Homebrew knife sharpening unit

HeavyHanded

HeavyHanded

Joined
Jun 4, 2010
Messages
6,642
Have gotten this past the proof of concept stage and am debugging it. Works very well for sharpening, allows use of a wide variety of bonded and solid abrasive materials and uses same physical mechanics as freehand.

Will need to upgrade my abrasives at the low end to whip up regrinds with any efficiency. Is capable of doing so now with off the shelf wet/dry but is too slow.

Video under 15 minutes, a short demo with explanation of functionality. Thanks for watching!

[video=youtube;r4N_j3c3MtM]https://www.youtube.com/watch?v=r4N_j3c3MtM[/video]
 
45Shooter said:
Going to be selling this as a system when everything is worked out?
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Whew, I really don't know. I built it to my taste and was able to use the existing drill press and DC motor with controller from a decomissioned machine at work. Am considering ways to shrink it down somewhat but it would be whistling expensive to create one as is, maybe $600 for the base unit and then the disks at $100 per. There are already a number of disk units on the market, so a patent is probably not viable even if there are some differences between mine and the rest. No patent protection, short on start up capital, crowded competitive market, etc, etc....I'd love to sell it if I can get all the kinks worked out!

My current role for it is to offer less expensive sharpening services in addition to or in conjunction with my Washboard block and the relatively modest amount of commercial freehand sharpening I do.

Not enough people know or care greatly about the difference between a fine freehand edge and a Chef's Choice edge at .50 an inch.


Thanks for watching!
 
Martin, Using Jointer disc stone is brilliant - flat hard surface and keeping the edge cool :thumbup:. Maybe name your new product a MultiCut Edge Maker due to dynamic angle changing as the edge traverse across the disc surface, combination of edge lead+trail+perpendicular directions.

Good video, I can clearly hear the sound of apexing on the jointer stone disc. I wouldn't worry about wobbling at certain speed - easy to balance production disc and axis of rotation later. Looking forward to seeing your next iteration of your MCEM device.
 
I'm not an electronics or motor guy on any facet, but I do a little key cutting a lot of the machines use a cheap sewing machine motor for it, not sure if that would fit your needs, or control of RPMs on it, but maybe something that could reduce size and cost. It is an amazing concept for sure reminds me of a pedal style pottery wheel
 
Great video, thanks for sharing Martin. I was wondering where the man had been - now I know :)
 
awestib said:
Great video, thanks for sharing Martin. I was wondering where the man had been - now I know :)
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Yeah, I haven't been as active as usual - this project has been simmering for awhile and I wanted to push it through. There will likely be more iterations, but then again maybe not for a bit.

I'm also trying to get some upgrades to the Washboard at the manufacturing end that, if successful, will make the tooling process a lot easier. I managed a pinched nerve in neck that makes benchwork (including sharpening and tooling WBs) somewhat uncomfortable, so both projects assumed higher importance with this one taking priority.
 
HeavyHanded said:
Have gotten this past the proof of concept stage and am debugging it. Works very well for sharpening, allows use of a wide variety of bonded and solid abrasive materials and uses same physical mechanics as freehand.
Click to expand...
Hi, I can't quite see in the video, but do you reverse the rotation when switching between the two sides of the knife? Sorby used to do a kit of discs and abrasives to do something similar but using a woodworking lathe as the power plant, of course the disc is vertical in that case and lathes don't normally reverse.

Interesting that you seem to be using the part of the wheel where the movement is pretty much along the bevel, rather than perpendicular to it.

Tony S
 
aesmith said:
Hi, I can't quite see in the video, but do you reverse the rotation when switching between the two sides of the knife? Sorby used to do a kit of discs and abrasives to do something similar but using a woodworking lathe as the power plant, of course the disc is vertical in that case and lathes don't normally reverse.

Interesting that you seem to be using the part of the wheel where the movement is pretty much along the bevel, rather than perpendicular to it.

Tony S
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Yes, I normally reverse when switching sides except for the final debur. On the jointer stones I can (and do) go both directions with intent to remove the burr with a leading action though am still more comfortable with a trailing action. I find it is just as fast if not faster to remove most of the burr manually with the disk stationary.

I do a lot of the shaping along the bevel but as I pull it off the disk is where the final scratch pattern is set on the outside edge. In fact if I forget to do this and just lift it off as I work, the grind pattern is a bit confusing to look at as it tends to sweep across a 90° range.

In use I can manage a final grind path of just short of dead parallel to just short of dead perpendicular. By habit I tend to align it at a 45° angle to the cutting edge with a bias toward draw cutting, just as I do freehand.

Thanks for watching!
 
Shoes, man. Shoes.


--- Fascinating concept and video thereof. Keep up the good work, and thanks for sharing this with us.

:thumbup:

~ P.
 
The round Chosera stones might be a good stone for this system.
 
pertinux said:
Shoes, man. Shoes.


--- Fascinating concept and video thereof. Keep up the good work, and thanks for sharing this with us.

:thumbup:

~ P.
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I leave them at the door... Am not wearing them in my machete vs Washboard video either, but by habit, not by choice. I realize it later when I watch the video after uploading :o
 
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