Intro: Ghostbusters Ghost Trap Build
We've GOT ONE!
Actually I've got two. I built two traps concurrently, because who hasn't wanted their own ghost trap?
I wanted a proton pack and a ghost trap as a kid and never got either. Now it's time to make a trap. My goal was to create an accurate trap while on a small budget.
The dials are not accurate. In the future I plan to replace the dials and add the resistor and plate from Nick-a-tron props.
• I built this trap based on plans from Sean Bishop.
• I initially built the trap in Google Sketchup to decide how I would build it and confirm the plans measured correctly. This also gave me a quick reference instead of searching through plans.
• I looked at many images from the original film. The props from the movie differ slightly as far as screws used and other minor details. I painted the side rods silver as seen in the second movie as I didn't like them red as seen in the first.
• 1/4" MDF for the trap body and cartridge
• 1/2" MDF for the top lip of the cartridge
• 3/4" poplar for the vertical portion of the handle
• 1/2" wood dowel for the side rods on the trap body
• 7/8" wood dowel for the handle that connect to the 3/4" poplar
• 1" wood dowel for the wheels. These wheels do not rotate
• Wood glue for wood items
• Epoxy for some screws and detail items
• Aluminum sheet for the side plates. I went with 1/16" plate for cost. 1/8" plate is more accurate
• #6 button and socket cap screws (see step 3 for quantity)
• #8 button and socket cap screws (see step 3 for quantity)
• #10 socket cap screw (see step 3 for quantity)
• Pilot light for the battery pack
• Micro switch for the battery pack
• 3/8" quick connect NPT plug for the battery pack
• Assorted automobile buttons on the trap body if you're on a budget or replica dials from Nick-a-tron props
• Table saw
• I used a scroll saw for the complex cuts in the trap body. A jig saw could also be used
• Drill and drill press for all of the screws
• Jig saw with metal cutting blade for the aluminum plates.
• Pneumatic saw for the opening in the aluminum plate. This saw is more precise than a jigsaw for such a small opening.
• Hand saw for small detail items
• Belt sander was used to smooth edges
• Files and rasps to smooth and true the edges of the aluminum. Cutting it will leave them rough
• Clamps ranging in size from 1.5" to 12"
• A table saw can remove fingers very quickly if you don't pay attention. Proceed with caution when using a hand saw, don't cut near or on your favorite antique.
• The aluminum plate when first cut will be rough with burs that can cut you.
• When drilling, make sure you don't accidentally drill through anything you don't want to.
• Spray paint must be used outdoors in a well ventilated area. A respirator or mask is recommended. Allow time to dry fully.
• Wear old clothes for painting. Chances are paint will find a way to get on your clothes.
Step 1: Trap Body
For the trap body (which holds the cartridge), I used 1/4" MDF. The MDF I used had a veneer which was sanded off. I measured and drew the plan onto the MDF. I used a table saw to cut the overall shapes and then used a scroll saw to make the cutouts at the bottom corner of the side plates. The trap body includes the two sides, a back, and the bottom.
I test fit the pieces together and then glued them. I used a clamp at the front where the bottom plates meets the sides and at the back where the sides meet the back. With a clamp the glue will be dry in fifteen minutes.
A note, I decided to make my knobs spin, which meant I needed to recess a screw head on the inside of the body. This was difficult as the trap was assembled. If you plan to have knobs that turn, plan ahead.
For the battery I glued scraps of 2x4's together then cut and sanded them down. I should have used 1/4" MDF to create a shell and reduce weight. I later had to hollow out my solid battery for the light, switch, and future wiring that would run into the cartridge.
The handle is solid Poplar. MDF is not going to be strong enough. For the curved recess of the handle, I used a rasp and then hand sanded it for a snug fit against the dowel.
Step 2: Cartridge
I used 1/2" MDF for the entire cartridge. I should have use 1/4" to reduce weight. The only part that needs 1/2" is the lip around the opening.
Cut your pieces according to the plan, test fit, and then glue. Clamping them helps them dry quicker. You can also use paint cans or other heavy objects.
The cartridge display is 1/2" and 1/4" MDF glued up and cut according to the plans. In dealing with pieces this small I cut them with a hand saw and then sand them smooth. With power tools, your fingers would be much to close to a moving blade for comfort.
The ears on each side of the display are Poplar, as that was 3/4" thick, which is the size I needed.
The rear tabs are 1/4" MDF. They are surface glued onto the cartridge and thus very flimsy. They should be a continuous piece that is part of the cartridge's back wall. Again, I should have done the cartridge in 1/4" MDF and not 1/2". That way the rear tabs could be integral and much more durable.
Test fit everything. I had to sand the cartridge down a bit to fit in the trap body. It needs to be snug as it's only a tension fit, but it also has to actually fit.
