Reworking the Detent Path?

Ludwig

Ludwig

Joined
Feb 25, 2007
Messages
1,877
I have a flipper that was modded by the previous owner. He acid etched the blade but in the process did not properly protect the path of the ball detent. Now the action feels gritty and just does not fly open like a flipper should. Also concerned this will speed up wear on the ball detent.

So I am planning to remove the acid etching from the flats of the blade around the pivot and giving the area a nice polish. Curious as to whether I should also try milling a small groove for the detent path though I do not know if I can be precise enough with my dremel. Would appreciate any advice if you have done something similar before removing acid etching or modding the detent path.

Thanks.
 
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I don't think the detent needs a path. If it made sense, I imagine a knife out there would have it. Just polish up the internals to a nice mirror and you'll be good to go!
 
If you have the tools/skills it wouldn't be hard to set up a jig that would allow you to pivot the blade at a fixed point away from the dremel tool. I would think a small buffing wheel on the dremel would do the trick nicely.
 
Leave it alone and work the blade a couple hundred times....the detent ball will clean its own path.
 
Yeah I have disassembled maybe 25 or 30 different knives (more productions than customs) and there were only one or two that had the milled path for the detent ball. Getting that done exactly right is probably beyond my expertise.

Otherwise leaving it alone was my first inclination too. I have been working the action continuously since last weekend. It has improved slightly but feel like it is taking a toll on the detent as well - going to try the buffing wheel on my dremel this weekend. Fortunately it does not feel like a deep acid wash so should not have to remove much metal.

I will follow up with the results. Thanks guys.
 
Ludwig said:
Yeah I have disassembled maybe 25 or 30 different knives (more productions than customs) and there were only one or two that had the milled path for the detent ball. Getting that done exactly right is probably beyond my expertise.

Otherwise leaving it alone was my first inclination too. I have been working the action continuously since last weekend. It has improved slightly but feel like it is taking a toll on the detent as well - going to try the buffing wheel on my dremel this weekend. Fortunately it does not feel like a deep acid wash so should not have to remove much metal.

I will follow up with the results. Thanks guys.
Click to expand...

What knife is it ?

Detent balls are usually very hard, ceramic ones are hard as hell...You should be able to put pressure on the lock bar and work it a couple dozen times and it should clean a path.

The contact area of the ball is very narrow.
 
Ah dang it I am a dunce for not thinking to put pressure on the lockbar to speed up the process. Holding it up to the light, I can see the contact point for the detent ball (steel) has worn down and flattened some from my efforts, nothing major. The acid etch is not deep so there might be something else worsening the gritty feeling of the action. Will have a better idea once I break it down.
 
Happy to say this little project was overall a success. When I broke down the knife (a Curtiss F3), there were two areas in the detent path where the acid etch was impacting the action. Another issue was part of the path was uneven with the rest of the blade surface, like a tiny step if that makes sense.

Brushed the surface clean and tried a small buffing wheel with green polish - too slow going. Went to the rubber emery wheel which was perfect for removing most of the acid etch and also evening out the surface in that one area. Buffing wheel finished the job but I could not get the acid etched areas to a perfect satin finish.

The action is now where it should be for a ball bearing flipper. I went slightly too far so a small patch of blade without the acid etch shows when the knife is open. The knife previously had some up and down play too but that is gone now - a nice bonus.

Thanks for everyone's input.
 
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