Bob,
I will open up a couple of switches to have a look at the wire size. As you know, there are other things that affect the coil performance. If the coils are physically larger in the 3010 switches, then that will have a profound effect on the performance. I have had the 3010 switches open recently but didn’t do a comparison of coil size and wire size.
Bruce Baker
Lee,
I don’t know why the switches would work differently with different brands of engines. One thing I would suggest is clean the track in with a Scotch Brite pad as dirt on the non-derailing rail will serious impare operation of the switches.
Bruce Baker
The coil resistance of the 022 switches is about 6.8 ohms. The coil resistance of the 3010 switches is 4.8 ohms. So the wire used in the 3010 switches is definitely larger in cross section than the wire used in the 022 switches. The coil bobbins for the 022 switches are about 1" long and 0.75" in diameter. The coil bobbins for the 3010 switches are 1.56" long and 0.60" in diameter. The plungers in the solenoids are the same size at about 0.25" diameter. The wire diameter of the 022 switches is 0.015". I cannot measure the wire size of the 3010 switch accurately without disassembling the coils. However, there is a small loop of wire going between the two coils that I can almost get a caliper on, and it measures 0.018"+/- in diameter. The volume of the 022 coils is about 0.37 in^3 assuming the core is 0.3" in diameter. The volume of the 3010 coils is about 0.21 in^3. Based on the ratio of the volumes and the resistance, the wire size of the 3010 coils should be smaller than the wire size of the 022 coils. It is very difficult to measure the wire size of the 3010 coils, so the measurement could be in error by several thousands.
Bruce Baker
Bruce,
To help clear up the problem I was having, this would happen when the Williams locomotive got to two or three sections of track away from the switch, basically as it approached the switch and not just at the switch! I took the Williams engine off and used a post war Lionel engine and there was no problem. So I doubt that dirty track was the culprit.
Lee F.
Folks:
Just to complicate things a bit - I’ve had the 3010 and 3011 switches on my layout since I rebuilt it in 1997 - no major problems, no derailments, running a combination of Lionel Postwar, Williams (traditional GG-1, RF-16 Shark, RDC’s, GP38, and scale-size Alco FA’s, and MTH Railking RDC’s. A couple of notes about the install:
1 - The switch controllers were problematic, so removed them, and went to TMCC and a SC-2 switch controller. My guess is that if you don’t want to use TMCC/SC-2 that some momentary contact switches should work just fine.
2 - I use fixed-voltage for the switches from my old KW. Voltage is set using a meter and is just under 13VAC. With less than this, the switches do not always throw completely.
3 - Following an article in “the other magazine” some time ago, I added a brass shim to the small guard rail at the entrance to the switch (the bottom of the “Y”) - the article also recommended adding a similar brass shim to the longer guard on the curved portion of the switch (same side as the small guard rail). After a while, I found that the longer shim wasn’t really needed.
4 - This is more cosmetic, but I wasn’t really happy with the lanterns and swapped out the factory bulbs for Miniatronics 14 Volt 2.4mm lamps (using the plastic bases from the factory lamps) - these are much smaller, generate a lot less heat, and provide a nice glow. The model number is 18-014-10. The also make the bulbs tinted yellow and these might really work well.
I have a right hand (3011) switch at the entrance to my engine service track where I had to switch the lantern to the other side. After I did that, the turnout did not throw all the way and I had to disassemble the switch a couple of times until I got everything aligned correctly (sorry - this is just a matter of trail and error) - onc
Mike,
My first attempt to make the switches so the train would not derail was to try to modify the guard rail that is near the points and on the side of the curved rail. Than, when this was not very successful, I did some thing else which works very well. I soldered a piece of brass strap to the inside of the straight rail near the points. This strap is 0.031 thick, 0.25 wide, and about 1.25" long. This piece stick out past the end of the switch. I feathered the end of it so it is about 0.125 high at the end, and feathered it to a sharp edge along the top from the end of the switch to the end of the brass. I also rolled the top edge slightly so it was tight against whatever piece of track was connected to the switch. This effectively makes a notch in the straight rail so that the wheels of the engine are aligned with the switch points. So far this has worked perfectly. My F-3 2333 runs through the switch without any noise as does my 2046 Hudson steam engine. I will try some more engines in the near future, including some new ones. I think that everything is going to work OK.
Bruce Baker
Bruce, I have been poring over your numbers, with the following results:
I find the volumes to be much closer. I agree with .37 cubic inches for the 022; but I get .33 cubic inches for the 3010. It looks like you forgot to multiply the cross-sectional area by the length.
The slightly smaller volume of the 3010 would explain a similarly smaller resistance, even if the two were wired with the same-diameter wire, but not as much smaller as you measured. With the volume discrepancy taken into account, it seems that the wire diameter should be very slightly larger for the 3010 to explain the resistance decrease. For a particular volume, the resistance varies inversely as the fourth power of the wire diameter. This leads me to a wire diameter for the 3010 only 6 percent greater than for the 022 and close to half an AWG increment.
Of course, as you make clear, there are possible errors in all the measurements and assumptions, particularly the actual diameter of the bobbin cores, the thickness of the insulation on the wires, and the density of the windings. But it seems possible to me that the two coils are wound with the same gauge of wire, or that the 3010 has the metric equivalent of the 022’s wire. Your number of .015 lies almost exactly in-between 27 AWG (.01420 inch) and 26 AWG (.01595) and, at .381 millimeters, almost exactly in-between the closest metric sizes in the Superior Essex catalog, .355 and .400 millimeters, which are very close to these two AWG sizes. So both might be 27 AWG or .355 millimeters, or both might be 26 AWG or .400 millimeters.
I should have qualified my statement, as: “All else being equal, If the coils have been redesigned for lower voltage operation, I think it more likely that they use fewer turns of heavier wire.”
Bob,
I will try to get some more accurate numbers this week end. I don’t mind partially disassembling the 3011 switch to accurately mesure the wire diameter. I will try to measure it with and without the insulation so we can get a better estimate of the packing density.
You and I seem to be wired alike: We want to understand these things even though we are not going to rewind the coils. However, sometime in the future the understanding of this problem could be valuable. I have access to MatLab and could model this using SimuLink if we want to get really serious. In that connection, I started modeling dynamic systems in 1966 and have done a lot of it over the years. However, recently I had to model an EMI circuit, and it took me a while to figure out how to write the equations to do it. In 1966 I started working for Electronic Associates that manufactured analog and hybrid computers. I used the analog computers for the next 14 years.
Bruce Baker