HO EZ track

[meangene]

I was wondering if anyone knows what track I would need to turn a 22" circle into a figure 8.

[Joe Satnik]

Dear MG,

The simplest figure 8 has a 90 degree crossing. 

The straight legs are the Radius (=22") minus half the crossing length (half 2" = 1"). 

So you need a combination of straights that equal 21" in length. 

9" + 9" + 3" = 21" for each of the four straight legs.

360 - crossing degrees = degrees of curve needed for each end.  360 - 90 = 270 degrees per end.

270 times two ends = 540 degrees of curves. 

540 - the 360 you already have = 180 degrees of extra curves. 

180/22.5 degrees per curve = 8 extra curves. 

You will need a table 110" long, which is 14" longer than a 4' x 8' sheet. 

Again,

Eight extra 22" radius curves,

Seven 9" straights,

One 9" straight terminal re-railer, and

Four 3" straights.
 
Hope this helps.

Sincerely,

Joe Satnik 

Edit: add bold, change turns to curves, eliminate extra "Hope this helps", change 22.5" to 22" radius curves, add "straight" to terminal re-railer. 

[pdlethbridge]

Joe, your gonna give him a headache.

[Joe Satnik]

Thought I'd put the formulas out there in case someone wanted to learn...  90 degrees being the simplest mathematically.

I suppose I could have asked him what size table he wanted it to fit on...

Joe

[Jim Banner]

Can you fit a 22" radius figure eight on a 4 x 8 sheet if you use a 60^o crossing?

Jim

[Nigel]

Can you fit a 22" radius figure eight on a 4 x 8 sheet if you use a 60^o crossing?

Jim

Hi Jim;

With 22" radius, to use the 30° or 60° crossings, there would be some cutting involved because there are only 22½° and 11¼° sections listed.  A 45° crossing could be used, but I did not see one listed.

[Joe Satnik]

Good to hear from you, Nigel.

Hey, great knowledge of the keyboard, with half, quarter and degree symbols.

Jim,

Nigel is correct.  In "Figure-8 Land", the crossing degrees have to be in multiples of your smallest fitter curve degrees. 

In this case, the smallest is 12-1/4 degrees.  60 degrees is not a multiple of 12.25 degrees.   

However,  there is a 45 degree crossing (# 44543),

and if we can believe the picture in the product section (a huge leap of faith at times)

is a correct and true picture of the product (we've been burned before) I calculate its length to be very close to 3 inches.

(Rant about critical dimensions missing from nearly every track piece package and catalog description....)

It just so happens that the Table top length of a 22"R x 45 degree Figure-8 is 94-5/8", which is under the critical 96" (or 8') sheet length.

However, each of the four straight legs calculates to  7.6125" long, or just under 7-5/8".

Closest quarter inch is 7-1/2". 

4-1/2" plus 3" fitter straights = 7-1/2". 

As far as getting power to the track, you would have to solder to the rails or

trim down a 9" straight terminal re-railer to 7-1/2".

So, simplest recipe for 22"R x 45 degree Figure-8 (solder power wires to rails)

12 extra 22"-22.5 degree curves, (28 total)

Four 4-1/2" straights

Four 3" straights

One 45 degree crossing.

Hope this helps.

Joe Satnik

     

   

[Jhanecker2]

I think Atlas make a set of wired rail couplers in code 100 that might make soldering unneccesary  .  John II.

[full maxx]

I think Atlas make a set of wired rail couplers in code 100 that might make soldering unneccesary  .  John II.

I saw these also and was gonna ask about them , if they make a bump or if their worth getting ...obviously soldiering to the rail would be a better connection but they dont sound like a bad idea

[Chris350]

I think Atlas make a set of wired rail couplers in code 100 that might make soldering unneccesary  .  John II.

I saw these also and was gonna ask about them , if they make a bump or if their worth getting ...obviously soldiering to the rail would be a better connection but they dont sound like a bad idea

I use these and with a little care in placing the wires there is no bump.  I still solder them to the rails however.  Once I have all my tracks laid the way I wan them I solder all my connections.

[Joe Satnik]

The trick is to get the Bachmann (captured) rail connectors off the rails without destroying the track piece. 

[brasshat98]

How many 18" radius tracks form a figure 8 using the Bachmann 30 degree crossing (as suggested by Bachmann)?

[Joe Satnik]

Dear brasshat98,

360 - crossing degrees = # of degrees per loop

360 - 30 degree crossing = 330 degrees per loop......x 2 loops per figure 8 = 660 degrees of curves needed. 

660 degrees / 30 degrees per curve section = 22 curves. 

Since most start with 12 curves from their oval or circle, 22 - 12 = 10 extra curves needed for the 18"R x 30 degree figure 8.

Problem is, the recommended 30 degree Bachmann crossing is actually too long for that figure 8.   Gaps and kinks guaranteed. 

Go figure....

Hope this helps.

Sincerely,

Joe Satnik

[mf5117]

pi r square , cornbreads round ....... and if you divide the circumference by the radius of a pumpkin   you would get pumpkin pi .... very good post Joe and Nigel ...lots of good information  thanks . I'm looking at  purchasing a different scale of track . And I don't want to over buy like I did with the HO EZ TRACK . mind you I'm glad I have all of it .But trying to put a little more thinking into this next venture ... thanks again mark f