Rebel Hardware Competion - Hardware Droid Caller

(Please bear in mind that this is my first serious attempt at prop building!) The following steps are my "revised" ideas, based on trial and error (some of the former, and a lot of the latter!). I know next to nothing about electronics, but with a scribbled diagram from a clerk at Radio Shack I was still able to fashion a circuit that works, so anyone can do it.

I used 12" chrome-plated brass sink pipe for the HEAD & BODY; the 12" pieces are cheaper to buy than the 6" extension pieces. Buy the stuff labeled as PROJECT GRADE, it's thinner, and easier to cut & drill through. The 12" pipe is only a dollar more, and you can get 3 BODY CASINGS out of it. Another possibility I thought of after I started, was to use tubing from a Tensor Halogen Lamp. The black powder coated tubing would be perfect to match the screen-used flash guns.

You have several different ways to go with the momentary contact switches; I think the one above looks the best (it's also available with a red button). The thing to keep in mind when selecting the switch is that the "internal" part of it needs to fit in a small tube with a battery pack, a buzzer, and wiring. Part of that problem could be relieved by going with an "N" battery; it will power the buzzer, and it's half the size of a AA, but that's all I know about it!

Right at the very end of the project, I had to alter my idea of securing the buzzer. Originally, I had it held in place by two of the "claws" on the bottom endcap. To my dismay, I discovered that the buzzer loses volume the more it's secured; tighten the "grip", and you go from "BZZZZZ!" to "bzz..."! My solution to the problem is crude, but effective.

On a side note, I checked eBay to see if they had any original Linhof flash guns: no flashes, but the Linhof stuff they had were selling at prices that made 3-cell Graflex flashes look like K-Mart Specials!!

