largest drivers on Lego track

[Aerolight]

What is the largest wheel that can be run on Lego track in a 6 driver layout? and has anyone tried making drivers with a smaller flange further from the track as this should allow for larger wheels (like real trains put a gap between the flange and the track when on a straight, as with Lego drivers the axle can move only a little left or right when on a straight and locks up entirely when on a turn).

[supertruper1988]

13 minutes ago, Aerolight said:

What is the largest wheel that can be run on Lego track in a 6 driver layout? and has anyone tried making drivers with a smaller flange further from the track as this should allow for larger wheels (like real trains put a gap between the flange and the track when on a straight, as with Lego drivers the axle can move only a little left or right when on a straight and locks up entirely when on a turn).

When you say "LEGO" track do you mean only pieces produced by LEGO or are you including larger cureves produced by third parties that are compatible with LEGO?

[coaster]

4 hours ago, Aerolight said:

What is the largest wheel that can be run on Lego track in a 6 driver layout? and has anyone tried making drivers with a smaller flange further from the track as this should allow for larger wheels (like real trains put a gap between the flange and the track when on a straight, as with Lego drivers the axle can move only a little left or right when on a straight and locks up entirely when on a turn).

The problem with smaller flanges is you ride on the flanges when crossing another rail on a switch for instance.  The rail has to break to allow movement on the crossing path, so to prevent bumping there is a raised area that supports the flange.  If you go smaller, it will be fine most of the time, but you'll have a definite bump on such crossings.

Also, are we assuming you are going flanged-blind-flanged, with the wheels as close together as possible?

[Black Knight]

Not sure if this helps, but you can also create a Gölsdorf axle if you must used flanged wheels; I know the BlueBrixx BR23 uses one but there are most certainly earlier and more clever implementations.

With blind drivers and some extent also Gölsdorf axles you can put them together as close as the geometry of the wheels and axle holes allows.

[Aerolight]

I never knew that the large flange was for points the more you know, I am going to try to 3d print the largest I can with a narrow vertical flange with this I should be able to get the size I would like (>40mm) to not bind on curves (but I don't know if the large diameter will just cause the loco to ride over the rails regardless). Due to the large flange size f-b-f is required for correct spacing. As for sliding axles the engines frame is locked at 4 wide due to conjugated valve gear and suspension. One of the reasons aside form scale for the large wheels is to get the piston above the leading truck not exactly scale but locks far less derpy on tight Lego track. I am away for my printer and Lego for a while yet so have plenty of time to think on it as the best result possible would be a flange that allows enough space for moving brakes, which I have done before but will fully print this time if there is space.

I didn't want to post before its finished but if your curious it currently has fully working valve gear, just not conjugated yet (although I have designed it already just need to print), controlled by a separate motor. Unlike my previous attempts this is fully printed with realistic geometry, 9 wide and only peaks 1 stud higher than the Lego drivers (scale).

[dr_spock]

Since you have access to a 3d printer, experiment. 

I printed some 48mm wheels before.  BFF might be pushing it on R40 curves.

[UltraViolet]

  I've never heard of 'drifting' a locomotive!   Seriously though, those 48's would look great on one of those older single main driver locos with the one really large drive wheel per side, especially if you go all-out with 10-wide.

[Aerolight]

I just finished modelling the wheels and am settling (at least for the moment) on a 4 drivers config with ~43mm diameter (will finalise one I can put my micrometre on the OG wheels), with only one change the the geometry other than diameter; I made the drive pin hole a drive cross hole (for easier 90 degree link) and made it only as deep as the outer wheel, 7.25mm. This should make it run smother especially with suspension.

The larger wheels also mean I can use a different type of suspension, for 30mm wheels I use a linkage system that stretches a rubber lift arm but it takes up one stud of space above the axle line, is hard to drive internally and is to soft for how large and heavy this train is going to be. But the larger wheels mean I can use a 'realistic' sliding block system that compresses the rubber lift arm instead and is only one stud thick on each side leaving room inside the frame for the crank for the third cylinder and gearing to a motor.

The last problem is how to connect the motor to the front axle, with only 2 axles the rear has the crank for the middle cylinder so it must be connected to the front, and since the middle cylinder is in the way of it going toward the back the drive must come out the front on the front axle then up and over the pistons to the motor (easiest solution is to not have the middle cylinder driven in the first place as you wont be able to see it unless u turn it upside down). So still some things to think about.  

[Tcm0]

3 hours ago, UltraViolet said:

  I've never heard of 'drifting' a locomotive!   Seriously though, those 48's would look great on one of those older single main driver locos with the one really large drive wheel per side, especially if you go all-out with 10-wide.

insert multi track drifting meme here

[UltraViolet]

4 hours ago, Tcm0 said:

insert multi track drifting meme here

Well, there was this video:

Crossover Madness LEGO train - TRIXBRIX - YouTube

  Things get crazy at around 1:30 mark.  Something about this creeps me out!

Edited March 28, 2021 by UltraViolet
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