My Engine Blew Apart! (No kidding)

[TheKman]

I've designed my first engine, a diesel. Blueprints went just fine, but I'm reasonably sure I jacked something up based on what happened when I tried to test it.

I was able to select and place my engine on the track and add the engineer. I hit save. Well, the engine blew apart! All the cars and a steamer in the yard derailed, my engine went high up in the air, did maybe 5 360s, the bogies blew apart and then the engine crashed in to the ground.

Can a video be posted here so all can look at what happened? I have never seen this before......

Thanks.

[Chacal]

The Ford Pinto used to do that, if I recall correctly.

[TheKman]

OK...... I'm getting nowhere with trying to figure out why the darn things explodes.....

Enclosed is the simulation and blueprint .xml files. If someone would take a look and see if I did something wrong please.

Thanks.

[GreatNortherner]

Hi,

I've had something like that happen to me a few times in the past and I think it was always caused by something being way off in the dimension data (particularly collision box and coupler positioning). Not saying that it couldn't be caused by something else (I don't know) but coupler and dimensions values might be a good bet to start the hunt for that gremlin.

I've always found this little "formula" very helpful to end up with coupler and collision length settings that have always worked for me:

CouplingPivot = CollisionLength/2 - 0.375
Pivot = CollisionLength/2 + 0.375
...and of course the pos/neg of the above results for the two ends of the vehicle.

Not sure if that has an impact (and if how much), but you might also want to use the height settings for the couplers from a DTG vehicle. That's the third line from last in the coupler position matrix and DTG cars seem to have it usually set to 0.8763 or 0.83. I also noticed a discrepancy in the Front/BackPivotY setting (2nd line under EaseOfDerailment), which you have at 0 in your BP while DTG's models always seem to use -0.5 here.

Also, I never use the editor's preview function to position couplers, as I find the numbers I get from that (with those many decimal positions) somewhat suspicious. Instead, I always enter those directly into the input fields, starting with CollisionLength which can be fairly accurately estimated by measuring your 3D model in the 3D software (take length of the main frame and add a bit extra for the couplers) and then calculate the rest.

Hope this helps (if indeed this was the source of the "exploding train").

Cheers,
MIchael

[TheKman]

Hi,

I've had something like that happen to me a few times in the past and I think it was always caused by something being way off in the dimension data (particularly collision box and coupler positioning). Not saying that it couldn't be caused by something else (I don't know) but coupler and dimensions values might be a good bet to start the hunt for that gremlin.

I've always found this little "formula" very helpful to end up with coupler and collision length settings that have always worked for me:

CouplingPivot = CollisionLength/2 - 0.375
Pivot = CollisionLength/2 + 0.375
...and of course the pos/neg of the above results for the two ends of the vehicle.

Not sure if that has an impact (and if how much), but you might also want to use the height settings for the couplers from a DTG vehicle. That's the third line from last in the coupler position matrix and DTG cars seem to have it usually set to 0.8763 or 0.83. I also noticed a discrepancy in the Front/BackPivotY setting (2nd line under EaseOfDerailment), which you have at 0 in your BP while DTG's models always seem to use -0.5 here.

Also, I never use the editor's preview function to position couplers, as I find the numbers I get from that (with those many decimal positions) somewhat suspicious. Instead, I always enter those directly into the input fields, starting with CollisionLength which can be fairly accurately estimated by measuring your 3D model in the 3D software (take length of the main frame and add a bit extra for the couplers) and then calculate the rest.

Hope this helps (if indeed this was the source of the "exploding train").

Cheers,
MIchael

That's now what I suspect as well. I'll remeasure for the collision box and check the couplers again. I have made many models in which the Front/BackPivotY is zero and had no issues. I seen many bin files of other models people have done with no values for those as well. But I'll add that in as well. Thanks.

[TheKman]

Front and back pivot x were way off. I had them too far in. I also made front/back pivot y -0.5.

The engine still does the funky monkey but it doesn't jump in the air. All the motion is at the bogies. They just spin like crazy and the motion derails the engine. So looks like I did something wring with either the bogie design or with blueprint, might be both.

[Brickrail782]

Front and back pivot x were way off. I had them too far in. I also made front/back pivot y -0.5.

The engine still does the funky monkey but it doesn't jump in the air. All the motion is at the bogies. They just spin like crazy and the motion derails the engine. So looks like I did something wring with either the bogie design or with blueprint, might be both.

What locomotive are you working on, by any chance?

[TheKman]

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Front and back pivot x were way off. I had them too far in. I also made front/back pivot y -0.5.

The engine still does the funky monkey but it doesn't jump in the air. All the motion is at the bogies. They just spin like crazy and the motion derails the engine. So looks like I did something wring with either the bogie design or with blueprint, might be both.

What locomotive are you working on, by any chance?

SP narrow gauge Little Giant #1. My friend and I have been working on it going on 5 years. Our skills early on slowed us down. My friend did the initial design. My part has been clean up on the model, helping him with the design, and all the texture work. We are a long ways to being done. Once we have a working engine testing needs to be done. Since it's my friends model for the most part, it'll be up to him as to when/if it's made either free or payware.

[TheKman]

Well, I may have found the problem. Bogie blueprints. The gauge of the wheels were all wrong. Two wheels at standard gauge, one at narrow gauge, and one not even close to either. All should be U.S. narrow gauge. Have that corrected but haven't done a new blueprint yet to see if that fixes things.