Sharpened blades seem wrong

post a picture and we can compared it to what we have on our stock blades. 

Hiya I've got a couple of pics and am attempting to stick em in this post;  The first is looking along the tooth and the second down onto it.

Here is a link to the only thing I could find, regarding the difference between sharpening a rip blade, vs. a cross cut blade.

www.lostcrafts.com/Farm/Blacksmithing-22.html

Of course, if you really want a definitive answer, something you could take and show the fellow if your right and he is wrong, $32.50 buys you a new 12-tooth Mafell blade.

www.toolnut.com/mafell-092560-12-tooth-tct-saw-blade-120mm-1.html

Perhaps contact mafell UK. I'm sure they can tell you what it should be. I take it you're not to close to a British dealer?

I can only talk handsaw sharpening as that's just about all the sharpening I've done apart from the occasional blade of a Lucas Mill, which was sharpened in one plane only.

It really depends on the use the blade will be put to. USUALLY ATB teeth are better for x-cutting. The alternate top bevels have sharp triangular knife-like points to sever the wood fibres, with the intermediate wood between the two "cut" points easily crumbling into the kerf. Ripsaws generally have flatter points (sometimes completely) and act more as "chisels" to sever the fibres ALONG their length, which is a much tougher job to do, with deeper gulleting for swarf clearance.

Generally in handsaws (& chainsaws for that matter) ripsaws have fewer teeth, deeper gullets, flatter bevels and much shallower sharpening angles (5-15 degrees, usually 10). X-cut saws have shorter tooth pitch (more PPI), alternate top bevels or maybe "triple chip" (2 x ATB & a third double bevelled flat-topped tooth in series) shallower gullets and about 30 degree angle. If the saw or chain has depth limiting "rakers" then generally the ripping blade benefits from shorter rakers, whilst the X-cut will suffer less kickbacks from taller rakers.

In addition, the hook angle of ripsaws is generally much greater than x-cut ones. In this instance, this is where circular blades are much different to handsaws. A rip handsaw would have a "zero" or maybe only slightly negative hook, whereas a x-cut would have up to about 30 degrees of negative camber on the face. Circular saws would instead have a positive hook of up to 30 degrees or a reduced hook of about 5-10 degrees respectively, or even a "negative hook" (bit of an oxymoron there) of up to -5 or even -10 in metal cutting miter saws & radial arms.

12 teeth are an extremely small count for a 240mm +/- blade. Yes, I know it's the standard blade, but its still an "unusually" small count for general purpose use. I suspect your doctor sharpened what he saw & therefore thought was a ripsaw at the more extreme geometry required for ripping blades. I use 18t ripping blades in my 240mm saw (Elu) to reasonable effect. Anything including or less than about 24 teeth in a 240mm size would "normally" be regarded as a ripping blade: anything above about 30 teeth as a x-cut. Without having been told otherwise, It's not at all unrealistic for your doctor to have misinterpreted your blade as a dedicated ripper without being told otherwise, meaning that he has used his 30 yrs of experience to anticipate the (incorrect) use to which the blade would be applied. So maybe both of you are both right & wrong at the same time!

I've now had a look at a stock blade at the nearest dealers.  The teeth have definitely been re-ground to a steeper angle.  I've spoken to the owner of the sharpening company and he really does seem to know his stuff.  However getting any info out of Mafell is a bit tricky. We've phoned them in Germany and the "saw doctor" and Mafell chap think that a "steeper" grind should work fine, but no-one knows the stock angles and whether steeper ones are going to cause big issues.

All I know is the grind looked wrong, is different to stock and something doesn't "feel" right when I'm ripping.  I may just be over-reacting.

As an aside, whilst at the dealers (who stock both Mafell and Festool), I mentioned that if I'd waited I could have got a Festool HK 85 EB-Plus FSK420, which seems like a KSS80 clone, for £300 less than the Mafell.  The chappie there didn't recommend it and said it felt more like a toy!!