*UPDATED WITH PICS* Benchmade 710 M390 Problems...

Sulaco

Sulaco

Joined
Nov 15, 2003
Messages
2,422
*Please see my update at post # 19 and further down with more pics.*

I received my Benchmade 710 M390 (from knifeworks.com) this week and have noticed a few disturbing problems.

The first thing I noticed is the blade not being centered. I used a technique of tightening and loosening different screws and got it mostly centered, but it's not dead-center (like every other Benchmade AXIS folder I own is - dead. nuts. center.).

The next thing was the unbelievably bad grinds. They actually have "wavy" lines in them, almost like the person that set the bevels had shaky hands or didn't use a guide or something. Really bad.

I guess what really bothered me is, when I did the Sharpy trick and used some coarse diamond stones to set the bevel at 20 degrees per side, it only toke a few swipes per side to remove the black left by the sharpy. I remember reading that M390 is supposed to be fairly easy to sharpen, but this seemed almost hard to believe. I finished up the edge on ceramic stones and it got super sharp. I was happy with it and didn't think anything else about it.

I used the knife once or twice this week to cut some light materials, like some plastic tags and some paper here and there. Not really enough to determine much, but after looking at the edge today, it looks like it's started to roll some!! Is it possible the blade just missed being heat treated at all? Or maybe it was just a poor heat treat?

I've also noticed a couple of really small nicks in the edge of one of the liners. Interestingly enough, it's the liner which the blade was closest to before I tried straightening it up some. They aren't bad, but for an expensive knife like this, I didn't expect to see imperfections in the finish of one of the liners.

The last issue is the very significant amount of blade play, both vertical and horizontal. I can adjust the horizontal (side to side) blade play by tightening the pivot screw down, but then it's so tight, it's really hard to get the blade out using the thumb stud. So I have to back off enough to make it usable, which re-introduces the horizontal blade play. The vertical (up and down) blade play is what really bothers me. It's my understanding that an AXIS lock should never have any vertical blade play. If I flick the blade out pretty hard, it lessens the amount of play. However, if I then wiggle the blade up and down, just within the amount of movement available while locked open, the play will get worse until it's equal the amount if I just opened it slowly until it locked.

Needless to say, I am not pleased with the knife as it is. I've owned or now own, many, many Benchmade AXIS lock folders and every single one locks up as tight as a bank vault. I know that phrase gets thrown around a lot, but they really have all locked up that tight. I've had one problem with a Benchmade knife in the years I've owned them. It was a Mini Griptillian which had an over harded blade (154CM) which chipped every time I used it. Benchmade replaced that knife and I haven't had a problem since.

I emailed Benchmade and Knifeworks and hope to hear back soon. It's really a hassle to have to deal with this on a brand new knife. Especially a special run knife like this one.

Well, I just wanted to share my experience and "vent" a little bit about my frustration.

Anyone else had any issues with these 710's using M390 blades?

I'll let you guys know once I get this resolved.
 
Last edited:
My M390 710 has been fantastic, sorry to hear about yours. It arrived hair whittling sharp and still shaves and slices newspaper against the grain. This is after 3 weeks of pretty heavy use. There's no play, and the edge came in around 30* inclusive. Are you sure the rolling isn't a burr you didn't take off?

I'd contact Benchmade if you think you got a dud.
 
No it isn't a burr. I work up to burr's regularly so I can tell the difference.

Handwrecker said:
My M390 710 has been fantastic, sorry to hear about yours. It arrived hair whittling sharp and still shaves and slices newspaper against the grain. This is after 3 weeks of pretty heavy use. There's no play, and the edge came in around 30* inclusive. Are you sure the rolling isn't a burr you didn't take off?

I'd contact Benchmade if you think you got a dud.
Click to expand...
 
Yeah, I'd say send it in to BM. Some of the things you mentioned (e.g., blade not dead center, some horizontal blade play) are likely within spec, but others -- particularly the vertical blade play and possible bad heat treat -- are significant problems that impair the functionality and safety of the knife.
 
Yeah, it's definitely going back, I just wanted to see if it was something Knifeworks wanted to take care of since I just got it a few days ago. But it will probably end up back at Benchmade.
 
the only problem I had with mine was the blade was scoring the inside of the plastic back plate/spacer. I sent it back to BM, they fixed it and even put in barrel spacers for me at my request. It's now relatively flawless. It came sufficiently sharp, but not what I would call razor sharp. I think I got it back in less than two weeks.
 
I would just return it for a brand new one. I wouldn't wait for a repair on a knife I just bought.
 