BUILDING A HARDWARE DROID CALLER

To begin with, I wanted a "brushed finish" on the BODY CASING of the caller, so I used the metal finishing pad and just scuffed down the bright chrome. Use light pressure, and try to keep the "pattern" even throughout. Next, measure 3" on the 1" pipe. This will be the BODY CASING. After you've marked it, use the masking tape to cover the pipe on both sides of the mark (photo 1 shows the pipe after masking, and with 1 casing cut); this will protect the pipe from scratches while cutting. Using the cut-off tool of your choice, cut the pipe. If your pipe cutting skill are as superb as mine, you'd be smart to buy two of each size (see photo 3)! For the HEAD CASING, use the 1" pipe, and make your cut at 1 1/8" (photo 2 shows the two other pieces that make up the HEAD ASSEMBLY). If there are any sharp edges, file or Dremel them smooth (take care not to grind off the chrome on the outer edge of the pipe, or you'll have a nice brass ring where the CASING meets the endcaps!).
Photo 4 shows the six pieces we'll be working on next: BODY CASING, HEAD CASING, metal endcaps, blask plastic endcap, and the cabinet knob.
Using the size of the "claws" on the metal endcaps as a guide, measure and drill a 1/16" pilot hole thru the BODY CASING at one end; around" down from the cut edge. Repeat at the other end, and then enlarge each hole with a 1/8" bit (see photo 5: I used 6-32 X 3/8" thread-cutter screws for assembly, so the 1/8" bit worked fine). Using pliers, straighten two of the "claws" that are directly opposite each other, forming brackets. Place one endcap on the pipe, making sure that wide part of the bracket lines up with the hole, and mark it. Remove the cap, and secure it in a vise. Drill a pilot hole, and then enlarge with the 1/8" bit (photo 6). Put the cap back into the tube, and screw one of the 6-32 X 3/8" thread-cutter screws in. It will be tough at first, that's why they're called "thread-cutters!" Go slowly, taking care not to twist or misalign the screw.
Next, remove the screw and endcap. By placing the cap partially back in, guesstimate where to drill the hole on the opposite side, and mark it on the BODY CASING. Remove the cap, drill a pilot hole thru the CASING, and then enlarge. Put the cap back in, and mark the bracket. Remove the cap, secure it in a vise, and drill a pilot hole, and then enlarge. Repeat for the other end. Photos 7 & 8 show the finished BODY CASINGS with the endcaps screwed in place. Simple, but tedious...thank God for keyless chuck drills!! After you're done, it's a good idea (especially if you're making several) to mark the inside of each piece so it will match up correctly when you finally assemble it. I numbered each casing (1, 2, etc.), lettered each screw-hole (front "A", back "B"), and then wrote "Top" & "Bottom" on the matching endcaps. At this point drill two 1/16" holes in the "claws" perpendicular to the straightened bracket "claws" of the BOTTOM cap. These will be used to secure the buzzer. Drill them in the widest area, not in the tapered section, because we now need to cut off the tapered section, leaving a nubbin with the hole in it.
Next, we're going to drill all of the holes to finish up the BODY CASING. Remove the endcaps. Screw the D-ring bracket (thru the hole nearest the D-ring) to the CASING thru one of the endcaps screw holes; do this at the "top" of the pipe. Mark where the lower hole needs to be, and remove the bracket. Drill the pilot hole and enlarge; since we'll be using a rivet on this lower hole, use a 9/64" or 5/32" bit, so that the rivet can expand. Screw the D-ring Assembly back on and check the alignment (photo 9).
Take the "top" endcap, and mark the center of the cap. Drill a pilot hole, and enlarge it to fit whatever size screw comes with the cabinet knob (the ones I bought used 8-32 thread-5/32" was too tight, and 11/64" was too loose-since this will be tightened securely, I went for the loose fit!). Go ahead and drill the same sized hole thru the center of the plastic endcaps. Photo 10 shows the endcaps after drilling (the black plastic endcaps shown were too thick to fit into the 1 1/8" long HEAD; they were made in three layers, so I cut one "layer" off!). The caps I used have a finished edge that is flush with the outside of the pipe; this leaves an 1/8" black band between the BODY and HEAD assemblies. I like the look of it; if you don't, then cut that section off!
Now comes the hole for the momentary contact switch. The switch I chose to use needs a" diameter hole. To begin the hole, measure straight down from the endcap screw hole about 3/8" and make a mark. Measure the full" down from this mark; this will give us room to install a finishing washer around the switch, without hitting the endcap screw. Drill a pilot hole. When I went to enlarge it, I really ran into trouble! After buying a new" drill bit, I discovered that when it started to go thru the thin metal, it would bind up, and tear the pipe! I ended up with a ragged 3/8" diameter hole that had to be Dremeled out to"; see photos 11 & 12. I'm not sure how to solve THIS problem, other than to say "HAPPY GRINDING!"
The final hole we'll need to drill in the BODY CASING is the hole for the THINGAMABOB KNOB; don't let the technical jargon fool you, this is just an aluminum knurled knob with a threaded end (8-32 thread) I found at ACE Hardware in the "Storm Door Fasteners" area. For placement of this knob in relation to the momentary contact switch, see the TOP VIEW-Body-Internal Schematics Diagram-basically, if the momentary contact switch is at 12:00, the knob is at 9:00. Drill a pilot hole, and then enlarge. Since this piece is held in place by a nut on the inside of the CASING, I chose to drill a slightly loose hole. Photo 12 shows a good view of this hole in relation to the switch hole (notice that on one CASING, I drilled it opposite to the others; once again, just to give it a different look). Using the Dremel and a grinding point, smooth up the holes on the inside of the CASING if necessary. Do the same on the endcaps. We're about done with the BODY! Clean off the BODY CASING with acetone, Goo-Gone, or whatever tickles your fancy, wash it with plain water, and then dry it off. Take the # 6, and #18 finishing washers, and check to see if the THINGAMABOB KNOB will fit into the #6, and the momentary contact switch into the #18. If they're too tight, Dremel the hole a little larger; too loose, don't worry, they won't be for long!
