Great video Chris. I just started building knives. I'm on my 3rd pocket knife. My first knife I didn't know about ruple gauges. My second knife I used the gauge and the spring was off a few thou. My 3rd knife I got the spring perfect at all 3 positions. As a tool and die maker that has over 20 years of experience these things come pretty easy to me but I enjoy the precision. Some things I noticed while watching your video that may help you out. 1. Get a dial indicator set up on the lathe to get your bushing length much closer. This will cut down lapping time. 2. Never dial out your cutter after your cut. leave cutter at depth... after cut just move cutter to the right. measure. if it's really close just feed it again for a clean up cut... measure.. make a cut. etc.. On my next slip joint I may have to try some alumabronze and make a pivot bushing. I've just been using stainless pins so far. Do you harden your stainless Liners by any chance? I got some .040" 17-4 that I plan to heat treat.
Hey Brent. Thanks for the advice, and sorry for the delay in replying. I'll should give your suggestions a try. I'm always looking for better and more precise ways of doing things. I don't harden my stainless liners. I'm using either 416 or 410, (I get them confused,) and I pretty much use the stainless as is. I like the 400 series over the 300 series because it seems to machine better, and also it's will stick to a magnet, which is really handy for various reasons.
I turn the bushing down from 3/16" stock so that I can make sure my hole is centered. By drilling fist, and then turning the stock down. my hole will be centered between the outsides. I actually do it a little differently now. Now I drill the hole and then cut the bushing off. I then place the bushing on a separate mandrel and turn it down. I get even more accuracy this way. I got this idea from Ken Honeycutt.
Thanks! Yes, you can make custom thumb studs using this lathe. In fact, the first time I saw one of these, probably almost 20 years ago, the gentleman was using his for making thumb studs. The lathe is very precise and great for small detailed work. I've even used mine for making some corby style bolts using a 1/8" rod, turned down to 3/32", and drilled and tapped for a 0-80 screw. Worked great!
Thanks Chris for explaining the details around the bushing, it makes sense . Should you design the back spring to be engaged into the tang by .06 to allow for engagement once assembled? Or what is your recommendation. Take care
Hey Jeff. Different people do it different ways, but if I were making up a new design, this would be my process. 1) I would draw the knife pattern just like it would be when put together, and I would have my pin holes marked and everything. 2) I would cut the pattern out, glue it to some steel, and make my parts. 3) When drilling the liner pattern, I would not drill the back hole, but I would drill the back hole in the spring. 4) I would then put the blade and spring in place on top of the liner, with the end of the spring touching the tang of the blade, remove the blade, rotate the spring down about a 1/16 of an inch, and then drill through the back spring hole into the back of the liner. This will position the holes in your liner so that there is some tension on the spring when all of the pins are in place. The 1/16" distance would probably be different depending on the length and thickness of your spring, so I offer that as a starting point. Hope this helps.
Hello Andy. This is a response to a similar question someone ask... " I still mill the reliefs on the liners. The bushing does create some offset, but with it being .001" wider than the blade, that only comes out to .0005" on each side when it's put into place. The main reason I use bushings is to help not bind the blade when peening the knife together. The milled liners keep the visible part of the tang from getting rub marks when the blade is opened and closed. The two operations go together quite nicely. Hope this helps."
Hello Israel. I still mill the reliefs on the liners. The bushing does create some offset, but with it being .001" wider than the blade, that only comes out to .0005" on each side when it's put into place. The main reason I use bushings is to help not bind the blade when peening the knife together. The milled liners keep the visible part of the tang from getting rub marks when the blade is opened and closed. The two operations go together quite nicely. Hope this helps.
It's a 1" digital micrometer that I picked up from Harbor Freight. Here's a link: www.harborfreight.com/hand-tools/measuring-marking-layout/calipers-micrometer/digital-micrometer-63647.html
Its a great video explaining how you make your bushing.
Thanks Ralph
Thank you for teaching about bushing pin.
As I just purchased Chriss Reeve Sebenza31, I deeply impressesd.
I will keep watching on your youtube.
Thanks!
I really appreciate you sharing this video. I have been very interested learning to use pivot bushings.
You're welcome, and I'm glad it was helpful.