The bottom plate and wheels were cut per the plans and glued to the trap body. I had planned to make the wheels movable, but decided not to.
Step 3: Aluminum Plates and Screws
The button head & socket head screws and aluminum were sourced from the local
hardware store. The hardware store saved me 30% compared to a big box home improvement store.
The aluminum plate must be cut with a wood board as a backing. Otherwise you will bend and ripple the plate. The same holds true for drilling, use a backer.
The aluminum plate can be cut with a jig saw and metal cutting blade. Use a file to smooth and true the edges. The jig saw can create jagged and ragged lines. I slightly rounded the edges so they would be smoother. Use a straight edge to check your progress on truing the edges.
I went thin on the aluminum as making two traps concurrently meant thicker aluminum was a substantial cost increase. I may fix this discrepancy one day (though I may not).
I marked hole locations for screws on the metal plate and drilled through with a drill press using a wood backer. I then used the plate to mark holes on the trap body by clamping the plates in place.
I drilled the trap body holes on the drill press as well.
For the display plate on the cartridge, I drilled a pilot hole at the opening location and use a pneumatic saw as it is more precise than a jig saw. A file trued the opening.
Paint the trap before attaching the aluminum plate to save from having to tape off. It's much easier to paint separate components than when it is all together. Glue was applied to the holes and the screw inserted. Most of the screws are 1/4" in length. The handle screw is 2.5" long to reinforce the handle.
There is a lot of contention on which screws are accurate, since the original traps mixed and matched. I did some research and looked at a lot of images. The final screw count and location used in this build:
#6 Socket Cap Screw - 20 - small side plates, heat sink, resistor, display plate, door hinges
#6 Button Head Screw - 5 - battery top
#8 Socket Cap Screw - 6 - front plate, cartridge ears,
#8 Button Head Screw - 8 - large side plates
#10 Socket Cap Screw - 1 - top of handle
Step 4: Paint, Details, and Conclusion
Paint the trap flat black before you assemble so you don't have to tape off. Painting the pieces apart provides a cleaner job. I used drywall compound on the edges of the MDF to smooth out the rough edge and on the battery pack to remove wood grain. This may take a couple of times if you miss any spots the first time. Wipe the trap down with a clean dry cloth and paint in a well ventilated area or outside. I wear a respirator so I don't breathe paint fumes.
I had planned to paint the trap hammered black and mist it with flat black, but decided that level of detail wasn't necessary. There are a few sand marks on the trap, but that will actually help when I weather it.
The trap doors are 1/8" acrylic sheeting. I cut the rough shape on the table saw and used the pneumatic saw to cut the recess. A rasp was used for the radius. I sanded the top and then painted it gloss black. Once the black was dry I taped off using clear tape and painted it gloss yellow. Hollow plastic dowels were glued onto the long edge of the door. The dowel extends past the door on the front. This side inserts into the ear on either side of the display. A screw is inserted into the tab at the back and into the hollow plastic dowel, allowing the doors to open. The back tab is rather flimsy in my build. As noted in step 2, make the back plate and tabs one continuous piece for strength.
The battery is held onto the trap with a dry wall screw. The battery needs to be removable so I can access the switch and light later. This screw is inserted into the opening where the 3/8" NPT fitting screws into the wood.
The side rods are 1/2" wood dowels. I chamfered the ends very carefully on a belt sander. Holes were drilled part way into the side rod with a dowel inserting into the side rod through the trap body and glued in place.
I printed labels from Hprops on slick paper and used spray adhesive to glue them in place. Use movie screenshots as a reference for location.
As I noted in step 1, I decided to make the dials movable half way through the build, which meant I had to recess a screw head on the inside of the assembled trap. Because I can't angle the drill head on, it's an ugly hole, but it doesn't show. My dials use #6 socket caps so that they will turn. The screw is fed from the inside, and the button is glued on. I'm sure there is a better way to do this, but this is my method.
The knob on the resistor side is from a 1988 Nissan pickup radio.The knob serving as the tear drop shaped dial is the volume knob from almost any '90s GM vehicle.
To the trained eye, it's not quite accurate. As mentioned in the introduction I will purchase the correct dials, resistor, and resistor plate from Nick-a-tron props. I had to forgo accurate dials as shipping would take too long for Halloween.
It also needs some weathering. Weathering helps a prop look used and real, instead of like a toy in pristine condition. I will use brown washes- spraying and rubbing paint on and off. I will also do a lot of silver dry brushing at edges and corners. Sand marks will be key spots for the silver.
Of course people love the prop and marvel over how real it looks. It was a lot of fun just to build. Now I finally have that ghost trap I always wanted. I ain't afraid of no ghosts!