Routing an existing track switching to braid

[Modlerbob]

I have a problem and I am seeking the best solution. My mdf track, Debary Glen, has been in operation for over three years now using copper tape to transmit power to the car. We have had to replace it once so far. The current copper tape is reaching the point where it has so many patches it is hard to keep all four lanes operational. So I have decided to buy tinned copper braid to replace the copper tape. I would go with steel braid but it is way too expensive. One of my racing buddies has purchased a router that is small enough to rout the outside lanes without removing the railings but we still have a problem to solve. That is, how to rout the underpass without dismantling half the track. One solution is to cut away the section directly over the underpass, rout the lower track and reinstall the upper track which would involve resurfacing some of the track at the joints. A second solution is to cut the lower track, pull it out and rout it and then reinstall it. Again, it would involve patching the surface where it was cut, but at least it is firmly attached to the table and doesn't need to be supported in the air. A third solution is to leave the copper tape in place in the underpass and install wiring to insure continuity. The tape in the underpass hasn't caused any problems in the past. The last solution we have thought of involves detaching the pier supports for the overpass from the table and temporarily installing support posts elevating the overpass high enough to get the router underneath. Two problems I see with this option are a) the stress may break the location where the mdf sections are joined and b) the difficulty of running the router through the opening and getting a neat straight cut.

So does anyone out there see a better method for solving this problem. I want to make sure we have the best solution planned before ripping out the first inch of copper tape. I don't want the track out of commission for more than a couple of days.

I will be getting the supplies I need from Slot Car Corner, the copper braid, router bit and power connectors.

[Pappy]

Bob, could you post a picture of the underpass?

[chappyman66]

Bob,
I think you hit all of the choices. I don't know of a compact or right angle router that would fit under the bridge.
For my money, I would leave the tape in place; if you set the gain right on the braid it will be so close that the cars don't notice the transition.
But, that is my opinion.

[nhdungeonracer]

[Modlerbob]

[Pappy]

Bob,

First thing I would do is un-screw the masonite covering up the sides of the overpass and see how it is constructed. it might be as simple as using a saber saw and making two cuts across the track. It wouldn't make a very wide cut and as nhdungeonracer said you wouldn't have to resurface the joints. All you would have to do is screw a splice across the joint at each end. It looks like there is already a piece of plywood across one joint, you might be able to unscrew it and replace it with a new piece after you cut that one in half. On the other end it looks like you might have room for an L shaped splice piece. Actually you could probably use an L shaped splice piece on both ends.

Another option would be to use a utility knife and a straightedge to make a shallow cut where you want the edge of the braid to be and use a wood chisel to remove the waste. MDF board has no grain and it would probably chisel very easily if you are real careful and have a sharp chisel. You are only going to remove about 20 thousands thick of material.

[Modlerbob]

Pappy, I know how it was constructed as I was there when it was assembled after moving from the previous location. One thing I'm afraid of regarding removing a section of the overpass is the amount of tension it was put under when we assembled the track creating some banking in the curve.

[Pappy]

Bob, I don't think that is going to be a problem. MDF board has no grain and will eventually just stay the way it is bent.

[buspor63]

If time is not a concern, I would remove the bridge. You only one time to do it right. You could cut the bridge section back away from the lower roadway and build a ledge for it to attach to. I did that on my track, the bridge is held in place by four drywall screws. Power is continuous by lap joint, the same may work for braid.

[mattb]

Probably the easiest way to do it is just take a sabre saw and cut out the over pass. Once it is out, it will be easy to rout for braid. Do the same with the overpass by itself, not mounted back to the track. Stand back and look at the track for awhile and you will see an easy way to mount it back as it should be. Probably the material removed when it was cut out will not be enough to worry about.

Best just to cut it out and you will figure a way to mount it back.

[Modlerbob]

All of the material is now in hand but a problem has made itself known. The existing routing on the straights isn't quite 1/8" wide so the tip on the router blade won't slip into the slot. So, I bought a 1/8" router blade. I've been told that getting the existing slots routed out to 1/8" will be a challenge requiring extra care to achieve smoothly.

[Pappy]

Bob,

The slots in the straights could have been cut on a table saw and most table saw blades these days are only about 3/32" thick. Not a big problem. Just use a straight edge and an 1/8" bit. You might want to purchase a template guide for your router, then you'll have more room for your straight edge. I'd just screw the straight edge down to the track with drywall screws and then fill the holes when you're finished.

[chappyman66]

Keeping the slots clean is easy. All you need is a router base wide enough to reach the next lane with a pair of guide pins (like the tape laying tool). The guide slides along one slot and the router bit cleans up the other one. Keep moving over a lane to get all the lanes.

The routing shouldn't take long sine you are removing very little material.

[Modlerbob]

Well, after a few delays, we now have one lane routed and braided. One down and three to go.

[waaytoomuchintothis]

I'll be watching. This is coming up for me late this summer.