Bachmann Online Forum

Discussion Boards => N => Topic started by: mrmtox on March 26, 2011, 08:58:09 AM

Title: derailment
Post by: mrmtox on March 26, 2011, 08:58:09 AM
I have just set up the "Empire Builder" kit.  The front wheels of the loco will not stay on the track for more than one circuit at any speed. It appears to operate best between about 55 - 65% power, but continuously derails. Any suggestions??? Thanks (I'm very new to this)
Title: Re: derailment
Post by: James in FL on March 26, 2011, 10:04:02 AM
Hi mrmtox,

Check the wheel gauge on the pony truck. Also check that the pony truck mounting screw is not to tight as to hinder pivot motion and vertical play.

The wheel gauge is easiest checked with a NMRA go/no go gauge, but can be checked with calipers if you don't have one.
Cost of the gauge is ~ 10USD at most LHS, on line, or train shows.

Good reading for beginners here
http://www.nmra.org/beginner/derailments.html

http://www.nmra.org/beginner/wheelsets.html

http://www.nmra.org/standards/sandrp/pdf/S-4.2%202010.02.24.pdf

Good Luck.



Title: Re: derailment
Post by: mrmtox on March 26, 2011, 10:28:58 AM
James - thanks for the tips - I'll try them this afternoon.  Where are you in FL? I'm in Tampa.
Title: Re: derailment
Post by: mrmtox on March 26, 2011, 10:50:50 AM
Wheel gauge and mounting screw are fine. It's almost as if that front truck needs a bit more weight on it. Is that reasonable?
Title: Re: derailment
Post by: James in FL on March 26, 2011, 10:59:23 AM
I live across Tampa Bay from you, in pinellas county, about a mile north from Maderia Beach.
I hope you attended the WGH show at the Tampa convention center last weekend, It was great to see all the manufacturers there.

PM me, maybe we could meet up at some up coming shows.

Guess we are both typing at the same time, some weight maybe what works best for yours I don't find it necessary on any of mine. You could try some tungston putty or small lead shot pounded flat and glued.
Title: Re: derailment
Post by: ericw95 on March 26, 2011, 11:40:50 AM
hey mrmtox, i had the same problems with a bachmann 4-8-4 northern i got a few months ago. Let, me tell you, the thing did not run too well out of the box. I had to make minute adjustments to the three screws on the bottom just to get the pilot to stop jumping the rails on turnouts, only to find the rear truck was not low enough to touch the rails. What i ended up doing was getting the smallest washers i could from radioshack and placing them over the truck on the screw holding it to the frame, and this corrected the issues for the most part. I think the issue is the weight distribution of the model, as it seems to lean towards the rear out of the box. hope this helps
Title: Re: derailment
Post by: mrmtox on March 26, 2011, 12:09:46 PM
Ericw - thanks for that. I'm fairly certain that is my problem - it just seems there's not enough weight forward. I'm trying to think of some temporary solution I can try today (so I can remove it if it doesn't work).
Title: Re: derailment
Post by: skipgear on March 26, 2011, 12:38:13 PM
First question - Does it derail in the same place all the time or does it happen randomly?

Check your track joints. I have seen many instances of missed rail joiners when assembling EZ track. If you can feel the joints, when you rub your finger across them, then they need to be addressed.

Also, check the guage of the track. I have seen quite a few of the 11.25" R EZ track sections under gauge which can cause the problem you are describing.
Title: Re: derailment
Post by: mrmtox on March 26, 2011, 01:06:36 PM
Skip - problem is random, track joints are perfectly smooth and I find no problems with gauge. My other loco (Royal Blue 4-4-0) runs perfectly.
Title: Re: derailment
Post by: ericw95 on March 26, 2011, 07:06:26 PM
putting a washer between the rear truck and the frame around the screw back there is a very cheap and somewhat effective short term solution. if i remember correctly, i got like 100 minute sized washers for like two bucks. it took a while to find something the perfect size to balance the thing correctly, then i had to readjust the screws underneath to find a balance at which the wheels weren't too loose. All in all, it took about an hour of tinkering with washers and screws underneath but it runs fine now. I probably woulda gone with a slightly more reliable loco if it was my choice, but this was a decent warranty replacement.
Title: Re: derailment
Post by: mrmtox on March 28, 2011, 10:39:49 AM
James, Eric and All: I just spoke to a technician at Trainworld and he kindly said to send the engine back and he would exchange it for a new one..I was very pleased with this  - I'm not one for taking something new out of the box and then having to pull my hair out (what's left) to get it to function properly. He said there should be a " tension spring" on that truck - mine had nothing.
Title: Re: derailment
Post by: ericw95 on March 28, 2011, 05:40:41 PM
hmm, i didnt get a tension screw. must be some manufacturing issue with the new line of 4-8-4s. Mine runs surprisingly well for a standard line loco so i think ill hold onto it as long as my solution holds up.
Title: Re: derailment
Post by: James in FL on March 29, 2011, 01:03:41 AM
Maybe I jumped the gun here referring to the version you have.
I should have asked "where are the traction tires" before offering advice.
First, does it have traction tires?
Second, if so, on what drivers are the traction tires?
#1 and #4 on right side?
#4 on both sides?
#3 on both sides?

I have three of these lokies, 2 with the tires on the number 4 driver and 1, the newest, on the number 3 driver.

None of the exploded parts sheets show a "tension spring" on the pony truck

According to "spookshow" the tension spring was only on the mid to late "70's version.
http://www.visi.com/~spookshow/bach484.html

I guess all this is neither here nor there, if Trainworld is going to replace it, let them.

Hopefully you will get the newest version in return; it has the split frame and runs far better (smoother) than any previous version.
If the shell was upgraded, and tender pick-up added, it would be worthy of the "Spectrum" designation.


Title: Re: derailment
Post by: mrmtox on April 05, 2011, 07:47:32 PM
The kind people at Trainworld  replaced my loco for no charge. Just received the new one. Same problem but not nearly as bad. It'll now go multiple circuits before the front wheels  lift off the the rails. I think I'll have to figure out a way to add a bit of weight to the front edge of that truck. FYI - no "tension spring" was on the replacement unit that they sent.  Anyone have a cleaver idea of how to add a few grams of weight to the front of the truck???? Thanks!!
Title: Re: derailment
Post by: ericw95 on April 07, 2011, 10:37:08 PM
like i already said, a washer over the back truck will redistribute the weight slightly so it rides a little more towards the front. mine had the same issue until i fixed it like this. really the only other way i could think of is a few pieces of led over the pilot to weight it down a bit.
Title: Re: derailment
Post by: ac12 on April 12, 2011, 05:01:08 PM
I did not see where you described exactly where the derailments occur, what kind of track is there (turnouts, crossings, 19"R curves, 9-3/4"R curves, etc.  Put something at the track wherever it derail, and after a while you might see a pattern.  This helps to troubleshoot the problem.

Is it the pilot truck/wheels or the first driver wheels that is derailing?

As was said by other, check that the wheels are in-guage then check your track.
I had some cars that would derail going thru a turnout.  Turns out the wheels were picking the frog and going the wrong way.  Fixed the guardrails and the problem went away.

The center of gravity (CG)/balance point of many steam engines is rear of center.  This causes them to want to pull a "wheelie," which is asking for a derailment.  I stuffed lead or tungsten putty into the smokebox to move the CG forward.