Large Scale Central

USA Trains SD70 MAC truck problems

General Discussion
#21
Curmudgeon said:
.................................

BTW, what, exactly, IS the gauge, of the wheels and track, other than "Dial calipers and track gauges etc. and I have found that the wheels and track were in tolerance with in .005 and in large scale that is not much! "


Dave,

Very good question, one of the guys on a German forum had a problem with a #6 USAT turnout. Told him to check the gauge. Wellll it turns out that the frog at 43.5mm instead of 45mm is “a bit tight”.

Question for Bill: Whose tolerance and what are the actual dimensions? (That would be “dementions” for one Ventilator :wink: :))

#22

I almost hate to do this.

G1MRA back-to-back 1.575", nmra, 1.566" min, with 1.575" desired.
That said, if you use the super-thick flange NWSL replacement wheels, you and you alone will have to determine what works on your particular railroad.

I too have a lot of experience in other, smaller scales.
55+ years worth.

At this late date, I developed a “fix” for old Athearn geared Tower Drives that stops them from stuttering at low speeds.

I would never say I’ve seen it all, as when you do, you get surprised.

If I had that problem you are experiencing, I would take a handful of golf balls and throw one on the ground every place they derail.

Take the next engine out, same thing.
When done with all 10, I’d look to see if I had golf ball clusters.

THAT would tell me track or roadbed issues.

Then, I’d get eye level and watch, to see what’s really happening.

You didn’t perchance do body mount Kadees that are interfering with truck rotation, did you?

#23
Curmudgeon said:
I almost hate to do this.

G1MRA back-to-back 1.575", nmra, 1.566" min, with 1.575" desired.
That said, if you use the super-thick flange NWSL replacement wheels, you and you alone will have to determine what works on your particular railroad.

I too have a lot of experience in other, smaller scales.
55+ years worth.

At this late date, I developed a “fix” for old Athearn geared Tower Drives that stops them from stuttering at low speeds.

I would never say I’ve seen it all, as when you do, you get surprised.

If I had that problem you are experiencing, I would take a handful of golf balls and throw one on the ground every place they derail.

Take the next engine out, same thing.
When done with all 10, I’d look to see if I had golf ball clusters.

THAT would tell me track or roadbed issues.

Then, I’d get eye level and watch, to see what’s really happening.

You didn’t perchance do body mount Kadees that are interfering with truck rotation, did you?


The track is inside on a raised level suspended shelf system. Not outside on un-level ground and no kadees either.
I am not the only one with this problem as by reading the forums of course every situation is different and I agree with everything
on here as what to check. But by not seeing the situation and having multiple locomotives, freight cars and long passenger cars with no problems
over the whole layout and checking everything that was mentioned about track I can’t see how someone can come up with blaming the rail as the problem.
It is code 332 Aristo stainless steel with stock wheels on the locomotives.
I wouldn’t waste my time on any forum with any problem if it was something simple like track.
I do know that track is always the first thing you check and it is 8’ flex track with split jaw rail clamps with staggered joints not parallel.
I came up with everything to check what some people posted using eyeball levels etc. with no luck. I have 10 USA 6 axle engines I did not test them all
so maybe some will fly big deal it’s still a lousy truck design. I figure correct them all. Or at least the ones that don’t run well.
Put it this way if you were manufacturing a large scale model six axle locomotive would you design a truck like that? I think not.
Because chances are it would be problematic.

#24

Bill,
Aristo ‘bit the bullet’ with its three-axle truck and cited an 8 foot minimum diameter. USA Trains ‘engineered’ the truck to negotiate a less than 8 foot diameter curve. Like its famous German counterpart, over-engineering to attain the ‘impossible’ is foolhardy and only complicates what should be a simple rigid truck design (with maybe some degree of equalisation built in). Possibly report on common defect like derailing only on specifically left or right hand curves, whether derailment alters when under load or running light, derailing through switches, does it derail coming out of a curve? This may highlight a specific problem with the design.

 If the axle is 'free to swivel' then theoretically it should behave like a 'powered' pilot truck'.  I would think that the traction tyre would be on a rigid axle,  so removing the driveshaft to the rotating axle will not degrade the performance significantly.  If it derails when unpowered, then the problem is with friction in the swivel assembly.
#25
Tim Brien said:
Bill, Aristo 'bit the bullet' with its three-axle truck and cited an 8 foot minimum diameter. USA Trains 'engineered' the truck to negotiate a less than 8 foot diameter curve. Like its famous German counterpart, over-engineering to attain the 'impossible' is foolhardy and only complicates what should be a simple rigid truck design (with maybe some degree of equalisation built in). Possibly report on common defect like derailing only on specifically left or right hand curves, whether derailment alters when under load or running light, derailing through switches, does it derail coming out of a curve? This may highlight a specific problem with the design. 
 If the axle is 'free to swivel' then theoretically it should behave like a 'powered' pilot truck'.  I would think that the traction tyre would be on a rigid axle,  so removing the driveshaft to the rotating axle will not degrade the performance significantly.  If it derails when unpowered, then the problem is with friction in the swivel assembly.</blockquote>

