T-Nuts For Alignment Pins/Bolts

Since we're building our two modules as a set that will join together, we may want some kind of "mechanism" that will help us to align the two modules when we connect them together with C-clamps. 

Or we may want to do without the C-clamps by bolting the modules together such that they align the way we want them to each time we set them up. The key to this kind of a setup is a threaded bolt slid through a T-nut on one module and threaded into a matching T-nut in the other module.  All we have to do is to tighten the bolt with a wrench, ratchet-and-socket, or nut-driver.   

Modifying T-nuts For Alignment Bolts & Pins
The first step is to drill the threads out of two T-nuts so that a 5/16" bolt will easily slide through one T-nut but thread into a mating T-nut.  

1) Clamp a T-nut into your bench vice with the "washer" part of the T-nut up.  Make sure the T-nut and the vice are securely clamped!  

2) Drill the threads out of the T-nut with a 5/16" drill bit.  Be careful!  The drill bit will grab the threads and try to twist the drill out of your hands!  In the photo below you should be able to see two T-nuts with the thread drilled out. 

 3) Once you've drilled out the threads, you have what I call a "blind" T-nut.  Remove the T-nut with a pair of pliers - the T-nut will be extremely hot!  Make sure the bolt freely slides through the "blind" T-nut. 

4) Drill the threads out of the next T-nut.

5) In order not to mix up these "blind" T-nuts, I paint the washer part and their corresponding bolts with red paint as shown in the photo below so that they'll be obvious when I scramble underneath a completed module set to bolt them together.  (I've made a couple of extra "blind" T-nuts for another module.) 

Marking the End-Plates For Alignment Pins/Bolts
Now that we've modified two of the T-nuts so that a bolt will easily slide through them, it's time to prepare the end plates in a way that ensures our two modules will align together in the same place each time we clamp them together.  To do this, we complete the following steps.

1)  Place the end plate of Module #1 and the corresponding end plate of Module #2 on your work surface with the "Top" down (or "Bottom" up) and the "In" side facing you.  (Or to state it another way, the "Out" sides should both be in.)

2) Make sure the "Top" edge of Module #1 is flush and even with the "Top" edge of Module #2.  

3) Clamp both end plates together with clamps at each end. 

4) Drill and countersink a screw hole at each end.

5) Insert and screw in a 1" flat-head wood screw in both ends so that, when we remove the clamps, the two end pieces will be securely fastened.

This is what the two carry plates should look like.

Locate & Drill Holes For Alignment Pins/Bolts

Now that we've got the end plate of Module #1 lined up with the end plate of Module #2, we're ready to locate and drill the holes for the "blind" and threaded T-nuts. 

In positioning these T-nuts, we have to make sure we have enough clearance underneath the modules so that  our wrenches (socket, nut driver, etc) won't be obstructed by the gussets or the Styrofoam.  For the modules I'm building, I find that the dimensions shown below  - 6" from each end plate and 2 1/2" down from the top - will do the job.  If you're using different widths of lumber or different thicknesses of Styrofoam, you'll have to adjust these measurements accordingly.

1) Measure 6" from both ends and 2 1/2" down from the "Top".

2) Drill a 1/8" pilot through both end plates at each end.

3) Countersink the two pilot holes in the end plate of Module #1 by 1/8" using a 1" Forstner bit or a 1" spade bit so that the "washer" part of the T-nut is below the surface of the wood.

4) Flip the end plates over and repeat Step 3) for Module #2.

5) Drill a 3/8" hole through both end plates at each end.

6) Make sure the barrel of the T-nut fits snugly in all 4 holes.

7) Keep both end plates screwed together!

Installing Blind & Threaded T-nuts
We're now ready to install the "blind" and threaded T-nuts for our alignment pins/ bolts.

So far we've installed T-nuts for the corner gussets and the carry plates.  Installing "blind" and threaded T-nuts for alignment pins/ bolts is no different.  We just have to keep our eyes open for a couple of things.

The end plate of Module #1 should still be screwed to the end plate of Module #2.  (Pssst.  Don't tell anyone but that's the secret in ensuring that both modules will properly line up with each other when we bolt them together!)

We gather the same materials and tools that we used for previous T-nut installations.  This time we will use a 1 1/2"x 5/16" bolt to torque the T-nuts into place. 

