Purpose: MAKE CATAPULT ARM Step 1 Tools: Sharpie, Square, Vise, Hack saw, Ruler, Punch, Hammer, File Materials: Flat aluminum ½ inch stock (see picture below) Gloves required 1. Pick up the aluminum ½ inch stock Using a Sharpie marker and a square, mark the stock 8 inches from one end 2. Cut the stock Place stock in vise and cut with hack saw 3. Mark the stock Using Sharpie, place a line at ¾ of an inch, 1 inch, 1 ¾ inches and 5 ½ inches from one end, to make a total of 4 marks (see picture below) 4. File edges Using a file, remove all rough edges
CATAPULT ARM Continued Step 2 Tools: Arbor Press Materials: 8 inch aluminum stock arm made in previous step, rod 1. Use Arbor Press Rotate the Arbor Press base plate to align the wide slot directly under the press rod (see picture #1 below) 2. Bend the stock a. Place the arm into the Arbor Press b. Put a rod exactly over the line at the ¾ inch location c. Push the ram down to create a slight (25 ) bend matching the sample piece provided (see picture #2 below) No Yes #1 #2
CATAPULT ARM Continued Step 3 Tools: Blue Drill Press, # 27 Drill, Electronic hand drill, Vise, 8x32 tap Materials: 8 inch aluminum stock arm made in previous step No gloves 1. Drill holes Using the blue drill press with a number 27 drill, drill a hole at both the 1 inch, 1 ¾ inches and 5 ½ inches locations (see picture #1 below) 2. Counter Sink Hole Using an electric hand drill with the counter sink bit, slightly counter sink the hole at the 1 inch location (see picture #2 below) 3. Tap Hole Clamp the arm in a vise and tap the countersunk hole with an 8x32 tap (see picture #3 below) #1 #2 #3
CATAPULT ARM Continued Step 4 Forming the Cup Washer Tools: Hydraulic Forming Tool Materials: Fender washer 1. Pick up the fender washer Take to the Hydraulic Forming Tool 2. Turn washer into a cup a. Place the washer on top of the die piece (see picture #1 below) b. Close the silver control knob by turning it clockwise (see picture #2 below) c. Pump the black handle until the washer is formed into a cup (see picture #3 below) 3. Take washer out of tool a. Open the silver knob by turning it counterclockwise (see picture #4 below) b. Press down on the die until you can remove the formed cup washer #1 Closed #2 2 c #3 Open #4
CATAPULT ARM Continued Step 5 Putting it together Tools: Screwdriver Materials: 8 inch aluminum stock arm made in step 3, washer cup made in step 4, Machine Screw 8-32 x.375 Flat Head, Thread locking adhesive 1. Attach washer cup to arm piece a. Place washer cup on top of the 1 inch mark b. Line up holes c. Take the Machine Screw 8-32 x.375 Flat Head and apply a small drop of thread locker on tip d. Using the Screwdriver and screw from c, screw the cup washer onto the arm piece (see picture below)
Purpose: MAKE AXLE SHAFT Step 1 Tools: Sharpie marker, Ruler, Lathe Materials: Pre-cut 3/8 inch diameter round rod Gloves required 1. Pick up the pre-cut 3/8 inch diameter round rod Using a Sharpie marker and ruler, place a mark ½ inch from the unprepared end of the rod 2. Prepare the Lathe a. Use the chuck key on Lathe b. Tighten the rod piece into the Lathe with the mark on the unprepared end just showing beyond the chuck jaws c. Remove chuck key 3. Turn on the Lathe a. Set the Lathe for Forward b. Turn on power switch 4. Cut the rod a. Advance the speed knob from zero to about half speed b. Using only the large black knob facing toward you, slowly advance the cutting bit into the rod and cut back to the line c. Turn the black knob to retract the cutting bit clear of the rod end 5. Turn off the Lathe a. Turn the speed control knob to zero (0) b. Turn the lathe off c. Use the chuck key to remove the rod
