Sharpening/replacing robo coupe slicing attachment blade?
This one http://i.ebayimg.com/images/g/mSEAAOSwoydWlvGI/s-l1600.jpg
Its essential to me for one of my prep jobs, but it keeps dulling so fast and they are expensive. Anyone know of a way to sharpen this blade or even replace just the blade itself? It looks like there are holes to screw it in place, but its welded or something in place with no screws when I get them.
Anyone have any luck with anything? I can't request a new one so often....
Posted Jan 28, 2016, 4:32 AM UTC
513
I see your ebay link and raise you another:
http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR12.TRC2.A0.H0.Xdiamond+file.TRS0&_nkw=diamond+file&_sacat=0
Look for some files 400 grit or higher. I think I've seen diamond files up to 600 which should be fine enough for your blade. Diamond files are also narrow enough to hit that edge through the curved slot.
If you are a knife nerd, get some abrasive cloth. One place that has nearly everything is:
http://www.sisweb.com/micromesh/
Tear off a 0.5" wide strip to drag through the slot and you can hone that edge. Micromesh has abrasives up to 13000 mesh which is far finer than the steel on that blade can represent. I got some rolls of their abrasives for work (I'm in metal work and sharpen tools often). A 2" wide strip of their 13000 mesh makes an awesome knife strop. It works very fast, because of it's very high abrasive density, and leaves a super fine polished edge.
I wouldn't bother going higher than 1000 mesh on that blade. It is important that you don't pull back on the strip. The angle left by the strip will be the tangent angle that you pull on the strip with. Pull perpindicularly to the disc and you'll round out an edge perpindicular to the disc. If you want to keep things simple, double side tape some of that cloth to a wide popsicle stick and treat it like a thin stone.
Thanks! I looked at some files in a hardware store and they looked very cheap, no info on grit. What do you think about this? Is it something I could cut a strip off and use for sharpening the blade? http://m.ebay.com/itm/Hg-Diamond-File-Sheet-600-S-Size-50-x-50mm-/301860126723?nav=SEARCH
If that stuff really is 600 grit, it looks like just the right stuff.
You could use an abrasive wheel on a Dremel to skive out a strip starting your cut on the back side of the material (cutting on the side without abrasive). Don't use aviator shears or other shearing devices as the diamond abrasive is going to damage your shears.
Without a dremel....how else can I cut this into strips? Maybe I can ask the seller to do it
This guy has the thread.
Have you sharpened a blade like this?: http://www.amazon.com/Robot-Coupe-27055-Blade/dp/B00HNQBM3S
Our restaurant was just given a used r2, and I would really like the blade to be sharp.
If you have Nella knife service in town you can set up a sharpening program. They'll switch you out a blade every other month or so for about $35. Usually for free if they provide you with any knives.
Not specifically. I've sharpened lots of things though and many curved things.
Looks like it'd be easy to sharpen. All of the edge is convex which makes it possible to access all of the edge with a flat stone which is nice. My guess is that it's a fairly soft stainless steel stampable alloy which would have your stones cutting pretty fast.
It's hard to describe the technique because it's a curved blade, but I'll try.
Terminology I will use:
-primary angle: the angle of the main edge that does the cutting behind the secondary angle
-secondary angle: the wide ground face that leads to the primary angle that is thinning the blade towards the primary angle
-relief face: the flat face on the other side of the primary angled face that is flat that you can't see in the product picture
-blade hub: the plastic knob that the blade is insert moulded into
I would start by putting black ink on the primary angled face with the side of a Sharpee marker. They seem to be common in your industry for marking stuff. Apply ink to everything on that face right up to the relief face and maybe even a 1/8" band on the relief face up against the edge. If your blade is badly rounded wrap around that radius with marker. Apply a 1/8" band of ink onto the secondary angled face agains the primary angled face.
Maintaining an approximate acute 45 degree angle to the relief face wipe a 400-600 grit stone against the primary angled face while employing a rolling motion to the blade hub so you wipe across the entire edge in one stroke. Move the stone in a retreating direction (opposite of relative cutting direction) while rolling the hub as going the other way may cause the blade to chatter against the stone. If you want to practice, put a strip of packing tape onto the stone to practice your motion without taking metal off to coordinate your motions.
Do this until all of the Sharpee ink on the primary angle is gone and all you see is a narrow band of bare steel on the primary angled face between the secondary angled face and relief face. Because of the curved edge, I would probably freehand the stone instead of trying to bear the blade on a table or use a sharpening jig.
Some areas may still show a bit of ink on the primary angle. Selectively continue to grind this face until the ink is gone trying to maintain the 45 angle.
At this point you will have a burr rolled over towards the relief face.
Remove this burr by laying the relief face flush against the stone and wipe that face on your stone in the direction that the edge is intended to cut. Very little wiping is necessary to remove this burr because it will be quite thin. The reason I recommend going in the direction of cut is that my impression is that it will not drive the burr upwards into the relief face and instead will grind off. If you have one, use a much finer stone, perhaps 1000-2000 grit for burr removal against the relief face.
Unless that blade has been beaten round terribly, you are not likely to have to intentionally thin the blade by grinding the secondary angle and you probably won't until you bash away 1/3 of that secondary angled face. At that point you're in for a lot more grinding and it might be worth buying a new blade if you're not great at freehand stoning with a coarse 200 grit stone.
Fortunately food processor blades are not expected to have the refined qualities of a good chef's knife. Don't worry about sweating perfect consistency of primary edge angle. All you need is for that edge to be substantially sharp. Honestly a 45 degree primary angle is close to the angle you'd see on the edge of an axe rather than the very acute angles on fine chef's knives so you have a fair bit of leeway on getting things good enough. Furthermore the steel on that blade probably cannot support very acute primary angles anyways based on my guess on that picture.
I would not bother trying to put on very acute primary angles in soft steels. They might be very slicey, but they're not durable and a food processor is basically a kitchen lawnmower. If the blade is soft, you will not not get great life out of a very acute primary-relief angle. If you can manage it, work under a tap trickling warm water. Soft steels grind quickly which means that the particles can clog stones quickly so a trickle of water helps to keep the cutting surface on a stone free of swarf. Warm water is nice so your hands don't freeze up but it doesn't make a difference in preventing a stone from clogging.
Practicing sharpening on basically disposable really blunt things is good practice because you're not risking much anyways. Fuck, $88 is about what I spent on a really good 13000 mesh stone. If you can bring that thing back into service, you can spend that savings accumulating some nice stones to keep everything sharp in your kitchen.
I hope these instructions help. I wrote them looking at my crappy Cuisinart blade. I'm not a professional cook. I'm a home cook that does metal stuff professionally.
Damn you beat me to it.