1) Make sure you have 2 "blind" T-nuts and 2 threaded T-nuts.

2) Load the barrel of a "blind" T-nut with epoxy and insert it in one of the drilled holes for Module #1.

3) Load the barrel of a threaded T-nut with epoxy and insert it on the opposite side of Module #2. 

4) Insert the 1 1/2 bolt through the "blind" T-nut and thread it into the threaded T-nut until it's finger tight (now you know why we painted the "blind" T-nut red, eh!?)

5) Using a 1/2" wrench (ratchet & socket, nut driver, etc), torque the T-nuts into place until they are snugly tight.

6) Remove the 1 1/2" threaded bolt.

7)  If I'm using bolts to connect Module #1 to Module #2, I prefer to alternate the "blind" T-nuts.  That is, one blind T-nut will be installed in Module #1 and the other one will be installed in Module #2.  If I'm using alignment pins, I install both of the "blind" T-nuts in Module #1.  In this case, I want to use bolts to connect Module #1 to Module #2 so I'll alternate the "blind" T-nuts.

8) Repeat Steps 2 to 6 but inserting the "blind" T-nut into Module #2. 

9) With the "blind" and threaded T-nuts securely installed, remove the two 1" screws that are holding the two end plates together.

The end plates should look like those shown below.

In our next blogs, we'll take a look at some Digitrax UP3/5 panels and work on some RJ12 telco jacks. This is in preparation for cutting and recessing holes in our side pieces so that we can install the Digitrax LocoNet

Carry Plates - Locate & Install T-nuts

We probably should have posted this blog a couple of days ago before we got into the T-nuts for the alignment pins/ bolts.  However, better late than never.  Today, we're going to install another set of T-nuts for our "carry plates". 

We're building two modules that we'll be able to "box" together with some plywood carry plates.  This will make transportation of our modules a whole lot easier and will protect the track and scenery.  In case you can't visualize what I'm talking about, here's my Bancroft and Irondale modules bolted together as a "boxed set" by the carry plates and four 5/16" bolts. 

I'm going to fasten the plywood carry plates to the ends of the finished modules with 5/16" bolts.  These bolts will screw into T-nuts that we'll now install into the end plates of our two modules.

If you're going to use your carry plates for stabilizing your legs when you set up your modules, you might want to use 1/4" T-nuts, as the bolts can do double duty.  Regardless of the size of T-nut you use, the procedures are the same. 

Step 1) Place the end plates on our work surface so that we are looking at the side marked "In".

Step 2) - Measure and mark the location of the holes for the T-nuts at 1 3/4" from the "Bottom of each side as shown in the photo below.

Step 3) Drill a 1/8" pilot hole at each end of the two gussets so that subsequent drilling operations line up.

Step 4) Counter-sink the holes by 1/8" so that the head of the T-nut will be below the surface of the end plate using either a 1" Forstner bit or a 1" spade bit. As you finish each hole, lay the head of the T-nut into the cut and make sure you can't see any of the head when you scan across the surface. (Protruding T-nuts will impact the accurate assembly of the pieces of our modules.)

Step 5) Clamp the end plate on top of a scrap piece of wood to reduce splintering when the drill bit breaks through the other side. Drill 3/8" holes right through the wood so that the barrel of the T-nut fits into the hole.

Step 6) Test fit each hole by pressing the barrel of the T-nut into the hole. You should have a nice tight fit.

Step 7) Locate and drill holes for the T-nuts on the two end plates of our second module.

Here's what things should look like after we've finished our drilling.

Step 8) Epoxy the T-nuts following the steps in our blog on "Installing The T-nuts". 

Here's what things should look like after we've installed the T-nuts. 

We're showing one of the end plates on Module #2 because we'll need this end plate for installing T-nuts for alignment pins/ bolts. These alignment pins/ bolts will be quite handy in making sure our completed module (track, scenery, etc) aligns up with our second module when we bolt/ clamp them together in a setup/ show. We continue that installation in our next blog.

Drilling The Screw Holes

So far, we've marked the end plates and side pieces for the screw holes (including holes for the middle cross members).  If I count the number of holes I've marked, I should have a total of 40 holes that need to be drilled.

Your pieces of wood should now be marked up as shown below.

