I have a whole bunch of engines of all kinds of brands, but only this engine derails. Wheels are right on too. Derails at same spot but can't fiqure it out, track in gauge, Shinohara switch. Thought it might be a high spot on the rain joiner from souldering, but no, high spot on switch, no, dips, no. No derail runing backwards through same spot.
Not much to go on here. So here's my questions at this time. Derails going off on the branch/sideing or main/straight though? Like front wheel set or rear wheel set of front truck or front or rear wheel set of rear truck? Both trucks derail? Did you look very hard at the frog point of the switch/turnout? How about the switch/turnout's point? Coupler trip pin? Piece of ballast laying in the frogs grooves? Size/number of switch/turnout?
I looked at the bottoms of my two BLI NW2, not much to go wrong there. Truck corners clear all body/frame corners when swiveled as if on level track. No strain on trucks as if from tight wiring.
happens when I am on mainline after I clear the switch after going though the divergant route of a right hand turnout going towards the throwbar and only when facing this direction, turn engine around and no problem.
I wonder if a wheel flange is picking/lifting up on the point rail and stock rail contact area? Is there a notch cut in the inside/web of the stock rail for the point rail to lay into (this would be close to the throw rod)? Are the tops (rail head) of both point and stock rails flush when moving over that area? Seems like you are past all the tricky parts of the turnout when this happens. Does this happens with cars following or without cars attached to the loco.? I do not think I have any Shinohara turnouts to look at.
Thought of that, and took care of any deviation. But no, and like I said if I hit the same spot with engine flipped, no problem, so must be a truck problem. Only differnce I saw in truck is it had some extra lubricant on one side. Could it be the wheel set is a hair wider on the one truck ?
rrebellCould it be the wheel set is a hair wider on the one truck ?
Yes, or narrower. It's not unusual for engines to come with the wheels slightly undergauge, to (in theory) help the engine go around sharp curves.
Checking the wheelsets with an NMRA gauge would be a good idea. Check too that all the wheels of the trucks line up correctly - it's possible the wheels on one axle are the correct gauge, but are skewed to one side or the other.
It's also possible something inside the engine, like a wire to the headlight or trucks are interfering with one truck, causing it to stick and not turn into the curve.
rrebell Thought of that, and took care of any deviation. But no, and like I said if I hit the same spot with engine flipped, no problem, so must be a truck problem. Only differnce I saw in truck is it had some extra lubricant on one side. Could it be the wheel set is a hair wider on the one truck ?
In your first post you said the wheels were right on. Maybe not. Now I guess you go back to the first thing you should have checked more closer.
Rechecked everything, still good on engine.
Now it's time for a dark room, a bright flashlight and an up close eyeball. Hopefully the track is close to get at.
One good thing, it seem like it happens at the same spot and only going one way in one direction with one engine.
There is not any chance you are controling that switch/turnout with a Tortoise switch machine and the throw wire is sticking up a bit to far at the center of the throw bar?
If you have any of that chalky white powder weathing dust stuff or just Baby powder or wife/girl friend/sister's eye shadow (light in color) dust the fuel tank ends and the back side of the coupler boxs and each truck's end and four corners.
Run it up to the spot just before it derails and then look and see if any dust is rubbed off of the fuel tank or coupler box back ends. Then start over and run it till it derails. Do not let the trucks swivel or tilt as you lift and turn over to look at the bottom for rub marks. Of course you have to realize the trucks may rub off dust upon derailing by tilting and not by rubbing on something they should not be rubbing on just before derailing.
I watch it close up, thought it might be a rail joiner too high, no. Nothing else derails there.
Did you check all clearances with the NJMRA gauge s suggested? Trucks and turnout ?
Gary
Look close at the ends of the trucks, to see that the side frame's end clips are snapped in place on/over the nubs of the truck body. If not snapped in place the clip will stick out some and hit the rear of the coupler box. I am sure you turned the loco. over and swiveled the trucks back and forth.
Checked all clearances and swivel. Both trucks behave the exact same way. It just seems to drop off the rails there. Both trucks in gage and at the same exact point. Unless there is some twist in the truck I can't see.
