Can't get a good edge on my Benchmade. Help!

[linus the cat]

I need some help in getting a good edge on my Benchmade 551.

Its not super-dull right now; in fact, I'd say that its sharp enough for most day-to-day tasks. Its doesn't catch when cutting paper. But in the past, I've had it much sharper. Indeed, an old Wyoming cowboy who does his own woodworking got it so sharp last summer after working with it for three minutes that I literally could shave with it. I was impressed!

On the recommendation of some friends, I bought a Spydero Sharpmaker. I've probably dragged my Benchmade over it a few hundred times. While its somewhat sharper than when I started, its still far from where I want it to be. Anyone have any suggestions, aside from sending my knife back to Benchmade?

 

[aquaman67]

If it makes you feel any better you're not the only one who can't get a good edge on a SharpMaker.

I'm going to try to mount mine so I don't have to hold it.

Have you watched the video that comes with it and there are plenty on YouTube that may help you.

EDITED TO ADD:

Did you mark the edge with sharpie so you can see were the blade is hitting the stones? You could be just missing the edge.

 

[Skimo]

Well if your buddy increased the angle of the edge, that would explain how he sharpened it so quickly, and would also explain why the sharpmaker is taking so much time.

 

[Morkte]

Put sharpie on your edge and see if the sharpmaker removes it. You could also use some lower grit sand paper (220-400), crocket20 has a video using the sandpaper on youtube.

 

[linus the cat]

Well if your buddy increased the angle of the edge, that would explain how he sharpened it so quickly, and would also explain why the sharpmaker is taking so much time.

This might be possible. I really have no idea what he did but holy cow it was sharp when he did it. I may send it back to Benchmade to have them fix the edge then use the Sharpmaker to keep it honed.

 

[Skimo]

Please remove your profanity.

 

[mkjellgren]

Benchmade is notorious for obtuse edge angles. Your knife isn't getting sharp because you probably aren't hitting the very apex of the edge. Try coloring on the edge with a marker and make a few swipes in your sharpmaker. I'd there is still marker on the very edge then you know you need to take down the "shoulders" of your bevel a bit so that you can hit the edge. The sharpmaker stones are not very aggressive and this makes reprofiling very time consuming and frustrating as you are finding out. The sharpmaker works much better if you can set the bevel angle at anything less that 40° and then never really let your knife get dull. It really should be called the sharpkeeper rather than the sharpmaker.

 

[Komitadjie]

Concur that you are likely not hitting the edge. Most of the Benchmades I've worked on have had a rather obtuse edge angle, whereas the Spyderco tends to have an acute one. You have a few options, though!

1: Just keep working with the stock Sharpmaker rods. This will take considerable time, but WILL do the job eventually.

2: Wrap the rods in wet-or-dry in the 320-grit range. This will work MUCH faster than the stock rods alone. Then continue sharpening as normal with the stock rods.

3: Use sandpaper or a benchstone to reprofile the edge, then sharpen with the Sharpmaker.

 

[linus the cat]

Please remove your profanity.

Done.

Benchmade is notorious for obtuse edge angles. Your knife isn't getting sharp because you probably aren't hitting the very apex of the edge. Try coloring on the edge with a marker and make a few swipes in your sharpmaker. I'd there is still marker on the very edge then you know you need to take down the "shoulders" of your bevel a bit so that you can hit the edge. The sharpmaker stones are not very aggressive and this makes reprofiling very time consuming and frustrating as you are finding out. The sharpmaker works much better if you can set the bevel angle at anything less that 40° and then never really let your knife get dull. It really should be called the sharpkeeper rather than the sharpmaker.

Good to know. I'll give this a try. Is there a system that works better than the Sharpmaker? Would it work alright for Spyderco knives?

Concur that you are likely not hitting the edge. Most of the Benchmades I've worked on have had a rather obtuse edge angle, whereas the Spyderco tends to have an acute one. You have a few options, though!

1: Just keep working with the stock Sharpmaker rods. This will take considerable time, but WILL do the job eventually.

2: Wrap the rods in wet-or-dry in the 320-grit range. This will work MUCH faster than the stock rods alone. Then continue sharpening as normal with the stock rods.

3: Use sandpaper or a benchstone to reprofile the edge, then sharpen with the Sharpmaker.

I will give option #2 a try before I send the knife off to Benchmade. Thanks!

 

[mkjellgren]

Good to know. I'll give this a try. Is there a system that works better than the Sharpmaker? Would it work alright for Spyderco knives?

Almost anything is better than the sharpmaker for removing lots of material (which is what you need to do to lower your edge angle enough for the sharpmaker to be effective), but once your back bevel is set, there is almost nothing better for quickly and consistently bringing your edge back to scary sharpness than the sharpmaker. I personally freehand all my edges and then use the sharpmaker to maintain them.

The reason it seems to work better on spyderco knives (at least at first) is because spyderco shoots for a 30° bevel from the factory. This means you can sharpen at 40° and be sure you're hitting the edge, then when 40° becomes less effective, you can hit it in the 30° setting for 50-100 strokes to thin the back bevel back out making the 40° setting effective again. With Benchmades, most come from the factory with 40-45°bevels, give or take a few degrees, so even straight from the factory they need to be thinned out to be effectively sharpened on the sharpmaker. From the sounds of it, the guy who wharpened your knives did so as quickly as he did because he added an even more obtuse microbevel, probably in the 50°-60° range. You'll need to get that edge down to 40° or less (preferably 30° inclusive) in order for your sharpmaker to work.

 

[cutter17]

Benchmade is notorious for obtuse edge angles. Your knife isn't getting sharp because you probably aren't hitting the very apex of the edge. Try coloring on the edge with a marker and make a few swipes in your sharpmaker. I'd there is still marker on the very edge then you know you need to take down the "shoulders" of your bevel a bit so that you can hit the edge. The sharpmaker stones are not very aggressive and this makes reprofiling very time consuming and frustrating as you are finding out. The sharpmaker works much better if you can set the bevel angle at anything less that 40° and then never really let your knife get dull. It really should be called the sharpkeeper rather than the sharpmaker.

This is oh so true!:thumbup: I've had some success with using the diamond rods for the Sharpmaker.

 

[singularity35]

This is oh so true!:thumbup: I've had some success with using the diamond rods for the Sharpmaker.

I bought a pair of 240 grit moldmasters to clip on the stones. Way cheaper than the diamond plus you don't have tearout.