Our next step(s) will be to drill holes for #6 Robertson flathead wood screws 1 1/2" long.  Drilling the holes will be either a 1-step or a 2-step operation, depending on the kind of drill(s) you have.  I use an all-in-one drill with "countersink" (formally known as a "screw digger set" that I got at my local Home Hardware, catalogue #1227W540).

You may be tempted to use gyproc screws.  Please don't.  The countersink on a gyproc screw is entirely different from that of a regular wood screw.  The gyproc screw is designed to hold gyproc in place so it has a flare, rather than a 60 degree angle, on the countersink.  If you use gyproc screws in pine (or spruce), it will crack the wood with that final torquing. 

If you don't have a combination drill/countersink, first drill pilot holes with a 1/8" drill bit followed by a 1/4" drill bit.  Be careful when countersinking!  We only want to pierce the wood a bit.  When we install the screws, the screw head will more than disappear below the surface of our wood.

Here's a closeup of some of our drilled holes.  Make sure your holes are 90 degrees in all direction to the surface of the wood.

And here's what the final product looks like. We've included the end plate of our second module in the photo as we'll need that second end plate when we install some more T-nuts for alignment pins/ bolts. 

Next we install some more T-nuts for carry plates (pieces of plywood that will make a nice boxed set of our two modules).

PS - Here's a tip on how to easily clean your track - something called "rust erasers".

Locating The Screw Holes - Side Pieces & Middle Cross Member

Locating The Screw Holes On The Side Pieces
In locating the screw holes for the side pieces, we follow the same procedure as we did for the end plates - with an added exception.  The side pieces will be sandwiched between the end pieces when we assemble the wood.  This will add an extra 3/4" that we have to account for when locating the screw holes for the side pieces as shown in the photo below.

To account for that extra 3/4", we make use of one of those extra pieces of 1"x 2" that we had cut with our cross member in one of our earlier blogs.

1) - Place the side piece "Top" down on your work surface and "Out" facing towards you.

2) - Place the piece of 1"x 2" alongside one end of the side piece (it actually measures 3/4"x 1 1/2") and draw a vertical line.

3) - Place your 2" (or 1 1/2") block of wood alongside one end of the side piece.  Draw a straight line along the edge about 8-9" long.

4) - Place the marked gusset on top of the block and draw a line along the top edge and the side edge of the gusset.  (You have now roughly located where that gusset will go.)

5) - Transfer the locations of the screws from the marked gusset into the lines marked on the side piece as shown below.  

6) - Complete the location of the screw holes by drawing a line mid-way between the two long lines as shown below.

You don't have to be exact to the 1/64", 1/32" or 1/16"of an inch in locating the screw holes.  The accuracy will be in locating the gussets which will be covered later on.  We've now completed locating the screw holes for one end of the side piece.

7) Place the marked gusset alongside the end of the side piece as shown in the photo below.  Transfer the locations of the screws from the marked gusset into the end and the line marked at the end on the side piece as shown below.   Complete the location of the screw holes by drawing a line mid-way between the line and the end as shown below.

8) - Repeat Steps 2 ) to 7) for the other end of the side piece.

9) - Repeat Steps 2) to 8) for the side piece.

10)  Your side pieces should resemble those shown below.

Our next step is to locate the screw holes for the cross member(s).

Locating The Screw Holes For the Middle Cross Member(s)

We've been spending some time locating the screw holes for the various pieces of wood.  In reality, the whole process takes less than an hour.  Imagine how fast we'd be moving if we were building a whole bunch of modules!  Zoom! Zoom!  Those modules would be built, ready to install the track in no time flat.

But.....  we've got one more set of screw holes to locate -the ones for the middle cross member(s).  If we're building a 4' module, we'll want one middle cross member.  If we're building a 6' module we might want two middle cross members.

1) - Place the side piece "Top" down on your work surface and "Out" facing towards you.  Using a tape measure, mark the mid-point of the side piece as shown in the photo below.  For a 6' module we will mark the 2' and 4' points of the side piece. 

2) - Place your 2" (or 1 1/2") block of wood on either side of the mid-point mark that you just drew on the side piece.  Draw a straight line along the edge about 5-6" long.

3) - Place the piece of 1"x 2" wood on top of the 2" (or 1 1/2") block and line it up in the middle of that mid-point mark.  Draw a line along the top edge and both side edges of the 1"x 2".  (You have now roughly located where the middle cross member will go.)