Rest the empty washers on the casing. See that huge gap underneath where the pipe curves? Not a problem! Starting with the #18, place the washer so that it's half supported on the edge of a vise, or block of wood, and bend it using hand pressure (the metal's thin, so be careful). This will elongate the round washer, giving it an "eyeball" shape. Put it back on the pipe and check to see if it's close to the curve. Repeat until the gap is pretty much closed. Repeat with the #6; this will be more difficult, but it doesn't need as much bending. See photo 13. Bending the washers will slightly distort them, so you'll need to grind the holes a little more; photo14 shows the #18 bent, with the contact switch in place. Clean off the finishing washers, and place the BODY CASING so that it lays flat (prop it on both sides so that it won't roll off!). Using a small amount of the black gasket silicone, glue the #6 washer in place. Use a very small amount of silicone, so that it won't goop out around the washer, or into the hole. The silicone will take 24 hours to fully cure, but after it sets for an hour or so, you can give the CASING a quarter turn, and repeat for the #18 washer. LEAVE IT UNDISTURBED FOR 24 HOURS!!!
While the CASING is curing, go on to the battery pack & HEAD assembly. Photo 15 shows the size differences between the "AA" battery pack, and the "N" battery pack. I chose to go with the "AA".
Start by taking the brass strip, and drill a hole about 1/8" in from the edge. Since this will be where the cabinet knob screw goes thru, use whatever size drill bit will give you the right size hole (once again, I went for the loose fit!). Now, measure down about 5/8" to" down from the edge and mark it. Using pliers or a vise, bend the brass ninety degrees (into an L shape), see photo 16. Make sure that when the hole in the "top" cap lines up with the hole in the brass bracket, that there is clearance between the "claws" and the bracket! You'll also need to drill a clearance hole for the back endcap screw. Mark where it will hit the bracket, and drill it out -make it a little larger than the screw. When assembled, this will help keep the Battery Pack Assembly from shifting. Measure down from the bend about an inch, and cut the strip at that point; see photo 17. Take the battery pack, and enlarge the small mounting hole on the "+"/positive end. I used one screw thru the battery pack directly thru the bracket, and another one thru the battery pack only (the brass strip I used was too narrow!). Align the battery pack about" down from the bend, and mark the placement of the mounting hole on the bracket. We will be using two of the RADIO SHACK "round head machine screws" & "hex nuts" to secure the battery pack to the bracket (the" long ones to be precise). Drill a small hole, just big enough for the screw to go thru; see photo 18. Screw the battery pack to the bracket, and check the fit and alignment. Now remove the battery pack, and pick up the 1 1/8" X 1" HEAD piece.
Mark the pipe about halfway down the side, so we can drill a hole for the DOHICKEY. The DOHICKEY consists of the 10-24 X" stainless steel socket head screw (allen head), and the 5/16" vinyl or rubber grommet. Drill a pilot hole, and enlarge it to 3/16"; photo 20. Put the grommet on the screw, and attach it thru the hole with the nut. Tighten it just enough to hold it in place. You don't want to distort the grommet very much, or it loses it's dohickeyness, and ends up looking like a couple of mismatched rubber washers! Secure the nut to the threads of the screw with a drop or two of super glue. See photo 21 for the finished DOHICKEY piece. Now, we're ready to assemble the HEAD ASSEMBLY! Start by inserting the black plastic endcap into the 1" pipe. Take the screw out of the cabinet knob, and thread it thru the brass battery pack bracket. Place the cabinet knob on top of the 1" pipe so that the screw shaft is inside the pipe; this will form the EMITTER GIZMO. Set the whole piece on top of the BODY "top" cap, and align the holes. Set the bracket up underneath the "top" cap, and screw the whole thing together. Before you tighten it completely , align the DOHICKEY so that it faces left (see the diagrams page, and photo 22), and then tighten that sucker up good! Attach the battery pack by screwing the small machine screw into the nut thru the pack and bracket. Use the other machine screw and nut thru the other mounting hole to act as a "stop" to keep the battery pack from swinging in the breeze. The HEAD ASSEMBLY is done!
24 HOURS, 7 MIUTES, AND 32.3 SECONDS LATER... The silicone should be dry, so we can finish up the Droid Caller! Examine the finishing washers on the BODY CASING. If any silicone oozed out around the washers, or into the holes, use an Exacto knife to scrape it away. Screw the D-Ring Assembly into place. Using a rivet gun, secure the D-ring bracket to the BODY thru the remaining (bottom) hole. You might need to place a small washer under the head of the rivet if the bracket hole is larger than the head of the rivet; see photo 23. Remove the top screw. Next, we're going to attach the THINGAMABOB KNOB. You will need to cut off about 3/16" of the knurled aluminum knob, so that it won't stick out as much inside the CASING (it makes more sense visually than it sounds!). Thread it thru the #6 finishing washer and hole, and secure with the nut. Once again, don't tighten it any more than necessary, and put a drop of super glue on the nut and threads; see photo 24.
Now comes the real work-WIRING! Refer to the Basic Wiring Diagram for a clear, simple, and uncluttered view of the actual wiring; the photos are a little fuzzy. The battery pack and buzzer both come with enough wire already attached-unless you make a mistake. The red wire is positive, and the black wire is negative. To begin, strip another" or so from all four wires. Connect the two black wires by forming a hook on each end, and then "hook" them together. Twist the wires tightly back onto themselves, and then cover the connection with black electrical tape; see photo 25.
Take the nut off of the momentary contact switch; notice that one side has "teeth" on it. This is the "top" of the nut, but in order to accommodate the thickness of the finishing washer and the curve of the pipe, we have to turn it over and install the nut "backwards". Otherwise there isn't enough threads to grab onto the switch. Bring the two red wires up thru the nut as far as possible; see photo 26. Place the batch of wiring and the entire buzzer, into the BODY thru the top of the CASING, and feed the red wires thru the switch hole; see photo 27. Once again, bend a hook in each wire. This time we're going to "hook" the wire thru the holes in the posts on the momentary contact switch. "Hook", then twist back; one has been done in photo 27, both are connected in photo 28. Wrap the connections with electrical tape.

