+- The BESS Exchange is sponsored by Edge On Up (http://bessex.com/forum)
+-- Forum: BESS Forums (http://bessex.com/forum/forumdisplay.php?fid=1)
+--- Forum: Relevant General Discussion (http://bessex.com/forum/forumdisplay.php?fid=19)
+--- Thread: Powered Sharpener Setup Recommendations (/showthread.php?tid=515)
RE: Powered Sharpener Setup Recommendations - chino - 03-06-2020
Nice! If you are taking requests, can you video your sharpening while passing the blade on the Kally Rest?
RE: Powered Sharpener Setup Recommendations - Mike Brubacher - 03-06-2020
You do a really nice job with all your videos Brian and this one was particularly superb. Thank you much for your efforts in showing us the KallyRest! In addition Mr. Grepper, you've really done it now. Now you've got the Louisiana Junk Yard Dog on your tail and I'm telling you - Rupert is like a 30 pound snapping turtle - once he latches on he doesn't turn loose until it thunders. So do us all a favor and make it thunder!
RE: Powered Sharpener Setup Recommendations - grepper - 03-06-2020
Wow. Thanks Brian! A very well done, thought out and informative video. My complements on your videographer skills.
It was interesting to see that the method you developed slightly differs from mine. I generally use my index finger instead of my thumb. I put the finger on the knife handle side of the rest rather than the other side so that I can still have a finger on the blade when sharpening the tip. Not always but sometimes. There is no right or wrong way. It’s one of those whatever works best for you kind of things.
It looked like the base piece was not sliding smoothly on the mount bar. Especially when you removed the base from the mount bar it seemed to hang up at the end of the slot. It should slide smoothly. Tolerance is pretty tight there so debris buildup in the slot in the mount bar and/or on the slider block on the side of the base can cause that issue. A quick wipe with a rag resolves it.
Thanks again for making the video. It was cool to watch it.
RE: Powered Sharpener Setup Recommendations - blgentry - 03-07-2020
(03-06-2020, 06:58 PM)grepper Wrote: It was interesting to see that the method you developed slightly differs from mine. I generally use my index finger instead of my thumb. I put the finger on the knife handle side of the rest rather than the other side so that I can still have a finger on the blade when sharpening the tip.
I usually do both. I start with my finger or thumb on the opposite side of the rest from the handle of the knife. As I draw through and get closer to the tip, I usually stop (briefly), pull the blade out of the gap, then move my finger or thumb over to the handle side. Then push back into the gap and finish the rest of the blade. Like you said, this allows you good control all the way to the tip. The reason I don't start on the handle side is, there's usually not enough room for my finger or thumb over there when I start with the blade all the way choked up to the rest. Also, it feels more awkward on that side, since I'm crossing one hand over my body.
Quote:It looked like the base piece was not sliding smoothly on the mount bar. Especially when you removed the base from the mount bar it seemed to hang up at the end of the slot. It should slide smoothly. Tolerance is pretty tight there so debris buildup in the slot in the mount bar and/or on the slider block on the side of the base can cause that issue. A quick wipe with a rag resolves it.
Yes! I was sort of dissatisfied with that part of the video and glad I didn't make it look too bad. I just went out to the shop (garage) and wiped the heck out of both mating pieces. The tolerances really are tight. It slides much more smoothly now. The angle I was pulling it at (because the camera and my body were off to the side) didn't help. But now, even from that angle, it removes much more smoothly. Thanks!
Brian.
RE: Powered Sharpener Setup Recommendations - blgentry - 03-07-2020
(03-06-2020, 03:35 PM)chino Wrote: Nice! If you are taking requests, can you video your sharpening while passing the blade on the Kally Rest?
Well, you asked for it...
This video is really long. 17 plus minutes. I tried to show a lot of techniques and things. Filming this stuff is quite a bit harder than just doing it. Enjoy.
Brian.
