New Precision Craft Model E7 Running Poorly

[Herc Driver]

Hi Guys,

I'm helping out my LHS owner who had this engine returned to his store after a person bought and returned this E7 for poor running issues. He's given it to me to test on my layout and test track (since he doesn't have one in the store) and try to figure out what's going on with it.

I got it to my test track and confirmed, it runs terribly. At low speeds/power settings, it lurches forward with an audible squeal from the motor and wheel slip. At faster speeds, it runs marginally better, with the occasional wheel slip and motor squeal.

I checked and found all the wheels slightly out of gauge, and fixed them. I looked at the motor, wiring, truck assembly and drive shafts and found nothing wrong. The rear-most wheels are "traction tires" and the rubber surrounding the metal wheels look fine and without many miles on them. This is a DC-only engine running on a new DC-only powered oval track on a level surface with no grade. There should be no reason for the slippage that I know of, but I'm certainly no expert. I've cleaned the wheels, and the track, just to make sure there was good contact. There seems to be no electrical contact loss, and both trucks run well and without hesitation when slightly lifted from the rails (one end at a time of course).

So I'm at a loss to know why this thing runs so poorly at slower speeds, barely able to move forward (or reverse) at a low power setting without jerking forward, slipping, and lurching forward again all the way around the oval. This engine was from the 2007 production run by Precision Craft Models I believe, so it sat in the box for a while. I'm wondering if the traction tires are too old to adhere to the rails properly. Besides that idea...I'm at a loss to know what's going on here.

Any ideas?

Thanks!

[Charlie B]

Mark, once I had a locomotive do that and the magnets were in backwards in the motor. It would spin great, wheels turn and everything, until you put it down, then it had no power at all It was a bear to find this problem, and it may be the problem here but you probably can't reverse the permanent magnets in this one.
Charlie

[rrinker]

The squealing usually is a sign of no lubrication. I don't know of they ever changed, but originally BLI was NOT lubricating the locos from the factory, to keep it from getting all over like some manufacturers (ahem, Bachmann) who saturate things in grease before boxing them. If it's a high pitched squeal that varies with speed, it's probably the motor bearings. Open it up and check - I bet all the gears and bearings are completely dry. I use the Labelle products, the light oil for bearings, the gear lube for the gears. Doesn't take much, just a tiny drop on each one. They used to throw a small note in the box that said lubricate before running.
Also, look for any details (liek brake hangers) that might hit the rails and keep the wheels from firmly sitting on them. See if the trucks rock back and forth, they may have gotten twisted from sitting in the box, or may have been bad from the beginning. If all the wheels don;t make level contact with the rails, it won't run very well.

--Randy

[Herc Driver]

Excellent ideas...thanks.

I added a tiny amount of oil to the wheel gearing, and performance seemed to improve slightly. But I'm going to pop the shell off and try to place some right on the worm gears to see if that helps. When I last removed the shell, you could look at the drivers from the motor and they were spinning straight and true, and both trucks were receiving equal amounts of rotational energy (from what I could tell). It almost seems like a track adhesion problem...but maybe I'm only convincing myself that that's the cause since I can't come up with any better ideas. It would be one thing if one of the trucks were not powered, or a wire wasn't making good contact, or an extra frame weight wasn't installed. (Which makes me wonder if this engine's center of gravity and balance are to blame...hmmmmm.)

But I'm going to try to add just a tiny amount more oil and see if that helps.

Thanks!

[Herc Driver]

Finally figured it out...and here's the answer.

I found the plastic hex nut on the rear drive shaft was stripped just enough that it didn't keep good contact with the motor drum. During my initial testing, when I lifted the rear truck from the tracks with the front trucks supplying the electrical power from the tracks to the motor, the rear wheels spun since the motor drum could generate just enough contact to spin the hex nut on the drive shaft. So I wrongly thought, "since the wheels turn - it must be ok."

But today when I took the engine all apart and slowly spun the motor by hand, I noticed the rear truck gearing wasn't turning. I disassembled the engine further and saw the rear hex nut had rounded-off corners. No wonder it wouldn't run smoothly and lurched around the track.

