Home Forums General Discussion Technical Questions Dover composite with optic sensors - overshooting

Any Dover Composite gurus out there?

I have a car that is slowing and approaching fine, but doesn't stop level. It's overshooting about 1/2 to 5/8 inch in both directions. Every once in a while it stops level. I've checked compounding. Up and down speed are within 3fpm. I've replaced optics 2LR, and LD. Sensors seem to be working good. Car just doesn't stop until plate breaks the opposing leveling sensor. I.e. - on a down run, they car levels down slightly past floor level ubtil its close to or at the LU optic sensor. If i tighten the zone, car still overshoots, then relevels. Any ideas?

Check your LUD circuit. Possibly relay not picking or welded N/C contact.

Had that problem and it was 48v potter brumfield relay can't remember the name but it was the 2nd relay with the same name just called #2if that makes sense?upper right hand side of controller behind,can't think of it at the moment

Adjusted mox tap also

It could be your Brake not dropping out properly. Try adding a little Spring tension to the Brake. If that fixes the problem you may need to clean the core, or check out the resisters and relays related to setting the Brake. Make sure you don,t affect the pick when adding tension, and of course put everything back when you find the problem.

Check CFC relay. It aids in electrical stop.

Not sure where my original post went, but...
Does this unit use the selector cable attached to the cross head? If memory serves me correctly, too loose on the spring tensioner will cause goofy floor levels. Relay 14 will mess with leveling also. Location is normally near the bottom of the controller (back side?) to the right.

elmcannic is correct. If it is high in the up and low in the down tighten the selector cable, conversely if it low in the up and high in the down loosen the cable.

Another issue can be the little sheaves that run the selector cable. Bad bearings or a worn sheave can cause the sheaves to move around causing inconstant leveling.

Thanks for all of the great advice. You guys were spot on. The n/c contact on LUD was not making and not allowing CFC to pull. I did check/tighten the selector cable, but it didn't really do the trick this time. Again, thanks for all the great advice. Hopefully I'll get the chance to return the favor

Ridevertical,

Stopping high going up and stopping low coming down is probably electrical. Check the following:

1. Make sure RE relays remain picked all the way in to the floor, to the point your selector runs off the LU or LD sensor.

2. Make sure CFC relay picks up for about 2 seconds after selector runs off the LU or LD sensor.

3. Generator been worked on lately? Possible that the compensating field is in backwards. Swap D1F and D2F wires to the generator on the back of the controller. You should see the situation either get better or get worse.

4. Check to see that the LU and LD sensors drop off the sensor about 1 mark on the dial from floor level. Possible that they selector is remaining on the sensor too long.

5, Does the car make a smooth approach into the floor, up and down, no hesitation six or so inches from the floor?

Just some thoughts

Glad you got it.

Yes indeed! Well done.
Always nice to hear the outcome of troubles we have.
Thanks for posting.

very good line of approach to this problem

I know with Composites there is some possible causes. Remember that the series field of those Dover generators are sometimes touchy during the change of seasons. You can adjust 2lr on the leveling ring to advance or retard that leveling step and sometimes gain control just a little longer if your coming in a little hot. That MG is a bucket of energy and by the time your floor level, you have to dump it all out. slowdowns, and resistor taps. You can move 2lr and many times fix it. (for now)

you will also get better stability with Helwig E41/C MG brushes also. Not so much carbon dust and won't damage the comm.

Ive had the shoes on the carriage worn and caused the carriage to drop and then the contact screws were hitting the stationary contacts causing similar problems.