AXLE SHAFT Continued Step 2 Tools: Milling Machine Materials: 3/8 inch rod from previous step No gloves 1. Insert rod into Milling a. Clamp the rod into the Milling Machine vise so that Machine it is centered and fits tight into the vise slot b. The top of the rod should be above the top of the vise about 1/8 of an inch 2. Turn on Milling Machine a. Press red power switch b. Advance speed knob from 0 to about 1/2 speed 3. Cut the rod a. Using only the large black knob toward you b. Advance the cutter bit into the top of the rod to create a slot (see picture below) c. Reverse the black knob d. Return the cutter bit to its original location 4. Turn off Milling Machine a. Turning the speed knob to zero (0) b. Depress red power switch 5. Remove the rod Take rod out of vise
Purpose: Mount Axel to Catapult Arm Tools: Arbor press, Gray Drill Press #27 Drill, Screw Driver Materials: Catapult arm made in section 3, Axel made in section 4, Machine Screw 6x32 x.675, Internal Tooth Lock washer #6, Machine Screw Nut 6x32 1. Align both pieces Center the hole at the 5 ½ location of the catapult arm directly over the center of the axle shaft 2. Insert arm into axel Using the arbor press, press the catapult arm down into the slot of the axle shaft 3. Drill together a. Take the assembly to the gray drill press with the number 27 drill b. Clamp the assembly so the hole in the arm is directly under the drill point c. Drill down through the arm hole, and then through axle shaft (see picture #1 below) d. Remove the assembly from the vise 4. Attach Using a Machine Screw 6x32 x.675, Internal Tooth Lock washer #6, and a Machine Screw Nut 6x32 securely attach the axle shaft to the catapult arm (see picture #2 below) #1 #2
Purpose: MAKE FRAME SIDES Step 1 Tools: Ruler, Sharpie Marker, Shear File Materials: 2 pieces of 3x4½ inch Sheet Metal Gloves required 1. Pick up 2 pieces of sheet Using a Sharpie marker and a square, draw a line 4 metal inches from one end 2. Cut the pieces of metal a. Take the material to the shear and place it under the red guard b. Cut at the ½ inch at the line you drew (see picture #1 below) 3. Mark each piece Using the template provided, mark the holes on both pieces (see picture #2 below) 4. File each piece Using the file, remove all sharp edges on both pieces #1 #2
FRAME SIDES Continued Step 2 Tools: Hammer, Center punch, Mounted Punch, Sharpie Marker 5/32 nd Hand Punch, Materials: 2 pieces of metal from previous step 1. Make a dimple in the Using a hammer and the center punch, put a pieces of metal dimple in the center of each of the circles you drew in the previous step (see picture #1below) 2. Punch the pieces of metal a. Using the large mounted punch, punch a 3/8 inch hole in only the top corner of each piece (see picture #2 below) b. Using the 5/32 nd inch hand punch, punch all other holes in both pieces (see picture #3 below) #1 #2 #3
FRAME SIDES Continued Step 3 Tools: Ruler, Sharpie marker, Brake Materials: Pieces of metal from previous step Gloves required 1. Prepare the metal pieces Using a sharpie marker, draw a line at ½ inch up from the bottom of the piece (the side with the small holes) (see picture #1 below) 2. Brake the pieces of metal a. Take the pieces to the table mounted brake b. Attach both pieces under the holding plate with the large holes on round pegs (see picture #2 below) c. Bend the small tab up to 90 (see picture #3 below) #1 #2 #3
FRAME SIDES Continued Step 4 Finishing it up Tools: Arbor Press Materials: Frame Sides made in previous step, 2 graphite bearings 1. Insert graphite bearings a. Obtain 2 graphite bearings b. Using the arbor press, press in the graphite bearings into the large hole in each frame side s upper corner c. The lip of the bearing needs to be on the side with the bend
