what's the limit on train wheel distance?

[IronFish]

I'm just wondering what the limits are on bogie-less train cars are.

for example

This (no bogies 4 wheels)

vs.

This (two bogies, 8 wheels)

How many studs apart can you get two train axles before it isn't able to go around a turn properly?

Sorry if my question is a little confusing.

[dr_spock]

The cow car is about the limit for standard Lego curved track. After that it starts to drag in the curves.

[IronFish]

The cow car is about the limit for standard Lego curved track. After that it starts to drag in the curves.

Really? Isn't the 7898 box car longer?

[jtlan]

The cow car is about the limit for standard Lego curved track. After that it starts to drag in the curves.

I'd argue that's actually too long already. The spacing on the two-axle cars from the 90s is probably better. In general I've found that 10 studs, measured between the centers of the axles, is a safe limit (the cow car and other modern Lego two-axle cars are one longer than this).

[LoneBrickerSG]

Really? Isn't the 7898 box car longer?

That one is very close to the one from 3677, which I have.

I can attest, the 3677 box car is really at the limit of how far a pair of wheel sets can be separated. This thing hates going around corners. That's why I added bogies to mine.

[THERIZE]

I never had problems with this? I just make shure there is enough weight to keep everything on the rails.

[LoneBrickerSG]

I never had problems with this? I just make shure there is enough weight to keep everything on the rails.

I don't think it's a problem, necessarily, but for people who want to minimize rolling resistance on trains these straight cars can be problematic. If I take the boxcar I mentioned and push it down the track, it will stop in the middle of curves.

[dr_spock]

I think it depends on what your application of 2 axle cars will be. If you have a string high rolling resistance cars with the axles too far apart, then it is going to affect your train's performance in curves. If it is for a British Pacer railcar which has bad performance in real life then it may not be as problematic. I used 14 studs in my

. I can feel the difference hand rolling the passenger car between straight and curve.

The OP could grab a couple of 6x16 plates and wheels and try different spacing to see for himself and figure out the limit for his particular appllcation.

Edited September 4, 2015 by dr_spock

[IronFish]

I think it depends on what your application of 2 axle cars will be. If you have a string high rolling resistance cars with the axles too far apart, then it is going to affect your train's performance in curves. If it is for a British Pacer railcar which has bad performance in real life then it may not be as problematic. I used 14 studs in my

. I can feel the difference hand rolling the passenger car between straight and curve.

The OP could grab a couple of 6x16 plates and wheels and try different spacing to see for himself and figure out the limit for his particular appllcation.

will do, thanks for the suggestion!

[A Gallifreyan Cat]

If you model american freight, you don't really need to worry. They all have bogies.

[dr_spock]

If you model american freight, you don't really need to worry. They all have bogies.

Unless it is something imported like this on the Union Pacific roster.

[Brickthus]

Remember that real railways have very little track at the 40ft radius of L-gauge standard track!.

For the UK it makes a 'Pacer' DMU difficult.

I use a wheel steering technique for long 4-wheel wagons. This has enabled me to stretch the wheel base from a fixed 14-15M to 19M. I sued a balance of belt tensions between the coupling turning and the wheel turning to get proportional steering of the wheels. It is also quite successful at reversing down a siding as long as the last car (usually the brake van) has the 2 wheelsets linked as in the lower wagon image.

Mark

[Hod Carrier]

Unless it is something imported like this on the Union Pacific roster.

Woo!! Cool 'bago. Not sure those attachments at the front are road legal, though.

[THERIZE]

Woo!! Cool 'bago. Not sure those attachments at the front are road legal, though.

I'm pretty sure hat is just a block of iron to plough through everything. every american diesel has a reinforced front I believe.

[Chromeknight]

I'm pretty sure hat is just a block of iron to plough through everything. every american diesel has a reinforced front I believe.

Zombie apocalypse ready.

[HenrikLego]

Anyone has any good ideas for how you can have a long distance between wheels? Without a bogie. I'm trying to get this to run smoothly through curves but haven't been successfull yet...

I've tried just using a 2x2 turntable. That didn't go to well, then I tried a 2x2 turntable with a rubber band to get it back to it's initial position, but that didn't work well either. Got to rigid and didn't turn well at all.

So I'm kind of lost. Any help would be great!

[dr_spock]

Anyone has any good ideas for how you can have a long distance between wheels? Without a bogie. I'm trying to get this to run smoothly through curves but haven't been successfull yet...

I've tried just using a 2x2 turntable. That didn't go to well, then I tried a 2x2 turntable with a rubber band to get it back to it's initial position, but that didn't work well either. Got to rigid and didn't turn well at all.

So I'm kind of lost. Any help would be great!

Have you tried Mark Bellis' clever solution? -> http://www.brickshelf.com/gallery/mbellis/Trains/Wagons/tube_wagons_underside_loft_feb05.jpg

[Hod Carrier]

What you've tried so far is a form of floating axle. While that works well on the real railway because of the self-steering effect caused by the interaction of the profile of the wheel and railhead, LEGO axles do not interact with LEGO track in the same way.

What you have to do is force the axle to steer. The easiest way to do this is to link each car to the next one, probably via the coupler, in much the same way as Mark Bellis illustrates above. Railway modellers use much the same solution to overcome the same problem.