How To Operate Milk Car Without Sliding Shoes?

I think the biggest problem is going to be the electronics. The operating coil draws a lot of current, and the electronics to drive it are going to have to survive the spike and back EMF of the coil. Any possibilities with a 3rd rail Milk car kit? (Electric RR co.) If you have TMCC that is your answer.

Yes, the ERR kit is the answer and I have one installed in a milk car.  But Chuck is correct, it is for use with TMCC

I love my k-line milk car. Operates anywhere without a special section and doesn't launch cans into the next zipcode.
Don't know why these k-line operating cars didn't catch on more.

I like your idea of Teledyne control, and I also understand not wanting to blow the whistle all the time for the milk car operation.  You could install a separate whistle controller to an isolated section of tubular track in front of the milk platform.  This way, the DC voltage to activate the relay is only sent to that one section of track and not the entire layout.  Below represents utilizing track power to operate the car (which would require the locomotive to be parked in neutral during milk car operation).

If you wished to run the isolated section on a separate accessory voltage post, you could insert a SPDT (single pole, double throw) switch that normally connected to track power, but when you press the button, it switches to the accessory power that you will rectify to DC on its way to the isolated track.

Note: The 167 controller consumes about 5 volts it's self. So there may be issues when the locomotive runs inside the insulated track section.

I do not run TMCC, all but one of my locomotives is Conventional, and that one is LC+, so the ERR solution is out.  I have seen some info about the KLine car and am looking to create something similar in a Postwar car.  Does anyone have the schematic for the KLine? I couldn't find anything with a search.  

And as far as the  lack of power concern, I am picturing being pulled up the platform with the locomotive in Neutral, so I should be able to crank some voltage if needed

The thread that I found that gave me alot of this idea is here.  In it, GRJ suggests a type of remote relay that I am wondering if something similar could be adapted to the Milk Car mechanism.

https://ogrforum.com/...in-conventional-mode

Good discussion so far, Thanks for all your ideas.

-David

You should be able to do this about $5 per car.  See this OGR thread.

You say you have a "few" milk cars so I figure that's more than 2.  The remote fob in the linked example is a 4-channel (4-button) remote.  In the linked example the receiver in each car only drives a DC motor so I used a low-cost transistor (which is a DC switch).  But as GRJ has shown you can buy a wireless receiver relay module for about $2-3 which would switch AC voltage.  BTW your 2nd link to what is presumably a relay module gives me an eBay error message:

Plus, per OGR terms of use, you're not supposed to have direct links to eBay listings.  Your mileage may vary but I've had posts of mine deleted, modified, etc. by OGR moderator when including such direct links.

You can get an AC-to-DC converter module on eBay for $2-3 to power the wireless receiver relay.  The issue in my mind is if you have enough space in your car to fit (1) AC-to-DC converter module, and (2) wireless receiver relay module.  Perhaps you could post a photo with the shell off.

Separately, given this being a discussion forum, here's yet another path to consider.  In this somewhat long and arguably tedious OGR thread, member rjr eventually ended up using an optical activation scheme for his coal loader cars.  Basically you place a bulb in the track bed and each operating car can sense this bulb when positioned over the bulb.  The point being you don't need the operating car to work ANYWHERE on the layout!  That is, you are probably unloading your milk at a platform...else you'll be crying over spilt milk!   Thus, in such a scheme you don't need to remember/know which car you want to activate...but rather you activate whichever car is sitting on the activation track.  And of course you can have multiple activation tracks (different unloading platforms).

In this case the electronics in each car becomes simpler in that you don't need a wireless receiver relay...but rather just some optical detector that senses a light beam coming from the track bed.  More details can be provided if there is any interest.  But the idea here is a generic eBay relay module is about $1 (free shipping from Asia).  An optical detector is, say, 10 cents.  You still need an AC-to-DC converter module to provide DC voltage to the electronics in each car.  So each car is less expensive.

But now you need a light source in the track bed of each platform.  Again, this would be a 10-cent LED that would be controlled by the remote fob.  Upon reflection, you would only need a 1-channel transmitter fob controlled 1 wireless relay that would simultaneously turn on all the light beams at multiple platforms...since if there's no operating car sitting above the light beam then nothing happens anyway!  In other words I'd think you'd not be operating multiple milk cars at multiple platforms at the same time.

rogerpete posted:

I love my k-line milk car. Operates anywhere without a special section and doesn't launch cans into the next zipcode.
Don't know why these k-line operating cars didn't catch on more.

True, however my K-Line milk car is finicky.  I did buy it second hand so there may be an issue I haven't uncovered as yet.  

As for David's original question, I too went through the pain of sliding shoes and K-Line Super-Snap switches.  My yet to be built layout will be totally tubular, as a result of that experiments.

Thanks for the reference, Stan.  I have used that system since that thread for my Lionel log cars (save a prewar car that hasn't enough room), 3 operating Lionel milk cars, and 4 Lionel & 1 MTH coal dumper cars.  System works flawlessly.  Although I started with an infrared theory, is would up using tiny incandescent bulbs between center & outsiderails, located so the car can only unload precisely where it should.