The 225 flex shaft is the only attachment that came with my Dremel 4000 kit. My father-in-law and I gave it a quick try when we were testing all the pieces that came with the tool, but then I put it away. Recently, after ongoing difficulties with making long cuts, I decided to give it a more thorough test.
Dremel says that it’s very important to suspend the rotary tool above the working end of the flex shaft. While they have apparently retired the 2222 flex shaft tool stand, at least in North America, they will happily sell you the 220-01 workstation that can do the same thing and more. An alternative solution is also available from a third party. The flex shaft is essentially a hollow tube with a square wire rotating inside of it. Failure to elevate the tool above the flex shaft can cause the internal wire to disengage from the working end, possibly causing damage. I also didn’t want the 4000 to rest on a table top while it was running, so I looked for a way to hang it.
This is the solution that I came up with, and one that I absolutely do not recommend: suspending the rotary tool from a clothes hanger tied to an overhead lighting fixture.
Safety concerns aside, this set up actually worked well enough for me to test the flex shaft more thoroughly. It was a mixed bag. On the one hand, not having to deal with the bulk of the rotary tool makes life much easier. Another big advantage is that the flex shaft’s grip has a much smaller diameter than the Dremel 4000, allowing you to get closer and cut deeper into the material you are working with. On the minus side, the shaft is not super flexible, especially with the wire spinning inside of it at many thousands of revolutions per minute, and at times it can feel like you are fighting against it. There is also the fact that the suspended rotary tool remains more or less stationary, so your working range becomes very limited and often you have to move the material you are working with rather than the tool.
All of the above gave me the crazy notion that the best way to work with the flex shaft would be to wear the tool holder on your back, so that the rotary tool would be always suspended right above your head, giving you the full range of motion with the flex shaft’s working end. Crazy or genius?..