Learned something new today.

You were over the draw bar limit Matt, gotta run the train DP or manned helpers

Yep. Kept having problems with three up front. At first glance it looked like the locomotive's coupler was too high. A second check with the height gauge revealed what was going on. Here's a shot of the problem once fixed -- 25 sMPH vs. 15 wit no problems. It was only 14 cars, but 12 of them were Atlas; the other two were weaver 57-foot mechanical reefers. Interestingly enough, I think converted hi-rail diesels with die cast pilots will actually have fewer problems because of a more rigid mount than their scale-wheeled counterparts.

This is bad news since I like to provide insulating (plastic) draft gear boxes on my locos and I like to run long trains.

Ed

MAtt, are you using the MTH transformer. I was wondering how one keeps the rear power from pushing or pullng the train more than needed. I would think that one could get derailments by scrunching the cars or pulling them apart on turns. I see so many UP trains doing this rear engine as the caboose is gone. The video looked real good.

Ed, it's not necessarily bad news.

I think I know why this happened, and specifically why it happened with my new GP35's. With most scale equipment, the Kadee center holes are used which puts a metal screw through the plastic sleeve in the box. MTH uses only the side holes so the center post in the plastic box is unsupported. I compared the GP35's with my GP38's and indeed the GP38's had the 740's with metal boxes while the GP35's had the 745's with plastic boxes. Up until my most recent order, I had been using the metal-box Kadees.

New rule (learned something else today) is that the MTH locomotives get the metal boxes and plastic boxes are reserved for brass rolling stock (not that I buy that much). When I make my next Kadee order, I'll order some extra metal boxes for the GP35's. The other option would be to glue a 2-56 screw into the center hole to prevent it from flexing.

Phil:

I was running the three powered units as a consist under DCS. They're very evenly matched.

Matt thanks for brining us up to speed. The video looked cool.

Hope you are still trying to take it easy and not over doing things Mat. Take care

 The other option would be to glue a 2-56 screw into the center hole to prevent it from flexing.

I was going to suggest more screws, until you mentioned that the entire pilot may be flexing.  2- railers pretty much have to use plastic boxes or plastic couplers.  There are four holes in the earlier Kadee boxes, and one could fill them all with 2-56 steel, screwed into something solid like the sheet metal frame.  Go ahead and put a screw all the way in to something solid.  Drill #49 if you have not done extensive tapping in steel, and use cutting fluid.

 I've built long trains and have not seen this happen. I have snapped couplers and derailed. Adding distributed power works great. It will be fun when I add the mountain grades soon.

 I do this in G scale and those guys don't listen when I tell them how good it does.

I've never bought plastic boxes for just that reason, but if the center holes are used it should help. Like you said though Matt, many of the MTH 3/2 engines use the outter 2 holes of the Kadee box.

I've had issues with long trains on grades in a curve with Kadees before. Just like real trains, when a portion of the train gets on the downhill side, it cause slack in the train (meaning the couplers bunch up), but the rear of the train is still on the uphill side (causing the rear to stretch the coupler slack out)....that causes the train to separate because of the delayed action in the Kadee.

Same thing happens when you couple a Kadee to a 3 rail coupler on a grade in a curve. The slack bunches it up, and the curve causes it to separate.