As noted in a previous article I went looking for some information on the Front Range HO website only to find the website no longer exists. I was looking for information on magnets for the pancake chassis. I had saved that information a while back. It took me a while to locate it. Again, I would like to thank Front Range HO for this information. If you're interested in that magnet information then click on the read more link.
There were many different Aurora magnets made for the pancake motor. The only way to determine the orgin is by their colors, or lack of them. One thing we've learned is you can always be surprised - magnet colors that are historically "supposed to be weak" can sometimes turn out to be stronger than you would guess! We know this through measuring with both our own home-built analog tester, and FRHO gauss tester & BRP comparative tester. Let's take a look at some different magnets by strength. We'll rate their strengths from 1 to 5 (5 being strongest) since that's how our analog meter rates them.
By the way, only tall (White/Red) & (White/Black) Magna-traction & X-Traction magnets rate a 5+. Before you get any wise ideas, cutting or sanding a set down will reduce their strength slightly. Also a pair of MT or XT magnets may be matched before you cut, but may not be matched when you are done. Keep this in mind if you decide to go that route, re-matching if necessary. Remember, actual gauss will vary from meter to meter, so our rating is a comparative rating based on our analog gauss tester.
Depending on the rules, sanding or grinding the small rectangular "end faces" will not only produce a nicer fit (resulting in less chassis "twist"), but also bring the magnets just that much closer to the armature.
Some or all genuine Super II chassis came with fully oriented parings without the dimples! I don't currently own a Super II (it's been many years since I have) so I can't confirm or deny this, however, it went uncontested in the usually spirited discussion list. It was also reported that there were carded black/red parings offered by Aurora that also displayed the dimple.
Bee careful when choosing these by color alone due to these colors being available as A/FX too. Pairing a rating 2 magnet with a rating 3 magnet can actually yield a lower performance then two magnets with a 2 rating. did you catch that?
The Grey tipped Armatures magnets came Black/Black as well, but the rear magnet had a white stripe on it. the pairs with the stripe were stronger than the pairs without. So again chance for mismatch due to the front magnets always being unpainted black coming in 2 strengths! Without measuring the chance for mismatch is high.