Great video Chris. I just started building knives. I'm on my 3rd pocket knife. My first knife I didn't know about ruple gauges. My second knife I used the gauge and the spring was off a few thou. My 3rd knife I got the spring perfect at all 3 positions.
As a tool and die maker that has over 20 years of experience these things come pretty easy to me but I enjoy the precision. Some things I noticed while watching your video that may help you out.
1. Get a dial indicator set up on the lathe to get your bushing length much closer. This will cut down lapping time.
2. Never dial out your cutter after your cut. leave cutter at depth... after cut just move cutter to the right. measure. if it's really close just feed it again for a clean up cut... measure.. make a cut. etc..
On my next slip joint I may have to try some alumabronze and make a pivot bushing. I've just been using stainless pins so far.
Do you harden your stainless Liners by any chance? I got some .040" 17-4 that I plan to heat treat.
Hey Brent. Thanks for the advice, and sorry for the delay in replying. I'll should give your suggestions a try. I'm always looking for better and more precise ways of doing things. I don't harden my stainless liners. I'm using either 416 or 410, (I get them confused,) and I pretty much use the stainless as is. I like the 400 series over the 300 series because it seems to machine better, and also it's will stick to a magnet, which is really handy for various reasons.
Hi Chris,
Thanks for sharing.
Very informative.
You're welcome, Stefan!
Chris. Why do you make your pivot hole in the blade .172dia and not .188 3/16????????
I turn the bushing down from 3/16" stock so that I can make sure my hole is centered. By drilling fist, and then turning the stock down. my hole will be centered between the outsides. I actually do it a little differently now. Now I drill the hole and then cut the bushing off. I then place the bushing on a separate mandrel and turn it down. I get even more accuracy this way. I got this idea from Ken Honeycutt.
Hey Chris great video. Can you make custom thumb studs for folders with this lathe?
Thanks! Yes, you can make custom thumb studs using this lathe. In fact, the first time I saw one of these, probably almost 20 years ago, the gentleman was using his for making thumb studs. The lathe is very precise and great for small detailed work. I've even used mine for making some corby style bolts using a 1/8" rod, turned down to 3/32", and drilled and tapped for a 0-80 screw. Worked great!
Thanks Chris for explaining the details around the bushing, it makes sense . Should you design the back spring to be engaged into the tang by .06 to allow for engagement once assembled? Or what is your recommendation. Take care
Hey Jeff. Different people do it different ways, but if I were making up a new design, this would be my process. 1) I would draw the knife pattern just like it would be when put together, and I would have my pin holes marked and everything. 2) I would cut the pattern out, glue it to some steel, and make my parts. 3) When drilling the liner pattern, I would not drill the back hole, but I would drill the back hole in the spring. 4) I would then put the blade and spring in place on top of the liner, with the end of the spring touching the tang of the blade, remove the blade, rotate the spring down about a 1/16 of an inch, and then drill through the back spring hole into the back of the liner. This will position the holes in your liner so that there is some tension on the spring when all of the pins are in place. The 1/16" distance would probably be different depending on the length and thickness of your spring, so I offer that as a starting point. Hope this helps.
@@cfcrawfordyout That makes sense. Will try that next on the next knife. Thank you Chris!
Thanks for showing this it’s very helpful. With a bushing is it not necessary to mill the liners out?
Hello Andy. This is a response to a similar question someone ask... " I still mill the reliefs on the liners. The bushing does create some offset, but with it being .001" wider than the blade, that only comes out to .0005" on each side when it's put into place. The main reason I use bushings is to help not bind the blade when peening the knife together. The milled liners keep the visible part of the tang from getting rub marks when the blade is opened and closed. The two operations go together quite nicely. Hope this helps."
@@chriscrawford5392 thanks Chris.
Thanks Chris. Does this allow you to not mill a releaf on your liners?
Hello Israel. I still mill the reliefs on the liners. The bushing does create some offset, but with it being .001" wider than the blade, that only comes out to .0005" on each side when it's put into place. The main reason I use bushings is to help not bind the blade when peening the knife together. The milled liners keep the visible part of the tang from getting rub marks when the blade is opened and closed. The two operations go together quite nicely. Hope this helps.
what micrometer are you using?
It's a 1" digital micrometer that I picked up from Harbor Freight. Here's a link:
www.harborfreight.com/hand-tools/measuring-marking-layout/calipers-micrometer/digital-micrometer-63647.html