Question on a semi-rebuild

[nevermind35]

Hey steve I've just spent all night reading throughout your forum and thought that you might be able to help me. If you're familiar with the Bradley Alias or the Benchmade 755 you'll know that the lockbar has a step toward the end of the lockbar's travel. I bought a used Bradley Alias 1 about 6 months ago and alas the lockbar has finally wore its way to the step and there is very noticable vertical blade play. This knife has been fitted in the past with two seperate custom g10 scales each made from a different maker (Before I owned the knife). One of them was better fit than the other but both changed the lockup when installed. On one it makes the lock preatty darn sticky upon release and the other locks and unlocks great but it has side to side play no matter what I do. In the past I have used it extensively with each installed and I think it may have damaged the knife doing so.

I also just bead blasted the knife with my new media blaster using "medium" grit glass bead. I'm a newby to blasting but I duct taped the washer area and the lockbar face so as not to change the finish/lose material in those spots. I bought the glass media at my local Harbor Freight and don't know how aggresive it is compared to others. I thought that also the glass might be a high enough grit that it actually removed enough metal in the stop pin holes that there is a bit of stop pin play. What kind of media do you use?

I was wondering if it would be possible for you to grind down the step in the lockbar face so that it could wear the full way like most framelocks. Possibly in combination with milling a new slightly larger diameter stop pin.

By the way after checking your sub forum out I really like the kind of work you do and how you take so much pride in your testing of knives to find out how to make a better one. I believe that you are a maker that is going to blow up in the knife industry.

 

[STR]

Hy Ryan. I'm not sure why the new scale would change the lock up unless the hole placement for the stop and body screws are off some. It could be all or just one slightly off and that is all it takes. If the stop pin is on a bind, even a small one it can affect the lock up so first thing I'd like to know is do you have the original side that came on the knife when new? That seems to me to be the easiest way to see if the lock has actually worn or the scale has.

Secondly if you don't have that scale side I'd suggest a new side using the lock side to make it not one of the old scales. My suspicion is that the first scale was off some, the second scale was made from that off scale and you ended up with sub part scales both times. I am really of the mind set here that the lock or stop pin either one does not need adjustment. The scale needs replaced with a better fitting one as my hunch is those other parts are still fine.

It is also possible if the knife was tweaked in other ways that the washers were replaced before you got it. The side to side play could be washers too thin because they used the wrong size. I see that a lot but it could just as easily be that the screw hole is recessed too deep in the replacement scale for the pivot to tighten down.

The media you are using is probably fine. Mine started out as a #80 glass bead. I recycle mine in the box over and over and over and it is nothing like that original powder now and in fact when I compare it to the original you would think its a different one. Mine has bead itself down to a fine talc like powder at this point and I'm sure its much finer now than what I bought. They all do this over time. I'm not sure what medium grit is as far as the number but if you are running your compressor from 80 to 120 psi I'm sure it will do the job. On some softer materials like Micarta or G10, carbon fiber and others it may eat away some material if you stay in one spot too long but some folks like it to eat out material. If you've ever seen an Emerson custom with the green Micarta he really beads down on it good with his blaster pock marking the hell out of it for grippiness. It works quite well.

My 'Read this if you need to mail me work thread" which is a sticky post top the page would be what you need to get the knife to me so I can give that knife an eval and let you know what I think. I'm not sure if I'll want to mess with making a new side for it but I can certainly look at it, weigh the pros and cons of one way vs another and try to zero in on what is going on with it for you and get back to you. I've worked on several of those models and they are pretty straight forward. That knife was made by BenchMade for Bradley so its not crap and there are only so many things that it can be to cause that one any problems. I think if we can find the source of the issues it has that we'll be able to go from there.

Thanks for asking. Oh and for the compliments too. Nice to hear but I don't expect I'm ever going to get after it enough to really affect the industry much. I'm kind of contented just doing my think keep it low key and low volume.

STR

 

[nevermind35]

Thanks for the advice Steve. I do infact have the original titanium scale. I should have been more clear but I was very tired when asking the question last night. I bead blasted the original titanium scale the other day and installed it and now, with the original scale, it has pretty bad vertical play. I believe you're right in that the two custom g10 scales have a very slightly different screw hole pattern. I think opening and closing the knife with these scales installed may have tweaked the lockbar surface it just enough to cause some problems. When looking at the titanium lockbar face with the knife apart I can see that it is pretty deformed. Much more deformed than any of my other titanium framelocks. I starting to question if Benchmade heat treats the face of their lockbar. I can see a color change right at the tip of the lockbar in some of my other knives like the Sage 2 and my Buck TNT. However both my Alias 1 and my min skirmish have a constant coloring throughout the lockbar. I read you're "Did you know?" section and that plus what you just explained to me has given me a few ideas of things to try. If I can't figure it out I think I'd like to send it out to you if you have time.

One thing that I don't quite understand: You say in your "FAQ" that some stop pins are assymetrical. How common is this and does it really make much of a difference in lockup when you rotate it? I'm going to retake the knife apart now and switch sides on the washers, rotate the stop pin and see if it changes anything. Thanks again Steve for being such a friendly informative guy.