quick question on spacers and pivots

C

clockworkfish

Joined
Dec 1, 2010
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161
Hey so i'm planning on making a lockback but im sure that this question relates to any folder with washers. so lets say you have a 1/8th inch blade and .005 washers, if you wanted to have perfect fit and finish would you need to have a back spacer that is exactly .135? or if you used 1/8th material instead would that make the pivot wibbly wobbly or off center?

oh and bonus question, planing on using anodized aluminum for the handles, will the anodizing effect the tolerences enough that i should worry? if so are there any ways to account for this? would simply drilling/reaming the holes after anodizing be the solution?
 
I am not an expert so take my words for what they are but I have been working on a folder and had a similar question. The answer was given to me from Chuck Bybee of Alpha knife Supply, great Guy by the way, and it was to add up the thickness of the blade when it was finished along with the thickness of the washersdesired and lap the spacers to match. If you use a shouldered preset length spacer you can take up the differance with thicker washers or recess the shouldered stop pins into the handle material to get the tolerance you want as long as the stop pin is close to the final dimensions.
 
ok so useing the example i had before (1/8blade, .005 washers for a total of .135) would i take an oversized piece of material (like a 3/16 piece or .1875) and then reduce it to .135?
 
I buy my steel oversized so that after removing the scale, making certain its flat, grinding and maybe a mistake that needs fixing and finally polishing it is around what I want for the final thickness. There is not a set thickness and the steel type being used as well as the size and design should dictate the thickness needed.

For the folder I am working on I purchased .188 which is the 5/32 material I want but its oversized because its a CMP steel and needs to be ground down. I do want my finished blade to be around 1/8 and on the + side a bit. IMHO 3/16ths is a lot of material to remove for a final of 1/8 not to mention more money in metal, shipping, your time and belts. If you cant find 5/32 in the steel you want places like Aldo's and others can surface grind it to the thickness you want for a small fee if you buy it from them.
 
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do you know if the "ground steel" at aldos is surface ground to the exact dimension? or is it something way different?
 
Are you makeing a lockback,or a frame lock?
In folder makeing a caliper and a micrometer are your best friends.Yes blade thickness + washer thickness = backspacer thickness.If they are not the same it will cause all kinds of little problems,binding blade,sticking locks,off center blade.
Also measure everything,just cause you bought a .015 washer,it could be anywhere from .014-.017

Stan
 
SBuzek said:
Are you makeing a lockback,or a frame lock?
In folder makeing a caliper and a micrometer are your best friends.Yes blade thickness + washer thickness = backspacer thickness.If they are not the same it will cause all kinds of little problems,binding blade,sticking locks,off center blade.
Also measure everything,just cause you bought a .015 washer,it could be anywhere from .014-.017

Stan
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making a lockback and was thinking i would waterjet cut all the parts out of the same sheet of steel (im thinking cpm-154) sounds like its doable just so long as i take off a bit more material outta the blade (taking it down .005 on each side and measuring with calipers/micrometer as i go.)

oh and the lockbar does not need washers right?
 
Your conversation here leads me to believe you have no idea of the accuracy required to keep the blade sides parallel top to bottom and front to back and the spacer as well.You will be using up a lot of steel before you get these even close enough to concider using. I believe you will manage far better if you try a small straight knife first and as well read more of the WIPs on making the folder type you want to try. Perhaps a kit would be a good way for you to go - for the first one at least? Frank
 
Frank Niro said:
Your conversation here leads me to believe you have no idea of the accuracy required to keep the blade sides parallel top to bottom and front to back and the spacer as well.You will be using up a lot of steel before you get these even close enough to concider using. I believe you will manage far better if you try a small straight knife first and as well read more of the WIPs on making the folder type you want to try. Perhaps a kit would be a good way for you to go - for the first one at least? Frank
Click to expand...

Sorry, i have a tendency to ask a lot of stupid questions, because i want to make absolutely certain i'm thinking correctly. Worst comes to worst i find that i am way off. I've made a few fixed blades but never a locking folder, i am aware that the tighter your tolerances and the more flat, and accurate you can get each part the better the final product will be. Also there are not many lockback WIP threads, i have found like one or 2 but none really go over stuff like that, or how far the spring needs to be bent. the kit does seem like a good idea though.

regardless i was just not sure if i would be able to use one plate of steel for the lockbar, knife, and spring or if it would be wiser to use multiple. i plan on getting the handles cnc'd and the blade, lockbar, and maybe the back spacer waterjet cut (just marking out the pivot hole and then drilling and reaming at the mark so that way its as true as possible, also doing this on a mill rather than a drill press in order to keep the bit as stable as possible.

Since i do not have access to a surface grinder would using an endmill work just as well? or should i go old fashioned and use sandpaper on granite plate?
 
You are coming up sounding like you have a few ideas on what it's about. That's very good to read. Even one WIP should provide a huge boost in how to do it. Go over that carefully. Yes I have been told by an excellent maker, that you can use a fly cutter in a milling machine and it will do a great job . You will still need to clean up with the granite plate. Please for sure to make some working patterns before starting any metal cut outs. Frank
 
Why are you wanting to use washers?Get PG 01 and cut all the pieces from the same bar.Use .040 SS for the liners.
Make a few and see how they go together and the fitting of the parts.Then worry about getting fancy.
Stan
 
Not really,what the washer will do is keep the tang from rubbing aroud the pivot.These marks are on all production knives but unsightly on customs.Most makers mill relive the liners to stop this.
Make your first couple and don't worry about the marks,just making them work.
Stan
 
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