Send it back to Benchmade ASAP. Sounds like you got a bad one......hopefully, they'll replace it for you.
 
This is the response I got from knifeworks...



Hey Jason,



Since the knife has been sharpened and used, we cannot accept the knife back, because it is a manufacture flaw. Benchmade will be gladly to accept it back and correct the knife.



Thanks

Ashley
 
Sulaco said:
This is the response I got from knifeworks...



Hey Jason,



Since the knife has been sharpened and used, we cannot accept the knife back, because it is a manufacture flaw. Benchmade will be gladly to accept it back and correct the knife.



Thanks

Ashley
Click to expand...

Sounds fair, guess to benchmade it goes :)
 
Yeah, I can't complain, really, but it would have been nice not to have to deal with a warranty return and just send it back to the dealer. Oh well, I guess we'll see how BM handles it now. It does suck that they would let something like this get out to a dealer, though. I think the next time I drop a decent amount of money on a knife, I'll go somewhere local and actually put my hands on it versus risking having to spend more to send it back for repair.

Thalestin said:
Sounds fair, guess to benchmade it goes :)
Click to expand...
 
My 581 in M390 was also off center, whereas my older 580 in 154CM was dead nutz on center. Also a Spyderco Manix2 in M4 and a Para2 in 20CP both arrived off center. Do you think it's possible that the harder high-V steels are more difficult to drill & hone perpedicular to the blade?
 
Could be that. That could also be why the grinds were wavy, but it doesn't explain why it was so easy to remove so much metal when I cleaned up the bevels. It's almost like the actual cutting edge was soft, but just a millimeter or two up, it was much harder. I dunno, it's their problem now. I just sent it back. I really hate paying the Post Office 10 bucks though, to have Benchmade fix something that should have been right to begin with on my 3 day old knife.

I guess I should have gotten that Paramilitary 2 sprint run afterall...

RandomAyes said:
My 581 in M390 was also off center, whereas my older 580 in 154CM was dead nutz on center. Also a Spyderco Manix2 in M4 and a Para2 in 20CP both arrived off center. Do you think it's possible that the harder high-V steels are more difficult to drill & hone perpedicular to the blade?
Click to expand...
 
Love my BM's!
Anxious to see how their customer service responds...
My 755 in M390 has yet to show any significant wear or damage to the edge after more than a year of frequent use.
 
HuntBomb said:
Love my BM's!
Anxious to see how their customer service responds...
My 755 in M390 has yet to show any significant wear or damage to the edge after more than a year of frequent use.
Click to expand...

I love all my other myriad assortment of BM's also. But this one really had me bummed. I talked to CS before I sent it in and he advised me to do so. I am sure they'll take care of me, but what exactly they decide to do is what I am interested in. I asked the person that gets it to contact me before doing anything so hopefully they will.
 
Planetcat said:
the only problem I had with mine was the blade was scoring the inside of the plastic back plate/spacer. I sent it back to BM, they fixed it and even put in barrel spacers for me at my request. It's now relatively flawless. It came sufficiently sharp, but not what I would call razor sharp. I think I got it back in less than two weeks.
Click to expand...

Did it cost you anything extra for the barrel spacers? I just noticed that the same thing has been happening to my back spacer. I may have to have this done to mine, I much prefer open construction.
 
Handwrecker said:
Did it cost you anything extra for the barrel spacers? I just noticed that the same thing has been happening to my back spacer. I may have to have this done to mine, I much prefer open construction.
Click to expand...




No adding the barrell spacers is free. You just have to add $5.00 for the return shipping:cool:
 
Well, I had asked them to add the barrel spacers and send me an extra clip or two, they didn't do either. I also asked them to please make certain the blade was perfectly centered. It's not. And I asked them to remove the little bit of vertical blade play. They did. Mostly. But I can still move it. It came back absolutely swimming in oil so I'll have to take it apart and clean it.

And instead of replacing the blade, they just ground down another millimeter or two and re-profiled it. Compared to my also re-profiled D2 (which I did myself at 30º), they were a bit more judicious with metal removal than I would have liked.

I suppose it's as good as it's going to get unfortunately. But I'd advise anyone who actually expects getting their money's worth to either personally inspect a Benchmade before purchasing it, or buy it second-hand and know what you are getting. I won't be buying another new one for the foreseeable future because of this experience.
 
Sorry to hear about that, man. I would've thought BM would really go above and beyond to make good on their guarantee. All of the Benchmade's I've owned I've been more than happy with, but I haven't ever had to send one back to the manufacturer. Hope you have better luck in the future.
 
You must log in or register to reply here.
Back
Top