Shaping Small Parts From PVC

With a Pyrex measuring cup, a little water, a piece of PVC, and a microwave you can shape plastic pieces that enable you to do and make useful things.

WARNING: Our PYREX cups are several decades old and work well with high heat.  I just learned PYREX was sold to a company off-shore that uses a different composition for the glass, and it is prone to exploding violently under heat stresses that were no problem for the original PYREX.  It sometimes explodes as you are removing it from an oven.  (October 12, 2009)

Pictured is a half-round piece of PVC I had left over from another project. The flat square was made by cutting a piece from the half-round and heating it while the water in the Pyrex cup boiled in the microwave for two to three minutes. I removed the cup from the microwave and used the tongs to pull the PVC piece from the very hot water. The tongs also helped to unroll the softened PVC so I could place the piece of wood over it and hold it flat against the countertop until cooled and firm. In the absence of a good supply of Plexiglass, some PVC flattened with the aid of a microwave and some hot water offers some impromptu versatility.

My brother and his wife have a nice tripod for their camera. The tripod features a quick-release plate for speedy attachment and removal of the camera. The plate with the quarter inch x 20 thread screw fastens to the camera. Their plate is flat rather than stair-stepped, as you see in this photo from Google Images. Note the yellow lines I added.

Their daughter borrowed the tripod and forgot to remove the quick-release plate from her camera. They drove seven hours to our house on their way to a vacation before they realized they did not have the mounting plate they needed.

I flattened some PVC, squared it up, cut it to size, beveled two of the edges, and drilled for a bevel headed 1/4 inch x 20 thread screw. They were on their again way with a usable tripod.

We got a new sound system in our church with new microphones. The new microphones require a different holder. I removed a strip from some white PVC according to the circumference of the microphone compared to that of the PVC. I heated the PVC in the microwave with a measuring cup and water to soften it. Then I held it tightly around the microphone while it cooled. (It is a good idea to wear gloves because of the heat.) When it was cooled, it fit quite well with just the right amount of tension to hold the microphone. See the red arrow.

Part of the old microphone stand could be used again. (Black arrow) I had some steel that was the same thickness as part of the old stand. (Green arrow) I had to weld a piece to it and attach the PVC with short screws. (Yellow arrow)

I used spray paint on the white PVC and it has not rubbed off, not even inside the holder. Some people have been very surprised when I explained to them where we got this microphone stand and from what it is made.

This is an Amazon photo of the suction cup windshield mount for our Garmin GPS. I do not like it because it detaches from the windshield while I am driving. I want a mount that sits on top of the dashboard. I want to use the ball socket for this mount, too.

My wife is gone with the GPS right now, but, before she left, I measured the diameter of the ball mount with a caliper and did not disturb the caliper. It is about 17 mm or just a tiny bit more than 21/32 of an inch.

I set a fence on my bandsaw for 18 mm and ripped several strips from a flat piece like that shown in step 1. I need five thicknesses of PVC to gain a block of PVC a minimum of 18 mm high.

I did use pusher sticks to keep my fingers away from the bandsaw's blade.

I tried gluing the five pieces together with epoxy, but that did not work so well.

I marked the center of each piece and drilled them so I could tap all five holes with 10-32 threads.

I had some 3/16 inch steel rod that I threaded with a die for 10-32 threads. The length of the threaded portion was just right at 18 mm.

I turned all five pieces onto the threaded rod and tightened them finger tight.

I cut the steel rod so it was only a couple of inches long and chucked it in an electric drill. I held the spinning PVC block against a spinning grinding wheel to shape it into a sphere. I stopped often and checked my work in several different directions with my caliper. I tried to approximate the same amount of drag I felt on the caliper when I sized the original suction-cup ball mount.

I scribed a 17 mm circle with a draftsman's bow compass and used it, too, to check my work.

In a couple of days I will be where my wife is and will check my sphere in the GPS's mounting socket. I can fine tune the fit the rest of the way with some sandpaper.

This is a drawing of what I have in mind for a GPS stand. It will be made of wood. The sphere and its shank could pull out of its hole for storage in the car's glove box. The same is true for the two dowel legs.

Update: I have made this dashboard mount for our GPS and it works great. I made it to be a little more compact than is shown here. The sphere I made from PVC was just a little oversize, but I held some sandpaper against it while spinning it in a drill and it works as well as the factory version. I may be able to supply a photo later.

I am thinking about a mounting base for my Dremel that would allow me to make spheres very easily by rotating the mount for the Dremel. Here you see a piece of PVC that has been softened and formed to the contours of the Dremel's underside. I am thinking of using a radiator hose clamp to fasten the Dremel to the PVC and screws to fasten the PVC to a wooden base.

Being able to shape parts from PVC softened in water in a microwave opens some very helpful possibilities for the home workshop.