GENTLY tug the buzzer out thru the bottom of the CASING, while pulling the battery pack's red wire out the top. Push the switch down, then tug a little. Push, tug, etc. until the switch is completely seated into the finishing washer and hole; see photo 29. Connect the switch nut to the switch, and tighten it good and snug. This is where small fingers some in handy! Now, gently bend the switch posts outwards from the switch; this will give us more room inside the casing.
Take the "bottom" cap, and set the buzzer in it "upside down"-the wide part with the mounting holes should be facing up, into the BODY; see photo 30. Loop thin wire thru the mounting holes in the buzzer, and thru the nubbin holes. Loosely twist the wire to secure it. The wires should be just tight enough to keep the buzzer from flopping around, but not any tighter. IF YOU WANT A GOOD, LOUD BUZZ, THE BUZZER NEEDS TO BE LOOSE! Insert the bottom cap, and screw in place. We're just about done! Carefully bundle up the black wire, and tuck it into the CASING, keeping it away from the buzzer at the bottom. Insert the HEAD ASSEMBLY, and check the clearance; if necessary, adjust the switch posts and wiring bundle. When you get it squared away, install a AA battery, and reassemble it, this time screwing the HEAD ASSEMBLY in place. Press the switch, and see photo 32!

HARDWARE DROID CALLER

Materials:

HARDWARE STORE (ACE, HOME DEPOT, ETC.):

RADIO SHACK:

MISC:

TOOLS NEEDED:

NOTES:

BUILDING A HARDWARE DROID CALLER