Domino 500 max cut depth

[rfm]

It is possible that this question has been already addressed, however I couldn't seem to find a search function on this forum.

I have a newly purchased Domino 500.  It comes with a 5mm bit.  According to the manual, the max cut depth is 28mm.  When I attempted a 28mm test cut with the 5mm bit, the end of the shaft burned the top & bottom of edges of the cut.  The obvious reason for this is that the diameter of the cutter increases toward the mounting point.

I have two problems with this. (1) I cannot find in the documentation where it states that there are differing maximum depths for different cutter diameters, and (2) I cannot understand why this insanely expensive tool wasn't designed such that the advertised max depth would be available for all cutter sizes.

 

[Grev]

Here's an old thread on this ... hope it helps.
Domino depth of cut

 

[RKA]

Unlike a drill the oscillating mechanism puts some lateral forces on the bit.  With the smaller bits there isn't enough meat to withstand those forces and of course the further you go out from the base of the bit the more significant those forces become.  They shortened the bit to offer an added option to use smaller dominos and still provide a service life that's measured in thousands or mortises. 

If you really need a deeper small mortise, maybe a mortising bit in a drill press would be a better option?  Obviously more fiddly, and you have to bring the work to the tool, but it will better meet your needs.