Lionel KW humming question

It's probably vibration of the transformer laminations - the stack of thin steel plates around the transformer core which are typically held together by a frame with rivets. I've worked on some different Lionel transformers but not a KW. I had an LW transformer apart and put it back together with machine screws so it was tight. I've heard of people using super glue on transformer laminations to reduce humming noise.  If you feel competent to work on it you can probably press on different parts inside with power on to find what is vibrating and needs better fastening (don't get zapped). Wait for some more feedback on this ...

671/681 posted:

My Kw is humming to the point of being bothersome.

Is it a particular tune you don't like? 

What, me worry?

DONT TRY TO REPAIR A TRANSFORMER IF YOU DONT KNOW WHAT YOU ARE DOING.

take it to a certified electrician or repair shop. Playing with electricity is no laughing

matter. My Dad was an electrician and taught us the respect that elec current deserves.

Don't try to repair it if you don't know what you are doing.

I believe that most hobbyists will work on their transformers while they are not plugged in. The key to eliminate humming is to secure the transformer laminations tight.  As Ace has said just use nuts and screws to replace loose rivets on the frame that holds the lamination stack. Sometime a C clamp can help hold things together while you make the repair.

I have seen a KW taken apart and I think that you might need a slightly larger screw to go in the hole if the base is loose. The KW has several screws to take out, I have not counted them.

I took my ZW apart and there are 4 screws that hold the transformer core in place on the bottom & bottom plate, and the top 4 screws that hold the cover help hold the transformer core in place as well.

Lee Fritz

Bruce,

    I do believe your KW is in need of some service, contact Jim Lawson here on the OGR he rebuilds and upgrades KW's & ZW's, his work is outstanding.  I own several of his upgraded Transformers, and everyone works better than brand spanking new.  Transformers are nothing to mess with, unless you know exactly what you are doing.

PCRR/Dave

The old Lionel transformers are not rocket science. If you have some basic electrical and mechanical repair experience you should be able to fix it yourself with the leads given here. Get an experienced person to work on it for you, if you are uncertain of your ability.

This shows the inside of a Lionel LW transformer. The lamination stack is held together with two long-shank rivets; one is visible here. I had this all apart, removed those rivets and put it back together with machine screws. Sometimes there might be other things loose inside a transformer that will make vibrating noises. Don't get zapped !

In my book, part of the fun of model railroading is being able to repair the hardware. That becomes increasingly complicated and often impractical with the newer electronic items.

Bruce,

    One of the OGR members has a KW, in great shape, for sale for $70.00.   I would purchase it and send yours out to Jim for upgrade and repair.  Then you have some serious power for your over all layout.

PCRR/Dave

The classic way of silencing a transformer is to drive wooden wedges into the space between the windings and the laminated core.

Thanks for all the replies. I got under the hood and I'm not sure of myself on this I may have someone look at it. It's supposed to be refurbished and I'm sure it is-really clean inside works well just a little noisy in my mind, maybe it is supposed to be that way?  Is it possible in the meantime to put a sound deadening material inside the case or would that not be feasible and complicate things? Also the right handle is a little tight would a little oil help or not a good idea?

Several years ago when I suggested wooden wedges, I got plastered with

hate mail.  apparently they did not know that manufacturers use this

technique.

Al W.

Has anyone tried super glue to secure loose transformer laminations, to reduce humming noise? That would certainly be easy.

Ace posted:

In my book, part of the fun of model railroading is being able to repair the hardware. That becomes increasingly complicated and often impractical with the newer electronic items.

I agree that it is fun to repair your own hardware.  With the newer stuff, as far as the board replacement level repairs that seem common place, it isn't any more complex or impractical, it's just different.  To some folks bolting transformer laminations together is just as scary as replacing a circuit board is to others.  Now if you want to actually understand exactly what every part on each board is doing, it will take a little while and a bit of effort to learn, and some special equipment to test,  but even that is not as complex as some make it out to be.  

On the issue of a wooden wedge, I can see how this might not be the safest thing in the world, but it will also probably work.  Superglue also seems like an interesting idea.  Has anyone tried using something like RTV silicone spread over the laminations?  

JGL