4) - Divide the rectangle just drawn into thirds.  Mark each third with a vertical line as shown below.  This marks the location of two wood screws that will hold the middle cross member in place. 

5) - Complete the location of the screw holes by drawing a line mid-way between the two long lines as shown below.

You don't have to be exact to the 1/64", 1/32" or 1/16"of an inch in locating the screw holes.  The accuracy will be in installing the middle cross member(s) which will be covered later on.  We've now completed locating the screw holes in the side piece for fastening the middle cross member. 

6) - If you're building a 6' module, repeat Steps 2) to 5) at the 2' and 4' mark on the side piece.

7) - Repeat Steps 1) to 6) for the other side piece. 

The side pieces should now be marked up as shown below.  

Next up, we drill the screw holes. 

Locating The Screw Holes - End Plates

Jigs - The 2" (or 1 1/2") Block of Wood
One thing I've learned in doing carpentry and machine shop work is the importance of "jigs".  They make life so much easier when it comes to assembling bits-and-pieces of wood and steel.  We'll be using a couple of jigs to simplify our work, act as a 3rd-hand, improve our accuracy, and make the project more enjoyable. Our first jig is simply a block of wood 1 1/2" thick (if we're using 1 1/2" Styrofoam) or 2" thick (if we're using 2" Styrofoam) and about 12" or 18" long.

Take a piece of 2"x 4" or 2"x 3" economy or construction grade spruce over to the saw service and get them to chop the lumber into several pieces - about 4 pieces should do the job - that are 12"-18" long.  Next, get them to rip the blocks in pieces that are 1 1/2" or 2" thick (depending on whether we use 1 1/2" or 2" Styrofoam).  It's okay if the thickness is a bit more than the 1 1/2" or 2". But it's not okay if the thickness is less.

We now have a bunch of wooden blocks - jigs - that we will use to mark the location of our screw holes and to help us assemble the bits and pieces of wood together. Take a pen and mark the thickness as we've shown below. A picture's worth a thousand words, so here's a few hundred.

Locating The Screw Holes - End Plates
Our module frame will be held together with wood screws and wood glue.  So, we need to locate the holes for the screws.  We'll start off with the End Plates as they're the easiest to do.  It will give you a good idea of how we locate the holes for the other pieces.

1) - First you need a good flat work surface.  Make sure there's no sawdust crumbs, glue blobs or other obstructions on the surface as these will throw everything out of kilter.  

2) - Next we make a screw-hole marker (our second jig).  Take one of the triangular gussets and make a mark at the 1 1/8" point from each end and in the middle as shown below.  We'll be using this marked gusset to locate the screw holes.

3) - Place the end plate "Top" down on your work surface and "Out" facing towards you (now you know why we marked each piece "Top", "Bottom", "In", "Out", eh!?).

4) - Place your 2" (or 1 1/2") block of wood alongside one end of the end plate.  Draw a straight line along the edge about 8-9" long.

5) - Place the marked gusset on top of the block and draw a line along the top edge and the side edge of the gusset.  (You have now roughly located where that gusset will go.)

6) - Transfer the locations of the screws from the marked gusset into the lines marked on the end plate as shown below.

7) - Complete the location of the screw holes by drawing a line mid-way between the two long lines as shown below.

You don't have to be exact to the 1/64", 1/32" or 1/16"of an inch in locating the screw holes.  The accuracy will be in locating the gussets which will be covered later on.  We've now completed locating the screw holes for one end of the end plate.

8) - Repeat Steps 3 ) to 7) for the other end of the end plate.

9) - Repeat Steps 3) to 8) for the other end plate.

10)  Your end plates should resemble those shown below. 

Simple, eh!?

Next we mark the screw holes for the side pieces and middle cross member using the same procedures - but with a slight adjustment.

End Plates, Side Pieces & Middle Cross-Members - "In" & "Out", "Top" & "Bottom"

We've previously looked at our triangular gussets, installed some T-nuts and marked each side of the gussets as "Top" or "Bottom".  In the next number of posts, we're going to work with the remaining pieces of wood that make up our module frame:

• Middle Cross-Member - the piece that's 1 1/2" wide, 3/4" thick, and 22 1/2" long.
• End Plates - the two pieces that are 3 1/2" wide, 3/4" thick, and 22 1/2" long.
• Side Pieces - the two pieces that are 3 1/2" wide, 3/4" thick, and 48" long.  

