Just finished 1/4 of my track work and testing engines. My Broaway Limited EMD SW1500 4-axel engine runs fine. But so far all my Scaletrains' EMD SD40T-2 6-axel engines are derailing in the turns.
HO scale, Peco 83 flex track, minimum radius is 20". Engines rated for 18" minimum radius.
Seems the leading 2 wheels come off the trace in the curves. The wheels look very small and these engines are very low to the ground. Since I have 7 Scaletrains 6-axel engines this makes this a big deal. Why would these engines wheels be jumping the rails?
What are my options of fixing? Help!!
Thanks.
They say the minimum radius is 18", but they also recommend a 22" radius. Based on your description, I'm thinking your radius is just too tight.
To prove that, run your engine to the point the lead wheels come off the rails. At that point, can you physically turn the trucks far enough to get the wheels back on the rails ? I'm thinking there is probably going to be something hindering the ability to do that.
Turn the engine up-side-down and turn the trucks from side to side and see if there is anything preventing the truck from turning any further. Some judicious trimming may be required to get it to turn further.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
I agree with what Mark says, and testing the movement of the trucks, the way he suggest. There really isn't anything you can do to the trucks to make them turn tighter.
You might have to rethink your track work, or stick with 4 axle locos.
Mike.
My You Tube
Another possibility is to check if your track is absolutely flat. I had a small dip on a section of a curve that was basically invisible until I laid a long straightedge on it. My six axle locomotive would do the same thing.
York1 John
Do they derail with the leading truck going in reverse also??
If they do......I would be willing to bet, the radius is too tight for that 6-wheel truck, assuming there is No lateral bind or trackwork dip.
Good Luck!
Frank
Here comes my standard suggestion... buy a few packs of Kato HO scale Unitrack from 28 inch radius down to about 18 inch radius. When you click this track together you now get an ACCURATE radius to test. This is the best way to confirm a locomotive's actual functional minimum radius for operation.
Run the engine on the Kato track, if it does not derail at the radius that your trackwork is at... the problem is your track. If it does derail... the problem is the locomotive.
I have seen quite a few people have problems with flex track curves that are supposedly 24 inch radius, but the loco will run fine on Kato 24 inch radius track. Their trackwork had slight spirals and kinks.
I use Atlas sectional 24" radius track for my minimum 24" radius curves on my layout, and avoid the problems.
-Kevin
Living the dream.
Once I learned to use flex track, I never used sectional. ALl those joints just ask for problems. You can get accurate curves with one of two tools, the Ribbonrail gauges or Fast Track SweepSticks. Or you can simply use a stick or piece of string and swing a radius centerline and lay our track against that.
For the OP, if there are joints in your flex track in the middle of the curves, are they soldered? You may have a nominal 20" radius curve, but you may also have kinks - even if they were 24" radius, above the minimum recommended for the locos, having a kink in the middle of the curve WILL make them derail. The basic 'trick' to avoid this to solder together two pieces of flex track BEFORE forming the curve.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I always add a full 10% to my 'minimum radius', and for me, with one brass steamer claimed to need a minimum of 30", I only lay, and verify before I glue the ballast, 33" curves. Maybe the rule for those less experienced should be 15%, just to cover the standard errors of hand-laying curves.
But......I have also found that, even though I have learned how to lay and to verify curves of a certain radius, I don't always get the rail heights right. Specifically, and it's worse when you lay flex with super-elevation, you don't always get the outer rail to the correct height to snag even a smidgen of the outer wheels' flanges, and with that defect, the wheel will take the path of least rolling resistance. As in, off the rails, outward of the curve.
Try finding the two or three worst spots. Then, use the clear plastic packaging that tools and electronics sometimes have over them and cut long, thin, strips of it. Insert several strips, end-to-end, along the curves mid-point outward, both directions. Only under the tie ends nearest the outer rail on the curve, so that those tie ends lift some. See if there isn't substantial improvement.
Let us know what happens.
Hi there,
I agree with pretty much verything that has been said. Here in Australia, Peco flex was and/is the standard but when the sleepers started giving way I set about making compound curves with Peco set track pieces.
Do you have "lead ins" to your curves? I use a short large radius curve to lead into a smaller one so that it leads the wheels into the curve rather than "hit it" all of a sudden. I also superelevated the curves by about .020" using styrene offcuts in strips which made a lot of difference to the operating ... once I had got it right.
We moved to our present location 30 months ago and I brought my layout (a 4x8) with us so the re-establishment also involved ironing out known problem areas now I could get to all four sides. I extensively tested the trouble spots finding where (and why) the locos were tripping up.
Generally speaking, locos do not derail just like automobiles do not roll unless they are "tripped". I had a couple of locos that were more prone to derailing so I used those exclusvely with test train lengths and found areas like slight drops in the superelevation, very slight misalignment with rail height or face to face with the rail at the joiner, or very very slight burrs at the end of the rails on the heads and inner faces of the rail heads. I had all these issues in a few areas.
While your loco may be seeming to come off in a particular spot, have a look anything up to about 8 inches before the point where it seems to come off. It may well be (as it was with me) that the wheels are lifting off and riding the head of the rail prior to coming off. And the performance can be different with running a light loco as compared to pulling a string of freight cars given the effect of the locos own torque and the load so a full test is in order.
