Munkul
Jack of some trades, Master of none
- Messages
- 7,366
- Location
- Cumbria
I'll be interested to find out if they're any good, from the horses mouth rather than merely Googling for a recommendation.
I hesitate to suggest anyone because I have used a professional blade sharpening outfit once: for my precious, irreplaceable twelve inch blades from a mitre trimmer I restored. Basically, I paid good money for them to be ruined beyond usability. They ground them so short they would no longer reach.
My other interest is to discover what if any special profile should be maintained. Easy to imagine they're a simple dead square right angle with a flat grind but I'd be interested to discover if that's true. I know some cropper/chopper/trimmer blades have a slight concavity, dunno if that's also true for these big crude sheet croppers.
Kennedy grinding have done our Wohlenberg high speed film cutting blades for years and years. We have both HSS blades and carbide blades, and about 1 year ago, we were having problems with blades chipping and causing marks in the film. Really important quality issue, even though the chips were so small you could barely see them with the naked eye.
Kennedy did EVERYTHING THEY COULD to alleviate the issue... trying different cutting angles, different honing techniques, the lot. Nothing seemed to work. They even bought a brand new blade off their own backs.
Eventually we realised that the problem was caused by tiny metal particles in recycled cardboard used to seperate film pack layers. Changed cardboard supplier, problem fixed.
We could not have asked for better service or expertise from Kennedy, and this was all over less than a grand's worth of sharpening per year, in normal years!