I put some aluminum faced tape on the bottom of my locomotive trucks to aid in it being detected by infrared sensors embedded in my track. After looking closer, I now see there are exposed gears on all 6 of the axles. I did not notice this before, but now that I have, I am wondering
A: What they are for?
And B: Will covering them up like this cause any harm?
I have already operated it with the tape applied for a brief period and haven’t noticed anything yet, but I also do not want to invite trouble.
Hello All,
They are most likely lubrication ports.
However, they could be clearance windows as the bulges in the gear covers could extend down between the rails and foul on turnouts.
I have a Bachmann USRA 0-6-0 that the gear cover would do this.
To solve this problem I ground down the bulge in the gear cover.
After performing this "surgery" the gear was exposed but it solved the problem of bottoming out over the turnouts with no ill effects on performance.
In my experience, covering them would not cause any mechanical problems, unless the tape you are covering the openings with presses into the gears causing binding or friction.
Is there a way you can place the tape on the truck covers without covering these holes?
Hope this helps.
"Uhh...I didn’t know it was 'impossible' I just made it work...sorry"
jjdamnitIs there a way you can place the tape on the truck covers without covering these holes?
I was thinking of doing this too, cutting out the rectangular openings with an X-Acto knife, but I am not sure if it will offer enough reflection. I did try to put in three smaller strips of tape instead of the one longer piece as shown, but that wasn’t enough to trip the sensors. The longer strips as shown seem to solve the IR detection portion, I just don’t want to gum up anything with the tape being over the gears.
I think the problem is that the trucks on the loco sit down so close to the track versus rolling stock that it throws off the sensors for detection. I may ultimately need to move the tape to the bottom of the fuel tank as it sits higher, but that requires increasing the spacing of my IR sensors which is a lot more involved than simply rearranging tape on the loco trucks.
Unless the gears are noisy, why cover them? Makes it a lot easier to lubricate them.
Simon
Cisco_KidI put some aluminum faced tape on the bottom of my locomotive trucks to aid in it being detected by infrared sensors
there's no need for the aluminium, most things will reflect IR. were you thinking of putting aluminum on all you cars? wouldn't you want your reversing section sensor to recognize a car with metal wheels?
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greg - Philadelphia & Reading / Reading
gregc there's no need for the aluminium, most things will reflect IR. were you thinking of putting aluminum on all you cars? wouldn't you want your reversing section sensor to recognize a car with metal wheels?
The cars are detected fine on their own with no need for tape. I need detection early on the loco and think the problem I am having stems from a combination of the bottom of the loco being all black, it is also not uniformly flat (at least on the trucks with the gear openings), and the loco trucks being real close to the tracks.
I placed my sensors (in hindsight) too close to the gaps where the loop transitions so need to get the sensors to trip on the loco trucks, otherwise I could place tape on the fuel tank bottom and this would not be an issue.
The reflective tape works fine on the loco trucks as mentioned in the OP, I am just trying to get feedback on if it will cause any future issues by covering up those gear openings. My other option, if I need to avoid using the tape on the trucks, is to relocate my sensors, which I would like to avoid as it is a lot more effort.
This is a 'tower drive', isn't it? The motor drives a 'tower' of gears to get the rotation down to wheel level, but those gears only drive one axle (usually the center axle in a six-wheel truck). Then a system of idler gears is used to carry that from the center axle out to the ones at the ends for six-wheel drive.
The chief concern I see about leaving the tape over the 'ports' is that its adhesive will start attracting dust and contamination, which will then 'transfer-print' to the lubrication on the gears and accelerate gumming them up. I would be tempted to say that, instead of cutting little 'windows' where these gears show, you might use a small rectangle of thin material like Kapton tape to isolate the adhesive in that part of the covering metal tape; the 'surrounding' adhesion to the cover would effectively form a sealing cover and actually reduce contamination.
I am ASSuming your IR system is one of those with two tubes along the centerline of the track, at an appropriate mutual angle for reflection -- one containing the IR source and the other the photodetector, fairly far down in the tube to provide reasonable 'projector-beam' lighting without lenses. That only depends on good reflection down the locomotive centerline to assure tripping -- BUT (1) you have a very long interrupted tape strip down each truck frame (so you have continuous reflection for upward of an inch of locomotive motion, but with 'wobbly' reflective material), and (2) you have both trucks reflective, so anything that depends on a reflected IR signal as a 'trigger' might be turning on with the front truck and then promptly right back off with the rear truck. It is interesting to consider the various ways this might be worked around with the IR detection circuitry.
One method I've thought about is to have the IR tube pair close to one side of the track, rather than right 'up the middle', and then have the two reflectors on a locomotive 'handed' so that only the one on the 'leading' side of the engine, either way, will trigger the system. That does not help, of course, with avoiding effects from trailing power. My "answer" to that was little doors or blanking plates that would be applied to the reflectors on trailing locomotives, so that only the ones on the ends of a given 'consist' would be active.
Putting tape on the fuel tank is not an unreasonable alternative: it solves most of the operational concerns, and in any case many signal systems only change indication after part of the lead locomotive has passed them.
I would at least consider using something like interference-mirror material optimized for your range of IR, instead of just foil tape. Adjust the angle between your tubes in the track to match the height of the applied mirror face, then use that dimension consistently as you apply it to other locomotives or equipment.
Thanks for the reply Overmod, your insight into my issue is pretty much bang on.
Instead of adding unnecessary quotes I will just respond to a few points you brought up. First your description of the “tower drive” seems to match what I have, but I admit I am a bit ignorant in this area, this being my first “non-toy” locomotive I guess.
I think you are absolutely correct in your assessment of the tape over the ports as this was my original inclination thus why I posted. I think your idea of using Kapton tape to cover the back side of the aluminum tape is ingenious and will be the very next thing I try.
Yes, your assumption of my using the two IR type system is also correct. I get good detection with a little spacing between the sensors and the normal rail-cars trip it reliably, but the loco sits a little close to have them detect it properly, especially truck detection.
I used reflective tape on both trucks in case I need to back out of the loop with the loco by itself only, as all my rail cars I have tested so far work great. I could just try to remember never to do that (drive loco out alone backwards) but why chance it. It would be one of those things where it is easy to remember now but months down the road I forget and cause issues.
Incidentally, gregc brings up a point to consider. If you don't have 'perfect' angle of reflection from source to receiver, you may be better with a diffuse instead of 'specular' reflector: use the dull side of aluminum foil instead of the 'bright' side, for example, but better still consider using the IR equivalent of satin to dull 'architectural gloss white' or even a little Scotchlite-type additive, so more area lights up for the receiver to 'see'. If you know or can find out the frequency band of your IR emitter, you can figure out without too much ado what a formula for the 'whitest' paint or film for it would be.
Ok, thanks to you both for pointing that out. At this point I am going to hope the simpler (for me) solution is to use some kapton tape on the back of the aluminum tape. If that doesn't work out those other ideas you bring up will be good things to keep in mind. Paint may actually be the ideal solution if it allows me to keep the ports open, but I will see how this (tape) works first.