One of the crew brought a new Athearn Genesis GP38-2 to my recent operating session. We were disappointed to find that it scraped the Kadee uncoupling magnets. Over the years I’ve had this problem a very few times. For locos that I own, I have ground down the plastic gear cover to provide clearance. That’s not a solution for someone else’s loco.
Is there a standard for clearance of trucks over uncoupler magnets? Is this a design problem with Athearn Genesis GP38-2s? Perhaps its just a manufacturing tolerance problem with that specific model? Any thoughts?
There should have been instructions, with the uncoupler magnet for rail height relative to magnet and trip pin clearance to magnet, for it to work properly. I believe you are assuming, that his trip pin clearance is correct, which might not be the case. There is a gauge for that also. The fix, is to bend the trip pin, up or down, what ever the case may be, low or high. They also make a tool for that, but I have always used needle nose pliers, to accomplish that.
I don’t find it on the Kadee website, my recollection of the proper height for a Kadee magnet is 1/64 inch above the rails–certainly no higher. Note that the glad hand should be no lower than 1/32 inch. Thus it will clear the magnet by 1/64 inch.
Not sure about the current crop of magnets, but the older ones even sat just a tad too high when using code 100 rail. If you are using code 83, the problem would be even worse. I’ve always set my magnets to be even with the railhead. If everything clears a turnout, it will clear the magnets.
Based on your description, your magnets are sitting way too high if the gear case cover is catching them. This guide should help you get your magnets and couplers set properly …
There is nothing ‘wrong’ with that Athearn engine(unless the gearbox cover is not snapped on correctly). Kadee specifies that the 321 magnet should extend 1/32" above the rails - Most folks just align it with the ties and glue it down. I never mount anything that extends above the rails. That is just too close and is asking for problems. The Athearn truck has been around for years and not caused a problem. Does this scrape on all of your magnets? The other possibility is that you are using a 321 magnet with code 83 track - The 322 magnet is for code 83…
Thanks for all the quick responses. I’m using code 100 track and glueing the 321 magnet to the ties. Every other locomotive runs over the magnet without a problem. The glad hand is not catching the magnet. The gear box cover is rubbing against the magnet. Since all other locos do not have a problem, it is reasonable to assume that the problem is with this particular locomotive.
I note that you didn’t reveal the heights of your magnets, which leads me to think you haven’t measure them. I recommend doing so. I also recommend measuring the clearance under the subject locomotive’s gearboxes. A comparison of the numbers should reveal the source(s) of the problem.
I look forward to your measurement results.
I just checked the clearance under a gearbox of one of my Genesis GP38-2’s, and it was .025. That would clear a properly installed magnet by at least .009 inch. NOT a lot of clearance, but clearance nonetheless.
And, currently, all my coupler magnets are electromagnetic, and are below rail height.
I note that, in your original post, you said “For locos that I own, I have ground down the plastic gear cover to provide clearance.” I’ve been playing with trains for over half a century, and I don’t recall ever having to do that. You comment later that “all other locos do not have a problem”, and yet you say you had to modify several to gain clearance. Thus, they DID have a problem. Just not anymore. This really sounds like the magnets are too high.
Again, do your measurements. I just did. You can too.
No problem on my part. But sometimes, I’m beginning to wonder, if some people even bother to look at some of the links others provide to help them with some problem’s.
Frank, In short no they don’t…Over the last 13 years on this and other forums I’ve seen replies that almost mirror my own with the same link(s).
Its annoying but,it’s understandable since anybodies eyes can skip over a reply especially a reply that is long winded and ends up complicating the simple while overstating the obvious.
Then you have the few members that skips/ignores certain members posts for various reasons and ends up nearly duplicating the ignored member’s post that contains the same links…Sad but,funny at the same time.
I have a switcher, a Proto if I recall correctly, that runs aground on Kadee magnets that are mounted according to the enclosed instructions. It’s the fuel tank that hits, not the coupler pins or trucks. This was mounted on Atlas Code 100 track. I had to remove the magnet and grind down the ties to drop it a bit so the engine could clear.
Do you know what I learned from this, other than the obvious? Sometimes, it’s hard to do track work 30 inches in from the edge of your layout.