I’m also wondering about the front truck having been installed backwards. Reason I say this is that I got a brass 4-8-4 a couple of years ago that was having problems on a 36" radius in one direction!! Checked the front truck and it was backwards, rubbing against the cylinders. Flipped the truck, no problems. On the photo, your front truck looks as if it is catching the cylinders with the lead wheels, which actually might be the REAR wheels. It shouldn’t be doing that on a 23" radius, as per your photo.
Try reversing it and see if that helps.
However, your first sentence REALLY made my day, LOL!
Larry, you may be correct, but it would seem that other locos would show signs of doing a bit of a hitch there, too, and Ken is adamant that the curve and track is not a problem. His other BB was just fine over the same section of track. [?]
Ken, one more thing, get a perfectly square un-warped piece of two by four as long as the wheelbase of both engines combined. Problem might be the engines are not free enough at the joint to follow any irregularities in track yaw or pitch. If you set the two by four on the rails and it rocks anywhere that could be an issue.
Hey thanks for all the ideas. I don’t think the front trucks are on backwards or up side down. Truck has a V shape where the screw goes, it is facing foward. On the side facing up there is a grove that a washer rides in.
It is a shame that it pulls so much better than the 4009. I gave it a nother shot tonight on the DC A line. Man it pulls like what I thought a Big Boy should. Pulled another 35 car train with no problems till it hit a left hand turn![soapbox] I am sure I could fix it, but why should I fix yet another new $300.00 plus engine? (I did fix a new BLI not wanting to waite 3 months to get it back).
Thursday it will no longer be my problem, going back for a full refund and then Friday I will either buy a PCM or a Trix. Waiting to hear from the Trix seller on warranty but more than likely it will be a PCM.
[sigh] I just got through running my Genesis BB pass one of the spots on my layout with 24" radius curves. This track is powered by a MRC Tech 3 with amp and voltmeters. NOW…the BB runs fair till it hit that tight curve, and noticably slows. And the amp meter needle vibrates. Signaling the amp draw is affected from the strain. Largest steam engine ever– the loco isn’t designed for super sharp curves! Its simply too BIG. Plenty of issues will arise from attemping to send this massive beast through ‘train set’ type curves. Wider the curves, the less trouble the giant will have. Couple the same train to it and send it through 26" radius or larger and see it the truck acts up.
My J1 squeals through 24" (That curve was handlaid with a little bit tighter radius in spots) and slows greatly and gets amp-hungry. I wont even try the Duplex on that.
Now the little Y3 from Proto eases through the 24 just fine although the front truck is super sensitive to track flaws greater than it’s flange depth. I depend on Kato to eliminate as much as I can and file down the rest to metal shavings LOL.
To the poster with the idea of a flawless 2x4 with a length of a engine, wont a simple 1 or 2 feet long Bubble level made of precision metal work just as well?
Many things will work in lieu of a two by four, but few of them will be cheaper. I would have said a two by two, but I haven’t seen a decent one of those in… I can’t even remember !
Something that hasn’t been mentioned but needs to be checked is, possible dips or rises in your trackwork that the BB can’t tolerate. You need a short bubble level that is made to hang on a string. With track power off, set the level crossways on your track and slide it along, watching to see if the bubble moves from center. If there’s a dip or hump in your outer rail, that can cause derailments on some locomotives or rolling stock that can’t flex enough to cope with it.
Ok you must not know your UP, i am defending Ken MR said both the athearn and pcm would run on 18’s and mr was right they do they run fine so he is not pushing the boundries just running on the edge on a brokejn trestles. Once again read up on your UP skills like i have spent my time doing. Don’t bother asking me trivia q uestions because i will get them right. no kidding i will.
Hark! Hear the babble of one unschooled in problem solving.
Bottom line, if all 4 axles are flanged there will be problems at tight radius. If there is any flaw like a twist or dip/rise in the rails anywhere the engine will fail to stay on the track.
I recall an old cartoon that had a door hinge cut and bolted into a boiler that is sawed in half to accept it.
I will throw in my 2 cents here to get back on track. First, I see that you are not having issues with the locomotive on 18" radii turns. You are having them on larger turns though. I just went through this with my BLI 2-10-2 and had to rework 3 of my curves. Here is some ideas that I did to locate my issues.
Check to see where the locomotive is derailing. Is it the same place in the curve or an approximate location.
As mentioned before check for dips and rises in the rail.
Verify that your curve is not tightning up to a tighter radii before the derail or at the derail point.
The biggest thing you will find is that these large locomotives require very true track. There can be a slight imperfection in the track that may not be noticeable to us, but it will be noticeable to the locomotive and try to get the best of you while trying to figure it out.
I was driving my dad crazy with the number of times that I was tearing up the curves to get the 2-10-2 to go around without derailing. It is all good now and well worth the time and effort put into it. It looks great on the layout and now we are back into making progress - starting the scenery now by painting the track tonight.
Jeff in the back of my mind I keep thinking it is my track. I know each engine can react driffrent just there quricks. (spell check) Bugs the Coboose out on me why the 4009 track like a champ across the same rails for 100 hours and 4020 cannot make it around one time!
It does derail in the same spots on the B-line and the feeder wire is not the problem as one pointed out. I ran the gauge in the derailing spot and it is not tight like I hoped. Only ran it 6 feet before it derailed on the A-line that is DC only. It is all so the Line that is at the edge to the leap of death (2"s and it on the floor)
Up Chuck as I said in my PM to you about the tress you don’t want this one but if you have $350.00 to spend I will bring it to you and 40 tress as well.
Jeff, one other thing that bugs me. Only the 4020 BB has a problem with my rails! If I relay the rails could the other engines start having problems? I have 50 other engines that think they are just fine. I like the Big Boy the best but?
I the PIC of 4020 there was no drag on the engine.
You have a larger roster than I do Anyway as far as redoing the track work, take your time and be particular about no imperfections. If you do this, then all your other locos shouldn’t care about the new track work.
If you are using flex track for the curves then make sure the fixed rail is on the outside of the curve and solder the joints. I stagger and solder my joints and do this while the track is straight before being laid. I also trim the rail hold downs on the ties where the track joiners are. This keeps the track from having a lump there.
Another thing I found with mine was a piece of cork was found under one of my rails and it was enough to derail the locomotive. My BLI 2-10-2 is designed for 22" radii and even the manufacturer states it runs best with 22" radii. They don’t say it has to be perfect track and that it is really picky about the track.
Just keep trying things I know it can be discouraging, but it will work out.
Anyway as far as redoing the track work, take your time and be particular about no imperfections. If you do this, then all your other locos shouldn’t care about the new track work.