Reprofiling M390 using Sharpmaker CBN rods

[Sharp Guy]

Nice job Pat! You've got some talent. Good to see you putting that to use. What else have you been messing around with?

Thanks Rick. I have a couple other things in the works but haven't had much time to work on designs lately. Been setting up a third 3D printer. :) I started designing something for the Hapstone and Edgepro type sharpeners. Got it about 2/3 of the way done, got a little stuck, and got busy with other things. I tend to work on things like that better if I step away for awhile and then come back and continue with a fresh mind.

[jpm2]

Those would sell...
I've always wondered why no one offered them. Been meaning to make some from wood or metal.

Yeah maybe. Problem is use isn't as easy as you'd think. There's a wide variance in stone thickness and it effects the angles. I noticed the same thing when I made the triangle bases for ZrowsN1s. Even though I tightened up the slots the angles still changed because the triangle stones are all a little different. Not much but it doesn't take much to make a significant difference. Pretty easy to correct with a little brass shim stock in the back though. But the amount of shim necessary changes for each stone/slot combination. It's even worse with the Moldmaster stones. Especially since you have to flatten them periodically. One of the Moldmaster stones in the grey base pictured actually has shims behind it to make it the same as the other side. I have 10 Moldmasters and one of them won't even fit the slots until I lap it. All others fit but some fit more loosely than others.

Gonna make a single slot (1" x 3/8") base to hold my double-sided Venev bonded diamond stones next. I don't want to buy another set. So I'll use 1 stone at a time and just flip it around to do each side of the edge.

I figured shims would be needed. My most used stones in a holder like that would be 1x6 diamond plates and doublestuffs.
If Spyderco made a holder for its doublestuff, I'd buy it.

[Sharp Guy]

I figured shims would be needed. My most used stones in a holder like that would be 1x6 diamond plates and doublestuffs.
If Spyderco made a holder for its doublestuff, I'd buy it.

The way I have the model set up it's pretty easy to change for stone size and angle. Anything over 1" wide would be a total rework. I also need a sample to get the slot size just right. The slots on the 1" x 1/4" aren't exactly those dimensions. It took several small single slot protos to get it right. Same with the shape for the triangle rods.

I noticed you're in TX. Anywhere near the DFW area?

[jpm2]

I figured shims would be needed. My most used stones in a holder like that would be 1x6 diamond plates and doublestuffs.
If Spyderco made a holder for its doublestuff, I'd buy it.

The way I have the model set up it's pretty easy to change for stone size and angle. Anything over 1" wide would be a total rework. I also need a sample to get the slot size just right. The slots on the 1" x 1/4" aren't exactly those dimensions. It took several small single slot protos to get it right. Same with the shape for the triangle rods.

I noticed you're in TX. Anywhere near the DFW area?

I can imagine the pains getting the slot dimensions and angles right, it's the nightmare I have about making one.
My plates are right at 1 x .25" or a couple thou under. Doublestuff is about 1.015 x .255", no problem shaving it down to fit.

I'm a few miles west of Texarkana.

[TkoK83Spy]

Stupid question...so I've marked the bevel and apex with sharpie and have begun grinding away at the 30 degree setting. I'm not hitting the apex, but more so along the bevel just below the shoulder. I'm guessing this is normal until it begins to thin out to that 15dps and then will start hitting the apex?

[vivi]

Stupid question...so I've marked the bevel and apex with sharpie and have begun grinding away at the 30 degree setting. I'm not hitting the apex, but more so along the bevel just below the shoulder. I'm guessing this is normal until it begins to thin out to that 15dps and then will start hitting the apex?

Yep. When you grind the bevel at a more acute angle than its already set at, you'll be grinding the shoulders at first, then eventually work your way to the apex.

[TkoK83Spy]

Making progress. Been at it for a little over an hour, both sides are grinding away evenly, with a bit more attention needed to the show side. The bevel at the tip looks perfectly even, with a nice and pointy tip. Still working to hit that apex though, Very close!

Need to take a break because the wife and kid apparently need attention and began playing drums with the empty sharpmaker rod containers on everything in my workout/knife room :eek: :p

[A.S.O.K.A]

Thats why I'm glad to have picked the Edge Pro years ago. I can adjust the rod holding the stone or plate based on thickness difference.

[awa54]

If anyone cares to try them:

https://www.idahoners.com/product-page/ ... eplacement

They certainly won't replace a guided system, or even a coarse bench stone for reprofiling, but at least you don't need to worry about wearing the abrasive off of the rods like you do with the Spyderco diamond and CBN rods.

[JD Spydo]

Also I've found M390 blade steel seems to respond well to a high quality, medium grit diamond benchstone. Most of the time I rarely have to use anything more aggressive than a medium grade diamond sharpening tool.

For a final edge I find my Spyderco Ultra-Fine 302 Benchstone ideal for finishing the M390 Millie in particular. The larger stone like the 302 seems to give me more versatility for finishing. Although the Ultra-Fine stones on the 204 Sharpmaker give M390 a good finish as well.

[Sharp Guy]

If anyone cares to try them:

https://www.idahoners.com/product-page/ ... eplacement

They certainly won't replace a guided system, or even a coarse bench stone for reprofiling, but at least you don't need to worry about wearing the abrasive off of the rods like you do with the Spyderco diamond and CBN rods.

