BEST RADIUS FOR ON30

[WBRANDY300]

WHAT IS THE BEST RADIUS TO UASE FOR ON30

[Hamish K]

There is no single "right" radius. It depends on the equipment you plan to run, what type of layout you are building and how much space you have. And most importantly, what you like the look of.

The recommended by Bachmann minimum radius for most Bachmann On30 stuff is 18 inches, but a few, e.g. the 2-8-0 and the 2-4-4 Forney have recommended minimums of 22 inches. However some people report successful running with less than the recommended minimum. The Porters and Davenports will run well on quite tight curves. Some models of large Colorado etc. prototypes by other manufactures require minimums of 26 inches or so.

Type of layout? narrow gauge "main line" (e.g. major Colorado narrow gauge routes), small "backwoods" operations, industrial (e.g. mining or logging), or something else? For main line type operations many people would say the largest you have space for - even in narrow gauge most real life lines had curves that scale to larger than most modellers use. On the other hand some "backwoods" and industrial lines did have very tight curves, so the minimum for your equipment can look good.

Finally, do what you like the look of. Some people criticise as unrealistic lines with lots of tight curves, but if you like how it looks - its your railroad.

Hamish

[WBRANDY300]

THEN A 30" RADIUS WOULD HANDLE MOST ANY LOCOMOTIVE AND ROLLING STOCK

[Hamish K]

THEN A 30" RADIUS WOULD HANDLE MOST ANY LOCOMOTIVE AND ROLLING STOCK

Any Bachmann equipment and most others should be fine -  I have read that the very largest K class locos (K36 and K37), made by MMI (not Bachmann} may require modifications to run well on 30 inch radius, but as I have only Bachmann equipment I don't know.

Hamish

[railtwister]

Hamish is right, the best radius is dictated by the locos you want to operate. I have a test layout that uses an 18" minimum radius, but the mainline curves are "eased" by the use of partial sections of 22" and 24" Atlas code 83 snap track. I have had no problems running any of my locos, including Bachmann Forneys, O.F. 2-8-0's, and Broadway Limited C-16's and their Goose. Some people complain that the C-16 won't stay on the track, but so far, I haven't had any problem. I believe the MMI K-27 needs a 26" or 27" minimum radius, and the bigger K-28's, 36's and 37's need even larger than that.

I think that having carefully laid track is as important as using the right radius. For good operation there can be no kinks, sudden changes of elevation, or twists in the track level. For this reason, I am a strong believer in using RibbonRail 'track sweep' curvature gauges when laying curved track, whether it is snap-track, flex, or hand laid rail. When I was building HO modules in the eighties, I bought a bunch of them in all the various radii I could find. It was pricey at the time, but they have served me well over the years (and it's fortuitous that they will also work for On30 track!). Sighting down the track at rail level to be sure it is 'fair and true' is also a must, but over the years, as my need for eyeglasses increased, this has been made more difficult due to the distortion of stronger prescriptions...

Regards,
Bill

[Jim Banner]

THEN A 30" RADIUS WOULD HANDLE MOST ANY LOCOMOTIVE AND ROLLING STOCK

However, to make a loop of 30" radius requires a table at least 64" wide.  Most of us do not have that much room.  An alternative, if you want large radii is an around the wall layout.  Then you can use up to 43" radius in the corners with shelves only 16" wide and still have the track 2" from the corner and from the walls.  Taking this even further, increase the shelf width to 21" or add a 10" x 10" triangle into the corners of the 16" wide shelves and you can use 60" radius curves in the corners.  Mind you, 60" radius will require a room larger than 10' x 10' just to make a simple circle.   And those 30" radius curves?  Using them in the corners will require a shelf only 12" wide.

Jim

[Heave]

I choked off 7 feet out of a availible 8 foot width of my train room to make Kato Unitrack 28, 31 down in radius with room for 34 inch.

I feel the large radius paid off handsomely in being able to run anything at the time in HO scale except prototype built brass engines.

I did handicap my railroad with kato number 4 switches. I needed number 6's to make it work but patted myself on the back and bought 4 axle power only.


Now I own On30. 21 inches in minimum to start on the logging line. Maybe I will stretch out to 30 inches again. But it will be a long time before I can think that big in On30.

At the hobby shop that layout in HOn3 uses 16,18, 20 inches to good effect. And that railroad was smaller than mine and did more with the railroad with it.

My two cents:

Quit stressing about radius. Just dont make them too small. take your biggest engine, choose a radius it can live with.

Then carefully lay your track to avoid Vertical changes in curvature before and after switches. To give your biggest engine a chance to settle all the wheels firmly down before changing tracks.

[ebtbob]

     If you are planning on running only Bachmann equipment,  then 22 in is a good standard radius.   I have a passing track on my On30 railroad where the inside radius is 18 inch.   My 4-6-0s,  2-8-0s,  and of course,  my 2-6-6-2 all run with no problems.   But.....the climax,  forget it.  It needs 22r.
      My On 30 railroad is a poor man's On3 and I have the space to have radius on average of 26in or greater.   That being said,  I have two of the MMI K27s,  first run.   That engine was rated at 26r or greater.   The easiest modification to reduce the minimum radius for those engines is to simply open up the  area where the wires pass from the engine to the tender.   The channel the wires sit in needs to be deepened so the wires are not pinched so tightly as they are out of the box.   The cure is to put the operational decoder or sound decoder like a Tsunami in the boiler so that there is only four wires going to the tender for pick up and speakers.
By doing that,  my two K27s do 22 inch radius,  but really do not look good on that tight a curve.

[mabloodhound]

This older PDF list Radii for some of the Bachmann On30 locos.
http://train-model.neuf.fr/on30/On30Loco_n_Car_Radius.pdf