Stromberg Carlson Rubber Feet Replacement

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This topic only applies to replacement of rubber feet on the SC 1243 or similar telephone bases. This is what they originally looked like:



These rubber feet were a bit more than 1/2" in diameter and just a bit more than 1/4" tall. They are one piece rubber feet with a groove that allowed them to be inserted in each corner of the base.  If missing, the corner would look like this:



Very similar rubber feet designed to be attached to the bottom of wood cabinets using wood screws are readily available from multiple sources, I found these on eBay:



The feet are 1/2" in diameter and 1/4" tall with an internal steel washer that allows a #6 machine screw to pass through to mount the foot.

This is what one foot looks like showing the recessed area on it bottom to accommodate the machine screw head and the flat surface which goes against the base of wherever it is being used:



There are 5 things used to mount one of these to the metal base of a 1243 creating a rubber foot almost like the original foot:



This is what the assembly looks like when attached to the phone base:



While my local hardware store only had truss head 1/2" long 6-32 machine screws, one can get 6-32 round head 5/16" long machine screws from major hardware vendors including Grainger which sells 100 for $3.15. Below I show how I modified a 1/2" long truss head machine screw to work.

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From hear on, I am using a 1/2" length screw that would be left as is or cut down to 5/16" before using. The first step is to insert the screw into the rubber foot, place the #6 washer on the screw and place the assembly into the base hole:



The #6 washer just fits the existing hole and acts as a machine screw centering component.

Then, the #10 flat washer is placed on top of the #6 washer effectively trapping the centering washer in the base plate keeping the machine screw in the center of the base plate hole:



Finally, the nut is placed on the machine screw and tightened down. Since the center hole of the #10 washer is larger than the #6 machine screw, it is important to keep the #10 washer centered on the machine screw when tightening it down.



This is what it looks like from the side, the centering washer is plainly seen in base plate hole.



It's obvious that the 1/2" machine screw is too long and can be left as is (not recommended), cut to a 5/16" length before assembly or simply buying and using a 5/16" machine screw.

As I said, I could only get larger, truss head machine screws from my hardware store:



The head would not fit into the rubber foot, what it should look like in this image:



The next reply will show how I modified the truss head to work. Any 6-32 machine screw will work as long as the head will fit into the recessed area of the rubber foot.

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To remove some of the truss head to get it to work, I discovered that a #6 screw fits into the chuck of a Dremel tool. This is the original truss head machine screw in my Dremel:



I have a speed control on my Dremel and by setting it on slow and using a regular steel file, I was able to easily remove enough edge material so the machine screw head would fit into the recess. This is what the head looks like after milling off a bit of material:



The final assembly, mounted, with either a cut off machine screw or an original 5/16" machine screw looks like this:



If it is necessary to cut a longer machine screw down to 5/16" it is highly recommended that the cutting be down when the screw is not attached to the phone base. Metal fragment from the cutting could get into the phone works and that would not be good.

Buying small quantities of washers and screws from a hardware store gets expensive. I paid $11 for 12 feet and the hardware to mount each foot cost $8.20. That's about $1.60 for each foot.

And since the replacement foot is just a bit smaller than the original feet, it is probably best to replace all 4 to keep them looking consistent and to prevent the phone from "rocking."

While the cost of replacing 4 feet is about $6.50, this was both a necessity for me (one foot was missing) and a learning project, a hobbyist thing to make something better than it was and to learn from the experience at the same time.

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I don't have a small, desk top lathe but having used on in the past, if anyone wanted to make an exact reproduction foot or feet, it seems a #2 rubber stopper (which can be found at Science and Surplus and similar stores including hardware stores), is about 5/8" to 3/4"  in diameter (tapered) by 1" long with a hole in the center would be a good starting material.

A metal rod stuck through the stopper, as a mandrel, would allow turning (cutting) of the rubber stopper with a lathe to exact dimensions. The original feet have a hole in the center and I suspect that it was used to cut the feet (there are not mold marks on the original feet)

Here are the dimension of a SC 1243 rubber food should anyone want to try this: