Connecting routed track sections.

[slothead]

This discussion came up in a build thread awhile back and I'm seeking input to finalize the method I'll use for my new oval.

Connecting adjoining routed track sections typically means putting a board underneath that provides a solid place both sections can be screwed or bolted to. However, as was noted in the prior discussion while this ensures the bottoms of the sections are aligned, it will also ensure any differences in thicknesses will be evident on the racing surface where it can cause problems. What's needed is a way to ensure the surfaces are aligned even if there are thickness differences and any offsets are underneath where they will have no effect.

What are some ways this has been addressed?

[WB2]

A router with a slot cutting bit. Cutters are available in various thicknesses and diameter.
Router base goes on the track surface; slot is cut the same dimension down on both pieces.
You then make a spline that is glued into one side of the joint.

[Brad_T]

If there are any differences in the thickness of the MDF you can put a shim under the thinner piece when you fasten it to piece joining the two sections and check the top alignment. The shim could be something as simple as paper or very thin cardboard. This method unlike the method above will mean that you have a piece on the bottom of your track that will not allow it to sit flat on a table if that is what you need.
If you are using screws to fasten use something like plywood, not a piece of mdf, the screw will likely hold very well in the mdf. Bolting is a good option, I used tapered head screws and countersunk them into the mdf, no filling required if you don't go too deep.
I use shims where the sections fold on my track to allow for any changes to the height at the hinge point where two sections butt together.

The picture below has several spacers due to the elevation change on my track. The screw comes up from the bottom and can be removed to add or remove shim material.

[slothead]

This idea might be just what I need to shim up supports for the outer edge of the banked turns.

[slothead]

I exchanged PM's with mattb and this idea occurred to me. Glue & screw tabs on the bottom of sections where they'll connect. Then align the surfaces and slots and lock the tabs together with clamps.

The 2 sections are pictured in shades of gray and the tabs are in shades of blue. The red half donut represents a clamp.



Two small clamps should be able to hold the sections solidly in place while also allowing them to be easily taken apart if needed. The copper tape for each lane can be laid down and around the tabs so when the sections are clamped together they will be pressed together. Wires screwed & soldered to the copper tape can also be used to ensure electrical connectivity. Also, each of the 6 or 8 sections could have a direct jumper connection from the main power taps.

Thoughts regarding this connection method?

[dinglebery]

Great method. One step better is to put some biscuits (if you have a biscuit joiner) in the pieces that get clamped together. This way they can't move vertically.

[slothead]

I've seen how biscuits can be used to securely align and join pieces together, but don't have a biscuit joiner and assume that method is slightly beyond my woodworking skills. Of course, I'm probably just being wimpy because I haven't tried it.

[WB2]

A biscuit joiner essentially does the same thing I mentioned in post #2.
Do not use a beech biscuit if you want to disassemble the joint. The biscuits are designed to swell from the moisture in wood glue during assembly. They will absorb moisture from the air, making the joint hard to pull apart or push together for reassembly.

[Pappy]

Here's how I do it in post number 41. https://www.hrwforum.com/forum/road-...ck-build/page3

First I planed the surface of the 2x4's so they would lay perfectly flat. Using my dado blades on my table saw I cut the groove for the 1/2" MDF keyway that keeps the wood from warping. Put two pieces together with the key in them and temporarily screw them together with two drywall screws. Then I trimmed one edge of the two pieces on my table saw so I would have a square edge. I then ran the two piece through my surface planer with the square edge down to get them the exact same width (they are about 3 1/4" wide now).

Using my drill press I drilled 3/8" bolt holes through the two pieces to bolt them together. Take the screws out and separate the pieces and mark them so you know exactly how they go back together. I screw them to the MDF from the top down and fill the holes with Bondo. I have found that even with wood glue between the 2x4's and the MDF you can knock the 2x4 off real easy which is why I screw from the top down, plus if I make a mistake on where I put my screw I can see it before I hit it with my router. Any variance in the thickness of the MDF sands out real easy with an orbital finish sander.

I'm not saying this is the way to do it all I'm saying is this is how I do it.

[HO RacePro]

The simplest and most rugged way to connect track sections is to screw them down to a table, or a board spanning the joint underneath. Use shims to make a level joint.

If you don't have one already, invest in a 6" digital calipers. I like the Fowler brand -- good quality but not as expensive as Mitutoyo or Starrett. You can get one for less than US$50.

Measure the thicknesses of the MDF before you assemble the joint. That will tell you what thickness shim you will need. Shim material can be purchased online from McMaster-Carr, MSCDirect or Grainger.

To screw the track sections down I use two rows of screws on each side. The first rows are about 1/2" from the track joint. The second rows about 2" from the joint. This helps keep the MDF not only level but square. I recommend screws at either edge of the track plus screws centered between each of the lanes.

I do not recommend using glue in track joints. A properly designed screwed joint will have more than adequate strength. Gluing the joint will make it impossible to disassemble without damage. You want to keep disassembly a possibility. Really, you do.

For joints that are supposed to be permanent, countersunk drywall screws work fine. For joints that will be disassembled I use flat-head machine screws, 10-24 or maybe 1/4-20. Using Tee-Nut Inserts in the table/board underneath make for very strong and stable joints. Tee-Nuts are available from McMaster-Carr and MSCDirect.

You can fill over the countersunk screws with Bondo auto body epoxy. Even screws for joints you might disassemble in future. I have found that you can bust through the Bondo easily with a Phillips screwdriver bit in at power drill, engage the screw and back it out in seconds.

Bondo does shrink a bit so you have to overfill it, but it sands flush easily and takes any paint well. You can also use acetone to remove excess Bondo. Just be careful with acetone. It not only. dissolves paints and plastics, but its vapors are highly flammable. Under the right (wrong!) conditions, explosive! Use with plenty of ventilation and nowhere near a source of ignition. No smoking!

Ed Bianchi

[slothead]

I don't anticipate any of the joints on my oval being stressed in any significant way so this may not apply, but a glued a board under a section joint on my road course and while working on an elevation it broke. The board was a piece of plywood but the surface of the MDF turned out to be the weak link. The section joint had been clamped and glued at least a week earlier and I thought it was bullet proof.

[mattb]

Joe, if you have enough room underneath, You can join sections evenly, with a face piece attached to the under side and end of each section. Then drill a 1/2 inch hole thru both pieces and drive a 1/2 inch dowel rod thru both pieces toward the outer ends. Probably 1/4 inc dowel would work. For a smaller table top track, then a 1/4 inch bolt at each outer edge. The dowel rods hold the vertical and horozontal position of both pieces. This is a easy to do and requires nothing more than a drill. Biscuits and interlocking shelves like Butch does are probably stronger, great for a free standing track, but the dowel rod method works and doesn't require great wood working skill. You will have the track surface above the table level if you do this. The face piece at the end of each section may not need to be more than a 1X2 furring strip. That is not a lot of wood to work with, but for light duty will probably work. To keep track flat, it will need a piece along the side of each section to make and "L" to keep the track from sagging. while the ends may line up flat, the MDF will sag if it is not supported, this could be a 1X along the outer edge to conform to banking and elevation and a shorter piece along the inside of the track or it could lay flat to the table. The size track you are doing, it could be pretty easy to align the slots with some 1/8 stock, turn about 1/2 the track upside down flat on the table, make all your joints and flip it back over. Maybe connect both halves at the center of the straights.

I am not good at describing this stuff. This picture shows how I joined sections together and you could do similar, but with smaller wood. This was a test piece to see how it worked, and it was smooth and solid.

[slothead]

Thanks for the description and photo. This is what I thought about doing as mentioned above. If I do this I'm thinking of using 1x2's (select pine or PVC) as what I referred to as 'tabs' at the ends of sections to mate up as you show. I'll do the same as you with my copper tape and add short wires for plug connectors. Since all the slots on my track are part of the same single lane I can also pool same polarity rails for common connections at power distribution blocks where power taps can connect too. The first version of the track will only have 6 sections which means just 4 joints, 1 at the entry and exit of each corner where a straight section meets up with the corner.

[RichD]

Another way to insure that the track sections will be aligned is to attach scab boards to the ends of the sections. Holes need to be drilled through the scab boards so that bolts can be inserted to hold the sections together. The trick is first to put something in the slots to align the sections horizontally, then flip the sections over on a flat surface to be sure they are aligned vertically before you drill holes through the scab boards. You would want to size the holes so that the bolts would be a snug fit. For tracks that will be taken apart be sure that the sections are clearly marked or sooner or later you will mix them up . This method is commonly used with commercial tracks, it was used with several of the Shoreline Model Raceways tracks, including this one: https://drive.google.com/file/d/0BzL...ew?usp=sharing

[slothead]

Thanks for the link to the Shoreline document. I download it and will check it out in detail.

[Fathead59]

Not sure if this will help , I am planning on building a set of tables with a leaf in the middle for a plastic track set up . To keep them level at the joints I was going to place scab pieces of wood mounted side by side to act as fingers , to lock them together and to keep them from moving side to side , and use door hinges to keep the from separating . The outer two tables will have the legs , center piece would be the leaf .

[SpeedyNH]

i saw another track somewhere that had outside folding leaves that used doorhinges.

[slothead]

Is your design meant to be able to take the track down when not in use and then reduce the table size? If so, and the track is not going to be attached to the table, there are multiple ways you could configure things.

[Fathead59]

The track I plan on using is Scaletrix , so it isn't going to be totally permanent , but after I get the track built I plan on using 1/4 in foam poster board as a border , so if you come onto a corner a little quick you will be able to ride the edge . Just brain storming . The system will be the digital system that Scaletrix makes . So I will be able to run 6 cars at one time . It is all in planning stages right now , I have at least enough track to build it

[slothead]

Some sort of borders are a must for realistic racing. The space inside and outside of the slots on plastic track is too narrow. And, as we all know the borders you can buy to go with any track type are way too expensive.

Do you have a track design in mind yet that you can show a sketch or image of? Or are you waiting to get the table done before you design the track?

[Fathead59]

I bought the Scaletrix bundles from Professor Motor , I also bought a few other sets off of eBay , thinking of making the set up for the bundles and maybe add a little of my own flair to it also . Right now it is all in my head and some of it on paper

[Fathead59]

So to a point it will be semi-permanent , at one time I was going to build a track that could be folded up against the wall when not in use , the wall side was going to have garage door rollers and standards , so I could raise it out of the way .

[Fathead59]

Speedy , the door hinges were going to be used to piece the tables together

[Broman62]

If this hasn't already been mentioned and you are a fan of "Pinterest", go there and check out the tons of pictures and articles about track mating for all different types of track builds!! i just discovered Pinterest a couple months ago and it has soooooo much good stuff to look at and get ideas from...just my 2Cents!!

Post pics of your progress!!

[slothead]

I checked Pinterest and saved some images of sections joints. Was able to get to images of the Parma track building guide and printed out the page on tongue and groove connections. That design, but using a dowel to center sections after ensuring the surfaces are flush has me intrigued.

[Fathead59]

I used Pinterest to build a adult size connect four and Jenga game , so maybe I will use it for the slot car table