Boom Plans

JIB-ARM PLANS

by Cody Deegancopyright © 2003

Jib-Arm Plans 2 Jib-Arm Plans 3

Materials Ndd

*There is an alternative to using these items. They can be replaced with a 1” od x 5” steel pipe which will need to be welded. See page 7 for details.

SAEQuantity Size Description

(1) 1/16” x 1 1/4” x 72” steel square tube(1) 1/8” x 1 1/4” x 72” steel square tube(1) 1/8” x 1” x 22” steel square tube(1) 1/8” x 1 1/2” x 48” steel angle(1) 5” OD x 1/2” bore pulley(1) 3 1/4” OD x 1/2” bore pulley (2) 8” x 1 1/4” steel corner brackets(1) 6” x 1 1/8” steel corner brackets(1) 2 1/2” x 6” caster wheel frame (8” wheel)(1) 1/4” x 4” x 4 1/2” flat aluminum(1) 1/8” x 4” x 10” flat aluminum(1) 3/4” x 2 3/4” aluminum square tube*(1) 3/16” x 20 feet aircraft cable(2) 1/4” cable clamps(1) 1/4” turnbuckle(1) 1/2” x 6” full-thread hex bolt*(1) 1/2” x 4” full-thread hex bolt(2) 1/2” x 4 1/2” hex bolts(2) 1/2” fender washers*(7) 1/2” washers(4) 1/2” Teflon washers

Quantity Size Description

(3) 1/2” hex nuts(3) 1/2” stop nuts(1) 1/2” wingnut*(3) .5” x .875” x 1.25” linear bearings(5) 5/16” x 2” hex bolts(4) 5/16” x 3/4” hex bolts(4) 5/16” hex nuts(5) 5/16” wingnuts(9) 5/16” washers(2) 1/4” x 1” hex bolts(4) 1/4” x 1/2” hex bolt(1) 1/4” washer(1) 1/4” hex nut(1) 1/4” wingnut (1) 10-24 x 1 1/2” machine screw(1) 10-24 x 1” machine screw(1) 10-24 x 3/4” machine screw(2) 10-24 washers(3) 10-24 nuts(1) 4” x 8” cork/gasket material(1) small tube 3M weatherstrip adhesive


METRICQuantity Size Description

(1) 1.6 mm x 32 mm x 183 cm steel square tube(1) 3.2 mm x 32 mm x 183 cm steel square tube(1) 3.2 mm x 25 mm x 56 cm steel square tube(1) 3.2 mm x 40 mm x 125 cm steel angle(1) 127 mm x 12 mm bore pulley(1) 83 mm x 12 mm bore pulley (2) 203 mm x 32 mm steel corner brackets(1) 152 mm x 28 mm steel corner brackets(1) 64 mm x 152 mm caster wheel frame (203 mm wheel)(1) 6 mm x 100 mm x 114 mm flat aluminum(1) 3.2 mm x 100 mm x 254 mm flat aluminum(1) 19 mm x 70 mm aluminum square tube*(1) 4.8 mm x 610 cm aircraft cable(2) 6 mm cable clamps(1) 6 mm turnbuckle(1) 12 mm x 150 mm full-thread hex bolt*(1) 12 mm x 100 mm full-thread hex bolt(2) 12 mm x 115 mm hex bolts(2) 12 mm fender washers*(7) 12 mm washers(4) 12 mm Teflon washers

Quantity Size Description

(3) 12 mm hex nuts(3) 12 mm stop nuts(1) 12 mm wingnut*(3) 12 mm x 22 mm x 32 mm linear bearings(5) 8 mm x 50 mm hex bolts(4) 8 mm x 20 mm hex bolts(4) 8 mm hex nuts(5) 8 mm wingnuts(9) 8 mm washers(2) 6 mm x 25 mm hex bolts(1) 6 mm x 12 mm hex bolt(1) 6 mm washer(1) 6 mm hex nut(1) 6 mm wingnut (1) 5 mm x 40 mm machine screw(1) 5 mm x 25 mm machine screw(1) 5 mm x 20 mm machine screw(2) 5 mm washers(3) 5 mm nuts(1) 100 mm x 200 mm cork/gasket material(1) small tube 3M weatherstrip adhesive

*There is an alternative to using these items. They can be replaced with a 25 mm x 130 mm steel pipe which will need to be welded. See page 7 for details.



Begin by pounding the 1” x 22” (25 mm x 56 cm) steel square tube into one end of the 1/8” x 1 1/4” x 72” (3.2 mm x 32 mm x 183 mm) tube until only 12” (31 cm) of the 1” (25 mm) tube are exposed. Layout measurements for the holes to be drilled as shown. Use a centerpunch to mark them all. Note the “x” marks on the 1/16” (1.6 mm) piece: centerpunch but do not drill these points. Drill all the other holes completely through the steel tubes.

If a 1” od x 5” (25mm x 130 mm) steel pipe is going to be used for the dumbbell weights, there is no need to drill the 1/2” (12 mm) hole in the steel square tube. See page 7 for details.


Attach the 1/16” x 1 1/4” x 72” (1.6 mm x 32 mm x 183 mm) steel square tube onto the 1” (25 mm) tube. Set the steel angle against the assembly as shown so that the cen-ter of the angle lines up with the tube joint. Drill (2) 5/16” (8 mm) holes all the way through at the centerpunched marks. (2) 5/16” x 2” (8 mm x 50 mm) hex bolts are used to hold the pieces together.

Check to make sure the bolts slide through the holes freely. Wingnuts are used to hold the pieces together securely and to allow quick disassembly. At this point, there is no need to attach the tubes together so remove the bolts and separate the steel tubes and angle piece.


