Yes, you should have your head examined for paying what you did, but we've all paid too much for drum stuff at one time.

I have one here like that as well I am not sure just what has happened on it but i will tell you it does not hold like one that has the hex rod parallel with the collet or in the proper place it is weird for sure..

When they made those they would have done the different machining steps on different Lathes.

They would start with a section of round bar stock.

They would chuck it in a lathe or lathes and turn the various outside diameters and dimensions.

They most likely had a different lathe for each outer machining function or they might do several on one lathe.

At the minimum the threads were probably done on a separate lathe since it would require a different setup.

After all of the outside dimensioning and threading was done it would go to another lathe to bore the inside hole. This was most likely done on a lathe but could have been done on a drill press with a special jig.

This page shows the process of boring a hole on a lathe.

http://www.technologystudent.com/equip1/mlathe4.htm

Then the hexagonal inside shape would have been broached on a press.

The last step would have been to cut the slots in the collet.

Most likely when the hole was bored into the part it was not drilled concentric to the center line of the part. It might have not been chucked in the lathe properly or in the jig if it was done on a drill press. Since the broach will follow the hole it would end up off center.

It shouldn't affect the operation of the part as long as it's not too far off.

Hi Thin Shell!

I think you're right on all counts! I spoke about this with Jim Petty and he pretty much gave me the exact same scenario. I don't even need this collet plate, but it came with my recently purchased Swivo arm. I just thought it was odd the way it was made! I appreciate your explanation!

I dont think this information being provided is correct and respectfully disagree.

... Actually this is from a different era and was made this way to accommodate the new swivomatic stuff {tom arm specifically w/ the longer 7 1/2" top hex rod}.. If you pull the hex rod out, you will see a set of grooves different from the ones on the outside or the bottom. Kinda like 2 sets of hex areas. These plates are from a very early B&B lugged bass drum and introduction to swivomatic and was made around 1958- 60 {usually Jasper shelled Rogers having the flatter 60 degree bearing edges and wider rerings}.

If you were to take a later date tom arm or plate and try it you would have problems with it fitting and would have to turn the tom to the next set of hex area in order for it to go on and visa versa. The mounting hole spacing is also different {vertical}. Having the holes closer to the inside of the collet as shown in the pic I provided.

That is why the plate holes you have been drilled and are round and not square. Someone wanted it for a later dated {bass or tom} and rather than drill holes in the drum, they drilled holes in the plate. These drums can be recognized by the assembly hardware that usually have the square headed nuts instead of hexed ones. I hope this helps.

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Hey there! You're explanation makes perfect sense. Yes, my collet does have those extra grooves running down into them. Thanks for sharing your knowledge!