A Question About Folder
- Thread starter Entropy762
- Start date
C Craft
Well-Known Member
Well, you are talking to man that has never completed a folder except for primitive friction folder! However looking at your pic, I would pull the pivot pin and shim both sides of the blade with a bronze washer!!
I will tell you this much the camera won't lie to you!! You have a wider gap to right of the blade, than to the left of the blade!! If you do not use bronze washer the blade will open and close in a different position every time!
If the gap was equal on both sides of the blade it would kick that blade pretty close to center!! Any that is what I would do. There are some guys on here that eat, breath, and sleep, folder's. The may have some other ideas!!
I will tell you this much the camera won't lie to you!! You have a wider gap to right of the blade, than to the left of the blade!! If you do not use bronze washer the blade will open and close in a different position every time!
If the gap was equal on both sides of the blade it would kick that blade pretty close to center!! Any that is what I would do. There are some guys on here that eat, breath, and sleep, folder's. The may have some other ideas!!
J. Doyle
Dealer - Purveyor
Its hard to say for certain without seeing it or at least knowing more info.
On well made folders with everything else right, the number one culprit is too much spring tension on the lock bar.
Outside of that, it could be one or a combination of several things. Is the blade binding as it closes? Does it close easily with the same tension throughout its entire travel? How far is your detent sticking out? How thick are your washers? How thick is your blade and backspacer?
There's a whole laundry list of trouble shooting.
On well made folders with everything else right, the number one culprit is too much spring tension on the lock bar.
Outside of that, it could be one or a combination of several things. Is the blade binding as it closes? Does it close easily with the same tension throughout its entire travel? How far is your detent sticking out? How thick are your washers? How thick is your blade and backspacer?
There's a whole laundry list of trouble shooting.
Ausbrooks
KNIFE MAKER
Additionally, look at the precision of your whole process. Be sure your drill press or mill is dead perpendicular to your work. Ream your pivot hole to an interference fit then use an adjustable lapping reamer to take out the last half thousandths so pivot has no slop. What helped me get blades dead center was getting a surface grinder and grinding the back spacer so that it is perfectly parallel, keeping side plates aligned exactly. If don't have surface grinder, use precision stand offs and either fit them to the blade or match the blade exactly to the stand offs. It's a process so just keep making them and you'll get there.
Entropy762
Well-Known Member
C Craft, yep that blade is way off. For washers I used brass shim stock. The gap on either side of the is equal.
J. Doyle, this is not a well made folder. The back spacer is part of the same piece of O1 for the blade. It is flanked by the same brass shim stock. The blade doesn't drag while opening or closing. I'm guessing now that the lock bar and detent are the culprit.
Ausbrooks, the only thing precision about the process is that my drill press is squared up. I don't have a rea mer but I did manage to lap the pivot hole.
Thanks guys. I do have two separate threads about this knife. It's very amateurish but it's a start.
Jake
J. Doyle, this is not a well made folder. The back spacer is part of the same piece of O1 for the blade. It is flanked by the same brass shim stock. The blade doesn't drag while opening or closing. I'm guessing now that the lock bar and detent are the culprit.
Ausbrooks, the only thing precision about the process is that my drill press is squared up. I don't have a rea mer but I did manage to lap the pivot hole.
Thanks guys. I do have two separate threads about this knife. It's very amateurish but it's a start.
Jake
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Entropy762
Well-Known Member
J. Doyle
Dealer - Purveyor
You need to have more width in your backspacer than blade. The width of your backspacer needs to equal your blade thickness + washer thickness. If it doesn't, that's at least part of your problem.
Also if your detent sticks out of your lock bar more than the thickness of the blade washer on that side, you have to relieve AT LEAST whatever that difference is off the back side of your lock bar. If you didn't do that, that could compound your issues.
Then you could still have the spring tension issues.
Also if your detent sticks out of your lock bar more than the thickness of the blade washer on that side, you have to relieve AT LEAST whatever that difference is off the back side of your lock bar. If you didn't do that, that could compound your issues.
Then you could still have the spring tension issues.
Entropy762
Well-Known Member
Thanks J. Doyle. Good points to look for. I knew this knife was going to be a bit of a basket case. I think I'm going to shelve it for now and use it as an example of what not to do. I have ordered some ball bearing (detent) for the next knife. I also need to get some fasteners, probably 4-40, instead of using roll pins. I already have a few 4-40 taps on hand.
Jake
Jake
John's nailed about everything, but I would say based on that there's no relief cut in your lock, it's lock spring pressure pushing the blade over. This is simple to test. Use something thin and flat to index the spring away from the blade. Does it come back to center when relieved of pressure?
bladegrinder
Well-Known Member
It's kind of hard by just looking at the pictures why your blade is so off center but one thing I did notice, and it may just be the picture but the lock bar looks like it was bent to close to the lock up juncture.
The lock bar needs to be carefully bent progressively the length of the bar, I use a 3/8" piece of micarta with a slot cut in it and go up and down the lock bar, bending it slowly and carefully.
I would try re-bending the lock bar and see if it makes a difference.
The lock bar needs to be carefully bent progressively the length of the bar, I use a 3/8" piece of micarta with a slot cut in it and go up and down the lock bar, bending it slowly and carefully.
I would try re-bending the lock bar and see if it makes a difference.
Entropy762
Well-Known Member
Kuraki, thanks. What do you mean by the relief cut in the lock bar?
Bladegrinder, I'll try that on my next folder. I have a sheet of stainless steel that I'm using for the liners. Thanks.
Jake
Bladegrinder, I'll try that on my next folder. I have a sheet of stainless steel that I'm using for the liners. Thanks.
Jake
I'm sorry I don't have a better picture at hand and the shadow the blade is casting makes it very hard to see in this one, but where the arrow is you can see I milled a channel half the thickness of the liner. This is the "hinge" of the lock spring. Because it's half thickness it has much less spring force than if it were full thickness.
Entropy762
Well-Known Member
Aah. Ok. I see where the relief is. That makes sense. Thanks Kuraki.
Jake
Jake