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We have a massive amount of Edge Pro products so we figured it would be good to have a whole section on how to use the machine and what to use on it.
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Re: Convex edge on an EP

Mon Jan 27, 2014 3:29 pm

3 or 4 years ago I used the EP and a strop with approx. 28 micron diamond paste to put a convex edge on a Spyderco Endura. I set the angle to 18 or 20 dps and created the edge bevel. Then I lowered the angle by 1.5-2 degrees per side and created this angle. Then I lowered the angle again and again. I created 4 bevels (or 5) on each side. Then I used a strop with soft leather with some coarse grit diamond paste I got cheap on ebay to smooth out the different bevels. Then I used strops with finer and finer grit pastes to polish the bevel. Creating a convex bevel this way eliminates the variance in the angle difference created by contacting the edge at difference distances away from the verticle rod with the angle marks. The farther away the stone/edge contact point is from the rod the lower the angle when the angel is not changed on the EP setting. I seem to remember checking this once. If I remember correctly (doubtful :)) an edge right at the end of the blade table and an edge 1" away from the blade table was about .5 degrees different. This seems like it would be a hard thing to accurately repeat but once you are used to it maybe it's not that difficult. But setting the different angles like I did then smoothing and polishing the bevel created a drastic convex bevel with accuracy. I don't know about free hand convex bevel angles but using the EP you can create one from 18 dps down to 10 dps easily. Then if you use a bench stone for quick touch ups you can keep the micro bevels at or under 20 dps. Just another way to create convex bevels on an EP.

There is the Edge Pal system that has a rod that holds the stones that is bent. As you stroke it I think the bent rod changes the angle smoothly instead of creating several flat bevels like I did. The Edge Pal is not mass produced though. But some here have added changes or features to the EP so maybe someone can make a bent stone arm that will change the edge angle as the stone is stroked. Then again, maybe someone has. :)

Jack

Re: Convex edge on an EP

Mon Jan 27, 2014 4:39 pm

Thanks Jack - that sounds like a sound approach (pun intended) ;-). Good info.

Re: Convex edge on an EP

Thu Jan 30, 2014 6:46 pm

Just vary your angle on your E.P, then use and aggressive strop to blend it all in..pretty simple to convex.

Re: Convex edge on an EP

Thu Jan 30, 2014 7:57 pm

Aah, the labour......

:)

Re: Convex edge on an EP

Thu Jan 30, 2014 7:58 pm

Don't remember the site but google "Edge Pal" and find the guy who makes them. He has pictures of different bevels at angle differences of .01 degrees difference. Yup, that's 1/100the of a degree. :) I saw pictures of these bevels on another forum. At first I thought he made a typeo but I contacted him and he swears by the claim. The scratch pattern on each bevel reverses itself to make them clear. He admits this provides no actual benefit for cutting and this level of accuracy is of no benefit for cutting. But, I think it's cool. The EP could do this as well probably if there were a more accurate way to adjust the angle other than just lifting the pivot. I think he has a screw or knob that turns a gear that raises/lowers the pivot. Possibly even a digital display to read the angles. I don't remember one though. You would also need to get rid of any play in the hole the stone arm slides through. Something similar to the change Madrookie made for the EP Pro model. Using this tool you could create a convex bevel by changing the angle 3 or 4 hundred times. :) I think i changed the angle on my Apex 4 times. :) Even if the tool could do this I think you would need to develope the "tough" to actually pull it off. Getting even bevels on the Apex at 2 degree increments takes some practice and a delicate touch.

Jack

Re: Convex edge on an EP

Thu Jan 30, 2014 9:12 pm

jackknifeh wrote: ... if there were a more accurate way to adjust the angle other than just lifting the pivot. ...


With a set of feeler gauges (something like http://www.amazon.com/Lisle-68100-Deluxe-Feeler-Gauge/dp/B0009OMY9C/ref=pd_sim_sbs_auto_2) and drill collar stop, I used the following procedure.

First lock the drill collar stop against the bottom of the pivot block. Unlock and lift the pivot block, and insert one of the feeler blades between the drill collar stop and pivot block. Lock the pivot block. Check the new angle.

Repeat as necessary with different blades of different thickness.

The typical feeler gauge set has blades between .0015 inch to .035 inch. Making .0015 inch pivot block adjustments possible.

I can easily set the angle precisely to what I want. And, as long as the drill collar stop has not been moved, go back to a previous setting.

Re: Convex edge on an EP

Thu Jan 30, 2014 10:04 pm

That's a good idea. I'll remember that if I ever need to be that accurate. When changing stones of different thickness there is a tiny flaw in the accuracy. The report Langarian wrote hit on this in one section. He explained the reason for the inaccuracy based on algebra. I didn't understand it because I can't tell the difference between a circle and a triangle. :) I had noticed it in the past but it was only noticable when using grits above 4k or so. I think this is because the coarser grits just create a new angle after one or two strokes. But the finer grits don't remove enough steel in one stroke to remove steel from the entire width of the bevel. You can see where it hit high on the bevel (or low, don't remember). Then I would make a tiny adjustment to get the stone to hit the entire bevel left by the last stone. But, maybe using a feeler guage to make this tiny adjustment could work. I would need to play with it to see what thickness would be needed. OTOH, this can really get more complicated than it needs to be. I've gotten pretty accostomed to making these tiny adjustments. Nothing wrong with another option though.

Re: Convex edge on an EP

Fri Jan 31, 2014 9:27 am

Doug,

Your feeler gauge idea was some world class stuff. No shit shipmate. I will never personally fuss with that, but building on the already great drill collar idea and other tricks is what the EP community needs.

Cheers,

Rick

Re: Convex edge on an EP

Fri Jan 31, 2014 1:09 pm

jackknifeh, Rick,

Thanks for the kind words.

But, to make tiny adjustments is not the reason I started using a feeler gauge. I am lousy at the small adjustments and not very good at the medium adjustments. For me, adjusting the pivot block was just so frustrating and time consuming. The proper technique seems to elude me.

But feeler gauges are easy.

Plus I have a calmer mental state to start the sharpening.

Doug

Re: Convex edge on an EP

Fri Jan 31, 2014 6:03 pm

MadRookie wrote:Aah, the labour......

:)



Coming from the guy who spends 5+ hours mirror polishing super steel , only to put a 1k microbevel on it haha!
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