Dick should steer you right as far as the products to use. He runs a good business. Several years ago he was at the Timonium MD train show and I think I ended up spending 2+ hours sitting at his booth talking train electronics with him and getting demos of his products. The club layout has several of his Tower Controllers and the BOD-8 current transformer detectors.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Yes Dick is a great guy and has helped a ton. I already have a list from him on what I need. Also ordered the two MR Craftsman mags with the signal articles in them. Waiting for Atlas to finish the BLMA take over so I can start ordering signals. I really like BLMA's stuff.
Two questions now for you guys. Do you have a brand or style of wheel resistor you like? I know there was a couple different styles out there and ways of doing it.......
And any recommendations on blocks? Setting them up? Or where they should be?
I'm still struggling since it's just a round donut style set up of not going crazy and putting 30 signals on a layout. I want to see more than just signals......
Mike
I was using all P2K wheelsets except for the odd car here or there that needed a different axle length. That worked out great until I started adding resistors to wheels for detection on the club layout - the slippery plastic used for the axles is not your friend here. Though I did get them to work reliably and so far they have held up - mainly because after they were workign I sprayed the axles with flat black paint to seal in the conductive paint.
In the future I will probably use Intermountain wheelsets - the axle is also metal, so you can just glue on a surface mount resistor at an angle bridging the insulating ring around the one wheel.
TO do the P2K's, I used I think 0603 size SMD resistors. A TINY drop of super glue glues them to the middle of the axle - if the glue oozes over the ends, it will insulate the connections and it will never work. I use thick CA and a toothpick to put the tiniest of dabs on the axle and then set the resistor in place with forceps.
Oh, before gluing on the resistor, I take a small burr in my dremel and scratch off the blacking on the back of each wheel, and also to rough up a line across the axle in line with the cleared spots on the wheels. The resistor gets glued in the middle of the roughed up line.
I picked up some silver paint on eBay - warning, this stuff is not cheap, but I got the smallest bottle and did over 100 wheel sets and still had half of i left. It may have dried up now that it's been sitting for a couple or years. I got the stuff that is 18% silver - yes, it's real silver. I think next time I will get the 36% silver, but the 18% worked fine. It's sold for use with electron microscopes.
I use 10K resistors - 2 axles per car. The club standard is a single 4.7K per car, but at least on longer cars I like to have both ends detectable if it spans a block boundary, and the detectors we have will detect a single 10K across the tracks. If the whole car is in the same block, it has an effective 5K, 2x 10K in parallel.
AFter the CA dries, I paint a line from each end of the resistor to the wheel with the silver paint. This is where the slippery plastic is a pain - even rouched up, the silver tends to be repelled. DOn't try to slop too much on at a time, if ti runs under the resistor or over it you now have a short. I usually do two coats before it appears like there is a solid silver line. Then you need to let it fully dry - the first few I made I thought I was messing them up since I put them on a piece of track connected to my multimeter and was getting open circuit no matter how much I slid the wheels around. It takes 15-20 minutes or more for the paint I used to actually dry - at which point I started geting the expected 10K resistance, give or take the 10% tolerance of the resistors. I also found that to work flawlessly withotu applying weight to the wheels, I needed to polish the treads, I did this with the fiber wire (not the steel fiber) wire wheel in my dremel. Unpoliched, even with two wheelsets (that tested good) in a car that was actually slightly over the NMRA weight, I would ahev to push down ont eh car to get the resistance to read. After polishing the treads - just the weight of the car gave successful reads. WHen I have a workign wheelset, I put it in my wheel painting jig and spray over the conductive paint and resistor with some cheap flat black so you don;t have this silver band flashign under the car as it runs.
It took me way longer to type this than it does to make a resistor wheelset (not counting the waiting for paint to dry). The first few went kind of slow but once I got the hang of it I breezed through the rest of them. My one wheel painting jig holds 4 wheelsets each easily accessible (the other hold 8, but 4 of them are below the other 4 so you cna;t really reach in to glue resistors). So I load up 4 wheelsets, do the Dremel part, glue the resistors on amd while waiting for the CA to dry I do the next 4. Then back to the first 4 and paint the silver paint on. Then they get set on the test track connected to the multimeter until I get a reading.