TromboneChat

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There are some plumbing washers pretty close in size. I had a bag of assorted ones in different shapes for some project or other.
The screw hole is usually a little smaller but you might could drill it out a bit.
That might work until you can find the right one.
Failing that, it would be easy to 3D print one that would fit, but I don't know if it would be soft enough. Maybe print at low density so it has a little flexibility, or even a bit of built in flex.

Just take it to your local repair technician. I keep about 6 or 7 different brands of rubber bumpers in stock at all times.....most techs do the same thing and might even have more variety of brands. They will simply try the different bumpers and see which fits and grips it the best.

From the photo, my first attempt would probably be a Yamaha bumper. After that I might try a Getzen/Edwards and then a Jupiter (but the Jupiter bumper might be cut out too deep). Those are just my guesses from the photo. Again, always best to just take it to a tech.

I have an old 8H where the size of the rubber bumper doesn't seem to work with any of the standard bumpers in use now. My first solution was to cut down a Bach bumper with a utility knife. It eventually either fell off or wore out, and then I went to a local plumbing warehouse that had a huge selection of washers in different sizes - very cheap. I bought an assortment for a couple of bucks, and one fit perfectly and was hard enough rubber to last forever (at least so far!). It looks a little bigger on the outside than the usual, but does the job.

Jim Scott

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Modifying an existing bumper (as CalgaryTbone described) is definitely an option. I have done work on some stencil horns that had crook guards with strange tips. One trick I have used is to start with a bumper that is close in size, but slightly too tight. With that bumper, I use one of my worn-down dremel tools to cut out the inside area of the rubber bumper hole. Sometimes I rotate the cutting tool by hand. I have also chucked it into my drill and adjusted the clutch to a very slow speed.

Here is a tool online that looks very similar to the dremel bits that I use for this. This particular bit might be too wide for this purpose, but it gives you an idea of the shape of the tool. Again, I just use worn out bits that most people would throw away.

https://us.dremel.com/en_US/products/-/ ... heel-point

I just stop by my local Ace Hardware ,those folks like to help. George.

If all else fails, maybe buy a foot of vacuum hose and cut off half an inch