O27- O34 track size question

Each circle has eight sections.  360 degree divided by eight is 45 degrees.  You can combine them but will not have a circle.  Direct answer to your question: 45 degrees, eight sections making a 360 degree circle.

How can a tight 27” diameter be the same degrees as a softer 34”. Diameter? Shouldn’t each piece if O34 curve be like 39 degrees or something?

your confusing the degrees of a circle with the size of the circle. IE the O-27 will make a circle 27" across, O34 will make a 34" circle, 45 degree's is like you look at a compass it has a total of 360 degree's no mater how big it is, so 1/8 of a circle is 45 degree's 2 section of track make 90 degree's so if you had track that was O72 that only took 8 pieces to make a circle it still would be 45 degree's ( yes I know O72 in most cases takes 12 pieces so 3 pieces still would be 90 degree's ) 

However you define it, the 034 is a great choice for a small layout. I am getting ready to build a 46" x 8' Marx layout. I have a case of new 034 waiting.

Steve

Wow! Marx is hard to find! Lucky you! 

Ok. I think I've got it.

as to my question

One piece of O27 curved track is 45 degrees.

One piece of O42 curved track is 30 degrees and a curved piece of

Marx O34" track is ?

Mike23 posted:

How can a tight 27” diameter be the same degrees as a softer 34”. Diameter? Shouldn’t each piece if O34 curve be like 39 degrees or something?

No, 45 degrees is correct. If you were to put an 027 and 034 on top of one another and compare them you would find the rails of the 034 to be a little longer thus making up for the slightly larger radius. Of course, the difference in radius would also be apparent. 054 is the odd one with a 30 degree curve or 12 to the circle. These odd curves are more difficult to mix into a track plan if you want curves less than 90 degrees. creating a 45 degree curve with then requires a half section. When you get bigger than that, you go to a 22.5 degree curve or 16 to the circle. Then the math is a little easier.

Big_Boy_4005 posted:

... 054 is the odd one with a 30 degree curve or 12 to the circle...

O-54 is 22.5° / 16 to a circle.  O-42 & Super O, as well as O-48 FasTrack, is 30° / 12 to a circle.

ADCX Rob posted:

Big_Boy_4005 posted:

... 054 is the odd one with a 30 degree curve or 12 to the circle...

O-54 is 22.5° / 16 to a circle.  O-42 & Super O, as well as O-48 FasTrack, is 30° / 12 to a circle.

Oops, thanks Rob. Been a while since I used sectional track. I knew there was an odd size in there somewhere.

Bill DeBrooke posted:

Each circle has eight sections.  360 degree divided by eight is 45 degrees.  You can combine them but will not have a circle.  Direct answer to your question: 45 degrees, eight sections making a 360 degree circle.

If you combine the two radii in a symmetrical way, you can create an ellipse. 

It takes 8 sections of 027 curved track and 8 sections of 034 curved track to make circles of 27 inches in diameter and 34 inches in diameter. 

Therefore:   the circumference length of a curved section of 034 track is longer the circumference length of a curved section of 027 track.

Edited

C =pie x D

C= 3.14 X 27 = 84.78 divided by 8 sections = 10.6 inches long per section for O27 track

C=3.14 x 34 = 106..76 divided by 8 sections =  13.35 inches long per section for O34 track

Just that simple.

Charlie

Wow. Thanks for all the help here cuz I'm just not getting it I may have to cut a piece of cardboard!  so one last question then, sorry.

So an O34 track laid on top of an O27 track match????? 

Two 45 degree angles on top of each other, <  and < match.  And an O34 track being a 45degree track and an O27 track also being 45 degrees on top of each other will also match??

Ok thanks everyone. So they are both 45 degrees but one is longer than the other which makes a bigger circle.

thank you

45 degrees is the amount of turn, not the arc.  If you attach an 027 and an 034 to straight sections of track and then attach another pair of straight sections to the other end of the curves, the second pair of straight tracks will both be pointing 45 degrees from the first pair.  But the two straights attached to either end of the 034 will be further apart than the two attached to the 027 curve.

Here is a diagram I found in the 2001 MDK, Inc. K-0001 book entitled "Operating O and O-27 Trains" page 234.  I think it may prove helpful in visualizing the differences between the diameter and size of various kinds of curved tracks.

 It doesn't show Marx's 034" diameter track.  However if it did, that track would have fit between the 27" and 42" diameter tracks

Here's another try:

The inner circle is O27 and the outer is O34 (not to scale). If the angle shown is 45 degrees, you can see that the inner (O27) track section is shorter than the outer (O34) track section, but each requires 8 sections to make their respective circles.

Jim

Aaaahhh! That picture by jim did it!! Now I get it!!!

thank you all! Here’s a picture for your trouble!

Jim nailed it. A 34" curve is actually a longer piece of track than a 27" piece of track.  It has to be since each uses 8 pieces to make a circle. Eight 34" curves makes a bigger circle. But, with each segment being 1/8 of a circle, each track has a 45-degree angle.