minimum radius for doodlebug

[austrian]

What is the minimum radius the Bachmann Spectrum doodlebug can negotiate? I would like to use it but my minimum radius is just 19 1/4"
Is it DCC ready?


Thomas

[Hunt]

Best on 22" radius or greater.

DCC ready, 8-pin socket

[austrian]

Hunt, thank you!
"Best" - what does it mean? Will it look good on 22 or greater but still run on 19 1/4 or is 22  the minimum. I intend it to run without a trailer could that make a difference?

Thomas

[rogertra]

Hunt, thank you!
"Best" - what does it mean? Will it look good on 22 or greater but still run on 19 1/4 or is 22  the minimum. I intend it to run without a trailer could that make a difference?

Thomas

Nothing really "looks good" on set track curves but I'm sure the Doodlebug will run fine on them.  After all, Bachmann must build all its models to run on its own set track curves.

Cheers

Roger T.

[jbrock27]

What's the difference between a few 22"R sectional track curves put together and a section of flex track set as a 22"R curve?

[Jerrys HO]

What's the difference between a few 22"R sectional track curves put together and a section of flex track set as a 22"R curve?

One has roadbed and one doesn't   apparently ole Rog thinks there's a difference in the radi.

To the OP... I have had my MTH SD70(yup MTH) run on my 18" "set track" and it ran fine. I am sure the doodlebug is close in length. Will it look funny, yup!

[jbrock27]

True dat, if we are comparing roadbed track to flex track.  But not as much difference between sectional track and flex track of the same make when doing what I described above, IMHO.

[Hunt]

Nothing really "looks good" on set track curves but I'm sure the Doodlebug will run fine on them.  After all, Bachmann must build all its models to run on its own set track curves.

Cheers

Roger T.

Roger T.

Not all Bachmann HO locomotives are built or recommended for 18" curve track radius.

The 22" curve radius track is part of Bachmann E-Z Track product line and is  included in any train set when appropriate.  An example, HO  Overland Limited train set, Item 00614

[ACY]

The manufacturer suggested minimum radius for the doodlebug is 22 inches the same goes for the trailer coach or any of the Spectrum heavyweight coaches. You will likely have issues operating on anything less than 22" radius as it was not designed to negotiate sharper curves (ie 18" radius).

[rogertra]

Nothing really "looks good" on set track curves but I'm sure the Doodlebug will run fine on them.  After all, Bachmann must build all its models to run on its own set track curves.

Cheers

Roger T.

Roger T.

Not all Bachmann HO locomotives are built or recommended for 18" curve track radius.

The 22" curve radius track is part of Bachmann E-Z Track product line and is  included in any train set when appropriate.  An example, HO  Overland Limited train set, Item 00614

jbrock27.

Thanks for the update.

As I have never used set track since I was around 12 years old, my first train set, which is 'mumble-mumble' years ago, I mistakenly thought Bachmann products would handle a smaller radius.

Cheers

Roger T.

[jbrock27]

Hello Roger.

I think you are crediting me with information that Hunt provided us.

[rogertra]

Hello Roger.

I think you are crediting me with information that Hunt provided us.

You are correct, apologies to both of you.  D'oh!

Cheers

Roger T,

[jbrock27]

No worries and no apologies needed to me.  For a second there, you actually helped to make me look smart!

[electrical whiz kid]

What is discussed here is "set track radius".  On my layout, I try, whenever possible, use a system, especially outside of yards, engine terminals, etc., known as "easement" curves.  Easement curvature was discussed by the late Linn Westcott Around twenty or so years back.  I do not know how difficult it would be to find the article via MR Archives, but I am sure it could be done.  Wikopedia has some info on it.

The main gripe I have always had with "factory curve segments" is  just that:  set at the factory; no allowance can be made for easements save using different s set radii pieces.

RIch C.

[rogertra]

What is discussed here is "set track radius".  On my layout, I try, whenever possible, use a system, especially outside of yards, engine terminals, etc., known as "easement" curves.  Easement curvature was discussed by the late Linn Westcott Around twenty or so years back.  I do not know how difficult it would be to find the article via MR Archives, but I am sure it could be done.  Wikopedia has some info on it.

The main gripe I have always had with "factory curve segments" is  just that:  set at the factory; no allowance can be made for easements save using different s set radii pieces.

RIch C.

Easements or transition curves were used on the railroad long before Mr. Westcott wrote about them in Model Railroader.

While they are used on the real railroads to ease trains into a curve by using a parabolic radius rather than letting them jerk into a curve as when using a fixed radius curve.  Their use on model railroads is purely aesthetic, though some argue otherwise, as we are not dealing with the same masses as found in the real world.  For those that say transition are needed in the smaller scales I ask when is it that we can run a model train at near warp speed around set track curves and they won't derail but try that on the real railway on curve way broader than set track curves and they will derail.  Think the Amtrak derailment Philadelphia and that happened on an easemented curves.

Easements really only work using hand laid or flex track.  It's possible to achieve something close using sections of decreasing radius set track but it's not the same.

I use easement/transition curves because they look goods.  Some modellers go to extreme lengths so calculate the transition from straight track to curve track but I use the simple "Bent Stick" method after all, we are talking model trains that weigh ounces not real locomotives freight cars that weight upward of a hundred tons.

For the bent stick method draw/plot your curve with its centre point one half inch away from the straight track.  So if you want a 32" radius curve, put the centre point 32.5" from the centre line of your straight track.  Draw you 32" radius curve.  You now have a 1/2" gap between the centre line of the straight track and the centre line of your curve.  Now take a piece of flexible wood or plastic about 36" long and using that, connect your straight and your curve centre lines.  I try to allow for around a 12 to 16 inch transition.  Now scribe a line connecting you straight and curve and there you have transition curve good enough for a model railroad with any mathematics.   

Probably more than you wanted to know.

Cheers

Roger T.