JR's Place - JoeCool's 1987 Ford Thunderbird Turbo Coupe - Motor Trend's 1987 Car of the Year

Build Your Own
Custom Instrument Cluster

Mechanical Construction and Considerations





Obtain a second-hand instrument cluster (IC) somewhere; mine cost me $35 from a NATO member. Electrical condition is not an issue, although you do need it to be mechanically sound. Also the condition of the clear plastic cover is not an issue either because it's not used with the custom cluster (CC); the Sport-Comp gauges protrude too far to let it fit back on.

Begin by carefully dismantling the cluster into as many pieces as possible. Remove and discard all the old gauges, the IVR, and the flexible wiring interconnect (FWI); however, if you want to try to use the old FWI for connecting the new gauges in the CC, set it aside and see my afterthoughts at the end of this article. Also, if you'll be including the firm ride LED in your CC, set it aside for reuse too.

Click for BIG pic - dialup beware!

Now you should have two main pieces that will be reused; the black plastic front bezel with the old gauge cutouts and markings (bezel), and the rear white thermoplastic housing that housed all those crummy old gauges. Now you need to decide what material will be used for the new front surface of the bezel. What is needed is strength and rigidity without a lot of thickness so that the new gauges mount securely but don't protrude too far. The choice will pretty much be a matter of personal taste and what you're comfortable working with. Choices include aluminum, steel, fiberglass-epoxy, and a plethora of other panel materials.

I wanted a carbon-fiber look, but a little research quickly convinced me that I didn't want to spend that much on the new bezel; manufactured carbon fiber sheets are expensive! So I took a trip to the local surplus store where I found a sheet of thin PC board (fiberglass-epoxy) material that cost a whole $4.00. It was easily large enough to cover the bezel twice over, which was a good thing because it was only 0.032" thick and was too flimsy to use alone. I cut it in half and created a double thickness panel using some 30-minute epoxy and bricks for clamping, creating a laminated panel which took care of the thinness problem neatly.

The dilemma now was that the panel was copper-clad PC board material painted flat black, but I still wanted that cool carbon-fiber look. I journeyed to a local hobby shop where I found some single-cloth thickness carbon fiber "accent panels" that cost about $7.00 each. These were laminated to the previously made PC board substrate, and presto! I had a panel about 0.072" thick that looked like a carbon fiber sheet, didn't cost an arm-and-a-leg, and was plenty strong enough to be the new bezel.

Click for BIG pic - dialup beware!

Now the hard part started: trimming the newly-made rectangular panel down so that it would fit just inside the edges of the existing bezel. This portion of the project began by making a thin cardboard template that fit inside the stock plastic bezel as snugly as possible. I used an old business folder that was laying around, and I carefully trimmed it so that it fit perfectly into the old bezel. Make sure that the bottom fits parallel and as tightly as possible to the bottom of the old bezel; thats where all the measurements for mounting the gauges will originate. Mark the positions of the mounting screw holes and the plastic locator pegs and cut them out of the template as well.

Click for BIG pic - dialup beware! Click for BIG pic - dialup beware!

Once the template is perfect, transfer it's outline onto the new bezel material. Then carefully cut and shape the blank. I used a band saw for cutting and then perfected the size and shape using a stationary belt sander and some sanding drums on a Dremel mototool. You'll want to cut and drill out the areas for the mounting screw holes and the plastic locator pegs now too.

Click for BIG pic - dialup beware!

The next step is to mark up the rear of the new bezel with the locations at which holes will be drilled for the turn signal indicators, the high beam indicator, and the firm ride LED. I omitted the firm LED from my CC for a couple of reasons: First and foremost I plan on removing the PRC struts in a future project and replacing them with a coil-over suspension; second, I always use the firm setting anyway.

The locations for the turn signal and high beam holes are easy: First carefully remove the plastic inlays in the old bezel that provide the arrow and lamp images and set them aside. A little note of caution here - I misplaced mine and when it was time to reinstall them, the little buggers were really hard to find! Next place the new bezel in position in the old, and from the rear of the old bezel carefully mark the proper hole positions onto the rear of the new bezel using a permanent marker or whatever scribing device you'd like. My choice was a 0.7 mm mechanical pencil with nice soft lead. Remove the new bezel and flip it around so you can work on the back. The next step is to locate the horizontal (left-right) center of the available area. Since the high beam and the turn signal holes were very carefully transferred to the bezel rear, those points will be used to determine the proper line. Carefully locate the center of the high beam hole and make a mark. Make another mark centered between the turn signal holes. Now draw a line between the two marks that is exactly perpendicular to the bottom of the new bezel. This line and the base of the bezel will be the origin for all the following measurements. The picture shows the rear of the new bezel with all measurements and markings complete and ready to be drilled, which brings me to the next subject, unpleasant surprises.

Click for BIG pic - dialup beware!

