Several weeks ago, Mark Grecco alarmed about a potential problem with Atlas HO Code 100 Snap-Track turnouts with part numbers 850, 851, 860 and 861. The issue is because of the wrong geometry specifications form the Atlas catalogs, where these turnouts are listed with 20 degree branches, while the real track pieces, measured by Mark are with 15 degree branches.
It is not uncommon the data in the catalogs to be wrong, but in this particular case it is possible that these parts are changed (replaced) with new ones while the part numbers are still the same. As we cannot be sure that this assumption is true, I decided to keep the old spec in the Atlas-HO-100 SCARM library and to add the new 15-degree parts with the numbers 850/15, 851/15, 860/15 and 861/15 with the next update of SCARM.
|These turnouts are labelled as “MS L” and “MS R” for the manual switches and “RS L” and “RS R” for the remote switches in the tracks selection panel. The updated turnouts will be marked as “MS L/15″, “MS R/15″, “RS L/15″ and “RS R/15″ respectively and will be positioned below the group of existing ones.|
If you already have Atlas 850, 851, 860 or 861 turnouts, you will need to check the degree of the branch in order to know which part numbers in SCARM to use. To do that, attach two 10-degree curves #835 to the branch followed by a straight as showed on the picture below.
• If the straight from the branch is parallel with the straight part of the turnout, it is a 20-degree switch – use 850, 851, 860 and 861 parts in SCARM track plan.
• If the straight from the branch is going to cross the straight part of the turnout (as in the picture above), it is a 15-degree switch – use 850/15, 851/15, 860/15 and 861/15 parts in SCARM track plan.
|It is also a good idea to check in your local model train store to see what kind of these tracks they have on stock before start planning a layout in SCARM, if you intend to use Atlas HO code 100 Snap-Tracks.|
Updated SCARM library for Atlas HO code 100 Snap-Track system is provided in the links below as a ZIP archive. Download and unzip it and then copy the .lib file into the Lib folder of SCARM (usually C:/Program Files/SCARM).
|The new updated library is included by default in the program starting from SCARM v.0.9.21.|
I am really sorry if this mismatch between Atlas catalog data and the real tracks caused problems to any of you. And finally, I want to thank to Marc Grecco for the information and measurements of the turnouts that he shared with us.