Tim: I agree with what Aristo did. I have no problems with turnouts as some people did. The problem is around curves it seems that the drive part forces the swivel end of the truck which is the non motor part the one axle end. So it’s like it’s pushing it off the track due to the reasons of weight and not being rigid etc. These curves are at least 8’ also. Also I think the swivel part does not swivel enough of play to help it around curves but you wouldn’t need that swivel design if the wheels were in a solid block that acted like an articulated truck.
I also agree with your fix too you will not loose much performance I really wanted to know how many people have this problem or a similar one like it.
Thank you for your post.

#26

Which is why I asked the questions I did.
Long-distance toubleshooting.
I am surmising the pivot wheels actually rotate when power is applied?
Reason for that question, too.
In all of this, did I ever see the answer to “does the truck and pivot swing smoothly and freely with the unit upside down?”.
Reason for that question, too.

Is the loco (or locos) derailing at the same places, or is it totally random?
Body mount Kadees?
Looking at the unit eye level, what exactly do you see when the drerailment just starts?Does the wheelset bind?
Climb the outside rail?
Or, does the pivot axle kick up at an angle?

Reasons for those questions, too.

Just because it’s indoors does not mean the benchwork is cross level.
Lay a torpedo level across the rails at the trouble spot to see.

#27

That was the problem with the above mentioned track. Cross level was way off. I put one of those new Sears levels that gives percent of grade as one of the read-outs, and it indicated an 8% grade across the rails. That surprised me as it certainly did not look it.

I guess I need to get my “sailor’s eye” recalibrated. :smiley:

SteveF

#28

This whole discussion reminds me of past threads on couplers.

After hearing of one person’s displeasure with Kadee couplers; I asked him about his roadbed.
After hearing about his “Method” of laying track; I asked whether he might be blaming the couplers for his problem, when in all probability it was his less than stable roadbed.
This of course brought on an onslot of complaints about my intolerance of anyone that didn’t use Kadees…from a whole raft of people who could only defend some idea that changing to anything less than Hook And Loop, or one of the rolling stock producers’ couplers was herasay.

This was one of the incidents where I simply told the whole bunch of people that they were “Twits”. (Not exactly the way to make friends and influence people !!!)

Of course I don’t even bother to offer any suggestions now, as it seems the twits are slowly overrunning the place.
It is probably my fault as much as anyones’, that I have grown to be intolerant of people who refuse to do any research, or use any form of common sense.
I’ve just about given up on the Chat room here, as I seem to have been told that I am not appreciated for my tone, or way of suggesting advice.

Thank you all; but I’m slowly fading from the scene, and will only respond if asked, from now on.

Let there be cheering from all sides, and the party begin…!!!

#29
Fred Mills said:
This whole discussion reminds me of past threads on couplers.

After hearing of one person’s displeasure with Kadee couplers; I asked him about his roadbed.
After hearing about his “Method” of laying track; I asked whether he might be blaming the couplers for his problem, when in all probability it was his less than stable roadbed.
This of course brought on an onslot of complaints about my intolerance of anyone that didn’t use Kadees…from a whole raft of people who could only defend some idea that changing to anything less than Hook And Loop, or one of the rolling stock producers’ couplers was herasay.

This was one of the incidents where I simply told the whole bunch of people that they were “Twits”. (Not exactly the way to make friends and influence people !!!)

Of course I don’t even bother to offer any suggestions now, as it seems the twits are slowly overrunning the place.
It is probably my fault as much as anyones’, that I have grown to be intolerant of people who refuse to do any research, or use any form of common sense.
I’ve just about given up on the Chat room here, as I seem to have been told that I am not appreciated for my tone, or way of suggesting advice.

Thank you all; but I’m slowly fading from the scene, and will only respond if asked, from now on.

Let there be cheering from all sides, and the party begin…!!!


I so agree with your comments! It is like I never laid track before or used a level etc. They think this is N scale where the track has to be so precise even though they still persist it is a track issue. That’s not even the topic at hand. Also I have to be clear one more time I DID not test all of 10 locomotives in question it was ONLY an assumption. So once again it is very possible that they are ones that are fine. So far 2 are in question. No kadees because these are no out of the box so no modifications yet like changing couplers etc.

#30
Curmudgeon said:
Which is why I asked the questions I did. Long-distance toubleshooting. I am surmising the pivot wheels actually rotate when power is applied? Reason for that question, too. In all of this, did I ever see the answer to "does the truck and pivot swing smoothly and freely with the unit upside down?". Reason for that question, too.

