Evening all, I've been back to work on my railroad construction projects the past few weeks. Finally. The N gauge version is a shelf layout in my office space and is about 8 feet high, maybe a little less. I spent a good bit of time making sure everything is level and at the same height and quite a bit more laying two separate tracks, sidings and so on. I finally got up the courage to do some running and broke out a single locomotive for testing. I fully expected problems of course and I got a few. Mostly just track cleaning and a few poor connections, nothing major and all quickly fixed. There is one curve though that refuses to cooperate but only with one locomotive. It is a simple curve connected to a switch siding and at first it was not correctly laid and needed work. I suppose this is what one gets working on either a step ladder or a two step unit. Always trying to keep balance and lighting is less than perfect. No matter what I did I could not get the locomotive to pass this section without derailing. I finally got sick of it and pulled out a second locomotive. Problem solved. This one goes as long as I want to run it with no problems at all. The problem child is a MiniTrix of some kind, not sure what model but with two 6-wheel trucks. It simply can't pass this section. The one that runs great is an Atlas GP-7 with of course only 4 wheel trucks. Both are nearly NIB with little or no run time so they aren't worn out and there is no apparent damage to either. The MiniTrix just refuses to pass this spot without trouble. Where could this problem be? Just a bad combination of siding and locomotive? They are both expensive enough that I would expect them to operate properly. Maybe I should just put the troublesome unit away for now and work on other things. Rick H.
Could you post a pic of the problem spot? Did you check the wheel gauge on the trouble loco? Do the trucks turn freely?
I didn't check the wheel gauge but it goes around every other curve on the layout easily. The trucks do turn freely. I am wondering if the curve is simply too sharp for six wheel trucks. I'll try and get a photo of the section in question and post it here. Rick H.
What is the radius of the curve? Some six axle diesels do not like nine and three quarter curves, while the Atlas four axles will run on them. If it is even sharper than nine and three quarters, few six axle diesels will run on those. I have seen Atlas four axles operate on curves as sharp as seven inches.
With sharp curves, a six wheel truck's outer flanges will be more forced into the outer rail and any track imperfection, even a slight difference in level, will be likely to cause derailments. The outer rail, particularly, must not have any low spots or the leading outer wheel will climb over the rail Doug
My only thoguhts are: Rail riding up and over a rail joiner. Locomotive picking switch points. Run 4/6 axle Atlas and Kato units myself. Not familiar with Minitrix. Agree that it sounds like possibly wheel, or track gauge issues. Hope it's a simple fix!
Check the gauge of your track and for small kinks in the radius. Like the others said it might be the six wheel locomotive. Joe
it is darned near impossible to get some real help without photos of the locomotive/mechanism in question and a photo of the trackage where the problem occurs...apart from that, everything discussed is speculative at best... Respectfully, Bruce
Well, obviously, the leading wheel of the six wheel truck is climbing over the rail, whether it's at a rail joint or low spot in the rail. How are you going to see rail levels in a photograph unless you can see it in real life and then photograph it close up? How are you going to be able to tell available side play in the axles from a photo? The suggestions are meant to give Rick things to look for. Doug
I'd also suggest looking at how freely the trucks on the Minitrix loco move in the frame. If things are a little tight, the trucks might not have enough play to make some spots.
It's a Minitrix diesel - to those who tinker with old Minitrix diesels the it's a familiar problem - check the wipers from the trucks to the contact plate on the underside of the frame. The plate and the wipers often get oxidized or dirty. The little wipers also get bent or lose their spring tension after a long time and since there are NO new Minitrix North American diesels they may have lost tension and are not be making contact as the truck swivels.You may have to adjust the bend in them to make consistent contact. Pretty easy fix.
OK, I'll take a wild guess with insufficient information. I'll guess you've got an old U28 or U30CG because that's the only six-axle Trix mechanism commonly out there. Now, what's really going on is that the inside wheels toward the fuel tank are just along for the ride. No weight on them, and they sorta roll along unassisted. It's really two powered four-wheel trucks with two inner idler wheels. So I'll guess that the second (rear) truck when moving forward is derailing? Those idler wheels derail rather easily on any rail irregularity at all. Other than that, the design is fairly bulletproof. They may be out of gauge, have a burr on them left over from molding, or be picking a rough spot. Really not enough information yet. But certainly solveable. Trix mechanisms are old-school and designed to handle sharp curves, and the trucks are also easy to remove from the mechanism. In fact, the easiest thing to do may be able to simply pull the pin out of the offending truck and roll it around with your fingers to see what is going on with your track. Trix, Model Power, and Con-Cor all made these, too, and the dies kinda wore out, as well as the precision of assembly over time. But they are pretty darn easy to work on. At one time I had ten of them.