I have a set of the Idahone course stones and they don't seem to cut very well. Maybe I just need to keep using them and see if they break in more?

[TkoK83Spy]

M390 is definitely tough stuff. Working away at it again today. No sign of sharpie left on the clip side, just the tiniest bit on the show side at the apex. Needed a break though. Probably have 2 hours in on just the CBN rods alone. Hopefully it's worth it when all is said and done.

Once its 15 dps on the CBN rods, I imagine it doesn't take long progressing through the browns to the fine and ultra fine?

[vivi]

M390 is definitely tough stuff. Working away at it again today. No sign of sharpie left on the clip side, just the tiniest bit on the show side at the apex. Needed a break though. Probably have 2 hours in on just the CBN rods alone. Hopefully it's worth it when all is said and done.

Once its 15 dps on the CBN rods, I imagine it doesn't take long progressing through the browns to the fine and ultra fine?

Diamond or CBN to medium is a pretty big jump. It'll take a while to polish out the scratches they leave. It'd be a lot quicker to microbevel. That's how I run my PE knives to save time.

[TkoK83Spy]

M390 is definitely tough stuff. Working away at it again today. No sign of sharpie left on the clip side, just the tiniest bit on the show side at the apex. Needed a break though. Probably have 2 hours in on just the CBN rods alone. Hopefully it's worth it when all is said and done.

Once its 15 dps on the CBN rods, I imagine it doesn't take long progressing through the browns to the fine and ultra fine?

Diamond or CBN to medium is a pretty big jump. It'll take a while to polish out the scratches they leave. It'd be a lot quicker to microbevel. That's how I run my PE knives to save time.

I'm not worried about it looking all pretty, and it's a user so that's definitely something I'll consider. (2+ hours in and not single mistake in terms of scratching the blade feels like a win though) So you say jump back to the 20dps now? I hit the apex earlier tonight at 15dps and stepped away since then.

[awa54]

If anyone cares to try them:

https://www.idahoners.com/product-page/ ... eplacement

They certainly won't replace a guided system, or even a coarse bench stone for reprofiling, but at least you don't need to worry about wearing the abrasive off of the rods like you do with the Spyderco diamond and CBN rods.

I have a set of the Idahone course stones and they don't seem to cut very well. Maybe I just need to keep using them and see if they break in more?

Yeah, i agree, for such a coarse stated grit they're very slow cutters. On top of that the set I got are slightly warped, but at least they aren't prone to dishing and shedding grit all over like Moldmasters and they *do* cut faster than the brown rods.

[JD Spydo]

As relatively hard as Spyderco's ceramic sharpening stones are I'm now wondering??? :confused: Are some of these newer/better blade steels reaching such high levels of performance to where Spyderco's ceramic stones may be borderlining on obsolescence?>> well as least for sharpening many of these newer blade steels anyway.

I'm already seeing a future in blade steel where it will just boil down to what selection of diamond stones or diamond sharpening tools you might have?

Albeit if that does turn out to be true I still say that Spyderco's Ultra-Fine stones is still a great stone for a finished edge.

[vivi]

M390 is definitely tough stuff. Working away at it again today. No sign of sharpie left on the clip side, just the tiniest bit on the show side at the apex. Needed a break though. Probably have 2 hours in on just the CBN rods alone. Hopefully it's worth it when all is said and done.

Once its 15 dps on the CBN rods, I imagine it doesn't take long progressing through the browns to the fine and ultra fine?

Diamond or CBN to medium is a pretty big jump. It'll take a while to polish out the scratches they leave. It'd be a lot quicker to microbevel. That's how I run my PE knives to save time.

I'm not worried about it looking all pretty, and it's a user so that's definitely something I'll consider. (2+ hours in and not single mistake in terms of scratching the blade feels like a win though) So you say jump back to the 20dps now? I hit the apex earlier tonight at 15dps and stepped away since then.

That'd make things go much faster.

[ZrowsN1s]

M390 is definitely tough stuff. Working away at it again today. No sign of sharpie left on the clip side, just the tiniest bit on the show side at the apex. Needed a break though. Probably have 2 hours in on just the CBN rods alone. Hopefully it's worth it when all is said and done.

Once its 15 dps on the CBN rods, I imagine it doesn't take long progressing through the browns to the fine and ultra fine?

I just did a reprofile of ZDP-189 most of it on the CBN rods. It's very sharp, shaves hair just fine, but looking at the edge through my loupe I can see that the CBN rods have left a jagged apex. A little time on the medium and fine stones have smoothed it out a little, but to truly take the apex to the medium finish, I can tell I'm going to need to spend more time on it. What I've got now is essentially a polished coarse apex (which is super aggressive, so it's not all bad).

[TkoK83Spy]

I cant shave very easily off the cbn rods...guess I need a little more work on them before progressing.

Really making me wish I had a guided system haha.

[ZrowsN1s]

I cant shave very easily off the cbn rods...guess I need a little more work on them before progressing.

Really making me wish I had a guided system haha.

I always run it over a strop first before I try shavin hair. Even the coarse finish. Helps make up for my bad stone technique I guess :D