RE: Powered Sharpener Setup Recommendations - Jan - 03-07-2020
Mr. Brian, Mr. Grepper and Mr. Mike, this is an exciting and inspiring thread for me. I was so curious if the concept works that I made my own wooden model.
I used my 2 x 60" belt grinder and on the miter saw I cut a wooden block for 15⁰ bevel angle per side. To avoid the pull of the blade into the gap I lowered the rpm to 800. This is the minimum of my regulator and corresponds to some 15 Hz three phase current! This really solved the problem with the blade pulling I faced at 1600 rpm.
Until now I have tested it on two knives only and without any experience, but it worked quite fine. I have measured the sharpened bevel angle with my laser goniometer and to my surprise the laser reflection was not 15⁰ but in a band between 10 and 12⁰. My preliminary explanation is that the when the edge displaces the belt from its straight path it starts to wrap the edge which lowers the bevel angle. The grind is no more flat but convex (sabre).
Thanks again for all your posts.
Jan
[attachment=991]
RE: Powered Sharpener Setup Recommendations - grepper - 03-07-2020
Another excellent, informative and enjoyable video Mr. Brian! I’m amazed at how good you are at it. Cadence, content and even lighting is all done so well. Thanks for taking the time to make them and for sharing with us. You make video production look easy but I’m totally sure the reality of it behind the camera was anything but quick and easy.
It was cool how you started with a very dull blade. It demonstrated the process very well. It even showed how burrs start to form in some areas along the edge and then it’s time to move on to areas that don’t yet have burr. That’s one thing I really like about the Kalamazoo 1” belt. It allows for working in small areas along the edge so as not to have to regrind areas that already have burr which only results in bigger and more difficult to remove burrs.
I also enjoyed how you demonstrated using light pressure against the belt. A few more light pressure passes is always better than trying to hasten the process with heavy pressure. Heavy pressure always in bigger, tougher and gnarlier burrs that are more difficult to remove.
Oh yeah, I’ve often wondered why bevels get wider toward the tip. I had not thought how the tapered blade gets thicker towards the spine. Good info. Thanks for the lesson. I learned something new.
RE: Powered Sharpener Setup Recommendations - grepper - 03-07-2020
Mr. Jan – That's a nice little belt grinder you have there. I find your post showing the wood angle guide very interesting because that’s the way the Kallyrest started.
To make a long story longer... On a warm summer afternoon years ago I was enjoying a sit on my back porch whilst delighting in some ice cold brews. I knew the Kally needed an angle guide so I started to ponder how it might be accomplished. Looking back, that ended up a much more involved ponder than it appeared on the surface. I was clueless. So, I decided a simple block of wood would serve as proof of concept.
The problem was that the balmy afternoon was so pleasant and the cold beer so tasty I didn’t want to get off my butt and do anything else. Earlier in the day I had been hacking through some small tree roots with a hatchet and it was sitting there by my chair. As everyone knows, copious alcohol consumption and hatchets always provide for hours of fun so I sat there in the chair, relishing the warm summer air and started to hack a guide from an old piece of wood I found around the place. I know that sounds like I’m making up a story but its true. In this case, fact is stranger than fiction. Here’s a picture of the “finished” product. Obviously, woodworking skills at their finest.
[attachment=982]
So I tried using it and it worked! Concept proved. But, it was a tad on the crude side and just didn’t embellish my shop décor. I decided to upgrade the unit.
[attachment=983]
Obviously, the next step was to create a device that was adjustable. I thought about using something like a door hinge from the hardware store, but that quickly leads to all sorts of considerations such as how to lock it in position, etc. I soon bailed on that line of thought. So I put on my thinking cap, the one with the little propeller on top, and started thinking about what manufactured, adjustable products were available. That’s actually more difficult to find than you might think. Then it dawned on me, what about photographic umbrella stand bases? Might one of those work?
