Adventures in Reed Machine Land

The Way of Cane Reed Machine Service

Recently I received a Pfeifer single profiler to service that had an extreme problem I had never encountered before: the carriage and shaft were completely "welded" together and would not move at all. Typically the carriage and shaft are difficult to move – but never completely frozen like this. A previous owner had taken the machine apart and tried to bang the shaft through the carriage probably with a normal type of metal hammer, but that didn’t succeed in freeing the parts and additionally deformed both ends of the shaft. I eventually got the problems solved which I’ll describe at the end, but I’d like to take a brief aside here to discuss one major point:

It is important to take proper care of the moving parts of your our reed machines.

Because we want to keep working on our reeds, we often forget about paying attention to treating our machinery with respect and care. This means cleaning them and keeping the moving parts well oiled.

There are two types of bearings used in the moving parts of our reed machines: plain bearings and ball bearings. The older machines that I have serviced and own usually have plain bearings and by that I mean that a hole bored into the carriage metal for the shaft to fit through and ride on.

I just measured the size of the hole and the shaft of my Pfeifer and both are 1/4". I cleaned off the old oil and gunk while I was at it and without oiling the parts before assembling them they would hardly move at all. Adding a drop of oil on each side of the carriage the parts then moved quite easily!

Here is a photograph of my Pfeifer’s plain bearing.

You can see it’s a very simple type of sliding system and it relies on being kept clean and well lubricated to easily move.

This type of plain bearing generates friction from the large surface area of the parts rubbing against each other. Microscopic bits of metal get worn away from use and collect in the oil (we hopefully used on the shaft!) and also in water that might get inadvertently on the shaft. This can turn into a cement-like mixture like I found in the Pfeifer I’m describing above.

The use of ball bearings in recent reed machines diminishes this sort of problem to a great extent. The wear from a machine with ball bearings is much less since the friction is taken up with many tiny metal balls that roll when the parts are moved against each other rather than just rubbing against each other along the entire inside surface of the carriage’s bore.

Here is a generic photo of a small ball bearing. The outer race would be held in the carriage (in the case of our reed machines) and the inner race is where the shaft passes. Although these bearings eliminate the problems of the plain bearing, I lubricate my machine's ball bearings anyway.

Here is a photograph of a Reeds ‘n Stuff carriage and shaft:

I often get machines sent to me because they are hard to move and no longer profile (or gouge) cane to the bassoonist's target dimension. The two factors that cause this are the lack of good, free movement of the carriage AND the gradual dulling of the cutting blades. Adding the lack of easy movement to a blade that no longer cuts well adds up to a basically poorly working machine; it's hard to move the carriage and it barely cuts the cane. No fun!

As to drifting away from the target dimensions the bassoonists used to get, the blade’s straight, sharp edge has been worn away. That is why over time the profile seems to get thicker. Many bassoonists complain that their machine's settings are drifting — but in my opinion, it’s that the blade has worn back from square so it cuts less into the cane.

Here's a microscopic photo of a worn blade's cutting edge. The bright white on the blade's center edge means that the cutting edge now has enough thickness that it will reflect light. You'll notice toward the sides of the blade the reflections are less and therefore sharper having received less wear. A really sharp blade will not reflect any light from the cutting edge.

This curve inward will result a heavier profile by several thousands of an inch and the dullness makes it hard to move the blade through the cane; additionally it gives the cane a rough surface.

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Returning to the adventure of the Pfeifer's service that I opened this post:

First I clamped the carriage in a vice. Then by using a small, soft-faced mallet I was able to very gently and gradually tap on the shaft and get some small movement of the shaft in the carriage's bore. I used penetrating oil on either side of the carriage and the shaft to move the oil into the bore to gradually get enough between the parts to free them up.

Then the problem of the deformed ends of the shaft had to be addressed since it would no longer fit into the support posts. There were two ways to go: one was to enlarge the holes in the support posts and the other was to restore the ends of the shaft. I didn’t like the notion of modifying the holes— that would generate a whole new set of problems and pitfalls— possibly ruining the machine. I settled on turning the shaft in my drill press and filing down the distorted ends gradually to where they would fit correctly back into the support posts. Since I couldn’t get the carriage off of the shaft yet, I had to deal with it still on while the shaft was rotating. I set up a jig to hold it in place. Luckily with a file it only took a few minutes to restore both ends of the rod.

The moral of this story is to regularly clean and lubricate the moving parts of your reed machines— especially the older ones with non-ball bearings.