Solenoids

Manufacturers of The Judge timers. Also manufactures solenoid start gates and light trees.

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John Shreffler
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Solenoids

Post by John Shreffler »

There seems to be an interest among the do-it-yourself crowd for solenoid powered starting gates. I am offering the same solenoid that is used in my line of solenoid gate latch mechanisms. They come with an elbow latch and tips on how to use them. $26 including shipping.
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Tubular solenoids are fine for tripping latches. Several years ago I was offering a "Full Motion" design using larger tubulars to open a gate against a spring strong enough to hold back the cars. It worked OK, but there was a major drawback: Tubular solenoids rapidly lose pulling power as you withdraw the plunger. Unfortunately, you need the maximum pulling power when the gate is closed and the plunger is extended. My remedy for this was to store power in a bank of capacitors to dump energy into the coil immediately. While effective, it added to the complexity.

I recently made a major purchase at a liquidation sale of a batch of Ledex rotary solenoids, and will be developing again a line of Full Motion start gates for various tracks. Image

The beauty of a rotary solenoid is that the torque is very high right from the start. The power of these are amazing. If you want to research them, go to Ledex.com and you will find all kinds of great info. The size of my units are 5S, about as big as a billiard ball. I will sell them separately for $54. This may sound pricey, but check with Ledex to see how much they will cost you to buy them there. Be sure you are sitting down.

The rotary solenoids will be integrated with a power conditioning unit which will accept inputs from light trees and GPRM signals. Image
The following picture shows this unit powering a 6 Lane Hot Wheels gate in a test jig as the geometry of the linkage is being worked out. The principles of operation should be clear from this photo. There is plenty of power to use on Pinewood tracks. It directly drives my 6 Lane BestTrack, for example. Image

Update 3/2/11: The Hot Wheels track that this gate went into is now in use, and is a fabulous piece of carpentry. See a video of it:
http://www.youtube.com/watch?v=gX47A4MR ... s5lCbPmGI=" target="_blank
Last edited by John Shreffler on Sat Apr 07, 2012 8:00 pm, edited 4 times in total.
John Shreffler
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Re: Solenoids

Post by *5 J's* »

John - what are the specs on the Tubular solenoids? Are they 24V or 12V? It appears from the picture that they take a special plug.
John Shreffler
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Re: Solenoids

Post by John Shreffler »

They can run continuous at 12 volts but I zap them with 30, and get ten times the yank. If you hit them with that for a second every 2 minutes, they will stay cold. Solenoids are robust, unlike most other components where you have to watch your voltages. It is rare to find a complete spec on this point. Ledex is an exception: they give you a complete table for each coil the voltage/duty cycle tradeoff. As for the connection, I have been soldering #24 teflon to the gold terminals and backfilling that cavity with black 5 min epoxy. If interested, I will ship yours that way. Here is the same solenoid on my Model BTG-2 for the BestTrack. I did try to find a mating connector but no luck. Then I noticed that on all my designs, a connector would just get in the way. For example here it would get tangled in your wrench for the mounting nut.
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I clip a little piece of LDPE (think Tupperware) to the entry port as a dam, and add a few drops of epoxy to the cavity top side. Also, it is used where the wires go through the hole. Great stuff, Johnny B Quick, Home Depot.
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John Shreffler
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