Think I may have fixed it. Only got in two runs, one fast and one slow. Put exstream preasure on truck side frames, like most of my force. No ovius snap or something but it seems to have worked, would keep tesying but daughter has zoom meeting.
It is the truck but it snaped out again, I guess, but no visable snap in. Extreame presure seems to fix problem. Now how to fix permanintly, will not send it off as second hand. Most of my DCC stuff is brand new but not this one.
Also thanks to the one that suggested checking the truck in this way.
Also of note is lots of people have had a problem with BLI front trucks over the years and different models, but could not find a solution yet. And here I thought I had done something wrong, ever relaid a peice of track.
Notice in the parts blowup, there are a couple of screws that hold the truck together, can these be tightened ?
Same old problem, only this engine, ready to e-bay it. Bought a few more engines, not this brand and all is good with those too. Slight presure on the engine as it goes through this spot stops derailment, weird.
rrebell Same old problem, only this engine, ready to e-bay it. Bought a few more engines, not this brand and all is good with those too. Slight presure on the engine as it goes through this spot stops derailment, weird.
Derails right after the switch, all switches are #4 code 70 Shinohara.
Might be a dumb idea, but if your phone has the ability to record slow mo, I'd try to get a recording of the engine derailing from multiple angles to see if you can see why it keeps derailing.
I used this to figure out how my k4 was derailing at this turnout, turns out the coupler would snag on the frog. In real life it happened so fast I couldnt see it, in a blink of an eye the lead truck would just derail.
https://youtu.be/sWpqTFTym7Y(idk why the quality suddenly got so bad)
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I agree, you need to operate the loco very slowly and see what is going on. I never filmed my locos, but the process is the same. Something is lifting a wheel. Could be a piece of plastic or a kink. That, and a truck that is not pivoting freely in all directions is creating the derailment. I suspect that it is the loco, but if it's the switch, a bit of filing should do the trick.
But I'm curious, when you say that your other locos don't have the same issue, how many locos are we talking about? What make?
Simon
It dose it at a crawl, don't need a camera. It seems the design of the truck is what is behind it, it dose not evenly apply the torqe to the wheels, I bet if I had a micro meter I would find the front truck is located in a slightly different place than the rear, which is why it dose not derail running backwards. There are dozens of people on the net to have this problem, none were able to fix it long term. I could take apart the truck and rebuild maybe but just not worth the effort.
How about swapping the front truck for the rear?
If the problem changes ends, you have narrowed it down to the trucks.
If the engine continues to derail the same direction, look at the frame or switch.
Code 70? Are you absolutely sure there isn't even a slight dip on one of the diverging rails?
rrebellThere are dozens of people on the net to have this problem, none were able to fix it long term.
I must be one of the lucky ones. I've got three and never had any tracking problems. I tore one down in order to use the trucks on a brass engine. I didn't encounter any obvious design flaws.
DES-3_gear-2 by Edmund, on Flickr
Good Luck, Ed
Checked for a dip, not there. Others have switch them to no avail so it must be in the deck the truck ataches to. Two people fixed theirs by pulling down on the right side of truck, tried it and even with force, no go. don't know if it was a permanate fix for those two, very old thread.
rrebellTwo people fixed theirs by pulling down on the right side of truck, tried it and even with force, no go.
Most of the (Athearn clone) diesel trucks I'm familiar with use two "fingers" on the worm gear cap to retain the truck to the frame. You can see these on my photo above where the rounded nubs nearly contact the brass deck.
BLI_SW_truck by Edmund, on Flickr
I wonder if you lightly sand or file a little of this off , probably doing one clip at a time, and see if you get any improvement? A slightly deformed molding or slight twist in the frame would cause uneven or insufficient "roll" (to borrow from aircraft axis) and cause a wheel to lift if it is not allowed to rock & roll.
Here is what the underside of the frame looks like:
BLI_SW_frame by Edmund, on Flickr
To check the seating of the trucks, you could put the loco on a sheet of glass to see if all the wheels touch the glass evenly.