Need liner lock help

Coach, it looks like you have far too much angle on the lock face. it looks like you have enough to work with to reduce it.
I set my lock face at about 7 degrees, yours looks like 30. at about 7 the lock bar should sit flush with the lock face when open.
don't do anything to the lock bar yet, but I think you need to change the angle on the lock face, yours is to steep and will let the lock bar slip.
that to me is the most critical part of building a liner lock and can really be frustrating.
one suggestion in the future would be go REALLY slow when grinding the lock face and don't go by how it fits with the knife disassembled, rather keep putting it together, take a little off, put it back together, check lock up and so on.
don't be disappointed in this little blunder I think you can fix it....if you keep making liner locks they'll get better but you'll run into little things that will drive you crazy. maybe some others will help here. good luck.
 
Also, make sure that your lock is engaging on the very inside edge of the lock only and not the outside edge.

You might also need to add more spring tension too. That's a quick easy thing to try too.

But I agree that your lock face on the blade looks like it's ground at way too much of an angle. You should get good proper lock up at anywhere between about 7 and 10 degrees, give or take a degree.
 
Thanks for the help. I did fix the angle of the lock up surface on the blade. It needs a tad more tweaking but I am waiting till after heat treat to do that. I'll be honest, I did the blade lock surface by eyeballing it. Never again. My kmg doesn't have an adjustable work plate. So I'm not sure what I'll do to remedy that. Maybe cut a wood block so it's at an 8.5 degree angle and use that when grinding the lock surface on the blade?

I heat treated the blade last night. I'll post up photos of my locking side to show how much bend I have. I think I may be close to it working out though. Lots of assembly and disassembly with these things!

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I don't have a lot of experience but I just tilted my platen to the angle I wanted which I did 8 degrees on that framelock I made and kept my work rest flat.
 
Justin Presson said:
I don't have a lot of experience but I just tilted my platen to the angle I wanted which I did 8 degrees on that framelock I made and kept my work rest flat.
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Duh! Thanks for the suggestion. That's the way to go. Put your angle finder on the platen, tilt it, and you're good to go. Thanks for reminding me my tools can already do what I need. I've just been so narrow in what I've been making. Never occurred to me to do that. Thanks!

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Sooooo.....new blade. Better angle? Got it working pretty well.
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A 11 degree angle on the blade face works much better than an 8 1/2. That flat surface to surface is not the way a liner lock stays open or even helps to allow it to close. The contact should be the inside EDGE of the leaf, looking at it from the bottom side of the knife is what should make contact with the blade cut out. As well for this to work correctly the blade cut out should be done with a 120 grit belt and the leaf with a 16 or the most 400 . Why not do the blade cut first then mark the leaf and do it much later when the liners are mounted to the back bar and the blade is installed with washers and a pivot fitted for length.This will avoid a false length measurement. I have the cut out done before I get the blade outline hardened.Yes, I know the information you posted came from a book and has been posted for years.That doesn't make it right. There are closing problems like blade sticking created by this as well. Here is as easy a way to cut the blade notch if you have a table and have a flat platen on your grinder and can position these at 90 degrees. Place a 1/8" thick piece of steel 7/8" away from the 120 grit belt parallel to it using say two layers of masking tape to hold it there. There you go the 11 degree angle without sweating it. Works first time and every time. Since I have my pivot hole already drilled with the contoured shape of the blade you can mark the distance the outside of the washer will be and bring your cut to just about there. Yes you can do this after heat treat too. After several hundreds of liner locks that this does work on I have no fears it won't also work for you if done with the information above. Save your 1/8" bar and use it on the next one too.
Now for testing your lock. Does your blade have side play when you hold the lock against the liner? Does your lock have up and down play when the blade is locked open? When you blade is locked turn it upside down and give it a sharp small wack on the spine, back of the blade. Did the blade jump free of the leaf?
Frank
 
I agree with Frank. Except I personally use a 9 degree angle and it works well for me but I don't doubt at all that 11 would work fine.

Everything on your knife looks really rough, and I'm not picking on you here, but you don't want a burr or rough edge anywhere giving you trouble.

Get stuff finished and smooth and it's a LOT easier to fit the lock, which is one of the last things I do. I also fit the lock to the blade and not the blade to the lock.

Frank described in more detail what I was talking about when I mentioned having only the INSIDE edge of the lock bar touching the locking face of the blade.
 
Frank! Man, thanks for taking the time to write all of that. I didn't get my information from a boom, I've been following the "how to" posted by Boss for his liner lock templates.

I'm printing your info out so I can have it right on my bench when I do my next folder. Seriously, thank you. Huge help.

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J. Doyle said:
I agree with Frank. Except I personally use a 9 degree angle and it works well for me but I don't doubt at all that 11 would work fine.

Everything on your knife looks really rough, and I'm not picking on you here, but you don't want a burr or rough edge anywhere giving you trouble.

Get stuff finished and smooth and it's a LOT easier to fit the lock, which is one of the last things I do. I also fit the lock to the blade and not the blade to the lock.

Frank described in more detail what I was talking about when I mentioned having only the INSIDE edge of the lock bar touching the locking face of the blade.
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Thank you. I agree, the whole thing does look like a turd at the moment. I just wanted it mechanically working properly before I did anything to the looks.
Looks like I'll be trying out some different angles soon. Thanks again for responding.

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There is lots of help here for liner locks and other folders. Calvin Robinson, a far away friend, is super on making and helping. I just get involved because like him I love to help people. If you have more questions on the a recommended order of doing, ask.
Frank
 
Please forgive the noob question, but why the large relief in the scale 'behind' the lock spring? Is it just to allow enough travel in the spring to disengage from the blade easily?
 
Wiredude said:
Please forgive the noob question, but why the large relief in the scale 'behind' the lock spring? Is it just to allow enough travel in the spring to disengage from the blade easily?
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It is to take some pressure off of the spring/lock bar. It makes it easier to open and close. Now, it did not need to be as big as I made it. But this is my first locking liner, so that's my excuse. I could have gotten away with making the space/relief half as long.

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