Mark The Wood - "In", "Out", "Top", "Bottom"!
As we go through the next steps, we'll be marking our pieces as "In" or "Out", "Top" or "Bottom" with a Sharpie marker. 

For our End Plates and our Side Pieces, we'll refer to the 3/4" wide part as the "edges" - as in "Top" edge or "Bottom" edge. And we'll refer to the 3 1/2" wide parts as the "In" side or the "Out" side.  

I can't stress enough the importance of marking each piece of wood.  A few minutes spent marking each piece is going to save us grief later on. 

Getting The Best Edge On "Top" And The Worst Edge On The "Bottom"
The idea here is to make sure we've got the best 3/4" edge on the top.  Once we've decided, we'll mark each of the 3/4" sides of each piece of wood as "Top" and "Bottom".  

If both of the 3/4" edges are nice and straight, it's a simple matter of flipping a coin and marking that edge as "Top" (on both sides) and the other edge (on both sides) as "Bottom".  If one of the 3/4" edges bows up and the other edge bows down, then the edge that bows up (carpenters call it the crown) is the "Top".

Getting the Best Side "Out" And The Worst Side "In"
In getting the best of the 3 1/2" sides of our wood on the "Out" side, there are two things we have to consider.  

Firstly, wood has a tendency to "cup" or "crown" along the wood grain as shown in the exaggerated graphic below.  

We want the "cups" marked "Out" and the "crowns" marked "In".

Secondly, wood has a tendency to curve "In" or "Out" along it's length.  For our 48" side pieces and our 22 1/2" end plates, we want the curves to curve "In".    

For our 48" side pieces, we want curves swinging into the middle of the module as our middle cross member and the gussets will "push" the curve out.

For our 22 1/2" end plates, our alignment bolts or clamps will pull the adjoining modules together.  We can also do some sanding of each end so that we can minimize any curves.  

We may find that the cupping conflicts with the curving.  The curving is easy to fix whereas the cupping is more difficult.  Given the choice between cupping and curving, the cupping will take priority.  Cupping will be on the "Out" side.  

If the wood has blemishes, gouges, or knots, the can usually be fixed with some plastic wood or epoxy before we start assembling the pieces.  If it's going to be difficult fixing these, we want these to be on the "In" side, keeping in mind that cupping takes priority over all.

Once we've decided, we'll mark each  3 1/2" side of each piece of wood as "In" (as in "Inside") and "Out" (as in "Outside") using the above criteria.  When we've marked our pieces of wood, they should look like the pieces below.  

The end plates will be butted up against other modules in a setup so it's very important that we get the "best" sides on the top and on the outside.  

Middle Cross Member

Let's next take a look at the 1 1/2"x 3/4"x 22 1/2" middle cross member.  It's installed on the underside of our module frame and is going to serve a number of purposes.  

Firstly, our modules are going to be lifted in and out of our vehicles, carted up and down stairs, and man-handled from one end of the hall to the other.  The middle cross-member is going to provide extra ruggedness to our modules so as to withstand all kinds of rough treatment.

Secondly, as we build our modules, the sides may bend in or out so the middle may vary between 22 3/8" and 22 5/8". The middle cross-member will keep the middle of the module at 22 1/2". For a 4' module, I use one cross-member. For a 6' module, I use two cross-members.

Thirdly, we'll be running some wires (called the track power buss and track feeder wires) and telephone cables (called the LocoNet) on the underside of our modules.  We need to keep them neatly tucked into place.  If we cut a notch into the middle-cross member, we can now thread these wires and cables through the notch.  (More on the wiring and fastening them to the underside of the module later on).

The notch in the middle of the cross member are a series of cuts so that we end up with a notch that's 1/2" wide and 1/4" deep in the middle of the 1 1/2"x 3/4"x 22 1/2" middle cross-member".  How you cut it out will depend on the tools you have (hand saw, table saw, chisel, etc). The notch will go next to the Styrofoam. To make sure we install the cross-member properly, we mark the side that has the notch as "Top".

Here's an exaggerated graphic of that middle cross member to give you a better idea of what we've been talking about.

And here's a photo of what our middle cross member actually looks like.  

Next up, we locate and drill the holes for the screws.