Interfacing Pipe to the Real World

Speed Rail (c) (pipe) is normally attached to the rest of the world with flanges or the pipe set into concrete. The floor and wall flanges are very useful to us in the film business. Drilling a few holes for drywall screws is very handy for lighter load applications. Drill your holes to maintain as much strength of the fitting. I find that 4 dry wall screws into wood will hold moderate loads. Don't hesitate to jump on, shake or rattle a rig to see if it will take more than the load that you intend to put on it. Remember the stress when thing accelerate, decelerate and get bumped.

6" stubs of pipe welded to about 3" square plates of 3/16" or 1/4" metal can be very useful. If you use aluminum, make sure that it is weldable. It can be coded with blue paint markings and 3000 or 6000 alloy numbers. Red paint and 2000 or 7000 alloy numbers are usually alloys that are not weldable. Check with your metal supplier. I have welded for almost 40 years, but still send out my structural welds to a certified welder. DON'T TAKE CHANCES.

If you are attaching to plywood, flat head bolts can be useful to maintain the flat surface on the plywood. A triangular wall flange will require a flat head bolt if the pipe needs to go through the fitting. A washer and nut has to go on the other side. Washers are desirable under nuts and bolts to prevent them from pulling through the plywood. You might consider buying one sheet of "marine" plywood which has no voids inside and often has more ply. A coat of paint will help preserve the plywood and color-code it "for rigs only". The paint might also make it slightly more "professional" looking. Leave enough plywood near a fitting so that the plywood doesn't fail from the holes that you have put in the plywood.

When attaching to metal, taping the holes is often best, IF THE METAL IS THICK ENOUGH. A 3/8"x16 taped hole in 3/16" steel would be safe, but in aluminum 1/4" is barely strong enough. Holes taped in cast aluminum are weaker yet. Using Helicoils will increase the strength of a taped hole and prolong the life of the hole. Do not attempt to drill and tape holes with a hand drill without some method to assure straight holes and tap alignment. Taping drill size and taped holes in a block of aluminum done on a drill press can assure aligned holes and taps when drilling by hand. Hold the block securely against the surface being drilled and taped. Drilling and taping is not often a field process. Nuts on the other side usually do the job in the field.

Always consider a more rigid shape than flat metal when attaching to something. Angle and channel are stiffer per pound than plate. A triangle brace can greatly increase stiffness. Larger, but thinner pipe can be much stiffer, although harder to find or make fittings for. Fortunately in the larger pipe sizes, pipe telescopes or almost telescopes so that fittings can be fabricated from the next size pipe.

Be careful to not score the wall of an inside tight fitting pipe with a set screw and jamming the pieces together. Tight fitting aluminum joints can jam when metal is pulled loose and piled up. Smooth surfaces, some lubrication and anodizing will prevent jamming. For thinner sections of pipe consider a plug inside the pipe to prevent the set screws of Speed Rail (c) fittings from collapsing the pipe. Sked. 5, 1-1/4" pipe makes a very light weight (5 lb. per tube) overhead frame for up to 12' x 12'. Be careful that the hi roller attachment doesn't crush the pipe.

Drilling holes in pipe can provide bolt holes for attachment of things, BUT HOLES WEAKEN THE PIPE. A 3/8" hole in 1-1/4" pipe doesn't effect it much, but a 3/4" hole would greatly weaken the pipe.

Remember, ALMOST ALL THE PIPE THAT WE USE IS MUCH STRONGER THAN THE FITTINGS THAT WE USE WITH IT. Steel Scaffold fittings are stronger than Speed Rail (c) and Kee Klamp. Well placed triangulated braces can reduce the strain on anything that you build.

Consider perforated telescoping square tubing for some applications. Unfortunately the best sizes will not fit into Speed Rail (c) clamps. Consider perforated steel angle, "Dexion" is a brand. Dexion makes a shear that cuts their angle in a stroke.

© Copyright 1999-2004 Ron Dexter. All Rights Reserved.