Is the loco (or locos) derailing at the same places, or is it totally random?
Body mount Kadees?
Looking at the unit eye level, what exactly do you see when the drerailment just starts?Does the wheelset bind?
Climb the outside rail?
Or, does the pivot axle kick up at an angle?

Reasons for those questions, too.

Just because it’s indoors does not mean the benchwork is cross level.
Lay a torpedo level across the rails at the trouble spot to see.


Do you have any USA Trains 6 axle locomotives? If so you will already know that the pivot truck only has so much motion.
As for derailing it goes off around corners all of them not in the same spot so it not a bad section of track once again if you have a USA trains
6 axle locomotive you will know that the drive wheels are pushing the pivot truck off the track so truck turns sideways similar to a skid. If the tracks were
not parallel or level or in gauge it would just derail and stop this keeps on going like a slide not tracking. The truck is not planning to the rail because the truck itself is
off center as you would see by looking at one flipped upside down and you will notice that there is not enough of weight in those areas either.
Also other people had this problem maybe in different ways but they had to fix the truck.
If you look at an Aristo Craft 6 axle engine like an SD45 you will notice when you flip it over that the trucks are on center and the center axle wheel pivots back and fourth
similar to a articulated design that way the engine can go around curves without jumping or being forced off by the power of the motor in the truck itself.
I have Dash-9’s and SD45’s with no problems on the same track in the same areas.

#31

I’ve worked on more than you’ve seen.
I was trying to help.
I know what can break, and I’ve fixed a lot.

You aren’t answering any quesions, so I’m done wasting my time.

#32
Curmudgeon said:
I've worked on more than you've seen. I was trying to help. I know what can break, and I've fixed a lot.

You aren’t answering any quesions, so I’m done wasting my time.


I thought so you didn’t answer none of mine either. So you don’t own any 6 axle USA’s I figured that from seeing
what you have posted.
I agree you are wasting your time since you have no valuable input.
Nothing personal we agree to disagree.

#33
bill said:
Curmudgeon said:
I've worked on more than you've seen. I was trying to help. I know what can break, and I've fixed a lot.

You aren’t answering any quesions, so I’m done wasting my time.


I thought so you didn’t answer none of mine either. So you don’t own any 6 axle USA’s I figured that from seeing
what you have posted.
I agree you are wasting your time since you have no valuable input.
Nothing personal we agree to disagree.

Hey Bill,

One very basic question: did you approach USAT regarding this problem? What did they reply? Any help?

#34
bill said:
Curmudgeon said:
I've worked on more than you've seen. I was trying to help. I know what can break, and I've fixed a lot.

You aren’t answering any quesions, so I’m done wasting my time.


I thought so you didn’t answer none of mine either. So you don’t own any 6 axle USA’s I figured that from seeing
what you have posted.
I agree you are wasting your time since you have no valuable input.
Nothing personal we agree to disagree.

Bill, With respect.
That sounds awfully personal to me.

Dave Goodson is probably the best known Large Scaler around. He has an expertise at diagnosing and fixing design problems in a wide range of LS locos that is unequalled in our hobby.
Dave reviews locos for Garden Railways magazine, so he knows what he is talking about.
If you had cared to read what Dave wrote earlier you would understand that he has probably had in his hands more 3 axle USA drives than you have ever seen.
Lighten up. With your attitude you are unlikely to get any help at all.
You can’t diagnose problems without having the correct information.
Take this advice and try answering his questions.

BTW. I agree the USAT drive is a crap design. As is the AC 3 axle truck.
In my 20+ years experience with LS, the only only 3 axle diesel truck that I think is any good design wise, is the one made by LGB in the WP&Y diesel. I have never ever seen a failure. They got it right first time.

#35
TonyWalsham said:
bill said:
Curmudgeon said:
I've worked on more than you've seen. I was trying to help. I know what can break, and I've fixed a lot.

You aren’t answering any quesions, so I’m done wasting my time.


I thought so you didn’t answer none of mine either. So you don’t own any 6 axle USA’s I figured that from seeing
what you have posted.
I agree you are wasting your time since you have no valuable input.
Nothing personal we agree to disagree.

Bill, With respect.
That sounds awfully personal to me.

Dave Goodson is probably the best known Large Scaler around. He has an expertise at diagnosing and fixing design problems in a wide range of LS locos that is unequalled in our hobby.
Dave reviews locos for Garden Railways magazine, so he knows what he is talking about.
If you had cared to read what Dave wrote earlier you would understand that he has probably had in his hands more 3 axle USA drives than you have ever seen.
Lighten up. With your attitude you are unlikely to get any help at all.
You can’t diagnose problems without having the correct information.
Take this advice and try answering his questions.