With a project like this one, especially if you put as much work into the new bezel as I did (all that laminating and careful shaping) surprise is a very bad thing. Work slow, take your time, and you'll be rewarded with a professional-looking result that everyone will "ooh" and "ahh" over. However, as I found, even if you're methodical, precise, and make each measurement two or even three times, "stuff" still happens. For me it was after all the holes had been drilled and cutouts laboriously and carefully made - the worst possible time to find any mistake!

The problem I ran into wasn't my error, except for the fact that I didn't catch it in time to factor it in. One of the manufacturer's drawings for the gauges I used turned out to be incorrect, or else the gauges themselves were out of tolerance, but I suspect the former. Either way, what happened was that the outer diameter of the tachometer and the speedometer (not the mounting hole size) was called out as being 3.75", but was in reality about .0625" bigger than the spec. That meant that all my careful layout and hole cutting was for naught; all my gauges were too close together and would not fit into their holes properly. Luckily for me I was able to "oval" all the holes and finally get the gauges to all fit, but I was pretty unhappy about it because I'm basically a perfectionist about my own work. Moral: As a good friend of mine liked to say, "Assume Nothing and Suspect Everything" - in this case even the manufacturer's specifications! Take your time, be careful, check everything and unlike me, all will certainly be well!

Information: Drilling holes in carbon fiber or fiberglass requires really sharp bits if you want the holes to look good. Drilling big holes (IMO > .125") should be done with either a forstner bit or a brad point bit. These types of bits insure that the material is cut and not torn from the outer radius of the hole when drilling such materials. I used forstner bits for the high beam and turn signal holes.

So, that being said, back to construction. Very carefully mark all the mounting holes for the gauges and whatever other holes you'll be drilling. Measure twice, drill once. My gauge layout pattern with all measurements is here. Note that as carefully as I tried to insure that the numbers are now correct, mistakes still happen. Therefore since I didn't actually use these measurements, please remember my painful lesson above and check everything! If you'll be including the firm ride LED, now is the time to determine where you want it to be located and mark that position as well as all the others.

Now carefully drill a small pilot hole in the exact center of each hole location, including the gauge cutouts. I suggest using a very sharp drill bit no larger than 0.0625" (1/16") in diameter. Do this because it's it's much easier to perfectly locate the center of the hole with a small bit. You should also center punch each hole location before drilling it. Once all the locations have a pilot hole, from the front of the bezel drill out the holes for high beams, turn signals, and firm ride indicator. When you're done with these the bezel should look something like this picture.

Click for BIG pic - dialup beware!

The next step is to cut out the gauge holes. I used my trusty 20-year old Dremel with part of the Dremel router kit and a custom-made circle cutting guide that was specially designed to cut the proper hole sizes. It was made out of 1/4" plywood, and a tungsten-carbide bit was used. Even with this quality bit, it was still a tough job to cut the holes; the poor Dremel almost wasn't up to the job. A higher power cutter is highly recommended.

Click for BIG pic - dialup beware! Click for BIG pic - dialup beware!

Here's how the new bezel looked after 2 holes had been laboriously cut out and I was waiting for my trusty Dremel tool to cool down, and how the gauges fit into the holes. After your Dremel cools down, carefully cut out the remaining gauge holes, then lightly sand the edges to remove any burrs or sharp edges. I used some very fine emery cloth.

Click for BIG pic - dialup beware! Click for BIG pic - dialup beware!

Once all the holes in the new bezel are properly cut to size, it's time to set the new bezel into the old one and mark where the old bezel will need to be cut out to provide clearance for the new gauges. This aspect of the job is not critical because the old bezel will be totally hidden behind the new one. However, you want to keep as much of the old bezel as possible because that's what will hold the new one in place. Cut out your clearance holes using your tool-of-choice, and you're ready to rock-and-roll!

Now carefully laminate the new bezel onto the old one with some 30-minute epoxy. The better the bond, the stronger the new bezel will be. It's best to rough up the mating surfaces with some sandpaper to provide a better bonding surface for the epoxy. Once the epoxy is completely cured, you can mount the gauges into the new bezel, and you're ready for the final major mechanical operation: Cutting clearance openings into that white thermoplastic rear housing. For this task I used a pneumatic die-grinder with a 0.25" diameter carbide bit, then cleaned up the mess with a sharp knife, some sandpaper, and my trusty old Dremel. Once again this task is not very critical, but be sure to only remove the smallest amount of material as possible from the rear housing to maintain structural integrity. Once you're done screw the two pieces (bezel and rear housing) together, and *presto!* you have something that actually looks like an instrument cluster!

Click for BIG pic - dialup beware! Click for BIG pic - dialup beware!



Article Links

Index
Mechanical
Electrical
Pre-Calibration
Installation
Afterthoughts

This article will be modified and added to as I have the inclination, so stay tuned!
Click HERE for a directory of all pictures and drawings.


Copyright © 2003-2017 by D. Joseph Frazier
- All Rights Reserved -

Disclaimer
Please note that while I've been as careful as possible with this article,
it may contain mistakes. I assume no liability whatsoever for any
detrimental effects using this information may cause to you or your vehicle.


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