LGB 20670 issue

seigezapf

seigezapf

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I recently purchased a used LGB track cleaning loco (yellow one). I found a manual online and figured out the main switch function. In position 1 (center) the locomotive moves forward and in reverse. In position 2, the cleaning motor runs but the locomotive doesn't move forward. The locomotive will run in reverse (without the cleaning motor running). I have tried adjusting the on-board speed control, but it doesn't seem to have any effect. Any ideas on what is going on? Thanks.

Craig
 
These units can take a lot of current to run, and a higher voltage than a normal loco.

If you have it up on rollers, will it "move forwards"? I had that issue with mine and found out I did not have a high enough voltage and not enough amps either.

Also, perhaps it has been modified.

Greg
 
Greg has pointed out that the power requirements of this loco are high. I always ran mine with a 5amp power supply.

Since you bought it second hand I assume that you have cleaned the locos power wheels and skid pick-ups to optimise the track contact and checked that the cleaning wheels are not fouled by the plastic swarf that normally wear off the edges of replaceable plastic cleaning wheels during the cleaning operation.

The other small tip I can offer, in case you've not noticed, it that the power adjuster for the cleaning mode is hidden under the black knob on the roof - ie you pull off the smooth shiny black cover to access the smaller black adjuster found underneath.
 
Are you using Analog or DCC to control the loco? If the latter, you may want to check it's still set for 14 speed steps. Some folks change this to 28 to give finer degree of control but I've seen a note somewhere in some LGB documentation (sorry, can't recall exactly where - memory is goldfish-like these days) that says not to do this.
 
Thanks guys.

Phil, I am running analog (track powered by an 18 volt battery). I did read that when using MTS (a DCC system I think) that the on-board speed control is disabled. I have wondered if somehow the circuit is expecting a DCC command to activate the main motor when the switch is in position 2. The fact that it will run in reverse while in this position is a bit confusing though.

Greg I have had it on rollers and on the track. The main motors run forward and reverse with no problem. In position 2, the cleaning motor runs well, but the locomotive will not run forward. GNB, I did find out about the control under the cap. It doesn't seem to have any effect. I will try it out with a 24 volt battery this morning, but the 18 volt battery has seemed to be fine for everything I have run. As a temporary solution I set the Position switch to 2 to activate the cleaning motor and ran a 2060 in front and in back. This worked OK though to keep the cleaning motor rotation speed up I had to run the two "helpers" pretty fast. Still it cleaned the track pretty well.



GNB I will double check the wheels and contacts and clean them if necessary, though it does seem to be getting power OK. The cleaning wheels seem to be rotating fine so I don't think there is fouling if that is what you meant. It is the main motor going forward in cleaning mode that is the problem.

Thanks again for your comments and suggestions.

Craig
 
I seem to remember with mine that the instructions said it would not work on a line with a shuttle unit, if you have one on this track you will have to bypass it (I did this with a switch: manual-off-shuttle)
 
Thanks Pugwash. I don't have a shuttle unit on the line.

With experimentation, I figured out the issue. It was voltage as several of you suggested. When I hooked up 24 volts it ran beautifully. It even ran fine at 18 volts. But, through my speed control the maximum voltage was reduced to 15.8 and it didn't run there.

Fool that I am, when I tried it with my R/C motor control, the transmitter was set the wrong way (I forgot to look) and the loco immediately backed right off my work bench. Many parts flew off, but survived. The small plastic pin that connects the cleaning unit to the loco did not. It sheared off. Now to search for a replacement pin. Arghhh.
 
seigezapf said:
The small plastic pin that connects the cleaning unit to the loco did not. It sheared off. Now to search for a replacement pin. Arghhh.
Click to expand...

I've repaired two of those this year. In one case a replacement was obtained from a British LGB repair agent. In the other, as no bits had been lost, the two bits of the plastic pin were screwed together with a single screw on the underside
 