Even something like that has design problems. Most basically, it has to be adjustable side to side for belt alignment and be able to move closer/farther away from the belt to accommodate varying belt thicknesses. There are a host of other problems too, but simply mounting it required some thought.
I decided it was worth a try just to see if there was any future in the idea. I purchased a couple of umbrella bases and had at it. Considering a rest hacked from an old piece of wood with a hatchet actually worked, not too surprisingly these did too, with the added feature of adjustability.
[attachment=984] [attachment=985]
While these things were somewhat functional they had their issues. They were pretty clunky to use, Rube Goldberg-esk, appeared to be basement made and I also feared MTBF could be problematic. I decided to make a far sturdier version from 1” aluminum rod. Built like a tank, it was far sturdier. No MTBF worries here.
[attachment=986]
But they were still basement made contraptions and suffered from a host of other usability as well as manufacturing issues. Clearly more needed to be done. It was around this time I started bouncing ideas off our own Mr. Mike and that changed everything. He convinced me I actually needed a manufactured product, something that I had not even considered. I decided to get serious and started designing in CAD with a goal of resolving all the problems seen with the earlier prototypes.
The Kally is not the easiest thing to design to and presents all sorts of problems. Even just mounting something on the Kally presents with headaches, let alone bent masts, varying belt tracking between units and other head-scratchers. The first attempt worked quite well and from a sharpening perspective performed as well as the current Kallyrest does. It was made from bent steel and attached to the original Kally tool rest/platen bolts. It turns out that manufacturing precision bent metal is a nightmare, and it was somewhat painful for the user to install. Once installed it was okay but still not where it needed to be. “Contraption” was an apt term to describe it. Way too many distinct pieces including bolts, screws, washers, lock washers and nuts. There had to be a better way.
[attachment=987] [attachment=988]
So once again it was back to the “drawing board” for a complete redesign. The result is the current Kallyrest. It resolves all of the problems with previous prototypes and incorporates lessons learned.
[attachment=989]
I need to give a big shout out and thanks to our own Mr. Mike. Without his erudite counsel, unwavering support and patience the Kallyrest simply would not exist. Thanks Mike.
RE: Powered Sharpener Setup Recommendations - grepper - 03-07-2020
(03-07-2020, 11:29 AM)Jan Wrote: I have measured the sharpened bevel angle with my laser goniometer and to my surprise the laser reflection was not 15⁰ but in a band between 10 and 12⁰. My preliminary explanation is that the when the edge displaces the belt from its straight path it starts to wrap the edge which lowers the bevel angle. The grind is no more flat but convex (sabre).
I have not really thought about it but how does a laser goniometer read on a convex, even if only slightly convex, surface? If it was reflecting off a perfect sphere for example, would not the angle reading vary greatly depending on where it beam hit the sphere?
Also, was the blade you measured flat or tapered? Of course, a tapered blade placed flat on a 15° surface would not produce a 15° bevel due to the angle of the taper of the blade. The weird thing is that I think that would increase bevel angle as opposed to decreasing it.
What is the large orange wheel under the grinder in your first post? A roll of orange tape on a beautiful brushed aluminum spool? A grinding wheel?
RE: Powered Sharpener Setup Recommendations - Jan - 03-08-2020
Mr. Grepper, thanks for the funny but interesting story how the Kellyrest was invented and manufactured!
Laser line reflected on a 2D convex surface consist of a bunch of lines reflected on the illuminated part of the blade surface.
Mr. Grepper thanks for reminding me the necessity to consider the blade tapper. The sides of my blade were convex with a mean included tapper angle of some 3⁰. This will explain major part of the observed difference!
The large yellow wheel is so called contact wheel and it is widely used in knife making. Its diameter is 10", and it is used as grinding wheel for hollow grinding or as a basic stock removal procedure before flat grinding.
After reversing the motor revolutions I use the contact wheel for knife sharpening also. Mounting universal support bar on the belt grinder allows me to use all my Tormek jigs.
Jan
[attachment=990]