I just got a new Athearn Blue Box loco FP45. It is powered. I put it on the test track with the body shell off and no power goes to it. I am running standard DC analog.
However, after testing, if I pick up the FRONT power truck–it gets power in the back. If I pick up the BACK power truck–the front truck gets power.
So, I can sum up the following:
The headlight works
The motor works in both directions (i can switch direction from power supply)
The gears seem to all work right (the loco wants to go forward/ reverse)
Conclusion: When both power trucks are on the rails, a short-circuit is occurring. But I can’t figure out where its coming from???
Please help! I thought the old “Blue Box” would go up and running right away…never had a problem with BB engines before.
Use an NMRA gage to check to see if the wheels are in par. If the axle stubs are pressed too far into the gear, the two ends of the axles will touch, and cause a short.
None of the 5 BB I got were in guage when I bought them.
What is the possibility that the metal conductor that goes from the motor to each truck is not making contact with either truck when the loco is resting flat? But when picked up from one end or the other the contact strip makes contact with the truck contact and you get power to the loco?
The contact strip on the top of the motor is the (+) positive conductor.
You can take a continuity testor to check if you have a short. With the loco off the track touch the contacts to both sides of the front and rear trucks. If you get a reading you have a short. Since Ataearn has plastic gears between the wheels on the trucks I don’t know how you can get a short at that point. I’d be looking for something around the lights to be shorting.
Because the hole goes all the way through the gear’s shaft. If the wheel stubs are pressed in too far (they are metal) they will touch each other, and cause a short.
The loco could have been knocked around in shipment, been assembled by an upset worker, or any other number of things that could have caused this.
And, holding the loco up at an angle, the trucks are probably not making full contact on the rail, so the short becomes “hidden.” So, it would be more likely that an inboard wheel assembly is causing the problem.
But, after going back and re-reading the original post, it would seem that the contact strip going across the top of the motor is not properly installed, or is not seating properly. He didn’t specify a short- my screw-up; he merely stated that he had no power.
If both trucks are geared like a normal BB, I don’t think you can flip one around. Isn’t that why they sell front trucks and back trucks as replacement parts? Maybe you got stuck with 2 backs or 2 fronts by mistake.[2c] I’d get an ohm meter out and start poking around to see where the short was.(or send it back)
Or as someone already said,one of the wheel sets is pushed together and touching inside the gear. Check with an NMRA gauge first to eliminate this possible issue. Then remove the trucks from the frame and check for shorts. Check for rust on the metal strap and contact points on the trucks. Reverse the trucks. Replace the metal strap that connects the trucks and motor with wire. Remove the light. Check the armature on the motor, if it’s been sitting a long time, the brushes may not be making good contact, they can be cleaned with a pencil eraser. Make sure the motor is seat properly.
I doubt that the trouble is with the axle halves contacting within the gear, it is possible but the gauge would be so narrowed the truck would barely sit on the rails. Ckeck the wheel gauge first to eliminate.
I agree the possibility of the wrong trucks. To check if they are right, make sure that both flat truck power straps are on the same side (engineer’s/ right side). You can’t flip a truck around. This would put the worm tower inboard and the drive facing away from the motor.
Athearn trucks pickup left rail though the frame to lower motor strap. Right rail is isolated from the rest of the truck and powers up through the straps mentioned. The long strap contacts both of these and feeds the top of the motor.
I always mark trucks when removing by scribing an F or R on the case.
If you have a SHORT, the Headlight wouldn’t come on.
I suspect ONE of the wheels in either truck is in backwards. One side of each wheel is insulated and you have a partial short. Pry off the bottom plate of each truck with a jewlers screwdriver. Old Athearn design…all 8 -12 wheels have to be lined up the same way. Other side is grounded.
(2) Make sure ALL ROLLING STOCK is off the track. Any car with a backwards METAL wheel would cause the same thing.
(3) If that doesn’t cure it, return it to where you bough it for exchange. What is strange is lifting one truck powers the other one, Motor is turning, so should both trucks.if so, one trucks wheels are in backwards.
Obviously no one tested the product. Atharn’s products lack quality control.
Make sure the truck is making solid contact to the bottom of the frame be sure its seated properly.Use a mirror if possible.
Check the truck’s pickup point on the frame.This can be done by removing the truck and making sure there is enough paint cleaned off the frame where the top of the truck makes contact.This is also a electrical pickup point.
Boy, I gotta see that on an Athearn, with the wheels pressed in too far.
Even looking at the drawing at hoseeker, and having rebuilt quite a few in the last 4 or 5 months, the gear secion in the middle goes all the way to the back of the wheels, as this is also a bearing surface for the gearbox itself.
If the light comes on, but no go, and that is what it looks like, then power is routing normally.
I have a letter in my files from NASA, and they tell me this is NOT rocket science.
Voltmeter, ohmmeter, making certain the contacts are on the proper sides.
Trucks are the same, if I recall, just the position of the two contacts in the gear cases, the lower one for frame contact, the upper one for the strip.
“I suspect ONE of the wheels in either truck is in backwards. One side of each wheel is insulated and you have a partial short. Pry off the bottom plate of each truck with a jewlers screwdriver. Old Athearn design…all 8 -12 wheels have to be lined up the same way. Other side is grounded.”
This is incorrect. All Athearn axles are insulated on both sides by the plastic gear. Their orientation in the truck is irrellevant. This also true of Atlas, Kato, & P2K.
Curmudgeon: The gear does not go to the back of the wheel, if it did then the bronze bearing that is supposed to be between the back of the wheel and the plastic gear is missing and there would be no contact at all as it is the bearings that transfer electrical power to the truck frame from the wheel/rail.
No separate bearing. BTAIM, you can’t press the axle stubs in far enough to short them out.
If it does have inboard bearings, and you did have them pressed in too far, the bearings would be effectively “seized” to the axle, and yet his unit operates when picking up one end.
That means no axles are shorted, or the short would feed all the way through the contacts from the power at the other end.
I am having a little difficulty understanding how it could have beed track tested prior to boxing…seems all manufacturers do a cursory run…unless it had been opened and messed with after shipment and before purchase.
The Athearn units I have use a black wormgear as part of the “tube” that the wheel axle stubs press into.
Depending on age, most older units were supported by the needle tips on the end into the sideframe, but on this one, looks like the gearcase.
The only Athearn I have with bearings on the axles inboard of the wheels is exactly 50 years old.
EDIT:
I went back again and looked at the drawing listed for this unit:
Check to see that the front and rear truck pick ups are properly paired up.The top pick up post should both come up on the same side of the frame, if they do not a short will occurer.