respectfully, fyi , and from my own experience
1 I do not suggest having any loco or anything else attached to the front (cleaning Wheel) end. the motor is delicate and any excess down pressure can burn it out. the point is it should be absolutely free to float.
2 be careful with 24 volts. I had the lights , forward direction and roof, blow on mine when my power unit spiked to 24v. as I blew five lamps a couple of times, until I had my unit repaired, I changed over to 18 volt lamps.
3 clean the cleaning wheel axels regularly, meaning pull them off and remove the tiny hairs of plastic from the flanges that accumulate, and all the brass oxide. this will also help the cleaning wheel motor. clean these things regularly and they last. one fellow suggested brakes dust cleaner. the stuff is messy and stubborn, but I have had success with a toothbrush and strong dish soap.
4 the roof pot for speed control only works in cleaning mode. I routinely run mine at half speed or slower.
5 my own quirk, and one I have shared, I reverse the cleaning motor leads, so that the cleaning wheel turn in the same direction as forward travel. Yes they lose, theoretically, some grinding power, but, since I run mine slowly, I find that this not only helps with slick wet tack and grades (if the track is sufficiently wet and there is a grade, the cleaning wheels have more purchase than the drive wheels. ALso, I find that the loco tracks better through points. I have done this for several years. There is not one jot of downside, nor is there any perceptible difference in cleaning.
6 NEVER leave unattended. it may run perfectly, but fate will cause it to stall and grind a divot when youre not looking.
 
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Thanks for the commiseration Rhinochugger. I do this kind of thing all the time so you'd think I would get used to it. It was a helpless feeling as the loco disappeared off the end of the bench.

Thank you for all of the suggestions Stevedenver. I have a voltage reduction unit, so I can set the 24 battery output where I want - maybe at 20 volts would work. I need to find an R/C motor control that will handle that voltage. I will keep in mind your suggestion of reversing the motor leads. If I use helpers again, I'll do them both from the back. Hopefully I won't need them if I supply enough voltage.

Having repaired these, Neil, I hope you can help me with some information. I too thought of a fix using a bolt the same length as the broken pin. I did though find and order a replacement pivot part. To install it, I'll need to take off the cowl on the main engine. I removed the two screws underneath, but the cowl still seems firmly attached. Is there something I'm missing in removing it?

Thanks for the comments and suggestions.

Craig
 
seigezapf said:
Having repaired these, Neil, I hope you can help me with some information. I too thought of a fix using a bolt the same length as the broken pin. I'll need to take off the cowl on the main engine. I removed the two screws underneath, but the cowl still seems firmly attached. Is there something I'm missing in removing it?
Craig
Click to expand...

Sorry Craig, but I can't remember any problem screws in this area but the exploded diagram on the web
https://www.champex-linden.de/lgb_p...87342ED1C368525693E0067D992/$FILE/20670-1.pdf
suggest three screws, one center front and two either side.

At the other end the two screws (marked 90 on that diagram) are hidden by almost impossible to remove covers that do however have access holes. Also, from my poor memory, the cab steps need to be removed if you need to take off the cab.
 
Thanks Neil. In the diagram I see the two 90's on either side, but not the center front you are referring to. In any event I took out the four screws for the cab and once the cab was loose the cowl came off easily. The cowl is held on by just the two side screws, but also a lip that fits inside the cab part. Putting back the two screws inside the covers might be a challenge, but I'm sure doable. Thanks again for your help.
 
Yep Rhinochugger, I didn't want to look.

I have, though, fixed her so she runs again. I have ordered the pivot part, but in the meantime a 6-32 machine screw, proper length of 7/32 brass tube, and tapping the base for the 6-32 screw (photos below) works well. I ran the loco directly off my 18 volt battery and it ran flawlessly. The problem I was having was passing the battery power through an R/C motor control which only passed 15 volts. I have ordered a higher capacity motor speed control. In the meantime I made several passes over my track. I love this thing.






To those who commented, your help through this has been very much appreciated.

Craig
 
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Just one thing to watch out for when cleaning the track under trees or bushes. The nectar, sap and pollen can clog up the cleaning wheels especially if the track is wet.
Otherwise, it has been one of my best buys. It goes out for three to four rounds of each loop and that is all it needs.
 
Thanks for the tip Keith. My track is 80% or more under bushes and trees. Maybe on wet days I can run my track cleaning caboose (pad) first.

Neil, I saw a spring on the diagram, but I don't know if there was a spring when it fell off the bench. When things hit the ground small parts can go anywhere. I'll look around again. I'm sure I can find a spring to fit if I can't find one on the ground. From the diagram it looks like the spring is above the cleaning module tensioning it down rather than up.

Do you think the spring important? The track cleaning loco seemed to work fine without it. But there must be a purpose for it to be there. Thank you for noticing that.

Craig
 
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