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Radii Such Fun !!

Posted: Sat Mar 03, 2012 4:37 pm
by scribe
Hi All

Well as you have probably guessed I am new to layout planning last layout I built was when I was 12 and was a single loop that used all the track !! Just wrestling with Xtracad but happier now i have learned how to handle it better. I did manage to download the Hornby OO track add-on but seems to be missing some points R8072 / R8073 that should fit what I am attempting to do struggling without them. Does anyone know of an updated Hornby track add-on for Xtracad ?



in Flummoxedville :-)

Re: Radii Such Fun !!

Posted: Sat Mar 03, 2012 9:57 pm
by Dragonfly
R8072 is identical to R612, R8073 is identical to R613. It's just a new number. :-)

Re: Radii Such Fun !!

Posted: Sat Mar 03, 2012 10:26 pm
by scribe
Thanks Doug

Will go and look up R8072 / R8073 but guess they are similar to R640 /R641 trouble I am having is can put an 2nd & 3rd degree curves in which fit with long straights no problems until I put some points in and doesnt seem to matter whether they are R612 / R613 short or R622 / R623 long Express points because when i do i cant get a radius that will fit working on a board 6Ft X 4Ft. I know it must be me but have been at it most of this afternoon and evening and getting frustrated :? Had to go on on E-bay and buy a Hornby Class 5MT R2881 Stanier Black 5 to cheer me up :-)


Re: Radii Such Fun !!

Posted: Mon Jun 04, 2012 7:11 am
by kristopher1805
its down to arithmetic, 4 foot is 1220 mm

A curve needs 19mm track width beyond the track centres and to deal with the overhang of about 21mm so you need 40mm for this

Therefore you have 1220 - 40 = 1180

This is just enough to place a R4 radius on the board as this is 571 mm x 2 = 1142 mm

You should have enough for a twin roundy R4/3 and R2/1 even inside this if you wish, the straights will be rather short at 610 mm (the extra 2 foot widths) as the standard is 167mm long then you can have a double length, a single and a Peco half length = 585mm, a standard setrack point is also 167mm long.