# LGB 20670/21670 Track cleaner engine differences



## Nemshick_s (Apr 9, 2017)

Hi,

I have had a garden railroad for app 20 years. The best purchase was the LGB 20670 Track Cleaner engine. Well it smoked . So, I figured that since it app 20 year old, I should buy the latest model (21670). With the old engine, I could, with the track voltage as high as 24 volts, turn to speed down almost to a stop. This new engine does not allow me to do this. With the old engine, it would take 2 passes and the track would be clean. I ran this new engine 9 times and the track is still not clean. Has anybody else experienced this?


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## Dan Pierce (Jan 2, 2008)

There is a big difference between the old and new track cleaners.
Old cleaner had lead weights, new cleaner has cast weights and could be lighter.
Old unit had a 3 wire motor block, motors had a direct connection to one rail, newer locos are digital and motors are wired different.

I assume you are track powered DC. I hope you are running linear power as pulsed power will not give this engine all the power it needs to run properly. On DC the cleaner motor runs at input voltage, but motor speed is controlled by the potentiometer on the top of the loco and may not work right with pulsed power.


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## Greg Elmassian (Jan 3, 2008)

Dan, do the new units come with and without DCC?

I had one years ago, and it had a (very dumb) DCC decoder.

Greg


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## Nemshick_s (Apr 9, 2017)

Hi, I'm not using DCC Control. I never felt the need to use that kind of control...

Interesting. I did not notice the weight difference. When they return it, I will check that. The new engine appears to be not as well build as the old one. In my opinion, when I turn the pot all the way up, this engine moves way too fast. So, what I'm looking for is to change the speed range. I have reached out to LGB to see if they will help. If they will not help, all I need is the schematic so I can play with it. Oh, the old engines circuit board burned up. It looks like a couple of resistors and a diode failed. My guess it was the NPN Transistor that failed. I could fix it if I has a schematic. Do you know where to fine one?


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## Greg Elmassian (Jan 3, 2008)

I was asking Dan, and it might run differently if it was DCC.

So, now the board is damaged, can you post a picture?

Greg


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## Dan Pierce (Jan 2, 2008)

The newer DCC engine runs completely different than the old engine.
In DCC mode the cleaner motor runs full speed, the engine motor is controlled by the digital speed.
IN DC mode the cleaner motor will run at track voltage, but the engine motor is adjustable.
From the 21670 manual:

https://www.champex-linden.de/download_lgb_bedienungsanleitungen_ab_2014/21670_betriebsanleitung.pdf




Analog operation (conventional transformer and throttle):• Set your layout speed control to zero.
• Place the 21670 on the track.
• Set the power control switch to Position 2 (see Operating 
Modes). 
• Set the 21670 on-board speed control to a middle position 
(Fig. 4). 
• Set your layout speed control to the highest forward 
position. 
The 21670 will move forward with a medium speed, and the 
cleaning wheels will clean the r


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## krs (Feb 29, 2008)

Nemshick_s said:


> Oh, the old engines circuit board burned up. It looks like a couple of resistors and a diode failed. My guess it was the NPN Transistor that failed. I could fix it if I has a schematic. Do you know where to fine one?


I have a hand drawn schematic of the LGB 20670 that someone in Germany sent me ages ago.
I always meant to draw it properly and publish it but never got around to it - I also wanted to take my 20670 apart to validate that the schematic is correct.
If you PM me your email address, I'll scan a copy and send it to you.
There might be enough information there to fix the board of your original cleaning loco.

Knut


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## Dan Pierce (Jan 2, 2008)

Note that MD now makes a replacement DCC board for the LGB track cleaner. I found the lights way too bright with this board , so you have to adjust each light dimming (front, rear, cabin, each flashing lght) and I had change the 15 to 10 in each CV. My system had 24 volts to the track. Systems with 20-22 volts on the track may need an 11 or 12 for proper light brightness to prevent bulb burnout. This does not help DC users unless they have access to a digital system for programing.


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