Got a Blue Box GP-38 the other day for cheap. Got inside and did some cleaning and tuning. Cleaned the commutator, oiled and lubed in all the right places. When put on the track it goes smooth in reverse at low speeds but going forward at low speed there is a slight jerky motion and the light flickers a tad. Can anyone point me in the right direction to fix this? Thanks in advance
Bruce
Hmm. That's a good question. Could one of the gears be cracked? I have an older Bachmann 0-6-0 that had a cracked gear and it did the same thing. (I've since repaired it) Another thought would be that something is out of alignment and it only affects forward. I've had this happen by the way. I hope this helps.
It sounds like poor electrical contact between the motor and the frame. If you remove the motor, you might find gunk on the metal tab that contacts the frame.
Make sure you have now motor mounts on hand before you do this. They could break when you pop the motor out.
-Kevin
Living the dream.
thanks for the replies, I will check gears and look at the motor tonight
Go easy on the motor mounts, but if they break, I've heard that E6000 does a pretty good job of fixing them.
I've not tried it on motor mounts, but it's done a great job in the past for me holding weights (I use bullets) in place inside rolling stock and repairing shoes.
Visit the Chicago Valley Railroad for Chicago Trainspotting and Budget Model Railroading.
Bruce, I had the same issue with a brand new one. Upon checking I found the motor wasn't seated completely and the motor contract was making intermediate contract in (my case) reverse.
Also be sure to inspect that metal pickup strip that connects the motor to the truck pickups to ensure its making good connact on all surfaces and there's no dirt or oil on it..
One more thing.. This happen to me after cleaning one of my GP40-2s. I didn't seat a gear correctly after cleaning the gears. I bought this engine used and it had to have a ton of grease on the gears!
Larry
Conductor.
Summerset Ry.
"Stay Alert, Don't get hurt Safety First!"
I have the feeling the front truck is the issue, going to look into it later tonite
If the light flickers at the same time the locomotive runs with a slight jerkiness, that suggests electrical problems, an intermittant open circuit that deprives both the motor and the light of juice. On my Athearns I have hard wired the motor power, that springy strip doesn't always make good solid contact with the strips coming up from the trucks. I get 1/4 inch Fastons from the hardware store. These will slip right over the strips coming up from the trucks and accept a wire. Install the fastons, crimp the wires into them and lead the wires back to the top of the motor. Cut to length and strip. Solder the wire (one from the rear truck one from the front truck) to the top strap. Remove the top strap from the motor (it just snaps off) to prevent melting plastic parts of the motor. The strip is stainless steel, it will solder but not easily. Buff the metal bright, apply a generous dab of rosin flux, use 60 40 solder, use a big (100 watt or more) hot iron or gun with a well tinned tip, and it will solder. Reluctantly, but it will solder.
Oher things to check. The gear towers on each truck can be full of hardened grease. You want to clean all the old grease out with solvent. Take a pipe cleaner and wipe each tooth of every gear carefully. Often bits of black flash, invisible against the black plastic gears, get into the gears. Cleaning them out will make the locomotive run noticiably more smoothly.
I have seen Athearns where the motor did not seat down flat to the chassis. Eyeball the U-joints, they ought to be running nearly straight. If one or both is running at a stiff angle, that's clue the motor is not mounted flat. Also eyeball the motor, it ought to look in line with the chassis.
I have never had any trouble with the bottom motor brush failing to contact the chassis, but that's just me. It's perfectly possible and it could be your problem.
David Starr www.newsnorthwoods.blogspot.com
I ordered theses from Athearn. Better motor mounts. Works on P2K models as well. Joe
http://www.athearn.com/Products/Default.aspx?ProdID=ATH84027
http://www.athearn.com/Products/Default.aspx?ProdID=ATH84026
Thanksfor the advice on rewireing, I was thinking of doing just that.
Take some time and read this link for tuning up Your Athearn Blue Box engines:
http://www.mcor-nmra.org/Publications/Articles/Athearn_TuneUp.php
Take Care!
Frank
The link in Frank's post is about the best out there, for tuning up an Athearn BB loco.
Another critical contact area is where the frame sits on the trucks. Both must be clean, as thats the path for the (-) side of the electrical pick-up.
Mike.
My You Tube
zstripe Take some time and read this link for tuning up Your Athearn Blue Box engines: http://www.mcor-nmra.org/Publications/Articles/Athearn_TuneUp.php Take Care! Frank
Frank,There's some good advice in the link but, some overkill too. Over the 60 years I used BB engies I found replacing the metal strip with wire and ensuring the contact poinrs are cleaned was more then enough to get them to run at slow speeds in fact mine could creep fromm tie to tie. I did replace the Athearn iron wheels with nickel silver wheels on two of my SW1500 simply because I planned on adding a decoder. A project that may never see complition.
You could also try taking the cap off the worm at the top of the truck and check if the thrust washers between the bearings and the worm on the drive shaft are present. The bronze on bronze contact when thrust in one direction can create the type of friction you are talking about.
Also check if there is a burr in the bearing hole for the shaft on the outside surface by LIGHTLY running a larger drill and making a a small chamfer on the lip as a burr can affect movement in one direction.
As for the flickering, again with the deburring, have you checked the tab on the trucks on which the frame rests? The torque of the motor in each direction can "push" the frame down on the trucks and have a solid contact or lift the frame and break contact, hence your flickering light and stuttering motion in one direction.
Do not chamfer that area too deeply and possibly just buffing the top with aluminium (aluminum to you in the US) oxide paper will suffice. Feel free to PM me if you need an illustration
Hope this helps
Cheers from Australia
Trevor
xdfordYou could also try taking the cap off the worm at the top of the truck and check if the thrust washers between the bearings and the worm on the drive shaft are present.
There should be a washer at each end of the worm gear.
Mike
That very link I posted above from NMRA addresse's that very issue in Trouble Shooting Tips.
As Larry points out...there is a little over kill on what can be done......but..no one says You must do it all. Do what works for You.......period.
I have many Athearn engines from the very early 50's, that still run great! Some even have the old cast wheels. My motto has always been, Including My owning a small fleet of semi's........''If it ain't broke, don't fix it''.
mbinsewi xdford You could also try taking the cap off the worm at the top of the truck and check if the thrust washers between the bearings and the worm on the drive shaft are present. There should be a washer at each end of the worm gear.
xdford You could also try taking the cap off the worm at the top of the truck and check if the thrust washers between the bearings and the worm on the drive shaft are present.