I have two of the LGB U series, 20721 fitted with a MTS decoder and 20705 which came with the Zillertal set which was already MTS. My problem is that the 20721 runs smoothly over switches even at lowish speeds. The 20705 has to be running fast or it will stop on the switches. Before opening anything up do any other uses have a similar problem/solution? Thanks.
LGB U series and switches
- Thread starter HGLR
- Start date
As Phil says but also check that all the wheels are picking up, use a meter and test every wheel and the sliders both sides. The front wheel should give positive circuit to the slider on the same side and to each wheel that has pickups.
Thanks for the suggestions. I had cleaned the backs of the wheels and checked skates as Phil suggested. Not sure about a meter but I had used one of the Kadee wheel cleaners and each pair of wheels picks up current and powers the rest. I am guessing this is the same sort of test a meter would achieve?
PhilP
G Scale, 7/8th's, Electronics
The other possibility, is the skates are shorting on the frogs, as the loco passes through the point (turnout) but this tends to cause the Central Station to 'trip'..
Bending the foot of the skate upwards slightly, or a strip of tape on the outer part of the skate, will cure this.
If bending, use a large pair of pliers, but bend so as not to strain (break!!) the plastic housing the slider moves in..
Bending the foot of the skate upwards slightly, or a strip of tape on the outer part of the skate, will cure this.
If bending, use a large pair of pliers, but bend so as not to strain (break!!) the plastic housing the slider moves in..
The Central Station is not tripping but I will try adjusting the skates in case they could be causing sticking. Thanks for the thought.The other possibility, is the skates are shorting on the frogs, as the loco passes through the point (turnout) but this tends to cause the Central Station to 'trip'..
Bending the foot of the skate upwards slightly, or a strip of tape on the outer part of the skate, will cure this.
If bending, use a large pair of pliers, but bend so as not to strain (break!!) the plastic housing the slider moves in..
Paradise
Registered
The early LGB U class had no pick-up sliders but I think both your models have them.
Does the troublesome locomotive do the same on all switches?
What type of switches/points are they?
LGB switches/points have a flange bearing frog which can lift the wheel's tread slightly off the rail when they go over the plastic frog. Also, the sliders won't get any current when one is over the frog.
At these particular times current should come from the other wheels or the sliders, depending where it is.
Run the locomotive over the switch slowly and precisely mark where it stops then work out exactly where each wheel and slider is positioned. If it is when the slider is over the insulated frog then you will know that the problem is probably with the wheel's carbon brush pick-ups or their internal wiring. If not the problem may be with the sliders sticking along with the wheel's pick-ups.
Does the troublesome locomotive do the same on all switches?
What type of switches/points are they?
LGB switches/points have a flange bearing frog which can lift the wheel's tread slightly off the rail when they go over the plastic frog. Also, the sliders won't get any current when one is over the frog.
At these particular times current should come from the other wheels or the sliders, depending where it is.
Run the locomotive over the switch slowly and precisely mark where it stops then work out exactly where each wheel and slider is positioned. If it is when the slider is over the insulated frog then you will know that the problem is probably with the wheel's carbon brush pick-ups or their internal wiring. If not the problem may be with the sliders sticking along with the wheel's pick-ups.
Paradise
Registered
That's a good point..
The drivers including the sliders are shorter than an R3 point rails but there is also the trailing wheel which has carbon brush pick-ups so it should still go.
Thanks for al the constructive suggestion. I will try them out later today and report back.That's a good point..
The drivers including the sliders are shorter than an R3 point rails but there is also the trailing wheel which has carbon brush pick-ups so it should still go.
Yes that would work just as well, so long as each pair of wheels and the pickups separately brings the motor to life that will be proof that all the contacts are working correctly.
Still “shiny and clean”.
Have now adjusted the skates but to no effect. The points are LGB R3, in answer to an earlier question.
On today’s testing it seems the loco goes more smoothly heading from west to east across the two points, both going forward or in reverse. Heading east to west is when the problems really arise. When the loco stops on the frogs slight sideways pressure puts the lights back on and travel begins. I have checked that the track is level. My other LGB stock works fine, even those with a shorter wheel base. Really a puzzlement!
stockers
Trains, aircraft, models, walking, beer, travel
The frog is high. It is a common situation. One of the wheels is flying clear of the rail and the skate is on the plastic bit. If you can fix the frog down (I dont know what your base is made of) it will help.
The difference between the two locos is probably down to the stiffness of the skates or the rigidity (or lock of) in the chassis.
The difference between the two locos is probably down to the stiffness of the skates or the rigidity (or lock of) in the chassis.
LGB R3’s can be a bit of a “good boy/bad boy” type of point. I have some that cause the skate to short out which has resukted in me using a short length of insulation tape to stop this. To prove either this or what Stockers has described get your head right down to track level, drive the loco over the frog either way and see what occurs. A small flash will indicate my solution, a slight lift up will indicate what Stockers has described.
The base is breeze block. How would you suggest testing the fixing down approach?
Brixham
No buffers were hurt at this sign
Perhaps the wheel contact 'bullets' are worn, fine when the wheels are centered, but on a curve the wheels will slide in the bearings , possibly losing contact with the bullets. A static test, which you have already done, may not show the problem. Do it again, but push the wheels sideways so that contact could be lost.
Malcolm
Malcolm
stockers
Trains, aircraft, models, walking, beer, travel
a thin long screw, either through the frog or close to it, in to the block with a plug. I have done a couple into lightweight building blocks with success.