Lapping

Joined
Apr 9, 1999
Messages
83
This is a topic more focused towards folder makers. I would like to know how many of you hand lap or machine lap their liners, blades and handles?
If you do, have you noticed a dramatic difference in the action, overall fit and finish and rigidity of the knife?
For the ones that do let me know if you have encountered inconsistencies in titanium (from one sheet having different thicknesses, grooves, manute warping, etc..).
Thanks a lot.
Allen Elishewitz
 
Allen: Have never found any titanium that was flat, or that stayed flat when assembled. Just turning the screws will deform .063 stock.
As for blade holes, I always lap mine.

How's the lapmaster working?

RJ
 
I lap my pivot hole with a brass barrel lap and 1000 grit lapping compound. I do so after heat treatment. I lap lightly using my battery powered screwdriver. I also lap the pivot pin to the hole. I find that it gives me consistent results.

I wish someone would make titanium sheet that came with a nice surface finish. As you know it comes scratched, grooved, and sometimes runs out toward the edges. Since I finish my knives inside and out it means a good deal of time flattening and finishing the liners.
 
Surface grinding works well if you get the right wheels to keep everthing flat.
most often within .0002
Close enough for folders.!

Titanium is always inconsistant thicknesses. Steels that are not p ground are also.


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Web Site At www.darrelralph.com
MADD MAXX !
 
Since I started lapping my pivot holes with a barrel lap, the action is a lot more consistent. I try to shoot for +.0004-+.0006 larger than the pivot itself.
RJ, the Lapmaster is finally working the way I want it to work and parts are coming out as flat as a flitter (I don't know how flat a flitter is, but it is pretty flat!).
What I have noticed about titanium is even though you flatten it with an arbor press, it is very uneven. That affects the knives tremendously. I have tried surface grinding my liners but the heat build-up ends up curling the titanium. Hand or machine lapping is definetely the way to go with titanium.
I'd like to hear any other ideas in refining the flatness, holding tolerances and improving action and slickness of a knife. I would like to compare to see if I am on the right track.
Thanks,
Allen Elishewitz
 
I think that flood coolant would help keep the TI flat. As I told you, that's why I use a massive, oversize bushing-to keep the liners parallel at least in the area of the blade pivot.



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Stay Sharp,

RJ Martin
http://www.martinsite.com
 
Well guys perhaps I shouln't be saying anything here but I do appreciate people helping me and I truly enjoy helping ( or at least trying to help others). I will have to try the pivot and hole lapping thing but have like most everyone else been putting lots of hand work into the liners. What I have found is that cleaning or leveling the liners on a 400 cork belt first does seems to really help. The fact that the cork belts run a little cooler seems to help . I use a piece of duck tape attached to the side oposite doubled back in the center to provide a holding "handle." Actually if the cork belt is worn some and you are loading it polish it would fit right in. Hope this helps some! Frank.
 
Do the roller bushings that TKS sells improve action or do you guys just stick the pivot pin right through the blade? Also, how snug should that pin be? What does the best fit feel like when you are fitting that pin?

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Peter Atwood

email: fountainman@hotmail.com

[This message has been edited by fountainman (edited 03-06-2001).]
 
Allen
It take some investigation to get the right wheels for ti, talonite and other materials that what to heat up.
Once you get them , they work great.

Pivots are nice when lapped.


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Web Site At www.darrelralph.com
MADD MAXX !
 
I sure hope that I more people will jump in here with more helpfull ideas on working the titanium thing. I sure would appreciate it. Thanks in advance for any ideas. Frank.
 
Where do you get "brass barrel laps" or do they go by another name?

And what about the compound? is it diamond paste or ????

How do you flaten your titanium liners? Use a arbor press or ????

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Tony Huffman
thuffman@texinet.net
Sporting Clays & Shotguns ... my other bad habit!
 
Hi Tony,
You can get a barrel lap kit from MSC. I use diamond as a compound, but you can use any grease base compound(less$$$$$). You can straighten tit. by bending it on an arbor press and checking its flatness on a precision flat surface. Also you can put your liner in a vise and twist it to releave any unwanted twist in the tit. that an arbor can not straighten.
Darrel, thanks for the tip about the stone but it is easier and I can get more consistent and precision parts with my lapmaster.
Allen Elishewitz
 
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