Frame lock - how far to bend the bar?

[C_Claycomb]

I have just come in from the shop ready to bang my head on a wall. I have been working on a frame lock and have ground just a hair too much off the blade lock bevel so that now the lock doesn't engage properly. There is vertical play. I have the lock bar bent so that the leading edge is 50% of the way across to the opposite scale without the blade in position. This looks like how other folk have done it, although I haven't seen any advice on an exact amount of bend.

How much bend is too much for a lock bar? Is there a recommended amount of bend?

If I bend the bar so that it rests just off the opposite scale without the blade in place, I think it may engage and save the blade. What do you think?

If I had absolutely nothing to lose, I would go ahead, but since I thought I might have a problem with getting lock up, I made two identical blade blanks when I had the chance (one off access to a surface grinder). So, I could go and just start in using blade blank B and leave the lock bar as it is. Of course, if I can get it to work on the first blade, I have the second blank to go make a whole other knife with




Normally I would not ask something like this, I would just go searching the forum, but I have struggled to find this information in amongst the wealth of excellent Frame Lock WIP threads. It seems like something people just do, and it works, with very few comments. Lots of comments about how far the lock should engage the blade, but not so many about how far over the lock should sit before the blade is installed.

Thanks

Chris

 

[Bob Ohlemann]

You can lengthen your lockbar by stretching it with a punch and a hammer. Just place the lockbar on a good bench block and work either the area at the tip of the lockbar where lockup should occur or you can stretch it in the area where you relieved the bar so lighten the tension. You can do both if you have to. It will take several good whacks to stretch the Ti but it will go. Once you have it fixed, you can clean the marks up with a file.

To answer your question, I generally bend my lockbar to the far side of the blade. Since I'm usually using .015 washers, the lockbar would be about .015 from the opposite scale.

Bob

 

[C_Claycomb]

Bob,
Thanks for reminding me of that lock lengthening method! I knew it could be done with liner locks, but hadn't thought if it for frame locks.

Thank you also for the advice on bar travel. That has set my mind at rest somewhat. I think I will try a bigger bend first, and see if that fixes the problem.

Cheers

Chris