Purpose: MAKE SPRING WIRE Tools: Spring bender tool Materials: Piece of 12 inch spring wire 1. Pick up the 12 inch spring wire 2. Bend the first end of the wire With the wire in a vertical position, use the spring bender tool to form a U bend on one end only (see picture below) 3. Bend the other end With the wire in a horizontal position, bend the last ½ inch over 90 degrees to exactly match the catapult example (see picture #1 below)
Purpose: MAKE TRIGGER Tools: Tin snip, File, Mounted trigger-bending vise, Small hand punch, Large nonmounted hand punch, Heat gun Materials: Flat strapping material, Shrink tubing, Nylon screw and nut 1. Cut flat strapping material Gloves required a. With a tin snip, cut a 5 1/2 inch piece of flat strapping material b. With a file, remove all sharp edges 2. Punch holes a. Create an attach hole by punching a 5/32 inch hole with the small hand punch b. Use the ¼ inch large hand punch (not the table mounted punch) to create the nylon screw hole 3. Bending jig Using the mounted trigger-bending vise, form the piece like the trigger on the catapult example 4. Cover trigger a. Obtain 1 ½ inches of shrink tubing for the trigger and slip 5. Attach nut and screw it over the curved trigger (see picture #1 below) b. Use the heat gun to shrink the tubing onto the trigger a. Obtain a nylon screw and nut b. Attach the nylon screw and nut in the hole c. Make sure that the top of the nut is parallel with the top of the trigger (see picture # 2 below) #1 #2 No Yes
Purpose: Final Assembly Step 1 Tools: Rasp, Square, Sharpie, Scribe, Hammer, Screwdriver Materials: Wood base, All parts made in previous steps, #7 x.5 sheet metal screws 1. Prepare wood base 2. Attach frame side to wood base a. Obtain a wood base b. Using a rasp, remove all sharp edges Gloves required c. Observe the example catapult for placement of catapult components d. Using a square and Sharpie draw a line 1 inch away from the end of the long side and a line 1 inch away from the short end (see picture below) a. Place 1 frame side on the wood base at the intersection of the 2 lines with the large axel hole at the center of the board b. Mark both mounting holes with Sharpie c. Remove the side and with an awl or a scribe and hammer, make 2 shallow pilot holes d. Using #7 x.5 sheet metal screws, fasten the plate in place 3. Attach axel a. Fit other side plate onto axel through the bearing 4. Attach frame side to wood base b. Place the axle shaft into the other bearing of the attached side a. Mark the other two holes. Make sure that the axle shaft does not bind b. Fasten the last plate to the wood base with #7 x.5 sheet metal screws DO NOT OVER TIGHTEN 1 inch 1 inch
FINAL ASSEMBLY Continued Step 2 Tools: Sharpie, Scribe, Hammer, Screwdriver, Bolt Cutters Materials: All parts made in previous steps, Foam piece, 3 inch nail, Self Tapping Screw #7 x.5 1. Attach the trigger 2. Attach the spring 3. Finishing touches a. Align trigger with the arm so that the end of the arm fits under the plastic nut b. Mark screw hole with Sharpie through trigger base c. Make shallow pilot hole d. Screw trigger to wood base with a Self Tapping Screw #7 x.5 a. Attach 90 bend into arm hole just below washer cup b. Thread spring wire between sides towards the trigger end of wood base c. Pull the end through the rear left side d. Pull wire 1 inch beyond the rear left side plate and make a mark with Sharpie in line with the left side plate e. With a scribe or an awl and hammer, make a shallow pilot hole f. Screw Self Tapping Screw #7 x.5 and washer part way into the wood base g. Hook U bend around the screw and under the washer h. Tighten the screw a. Obtain a piece of foam b. Place the foam between the 2 sides toward trigger, under catapult arm c. Obtain a 3 inch nail d. Cut off the tip of the nail using the bolt cutters e. Insert the nail into one of the sets of holes in the side plates through the foam Congratulations! Obtain a rubber bouncy ball and try out your new catapult!