- CV 122 on the Train-O-Matic Next18 decoder decides if SUSI is on or off. Default value is 66 (off). To turn SUSI on, set value to 71.

- Without changes, a Doehler & Haass SUSI sound module in combination with a Powerpack, will give stuttering sound. Most noticeable when driving. To avoid this, do the following:

In CV 961 (Threshold value ZVS) of the Doehler & Haass module, write the value 4. 

Background explanation of the sound stutter issue: The Doehler & Haass sound module only needs 5V to work, but by default it is set to stop working when it receives less than 10V (value 10 in CV 961). It will switch itself off when the voltage drops below 10V. So when the train looses power from the track, due to dirt on the track for example, the  powerpack will start to power the DCC decoder and D&H sound module. This energy coming from the powerpack will be around 8V. If the value of CV 961 is more than 8 (in this case the standard value 10, for example), the D&H sound module will turn itself off, because it receives less than 10V. Therefore, if you set the value below 8, like value 6, you tell the D&H sound module to switch off only when it receives under 4V. 

If you have any question, feel free to contact me!