A client has a TYCO C-420 that has a special meaning to him and his son. It apparently had been used a lot and in his word could not get out of its own way. He asked if I could do something to improve it.
Well knowing that there are limits to what can be done, I told him I would do my best.
Starting out, the job was to be difficult. It has a TYCO HT pancake motor rather than the classic Mantua motor. While each has its on problems, the Mantua motor would be yield a better engine. However, because neither were available in reserve. And the desire to do the minimum, I chose to try to use the existing HT motor.
To begin with, the engine was dripping with oil of some kind. It was everywhere.
Also, there were no traction tires. Because the drive is designed to have them, when missing the engine rocks off the contact surfaces. In addition, the TT add a significant amount to the average friction coefficient. The draw bar pull on these engines can increase by 60 grams with TT. So that was the easy fix.
Because of all the dripping oil, all drive surfaces were cleaned this required tearing down both trucks. The motor truck was removed and oil was dripping out of the cooling holes and out of the brush cavities. The motor needed a full cleaning.
Upon taking the motor apart, it was clear that the oil was everywhere. The brushes were swimming in oil. Not good. Interestingly, before starting the tune up, the engine was tested with new traction tires. Amazingly it ran, but very slowly. The SMPH at 16 volts was 42 SMPH. Not good for engine only.
The springs and brushes were basically worn out. Which by the way is a typical problem with these motors. So I needed these parts to continue.
Periodically, I get Tyco engines of all sorts that do not run. What this really means is motors that are in various states of abuse. Often The motor is broken and can not be fixed without parts. Those motors are replaced and are used for parts. Every six months or so some time is set aside and the best five or six of these motors are repaired and made ready to be put into engines that will not run. This was a good time to do this work.
It usually takes seven or eight broken motors to get five good ones. As with the motor above the common fault with these motors was:
1- worn out or missing brushes or brush springs. The brush and spring is the final electrical contact and must be clean and in good condition.
2- The brushes and brush cavity was caked with gunk, dirt or swimming in oil. Again must be cleaned and free of all dabre. This allow the brush and spring to do their work.
3- the communicator surface was covered by a couple of mills of gunk or dirt. Clearly no electrical contact can be made through it.
After cleaning all of the gunk dirt and oil and making the communicator surface shiny you can put the motor back together. The combination of the spring and brush, installed in the cavity, should make a surface that bulges above the cover when installed from above. If they do not, then they should be replaced.
Putting these motors back together can be tricky. I use scotch tape strips thar are cut in half-length wise. They are long enough to wrap around the plate tha the cavity is in. Holding the brush and spring in the proper position. Be sure not to cover the bearing hole that the rotor goes through.
After both spring and brush assemblies are secured with the tape, I reinstall the plate to the motor housing. Gently holding it in place, I put to screws in but do not tighten all the way. Then pull the tape out. If it breaks going one way, pull the remaining piece going th other way. Then tighten the screws holding the plate. Test the rotor rotation by hand to verify that there is no binding or foreign material sound.
At this point put a very small drop of a good bearing oil on the bearing points on either side of the motor. Be careful to not leave any oil on the surface or anywhere you wer not intending.
The result of this activity is usually five for five in terms of getting the motor running. The condition of the motor can still be poor. The torque and speed are both functions of the magnets flux. If that is low, then the motor will run, but is not suitable for use in a train engine. I listen to see which run fast and which do not. The ones that sound slow are rejected at this point. They are torn down and the magnets are thrown away.
The good motors have proper color feed wires soldered to them so they are ready to go into a candidate engine.
With this activity I came up with four motors to choose from for the clients engine. After finishing the installation, the typical performance tests were performed on the unit. The maximum speed at 16 volts was over 100 SMPH. Remember this is engine only. with a train it will be slower. The draw bar pull was now over 120 grams. The performance characteristic which was at -4 before the motor change now measures 36. These units will never be outstanding, but this is acceptable.
The unit has been shipped back to the client.