BTW. I agree the USAT drive is a crap design. As is the AC 3 axle truck.
In my 20+ years experience with LS, the only only 3 axle diesel truck that I think is any good design wise, is the one made by LGB in the WP&Y diesel. I have never ever seen a failure. They got it right first time.


As for the comments I had know knowledge who it was because the person didn’t say who it was so I think you can understand that it was confusing where he was going. So once again nothing personal and I am sorry if anyone was offended.
I do agree about what you think of USA’s crap design. My question would be has Mr. Goodson contacted USA with this problem I think
he would carry more weight with his reputation vs someone like me.

#36
Hans-Joerg Mueller said:
bill said:
Curmudgeon said:
I've worked on more than you've seen. I was trying to help. I know what can break, and I've fixed a lot.

You aren’t answering any quesions, so I’m done wasting my time.


I thought so you didn’t answer none of mine either. So you don’t own any 6 axle USA’s I figured that from seeing
what you have posted.
I agree you are wasting your time since you have no valuable input.
Nothing personal we agree to disagree.

Hey Bill,

One very basic question: did you approach USAT regarding this problem? What did they reply? Any help?


No I have not as of yet. But I intend too.
Thanks.

#37
bill said:
No I have not as of yet. But I intend too. Thanks.
Bill

If I had bought 10 USAT 6 axle diesels and I had those problems, I would by now have contacted USAT to find out what they could do regarding the problems.

If OTOH I would like to present USAT with the solution to their problem then I would take the worst of the offending 6 axle diesels and get to work, eliminating one “cause” at a time until it was perfect. And I would keep exact notes and pictures to prove what worked and what didn’t work.

Usually works for me, but it takes time and persistence. I would even go as far as setting up a test track with “special curves” just for that purpose, one that has absolutely perfect track.

#38

I forgot to mention, I would start with only one truck, that leaves one of the offenders on the engine. Turn the engine around by 180º and you should be able to replicate the same old problem and watch the solution getting to work.

Oh yeah, it will take quite some work and if you screw up a truck, best have a spare on hand. :wink: :slight_smile:

#39
Hans-Joerg Mueller said:
I forgot to mention, I would start with only one truck, that leaves one of the offenders on the engine. Turn the engine around by 180º and you should be able to replicate the same old problem and watch the solution getting to work.

Oh yeah, it will take quite some work and if you screw up a truck, best have a spare on hand. :wink: :slight_smile:


Hans:
You are correct thanks for the tips. I am planning on doing that also I live about 2 hours away from where USA trains is located.
I want to go there in person and I know who to see to show them what is wrong and what the fix should be. That was the whole purpose
of the post is to find out how many people have this problem. They don’t need to know about track issues they are hobbyists also and
have a knowledge that no rail is perfect. What they want to know is why in certain situations the trucks don’t react to curves etc. properly.

#40

Bill,
You sound like you have quite a bit of experience with track, switches, etc.
So forgive me and others on this board for assuming you were a rookie.
TOC is TOC, blunt, to the point, and knows more about lokies than myself and most people here.
You have to know him to love him. :slight_smile: :slight_smile:

Anyway:
It isn’t your track, or all of your rolling stock will have some kind of problem.
Put all ten lokies on the track, one at a time. Run them one direction, then the other.
Turn them around and repeat the same procedure.
Remove all the “good” ones.
How many bad ones are there? One, two?
If they all do it, then it is:
You are prolly the unluckiest dude in the world to buy 10 bad lokies; or there is something else.
The one or two–run them, one at a time, backwards, forwards, pick them up and reverse them and do the same. The lead truck becomes the trailing truck, etc.
Is it the lead truck that derails all the time. If so, the motor drive is a little off and climbing the rail. It may have a different RPM than it’s sisters in the block. Just slightly. Faster or slower.
It is definitely the swivel pilot. Could be tweaked a little to one side. Could be off-level because of the connecting bar, Could be anything!
Remove the offending swivel truck and replace it with one of your good ones off of another lokie.
Test again. It should not derail.
Put the good one back in it’s original truck and send the offenders to USA. (Not the whole lokie–just the motor block) and tell them to replace it!
That’s about all you can do.

As Tony stated, no large scale manufacturer has perfected the three axle truck except LGB. That’s why I stick with small two axle dismals.
Bachman, Delton couldn’t even produce a three wheel steam truck without blinding a driver or two–(Even though some real steamers had blind center drivers). The aforementioned, Bach, etc, couldn’t even get their blind driver to ride on the rail-head!
LGB has flanged drivers in all their products except the RhB Crok! Mogul, Mike, Mallets–all flanged!
But I digress…

jb
TOG