Would you like to get them centered and in the same place every time? Well you can if you make a drilling jig like the one shown below. This jig allows you to drill pilot holes directly in the center of the brush barrel relief molded into every TYCO chassis. After drilling the pilot holes, you simply increase the pilot hole with a1/8 in. drill bit. This jig also doubles as a tool to bend pick up shoes. Be forewarned, the construction of the jig does require a fair amount of soldering skill.

To build one you will need the following:

12in. length of 1/8in. brass tubing (rigid), soldering iron, 62/36/2 rosin core solder ( RadioShack ), Nylon tubing cutter ( K& S ), fine tip marker, 4 heat sinks ( alligator clips ), handy hands holding fixture, 3/32in.,7/64in., 1/8in. drill bits, a 3in. piece of 3/32in. tubing, Dremel with cutoff discs and mandrel, cork board for flat work, a 1/8 round file, a thin flat file, SAFETY GLASSES, and straight pins.

Now just follow these simple????? steps to construct your drilling jig:

1. On the 12in. length of 1/8 in tube mark off a 1&5/8in. + 1&5/8in. (3&1/4in.)+ 11/32in. + 1&5/8in. with a fine tip marker. (Fig.1)
2. Bend the tube at the first 1&5/8in. mark to a 50degree angle from outside tube wall to outside tube wall. You will use the short bent section as a lever to rotate the tube in the tubing cutter. (Fig 2)
3. Cut the tubing at the 3rd remaining mark from the bend to remove the excess piece of tubing, set it aside.
4. Cut at the 2nd remaining mark from the bend to produce a 1&5/8in. length of tubing.
5. Cut at the last remaining mark to produce an 11/32in. length of tubing.
6. Bend the remaining “V” shaped tube together to form a 30degree angle (about 7/8in. from outside tube wall to outside tube wall. (fig.3) You should now have a “V” shaped piece, a 1&5/8in. length, and a 11/32in. length of tubing
7. Take the 11/32 in. tube and file each end with a1/8in. round file to “ Fish mouth” it so that the tube fits snugly in the “V” about 3/4in. from the bend. This will become the center brace. (Fig.4)
8. Clamp the “V” in a holding fixture (Handy Hands).
9. Place the11/32in. “Fish mouth” tube in the center of the “V” and slide it down until it is seated in the “V” about 3/4in. from the bend. Place a heat sink on either side of the point where the 11/32in. tube meets the “V” and another in the center of the 11/32in. tube itself.
10. Solder the end with the heat sinks to the leg of the “V”. (Fig. 5)
11. Place a heat sink above and below the point where the unsoldered end of the 11/32in. tube meets the remaining leg of the “V”, also make sure that the heat sink in the center of the tube is still in place, and solder the remaining joint together.
12. Place a heat sink below the 11/32in. tube on both “V” legs and solder the “V” together where it is bent. (Fig.6) This gives the end of the jig added strength.
13. Remove the “V” from the holding fixture. Taking the 1/8in. round file, file directly across the tops of the “V” legs until the remaining 1&5/8 in. tube fits snuggly into the legs and forms a letter “A”.
14. Place the “V” upside down in the holding fixture. Place the remaining 1&5/8in. tube on the corkboard and move it under the “V” in the fixture. Push the “V” down onto the remaining tube until they fit together with one end of the tube 1/4in. away from the outside wall of one “V” leg, use straight pins to hold it down if necessary. Place a heat sink in the middle of the tube and one just above it on either “V” leg , solder the tube and the leg together.
15. Move the heat sink from the last step to the other leg of the “V”. Leave the heat sink in the middle, and solder the remaining tube end to the leg. You should now have letter ”A” shaped piece with a solid foot across the bottom. (I don’t know about you, but I was sure getting tired of hearing about that blasted letter “V”!!!) (Fig.7)
16. Make a mark 5/8in. from the short end of the 1&5/8in. tube (the end with the least overlap). WEAR SAFETY GLASSES FOR THIS STEP!!!!!!!! Take the Dremel and cutoff disc and carefully cut a slot completely through the tube at the mark that you made. Make sure that the cut is at a 90degree angle. Work the cutoff disc back and forth until the slot is about 1/32in. wide. Taking the thin flat file, smooth and square the slot until it is 3/64in. wide. Take the 3/32in. drill bit, put it in the Dremel, and pass it up and down in the tube that you just cut the slot in, this is will remove any remaining burrs in the tube.
THE TOOL IS NOW FINISHED AND READY TO USE.

TO USE THE TOOL

Place the tool, long side out, into the brush barrel relief molded into the chassis. Slide the tool up until it is seated firmly against the half round top of the brush barrel relief (Fig.8) Insert the 3/32in. drill bit and Dremel into the long tube end and drill the pilot hole (Fig.9). Now drill the hole for the brush barrel with the 7/64in. drill bit (Fig.10). Repeat process to complete the other side. The chassis will look like (Fig.11) when assembled. (Note: Using the 7/64 in. bit will make the chassis and front bulkhead difficult to assemble but it will also allow the brush barrels/bulk head assembly to stiffen the chassis and keep it from flexing. If you just can’t assemble the chassis, ream out the holes in the chassis with the 1/8 in. drill bit. You will lose some of the stiffening, but the bulkhead will be easier to assemble.)

TO BEND PICK UP SHOES

Place the front of the shoe over the LONG end of the tool (Fig12), and bend it around the tube with your fingers, keeping it straight as you bend. The HOOK end can be bent around the 3/32in. tube. These adjustments will allow you to adjust pick up shoe travel and front to back movement.

If you have followed the above steps, you should now have a tool that provides a sure way to drill your brush barrel holes in the same place, every time. Enjoy!