Like this virus bit, you will get through this!
Cheers from Australia
Trevor
https://sites.google.com/view/stagnesrailway
and http://yourmodelrailway.net/view_topic.php?id=15547&forum_id=21&highlight=st+agnes+renovation for your interest
I actually got it all "fixed". A few rough spots and rail height were smothed out. Ran several more engines and good is good. Even my 4-6-2 steam engine rans smooth over the fixed areas.
kenbenI actually got it all "fixed". A few rough spots and rail height were smothed out. Ran several more engines and good is good. Even my 4-6-2 steam engine rans smooth over the fixed areas.
Glad to hear it wasn't anything that would require tearing out track.
Always best to spend time now and get it right then find out after all the scenery is in that you need to rip something out. I am geberally not satisifed until everything I intend to run (obviously I don't test every car and every loco - that could take months - I test the most likely to cause issues, which isn't ALWAYS just the the biggest) can pass through a section of track forwards and backwards at speed way faster than they should ever be run without derailing.
kenben I actually got it all "fixed". A few rough spots and rail height were smothed out. Ran several more engines and good is good. Even my 4-6-2 steam engine rans smooth over the fixed areas.
Excellent News and thanks for feeding back to us...
rrinkerOnce I learned to use flex track, I never used sectional. ALl those joints just ask for problems. You can get accurate curves with one of two tools, the Ribbonrail gauges or Fast Track SweepSticks
I bought the Ribbonrail 30" guages to use on my next layout. 30" is the minimum radius for visible mainline curves and is for appearance only. All equipment must be able to run on 24 inch minimum radius, so they are verified on Kato 22" radius track components.
I carefully solder my sectional track into 3 section pieces with a single feeder in the center section and have never had any issues. Every piece of flex track gets its own feeders. Rail joiners are for track alignment only.
selectorI always add a full 10% to my 'minimum radius', and for me, with one brass steamer claimed to need a minimum of 30"
All my brass locomotives can run through a 22" radius S curve obstacle with no issues. The largest I have is a Sunset/Samhongsa USRA Heavy 4-8-2. I have tried two 4-8-4s, but neither could do it. My 2-8-8-4 makes it through with no issues.
kenbenI actually got it all "fixed". A few rough spots and rail height were smothed out.
That is good news. It is a good day when things work out OK.
Kevin, this is the beast I was referring to: Sunset CPR Selkirk 2-10-4. I tried to make it run on a 29.5" curve on my last layout, and lost that battle. When I accepted that Sunset had reported their product correctly, I immediately fashioned a curve-arc template with a flat back and 33" radius out of 1/4" mahogany plywood. I kept it handy, too.
In addition to the very good responses below; take a small level and set it across the rails and run it through the curves. If you transition between negative and positive superelevation you MUST correct that. Our club found that such superelevation transitions were a) common and b) always associated with derailments everything else being equal. And the derailments were mostly associated with six axle trucks either on diesels or (long) passenger cars.
I use various thicknesses of styrene sheet (0.005" to 0.015") to make the SE corrections.
selectorKevin, this is the beast I was referring to: Sunset CPR Selkirk 2-10-4.
The STRATTON AND GILLETTE could never have a 10 driver locomotive.
I really want a Westside 2-10-0 "Beast", but I have a big suspicion that it could never make it through my curves and become a shelf model.
I assume you mean "The Brute", based (I believe) on a John Allen free-lance engine?
https://www.brasstrains.com/Classic/Product/Detail/053241/HO-Brass-Model-Train-WMC-Westside-Freelance-Series-2-10-0-The-Brute
You might be right, but FWIW a Bachmann "Russian Decapod" 2-10-0 runs fine on my 22"R (actually 21-5/8"R) Unitrack test track.
BTW re the earlier post about "sectional track", I wouldn't consider Unitrack sectional track. My last layout had code 83 flextrack, and I had a lot of trouble with track losing power and kinks developing in spring and fall where the track joined. No such problem since switching to Unitrack for the new layout, plus their code 83 rail is narrower and closer to scale track than Walthers or Atlas code 83 flextrack.
Redvdub1In addition to the very good responses below; take a small level and set it across the rails and run it through the curves. If you transition between negative and positive superelevation you MUST correct that.
I got one of the round levels at Harbor Freight, probably $2. Very handy.
https://www.amazon.com/Bullseye-Precision-Mult-Directional-Leveling-Trailer/dp/B07JB1L2NF/ref=sr_1_3?crid=2QXB3KS3Z0RCJ&dchild=1&keywords=bubble+level+round&qid=1588259700&s=hi&sprefix=bubble+level%2Ctools%2C176&sr=1-3
Plus, do not accept kinks in curves or at straight / curve transitions.
And check your turnouts for "twists" to ensure they are level.
All before ballasting...run quite awhile before committing to the ballast step. (I waited 8 years...but less may be ok.)
Paul
Modeling HO with a transition era UP bent
wjstixI assume you mean "The Brute", based (I believe) on a John Allen free-lance engine?
Yes, The Brute ws the locomotive I meant to say.