A post needs to be attached to the end of the steel tube so that dumb-bell weights can be added to counter-balance the weight of the camera. A 1” od x 5” (25 mm x 130 mm) steel pipe can be welded to the top of the steel square tube. But if welding is not practical, then a post can be built as shown. Next, in-sert (2) linear bear-ings into the 7/8” (22 mm) holes.


Use a 1/2” (12 mm) drill bit to widen the top hole of the 8” (203 mm) steel corner bracket. Attach the pulley assembly as shown. Next drill a 3/16” (5 mm) hole completely through the steel bracket and one side of the pulley about 2” (50 mm) down from the top of the bracket. Insert a 10-24 x 1” (5 mm x 25 mm) machine screw and secure with a 10-24 (5 mm) hex nut.

Tighten the stop nut down just enough to prevent the pulley from wobbling, but not too tight to where it is difficult to rotate the pulley.

Feed a 6-foot (183 cm) video cable through the hole on top of the steel square tube.


Remove the 8” wheel from its caster frame. Cut a 1/4” (6 mm) thick piece of flat aluminum the same size as the base plate of the caster frame. Mark four holes on the aluminum from the holes on the caster frame, centerpunch, and drill with a 5/16” (8 mm) drill bit. Mark a spot in the exact center of the aluminum, centerpunch, and drill with a 5/16” drill bit. Use a 3/8” tap to thread the hole. Attach the aluminum to the caster frame with washers, nuts, and bolts as shown.

Attach the caster frame to the steel tube by carefully inserting a 1/2” (12 mm) bolt partly through one side of the frame, threading a nut, and allowing the bolt to pass through a washer, then through the bearing in the steel tube. Continue to thread the nut until the bolt passes through the bearing. Add a washer and another nut. Thread both nuts until the bolt passes through the other side of the frame, then lock in place with a stop nut.


Use a 1/2” (12 mm) drill bit to widen the center hole of the 8” (203 mm) steel corner bracket. Attach the pulley assembly as shown. Next drill a 3/16” (5 mm) hole completely through the steel bracket and the pulley about 2 1/2” (64 mm) down from the top of the bracket. Insert a 10-24 x 1 1/2” (5mm x 40 mm) machine screw and secure with a 10-24 (5 mm) hex nut.

Feed an 8-foot (245 cm) video cable through the steel square tube.


On the steel corner bracket, drill a 3/16” (5 mm) hole centered halfway between the ver-tical piece and the first predrilled hole on the horizontal piece. Then set a 1/8” x 4” x 10” (3.2 mm x 100 mm x 254 mm)piece of flat alu-minum centered on the horizontal piece of the corner bracket. Use the 3/16” (5 mm) hole and the last predrilled hole as guides to trace onto the aluminum with a pencil.

Centerpunch and drill the holes in the aluminum as shown. Attach the alumi-num to the corner bracket through the 3/16” (5 mm) hole using a 10-24 x 3/4” (5 mm x 20 mm) machine screw, (2) 10-24 (5 mm) washers, and a 10-24 (5 mm) nut. A 1/4” x 1” hex bolt with a 1/4” wingnut on backwards can be fed up through the 1/4” hole to attach to a camera.

1/4” x 1” bolt with wingnut


Use a video cable butt-connector to attach the video cables together. Attach the steel tubes together, mount the steel angle, and secure with the 5/16” (8 mm) bolts, washers, and wingnuts. Drill three 5/16” (8 mm) holes through the an-gle and square tubes as shown. Secure with (3) 5/16” x 2” (8mm x 50 mm) hex bolts, (3) 5/16” (8mm) washers, and (3) 5/16” (8 mm) wingnuts.

Cut a 4” x 8” (100 mm x 200 mm) piece of cork/gasket material and attach to the aluminum flat with 3M weatherstrip adhesive. When the adhesive dries, drill a 1/4” (6 mm) hole through the cork/gasket mate-rial for the 1/4” (6 mm) hex bolt that attaches to the camera.

Make sure the pulleys and caster frame are secured properly - tighten the stop nuts down just enough to prevent wobbling, but not too tight to restrict movement.


Slide two 1/4” (6 mm) cable clamps onto the ends of the cable. Loosen the eye screws of a 1/4” (6 mm) turnbuckle until they are fully ex-tended, then insert the ends of the cable through the eye loops. Take the ends of the cable and feed them back through the cable clamps.

Pull the cable fairly tight and then flatten the cable clamps with a hammer.

Next, take the 20 feet (610 cm) of aircraft cable and wrap it around the pulleys.


Adjust the tension of the cable by spinning the center metal frame of the turnbuckle until the cable is tight.

A 6” steel corner bracket can be used as a monitor mount. Widen the center hole on the bracket to 1/2” (12 mm). Remove the stop nut from the bolt holding the caster frame to the steel square tube. Run the bolt end through the widened hole on the bracket and re-attach the stop nut. Using the bottom hole on the bracket as a guide, drill a 1/4” (6 mm) hole through the caster frame and use a 1/4” x 1/2” (6 mm x 12 mm)hex bolt, a 1/4” (6mm) washer, and a 1/4” (6 mm) nut to secure the bracket.


The only parts I had to order online were the linear bearings, Teflon washers, and the caster frame.

I found frelon-lined linear bearings at this place:

http://www.qbcbearings.com/

Theyʼre more like the outer shell of a ball bearing, but they work good. They cost about $14.00 a piece.

I get Teflon washers at this place:

http://www.smallparts.com/

And I got the caster frame at this place:

http://www.castershop.com/

I bought the HS8-R, which is a heavy-duty 8” rubber wheel caster. It prices at $13.21. The wheel is easily removeable.

I found the pulleys at my local hardware store in the “swamp cooler parts” section.

Cork gasket material and 3M Weatherstrip adhesive was found at my local auto parts store.

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