So a tiny touch of CA glue (since I didn't know what else to use) made a solid contact between the plastic hex nut and the motor drum, and this E7 cruises along the rails without hesitation and at all speeds. I might open it back up and replace the 'bad" hex nut with a good one from my parts stock (it's easy to break the bond of CA glue if you put the parts in the freezer for about 10 minutes)...but that's for a another day.

What did I learn from all of this? When in doubt and there's no obvious answer, take it apart and look at each individual part. Had I done that before, I would have realized the part was bad and solved this two days ago.

But I also learned the value of friendship between a LHS owner and repeat customer. As a "reward" for solving this problem, my LHS owner gave the engine to me and my boys as a "payment" for fixing it for him. So we ended up with a nice pre-Christmas present!

[Charlie B]

Finally figured it out...and here's the answer.

But I also learned the value of friendship between a LHS owner and repeat customer. As a "reward" for solving this problem, my LHS owner gave the engine to me and my boys as a "payment" for fixing it for him. So we ended up with a nice pre-Christmas present!

Mark, That was one great gesture by the LHS. You are so lucky to have one that cares about it's customers. He couldn't have done it for a better guy.
I hadn't been to a local hobby shop for over 20 years, because I had been out of town. There was a new one that was only 20 miles away so we took a drive last week. I needed some spikes...They didn't even know what they were. They were catering more to the RC gang with a few train sets on the shelf, but really, they didn't know what a railroad spike was.
I then went to one of my old favorites but the original owner had died a while back. They had spikes but when I asked for ties, no dice. Of course he could order them and have them in a week, but I figured I didn't need to drive 40 miles once again for a package of ties. I did buy some other parts that some day I'll need.
Charlie

[Herc Driver]

By way of background...We have only two hobby stores here in Charlotte, and both are trying hard to add to their Nscale collections. Both have a good amount of HO and O gauge cars and accessories already. There's a great train store in Spencer, NC right across the street from the NC Transportation Museum, but that's over an hour away from my house, so I only get there maybe once a year.

I was happily surprised my LHS owner did that too. Granted, over these past five years I've been seriously back into the hobby, I've purchased almost every engine and car from him, so he's done well (at least I hope he has). But I was sincerely pleased at the gesture, and my boys really appreciated it too. I wish he derived more business from the "train crowd"...since most of his business is with RC cars and planes, and the school project rockets and derby cars, and the model car/plane/boat builder. I've tried to help him where I can as well...being in the store to answer train related questions to help him make some sales and add to his customer base...even fixed a broken Bachmann engine for a kid right there at the checkout counter. But I'm happy to help and foster a good relationship with him and his staff. I benefit because he'll order whatever I need/want and all without shipping costs to me, then subtracts a percentage from MSRP before he sells it. It benefits him because I'm a regular customer who keeps ordering from him exclusively, and that has to improve his store's bottom line. I'm sure I could save a buck ordering on the internet...but a day like today solidly reminds me why I normally don't purchase my train gear from cyberspace.

[P5se Camelback]

... There was a new one [hobby shop] that was only 20 miles away so we took a drive last week. I needed some spikes...They didn't even know what they were. They were catering more to the RC gang ... [There's a new one like that about 18 miles away. They are clueless about model railroad ... they said they could order anything for me but didn't know who Walthers was!] ... I then went to one of my old favorites but the original owner had died a while back. They had spikes but when I asked for ties, no dice. Of course he could order them and have them in a week, but I figured I didn't need to drive 40 miles once again for a package of ties. I did buy some other parts that some day I'll need.
-- Charlie

There is a dedicated model railroad hobby shop about 1 1/2 hrs. away ... I'll be making the trip up Interstate 75 for some much needed Floquil paint and misc. modeling supplies as soon as I can shake this nasty bacterial infection that I'm still fighting!

I'm currently back in this podunk facility that pretends to be a hospital for a couple days to get rehydrated and switch to the "Big Gun" antibiotic.