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Sharpening your roller knife?

on a buffer ?

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#1 jskeen

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Posted 25 August 2011 - 11:09 AM


My rolling blade on my homemade handle was pretty darn dull, and I needed to make up some tapered 107 bandsets to play with, I had tried sharpening it before by putting it on a shaft, chucking it in a drill and running it against a leather strop charged with tripoli compound, with less than stellar results. This time I decided to try holding the blade and moving the abrasive, ie A buffing wheel. By changing the tension on the fancy blade holding device (nut and bolt) in my fancy handle (scrap of wood) I got it where by buffing at about a 40 to 45 degree angle, the blade would slowly rotate as it was polished. About 1 or 2 minutes on each side, and it slid through the rubber like it was red hot! It didn't work that well when it was new.

Give it a try, you might be able to recycle some of those old blades you have stacked on the back of your workbench, if they are not actually nicked or bent.

James

#2 Charles

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Posted 25 August 2011 - 01:26 PM

Good tip! There is a commercially made gizmo for sharpening the blades of rotary cutters ... you can find it in a good fabric/sewing shop. But it costs about $20 locally.

Cheers ...... Charles

#3 AZ shooter

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Posted 25 August 2011 - 01:32 PM

Even though the blades might be bent they can be brought back to a working shape...When chiefs strop their kitchen knives on a steel it is more for straigthening a bent fine edge...A harsh abrasive may not be necessary to bring a blade back to life...

#4 bj000

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Posted 02 September 2011 - 07:06 PM

exactly. more often than not, the blade needs to be straightened , not sharpened.

View PostAZ shooter, on 25 August 2011 - 01:32 PM, said:

Even though the blades might be bent they can be brought back to a working shape...When chiefs strop their kitchen knives on a steel it is more for straigthening a bent fine edge...A harsh abrasive may not be necessary to bring a blade back to life...


#5 Hrawk

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Posted 02 September 2011 - 08:26 PM

I made up a small arbour and use a drill press to sharpen mine. Tried using various stones, but in the end the best result I get is from Ez-Lap diamond hones.

I like to get them crazy sharp, so I bring it down to about a 20 degree angle.

To keep them sharp as long as possible, it's all about the cutting surface. The self healing mats from Olfa are probably the best. I cringed when I seen pic recently of someone using a glass chopping board.

#6 philly

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Posted 02 September 2011 - 09:09 PM

I sharpened mine by hand with a fine india stone, works better than when new. I was ready to give up on it and get an Ingento 15" paper cutter but now, after sharpening it cuts fine.
Philly

#7 Hrawk

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Posted 02 September 2011 - 09:21 PM

I would describe the factory edge on 99% of knives and tools these days as being average at best.

I'm pretty sure a lot of people could extend band life considerably if their cutter was sharper.

Or just go crazy like I did and buy a Roto-Trim with a tungsten carbide blade. I've never had to sharpen this, nor do I think I could if I tried, not without a specialised grinder anyway.

#8 NaturalFork

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Posted 02 September 2011 - 09:28 PM

I bought brand new replacement blades at my local craft store and they SUCK. I need a tungsten blade as hrawk has.

#9 jskeen

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Posted 02 September 2011 - 10:34 PM

Steeling a long relatively straight edge like a kitchen knife is indeed more about standing the microscopic serrations that make up a cutting edge back up straight and aligning them. Sharpening an edge against a flat, abrasive surface like a stone or grinder belt is to reset the flat bevels that lead up to the fine edge after it has been worn into a rounded profile and no longer has a fine edge.

What I'm referring to doing here is more like stropping a straight razor on leather. Buffing from the center to the edge instead of from the edge to the center means it's going to be realigning the edge, rather than reshaping the bevel. The cotton buff is soft , and the abrasive loaded onto the wheel polishes the sides of the bevels and also coats them with a nice coat of wax that helps it slide through the rubber. It won't takes nicks out of the edge or fix wavy cuts if the blade itself is warped, but it will make a blade that you have to bear down on to get it to cut, slide through the rubber much better. Give it a try sometime.

#10 Hrawk

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Posted 02 September 2011 - 10:49 PM

Olfa make a tungsten blade. Well priced too. 45mm only.

http://www.olfa.com/...spx?C=17&Id=106


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