Model Train Noise

The more recent models that have plastic gears, and a couple of stages or more between the motor worm or gear and the axle isolate much of the motor noise from the track. Best of the lot in UK models probably the Heljan diesels where the motor sits in a compliant rubber cradle, and this combined with plastic shafts to the gear towers on the bogies means that practically no motor noise reaches the rails.

Attenuating what noise is emitted from loco bodies is not easy. Mass loading any large flat surfaces, and using a compliant material like blu-tack as the only contact between body and chassis (cutting space out of the chassis to accomodate pads of the material) are techniques you may care to try.

It is usually more effective to tackle the track. Much of the noise occurs because the track is bonded firmly to a fairly stiff large sheet of 'baseboard'. This acts as an efficient loudspeaker diaphragm. Placing a compliant material between track and baseboard prevents conduction to the baseboard and can dramatically reduce noise levels. One effective material is the closed cell foam from which campers sleeping bag mats are made.

***I tend to agree with Jeff (SRman) but for what its worth here are a couple of tips that will help certain causes of noise.

(1) Add random mass to the interior of a body. What happens in a noisy loco sometimes is that the body itself acts like a speaker cone, receiving vibration and through the transfer of that to the plastic, the body is "excited" by the vibration and significantly amplifies it.

This is best fixed by adding mass, but do not do it symmetrically.

Add small bits of lead sheet glued at random points... it will not need all that much, but do use enough glue to really couple the lead to the body - something like epoxy would be good.. These small differences in mass stop the propagation of standing waves and so prevent a tiny mechanical noise being amplified by the body into a loud annoying distraction...

(2) One thing that does help the pancake motors is to add a super slick bearing surface between the flat gears and the motor housing... and reducing gear slop a wee bit.

If you dig into the bottom drawer and find an audio cassette, then disassemble it, with luck you will find two teflon coated plastic sheets which act as a smooth bearing surface betweeen the tape and the plastic case of the casette. You are more likely to find the good stuff in a name brand tape by the way - TDK, Sony etc etc...

(As quality cassettes were always screwed together you will also end up with half a dozen handy small screws with luck) - AND you will end up with a nice thin springy thing that held a soft pad against the tape to hold it to the head... its usually phosphor bronze - good free power pickup material!!

Cut out two discs the same size as the gears and slip them onto the shafts so they are between the case and the gear - teflon side to the gear. This both reduces gear slop and smooths the passage of the gear.

NO other lubrucant really needed, although a little graphite is good. Oil on the sheet will be counter productive unless totally plastic safe with loads of added teflon.

(3) OR - if its a killer gear noise and it really drives you mad.

Use chainsaw chain oil - just a tiny drop. This stuff is sticky and is designed to stay on the chain as it revolves when cutting the tree, so its hellishly sticky - this stickyness reduces the gears ability to vibrate and make the noise. Be warned though - just a tiny bit, as it will also increase rolling resistance a bit.

Don't buy it - go to the local farm product / arden power tool sales/service company with a small jar in your pocket - tell them why you need it and I'll bet they will probably smile, take the micky a bit then give you a couple of teaspoons of it no charge...

and a couple of teaspoons will do many, many loco's!!

Cheers

Richard

Regarding gear noise, use of a purpose made light grease is much more preferable to chain saw oil!

There are a number available both here in OZ and in the UK, I use a an Electrolube GP Grease made in England, also a Food grade grease I got from a company that sold expresso coffee machines, not sure of the brand name, but it has 'ox' in it, but the best stuff I've found is a product called 'Liquid Grease' it's made in Lowestoft but is available out here in Angling Shops and is used for lubricating fishing reels.

It is slightly heavier than chain saw oil but is incredibly sticky and stays where is put, I haven't had any 'spin off' in any of the loco's I've used it on, and it quietens down metal to metal gears, better than anything I've used so far.

The other grease I use is Carrs Grease, this is really top notch stuff, and is very economical, and being white in colour is easy to see where you've put it, no, it's not the same as the horrible stuff Bachmann use on their mechanisms, it dosen't attract dust and is the best stuff for quietening the gears in Lima and Hornby Ring Field motors.

It is always imperative to check that the product is plastic compatible, as some have aromatics in them to keep them fluid which can attack the types of plastic used in models.

Both Triang and Hornby Dublo used to supply a little bottle or tube of oil with each loco, this was much more preferable to the 3 in 1 that we used to oil our bikes, lawn movers and other sundry objects with, anything oiled with that that had
plastic in it would disintergrate in three months!

So, to recap, any oil used must be plastic compatible, Seuthe Ultra Adhesive is the best I've used, followed by the oil made for the US market, the name escapes me at the moment, any of the oils sold for use by the Brands, i.e Fleischmann, Bachmann are OK,

On gears which are not running in an enclosed gearbox then a light grease is the way to go, but, please, please check it's suitablity as I have come across locos with no teeth on the worm wheel as the lubricant had caused it to harden and the teeth to strip.

You have been warned!