|
Post by zoinks007 on Feb 28, 2017 15:22:50 GMT -5
Today the mailman brought me two new GP38-2's, and as I usually do, I put them on a "figure 8" break-in layout and ran them for an hour. Unit #1 is awesome. Unit #2 is awesome backing up, but moving forward it's half speed, and nowhere nearly as smooth as #1, or even itself moving in reverse. This is after 30 minutes in the forward direction, 30 minutes in reverse, then back to forward (to see if it cured itself).
Diagnosing loco issues over the forum can be a crazy thing to attempt. I'm wondering, though, if there are common issues like this and if it's just a matter of more break-in time. I've not removed the shell to see if there happened to be an electrical contact issue, since it ran better than locos I broke in that had contact issues. Or, to say it another way, it ran well enough that I didn't suspect contacts. It just doesn't run great (like its sister) in the forward direction. Half speed or so, maybe approaching 3/4. Noticeably slower, though.
So my question is more of a general nature...when you are breaking in your locos and they don't run as well in one direction or the other, is it usually a matter of perhaps too much lube in a truck on one side or something (straw grasping), likely poor electrical contact in that direction, or just needs more break-in time to seat gears or some other moving part? Or an alternative I've not considered?
Hoping I didn't find the surprise in the Christmas pudding (to reference another loco issue thread). Even if so, nice loco and I'll work with it.
|
|
|
Post by markm on Feb 28, 2017 20:43:26 GMT -5
I usually run 15 minutes, both directions 3/4 throttle 1/4 throttle. Forward and reverse inconsistencies have been rare for me. For maintenance, details are a bit scattered. The TCS and Digitrax decoder installation instructions will show you how they open up. There are notes on the main AZL site and the AZL page of Monster Z for changing trucks and installing the snow plow that are useful. Trainboard has had some good discussions such as: www.trainboard.com/highball/index.php?threads/sd70ace-maintenance.102801/I haven't updated my link for the GP-38 discussion there. My first thought would be to check that the shell and fuel tank are on right. Hope this helps, Mark
|
|
|
Post by shamoo737 on Feb 28, 2017 23:51:46 GMT -5
Normally I would have suggestions, but with the GP38. I say don't work too much on the chassis.
|
|
|
Post by markm on Feb 28, 2017 23:59:44 GMT -5
Shamoo has a valid point. When you say "new GP-38s" are they new new or just new to you? The first production run had some chassis casting problems.
|
|
|
Post by shamoo737 on Mar 1, 2017 1:11:22 GMT -5
I don't see how taking the tank off will improve the performance. If the tank is loose and it's dragging. I only experience it on MTL diesels. All azl have tight fit tanks.
|
|
|
Post by markm on Mar 1, 2017 10:18:48 GMT -5
Shell and tank off, made no difference, runs in some spurts forwards, smooth backwards. My other 3 F3's better. Greg This isn't a unique problem. I don't have any F3s (AZL doesn't like WP or SN) so I can't offer hands on guidance. If you haven't seen it, check out this thread: azlforum.com/thread/770/switching-couplers-on-f3sit may give your some ideas. I don't see how taking the tank off will improve the performance. If the tank is loose and it's dragging. I only experience it on MTL diesels. All azl have tight fit tanks. It's a starting point. Unless one has x-ray vision, it's kind of hard to see the workings of the unit. This opens a whole new set of questions: "Did anything fall out?" "Any foreign objects visible in the mechanism?" "Is the PCB seated properly?" Monster Z has posted some good tech tips from Rob(A): zscalemonster.com/azl/pc_board.htmThese are also available from the tech tips link at the top of the American Z Line site, although Antony has better pictures. Hope this helps, Mark
|
|
|
Post by zoinks007 on Mar 1, 2017 11:29:29 GMT -5
In my specific case, the locomotives were brand new (hence the required break-in). I suppose there's nothing wrong with buying used, but I've not done it myself. I've not removed the shell, but if it stills seems off, I'll do just that. I can see some flashing perhaps slowing up some gears, or maybe the contacts were a bit off. I've even read that (rarely) the motor can misalign if not seated completely. So some things to check. This particular locomotive isn't completely fubar, just a bit off in the one direction. Noticeable, but not debilitating... I'd run it, for sure. But there has to be a reason it's off, and that's what I'd be searching for. Can't see a snap-on tank issue. If the tank were dragging, it would drag both directions I'd think. And looking at this specific model, there is obvious clearance. So not an issue for this little guy in my case.
|
|
|
Post by markm on Mar 1, 2017 12:13:39 GMT -5
In my specific case, the locomotives were brand new (hence the required break-in). I suppose there's nothing wrong with buying used, but I've not done it myself. The question goes back to when the unit was built. The first production run has a chassis casting issue that could cause it to degrade of time, just sitting on the shelf. You could have one of these. Contact AZL support. It could also be a problem with the lighting board not seating right. Yeah, I didn't think it would change anything, but if you're removing the shell, IMO the tank just gets in the way. Obviously, if you're unsure about opening the unit, contact the dealer. Mark
|
|
|
Post by gprose on Mar 1, 2017 14:02:18 GMT -5
I've also had issues with locos running faster in one direction than the other, I've never figured out why. With some of the GP38s I have they also have fluctuating speed issues (run slow then speed up and vise versa) never been able to figure this one out either.
|
|
|
Post by zoinks007 on Mar 1, 2017 15:47:54 GMT -5
The question goes back to when the unit was built. The first production run has a chassis casting issue that could cause it to degrade of time, just sitting on the shelf. You could have one of these. Contact AZL support. Which could be the case, since the units came with the outer white cardboard wrapper. My GP9's are like that, but locos like the SD70's and SD40's had no such wrapper. Those being newer releases, I assume AZL no longer ships using that wrapper. I'll peruse the forum to see if there is a discerning characteristic of the older chassis, and if so, I'll see if I can get them fixed.
Sounds about like mine...so there may be a systemic issue somewhere. Or it's a rabbit hole. I'll take my shell off and see what I can see.
|
|
|
Post by shamoo737 on Mar 1, 2017 16:07:40 GMT -5
GP38 doesn't have separate fuel tanks. It's part of the chassis.
|
|
|
Post by davestubbs on Mar 1, 2017 19:20:21 GMT -5
Take a look at the wiper on the trucks. 4 of my F7s had the copper wipers that the wheels contact get bent outward and caused poor pick up in one direction. pulled the truck apart bent them straight again and they run like champs. might not be you problem but worth a look.
|
|
|
Post by shamoo737 on Mar 2, 2017 0:21:49 GMT -5
In my opinion, the GP38 is the one engine that AZL messed up, but I am getting one from the second run just to test it. I will let the group know how it runs.
|
|
|
Post by modelwarships on Mar 6, 2017 16:29:19 GMT -5
If it runs better in one direction, check the board wiper to motor contacts. Sounds like the motor is torquing (rotating) away from the contacts and giving you intermittent contact in that direction. When running in the other direction the motor rotates slightly towards the contacts maintaining good electrical connection. It's a PITA to get right sometimes.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Mar 7, 2017 17:14:27 GMT -5
In my opinion, the GP38 is the one engine that AZL messed up, but I am getting one from the second run just to test it. I will let the group know how it runs. I was planning to buy (at least) one GP38-2 for a new layout. But after reading this I wonder if I should not but a GP30 instead ... Is there less trouble with it ?
|
|