Another basic question from a novice. [:p]
As I am starting to wire up for my reversing section, I read about metal wheels vs. plastic.
Now I can tell the obvious plastic but thought that metal wheels should be magnetic and, either they are not, or I do not have any. Think the latter is not true as I have 3 locos and none of those wheels show magnetism either.
So… the question is, other than plastic color, how does one know you have metal wheels? Is it as simple as seeing the chrome appearance? I bought some Proto-2000 wheel sets and think they are metal although the packaging does not say so.
Are I toooo dense???
Different brands of metal wheels are different colors. Some are darkened, some are almost a rusty color (Kadee ones for example). P2K wheels are metal wheels on a plastic axle. How about the sound that they make? Metal wheels make a nice clickety clack sound compared to plastic.
Metal wheels can be blackened to make them look like the plastic wheels. The giveaway is there will be an insulating grommet, or insert, where the axel enters one of the wheels. These inserts are much more visible on a silver plated or brass wheel but still have to be used on blackedned wheels. They simply maybe harder to spot.
In order to be attracted by magnets, the metal must be ferrous-based, like iron and steel. Many metals are not attracted by magnets including Brass, nickel, silver, gold, lead and tin. Most model railroad track is nickel-silver and solder is made from lead, tin and/or silver. None of them will attract a magnet. Most metals ARE electrical conductors, which is a different thing from magnetism.
If your wheels do not attract a magnet, it doesn’t necessarily mean they are not metal. They may be made of other metals. Usually, however, the axles are made of steel and are thus attracted by magnets. You can test your wheels and axles with a simple battery and light circuit or a VOM (volt-ohm-meter). If the wheels and axles conduct electricity, they are metallic.
Are you concerned about metal wheels electrically bridging a gap in the rail and causing a short circuit in a reversing loop? If so, you may be able to relax. If you wire a reversing loop correctly, the polarity of the rails will be the same as the train enters the loop. While in the loop, the polarity of the MAINLINE is reversed so that when the train exits the reverse loop, the polarity is once more the same for both rails. The only time you could experience a short circuit problem is when the end of the train is still on the mainline and the loco is in the reverse loop. Reversing the mainline polarity at this time could allow the metal wheels on cars just entering the loop to bridge the gap at the beginning of the reverse loop and cause a short. This is why the reverse loop should be long enough to accomodate the whole train within the loop before the mainline polarity is reversed.
Try gently tapping the side of the wheel with a metal tool (mini screwdriver, pliers etc). Metal wheels make a very different sound than plastic ones. Try one of each and you will hear the difference.
Sorry about resurrecting this thread, but I had to voice my discontent somewhere.
I bought some N scale Atlas (p/n 22020) 33" metal wheels for my rolling stock. They are utter crap, not because they are poorly made, but because the rolling stock derailed in MULTIPLE places on my layout after installation of four N scale rolling stock pieces. I was utterly dismayed and shocked.
What could be going wrong. I switched back to the plastic wheels for now until I can get some answers. Why are they derailing?
Check the gauge of the wheels. The best way is with a wheel gauge, but you can do a quick check by putting them up against a wheelset that you know works well. The wheels seem to be firmly attached to the axles, but in most cases they are just a tight press fit, and you can carefully slide them along the axles to get the gauge correct.
How do the axles fit in the trucks? Again, check the old axle fit vs. the new. Not all wheelsets are created equal. Slight differences in axle length will lead to binding or loose, wobbly axles.
When you re-attached the trucks, did you perhaps make them too tight? They need to move freely, and at least one truck on each car needs to have a small amount of sideways motion to adjust for uneven track.
Plastic wheels often have larger flanges than metal wheels. In a perfect world, this should not be a problem. But, the lower flanges on metal wheels will show up problems in trackwork more readily than the “pizza cutters” you find on some plastic wheelsets.
Hmmm, I may have to get a wheel gauge from the LHS.
I played with some of the rolling stock this morning, and you’re right, some of the wheels are not rolling freely inside the trucks. I will have to find a way to compress them (i.e. shorten them).
Also it seems like the rolling stock with the metal wheels “bounce” around a lot when going through turnouts, whereas with the plastic wheels they went through the turnouts smoothly and with no wobble. Hmmmm.
Atlas axles are a different length than any other brand (longer); especially in HO scale. Atlas replacement wheelsets cannot be used in Athearn, P2K, Exact Rail, or other brands of trucks.
Unlikely that the new metal wheel sets are the problem (possible, but unlikely). More likely, they simply don’t fit the trucks. Not all wheelsets and trucks are the same.
If the problem is the wheelsets, a gauge will tell you.
Attempting to build a layout without either a track/wheel gauge or a cheap multimeter (your other thread) makes it much harder to find and resolve problems. As I recall, your layout has some fairly sharp s-curves. If those are the areas where you are experiencing problems, the track configuration may be contributing.
The best time to do something about it was during the design phase, true. It would have been possible to design out the s-curves with some compromises. Hopefully you won’t find that you need to rip those sections out and re-do.
First off, it’s unlikely that changing the wheelsets will help appreciably. The MicroTrains stock wheelsets roll pretty well.
But if you want to try changing them out, Fox Valley Models offers replacement wheelsets for multiple different axle lengths for the different manufacturers. http://www.foxvalleymodels.com/metalwheels.html
You can check with them to find out which axle lengths are appropriate for which manufacturer.
