Wheel Dimensions (in Lego)

[ALCO]

hello! So I have finally realized I need larger driver wheels than the standard TLG size. I know BBB has XL drivers but in order for me to model that in LDD I need to know the dimensions of them (in Lego) ie. how many suds in diameter. The standard TLG wheels that come with Emerald Night are 4 Studs and on a Technic brick there are 3 wholes between each axle. How many wholes are between the axles on BBB XL driver? I can't seem to find that info on his site or anywhere else.

I'm working on an 8-wide FEF-3 and the standard wheels are just too small... :-(

If I plan to use BBB XL wheels I need to figure how how much longer it needs to be.

https://flic.kr/p/D7gKeQ

[greenmtvince]

My rule of thumb for 8-wide North American Steam is:

L = 57" Drivers

XL = 69" Drivers

M = 45" Drivers

The XL is two plates larger than the L.

I usually just flip the flanged L driver around in LDD to represent an XL in the model. It won't give you the flanges, but will give you the basic wheel clearances:

(The prototype here has 72" Drivers, close enough for XLs)

[LEGO Train 12 Volts]

There are four free technic holes between XL BBB wheels:

[ALCO]

Great! Thanks!

[LiLmeFromDaFuture]

I am still relatively new…

My question is a bit off topic but it is still relevant concerning you (at least). So how are you a "CITIZEN" with only 17 post—is that like a glitch or something?

[ALCO]

I am still relatively new…

My question is a bit off topic but it is still relevant concerning you (at least). So how are you a "CITIZEN" with only 17 post—is that like a glitch or something?

I got promoted by a moderator who wanted to send me a privet message. I guess you can only get those at the "Citizen" level.

[LiLmeFromDaFuture]

I got promoted by a moderator who wanted to send me a privet message. I guess you can only get those at the "Citizen" level.

Ah, okay—thanks!

[ALCO]

I know this is an old topic, but I've got a new project I'm working on and I'm thinking of using BBB medium drivers. I know I saw a reference to the size of the wheels of the real locomotive to the size BBB wheels that would look best. I just can't remember where I saw this topic... I'm working on a Baldwin decapod #1630 that is running at the Illinois Railway Museum and it has 52" drivers. I'm thinking BBB medium wheels might look best... What do you guys think?

My rule of thumb for 8-wide North American Steam is:

L = 57" Drivers

XL = 69" Drivers

M = 45" Drivers

The XL is two plates larger than the L.

I usually just flip the flanged L driver around in LDD to represent an XL in the model. It won't give you the flanges, but will give you the basic wheel clearances:

(The prototype here has 72" Drivers, close enough for XLs)

Haha, never mind! I just had to scroll up!

[Duq]

Does anyone still know how to use Google? One Google image search for

gave me this image:

It also showed an image from Holger Mathes' site. Unfortunately he's got some scripts on his site to prevent deeplinking so I can't show you his image here. Try his site:

http://www.holgermatthes.de/bricks/en/trainswheels.php

You can download the BBB wheels for LDraw from their website so you can work out in MLCad what the spacing for your wheels needs to be.

[ALCO]

Does anyone...

...It also showed an image from Holger Mathes' site. Unfortunately he's got some scripts on his site to prevent deeplinking so I can't show you his image here. Try his site:

http://www.holgermat...rainswheels.php

You can download the BBB wheels for LDraw from their website so you can work out in MLCad what the spacing for your wheels needs to be.

Thanks!

[Brickthus]

What scale are you building?

It can be 6, 7, 8-wide or larger.

It can also be 8mm:1ft scale (or 1 stud = 1ft because 7.9375mm:1ft is a mouthful!)

As I build to 8mm scale, 52" drivers (4'4") would be 34.4mm diameter as LEGO pieces.

This is closer to the large BBB driver than the medium but oversize wheels might make the wheel centres larger by at least 0.5 stud increment, which would stretch the model.

Therefore I might go for medium drivers depending on the wheelbase because I know the wheel limitations would not stretch the chassis dimensions. Where possible, find a 4mm scale drawing and multiply up if you're building to scale.

For some main line locos I have needed wheels larger than the largest BBB ones so I have suspended some Technic wheels off the rails. This works OK with a bogie of 4 up front and a tender for the motors. Examples:

- Class 9F 2-10-0 I added a tiny pair of wheels under the pivot of the pony truck. This has 2 train motors under the tender.

- Hall Class 4-6-0 for Hogwarts Express. Easy enough with 4-wheel bogie up front and 2 train motors under the tender.

- Idea for LNER Green Arrow 2-6-2 or A3 Pacific 4-6-2 using turned wheel hubs to get 3 cylinders with cranks at 120 degrees. This would follow the others for drive by train motors but uses smoother wheels.

Mark

[jtlan]

What scale are you building?

From ALCO's previous posts I infer he's building an 8-wide model, but 8-wide is not a scale. An 8-wide American locomotive would be about [15 inches : 1 stud], which scales the prototype's driver size of 52" to somewhere between the hub size of M and L drivers. I would suggest using M drivers, because the flange increases the apparent size of the wheel.

In LDD I use two wedge belt wheels and one tire to mock up BBB medium drivers. This gives the right flange/hub diameter, but not the right flange thickness or location for the connecting rod holes.