rift blade play adjustment

R

redman2006

Joined
Nov 6, 2012
Messages
306
I need a little help figuring out the trick to adjusting out the play. When I get the blade play out, the pivot is really tight and difficult to open. There does not seem to be a happy medium. Either I have play and a reasonable opening knife, or no play and it is really stiff.

I have lubed it a touch as well as having cleaned it. It was not this way right out of the box.

Any suggestions?
Thanks
 
You don't say if the knife is new or has been in your employ for awhile. (Maybe by saying since "It was not that way right out of the box...") Pocket lint and grit can get in the works if used. One thing I do when the knife is binding and adjusting doesn't do much is to fill a tub with hot soapy water and soak the thing for 15 minutes or so. Once that's done I run a pipe cleaner through the pivot area followed by using a hair dryer set to low. After that just a drop of the lube on both sides of the pivot is all that's usually needed. A few of mine have a really small window between tight and loose. It just takes playing with the pivot to find that sweet spot.

Hope that helps, just my thoughts on a day off here on the East Coast.
 
Thanks. Day off here too. A rare one.

I have not tried that exactly. I did clean it and blow it out with the compressor. I put a drop of CLP on the pivot. It still binds if it is tight enough to remove the play.

I have had it and used it for about 5-6 months or more now I think. It has not been abused, but there has been some torque on the pivot area when doing things like cutting zip ties(slip it under, twist enough to get the blade to cut). Most everything else has been basic cutting, hay strings, feed sacks, rope, boxes for recycle, etc.
 
Torqueing the knife under pressure. That could be one reason for the binding. You probably already have a set for maintenance, but Torx drivers T6 for the handle and clip screws and T10 for the pivot are the basic ones we all use for tuning. What I would suggest is loosening the handle screws and pivot bolt, and holding the blade opened, with a cloth to protect yourself see if you can rock the blade gently left and right. If it's doing what I think it's doing it's off-center and binding as a result. Try to tighten all of the screws first, and then the pivot all the way in clockwise. From the tweaking mentioned this could be the source of your troubles.

Hope, again that this helps!
 
I responded to a similar post last week:

kniferbro said:
I've had this problem with Benchmades since I started collecting. Not all but a majority of the models I have owned had the non existent sweet spot. I have fallen in and out of interest in Benchmade because of this but after recently getting another 710 that had no sweet spot I decided to really research into it. I ALWAYS see posts from satisfied Benchmade owners and just didn't understand why mine never were up to par. I stumbled upon a post on here by Lennyo that really shed light on the problem.

In a nut shell, the width of the blade + washers was way off compared to the width of the backspacer, causing the liners to not be parallel. This meant if the pivot was tightened down to eliminate play the washers were being pinched some where on their radius bogging down the action. This explains the weird wear pattern on the washers as well as why swapping washers seems to have fixed it.

On my 710 I noticed when I left the handle screws completely loose my 710 would operate as it should. I could dial it in to have zero play but still very smooth. Also when I would tighten the handle screws down I could feel with my thumb on the spine of the handle that the liners were bowing inwards at the screw points. After reading Lennyo's thread my conclusion: the backspacer was undersized compared to the blade+washers stack.

Well I couldnt add more material to the spacer so my only option was to reduce the size of the blade+washers. I used 1000 grit sand paper on glass to sand down the washers, reassembling the knife every now and then to check progress. I ended up with a perfect 710, rock solid pivot with a smooth action. It's not free swinging smooth... yet, but I'd rather have that final stage of breaking in to happen naturally. It's plently smooth as is.

Thought I would share my experience as it really made me dislike BM, although I LOVE their designs and the axis lock, their fit ruined it for me. I am competent enough to fit my own knife so I'm a happy camper now.
Click to expand...

There probably was a perfect balance between handle screw tightness and pivot tightness, which is now off causing your problems.

Quick way to check like in my post above, loosen the hsndle screws then try to set the pivot. If that works I believe my proposed problem is the culprit. After that, try to see if you can find that balance between pivot and handle screws again. Usually this balance point is when the handle screws first start getting snug, any further and you start bowing the scales/start making them unparallel.

Hope this helps.
 
Sometime I find you need to tighten up to almost too stiff and after a few days of use it works itself in a bit.

Stop cutting zip ties that way for a start. Besides putting lateral torque on the blade it is a good way to chip the edge.
In fact if I know I will have a lot of zip ties to cut I either use EMT shears or wire cutters.
 
I don't have to do a lot of them, but I figured it was better that way than down against the metal with the blade.

If I am doing something where I need to trim a bunch or cut a bunch loose, I go find the sidecuts.
 
kniferbro said:
Quick way to check like in my post above, loosen the hsndle screws then try to set the pivot. If that works I believe my proposed problem is the culprit. After that, try to see if you can find that balance between pivot and handle screws again. Usually this balance point is when the handle screws first start getting snug, any further and you start bowing the scales/start making them unparallel.

Hope this helps.
Click to expand...

I, too, have found the the scale screws near the pivot can have a big effect on how the pivot reacts to adjustments. They are sometimes too tight, which can make it almost impossible to find that sweet spot.
 
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