1. Home
  2. Model Railroad Forum
  3. Sector plate construction

Sector plate construction

I'm building a two-rail O scale timesaver based on Emrys Hopkin's "Less than Four Square Foot Timesaver" found on Carl Arendt's web site -

formatting link
then "shelf switchers" and "dense track" Has anyone out there built a layout using a sector plate that can provide advice on the following?

Bearing surface - I plan to use a cut down piece of 1 x 4 for the sector plate. The easy approach would be to let the moving end rest on the benchwork 1 x 2 that will be supporting the adjacent homosote yard surface, but I wonder whether wood sliding on wood will provide smooth enough operation of the sector plate, so there is little risk of derailing cars parked on the plate. I'm debating putting a strip of sheet metal or maybe plastic on the fixed 1 x 2 to be a smoother bearing surface, or maybe just wax the wood surfaces. Any advice?

Detent - I want to make sure the sector plate does not slip when aligned to the yard tracks to prevent derailmants, but because the plate will be used frequently while operating, I don't want a cumbersome alignment device like a door latch bolt. Will friction be sufficient, or do I need a detent? I've thought about perhaps recessing a 1/4" steel ball on the bottom of the sector plate so a little protrudes, and let this fit into dimples on the bearing surface at the proper alignment positions. Any better ideas?

Thanks. GQ

Reply to
Geezer
Loading thread data ...

On Tue, 2 Dec 2003 11:04:56 UTC, "Geezer" wrote: 2000

Wood on wood works. Just look at the drawers in a nice piece (read older) piece of furniture. Make at least one of the pieces hardwood. It will work much better and by all means wax it. Use something like paraffin that won't soak in and rewax often. There should be no build up as the new wax will dissolve the old wax. Rub it out nicely using a piece of paper bag.

The ball detent should work nicely. What I would do is drill a hole in the support piece and use the ball and a compression spring. It would work a lot better if the dimples in the sector plate were ball shaped. That way the ball would not hang up. Perhaps pressing a ball into the sector plate would give the right shape. Make the detents first then lay the track.

Reply to
Ernie Fisch

I have to admit that I've never built a sector plate, but the idea of how I would approach it has passed through my mind.

As the son of a cabinetmaker, I would try make both bearing surfaces using plastic laminate on a wood backing.

Formica

formatting link
is probably the most familiar brand name, but there are others who make plastic laminate, too. I suspect that most home improvement stores carry the material or you might have luck by contacting a custom cabinet maker in your area - Formica kitchen tops are usually made as a whole and then the sink openings are cut-out afterwards, so you might be able to get two sink cut-out pieces as scrap.

Plastic laminate comes in several finishes - my thoughts would be to use a gloss finish as the bearing surfaces. It will slide easily enough by hand but the weight of the sector plate would still be enough to hold it in place for train operation. The laminate is bonded to particleboard or medium density fiberboard (MDF) with contact cement (I think we always used 5/8" particleboard for Formica); since limiting warp is important I'd do the same for a sector plate. The lower bearing surface (with the Formica on top) can be a board braced with a couple of 1x2s or similar underneath and mounted to your layout; the upper bearing surface (with the Formica on the bottom and the tracks on top) can just sit on the lower bearing surface.

I would make the lower bearing surface as large as the movement of the sector plate required -- i.e. the entire sector plate was bearing on the lower bearing surface.

Reply to
Mark Mathu

Brass code 100 flex track: save it from a landfill (or vice versa); maybe some old deep flange Euro HO trucks. Or a local plastics fabricator might part with some scraps of that really greasy feeling stuff

I like your sprung ball in sub-diameter hole detent idea. Or you could try a solenoid plunger that sticks into a countersunk hole (tapered entry) in an adjustably mounted little block of metal or hardwood on the fixed side.

Reply to
Steve Caple

Look at cabinet latches in the hardware store or lumber yard. There are spring loaded balls and spring loaded rollers that you may be able to adapt. A magnetic latch might be an option.

Reply to
<wkaiser

Thanks for the responses. I'm going to check my home supply outlet for spring loaded latches, look for a piece of hardwood for the "track" for the sector plate, and look at waxes. It's really easy to takes the group's advice when it helps amplify and clarify one's preconceived notions! GQ

Reply to
Geezer

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.