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- Sep 13, 2021
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- 1,052
I just set a new world record: the longest I’ve made it before disassembling a new mechanical gadget to see how it works. LOL! But now that my family from out of state have gone home…
The Buck 591 Paradigm Shift Auto:
Observations:
The blade shape and opening/closing mechanism is obviously related to the 293 Inertia. They both use the same coil springs to open the blade.
The blade washers/bushings are notched so they stay fixed relative to the blade, so the smoothness of opening closing is between the bushings and the liners - interesting choice since the liners are likely less precisely machined than the sides of the blade. Mine was sticky upon closing. Opened perfectly, but when you released the lock and started pushing the blade closed, you had to overcome some stick before it would move freely. I tried a drop of oil before disassembly but that didn’t solve it. While apart, I rubbed both sides of each washer in circles (approximately 20 each side) on an old Buck hard Arkansas stone. That fixed it - and helped me resist the temptation to drill the three rivets securing the liners to the backspacer so I could smooth the inside of the liners on a stone as well. If I had drilled the rivets, it appears M2x8 pan head bolts would fit for reassembly with just a couple thousandths filed off the length to fit the recesses in the G10 scales. The M2 hex nuts I have would need the peaks files down in order to fit in the recesses. Maybe another day, but not tonight.
The cross pin that locks the blade both open and closed is actuated by a ramp in the rotating bolster. It is greased from the factory with a heavy good old fashioned machine grease - something that will stay put. I reassembled with similar.
During reassembly I used a lighter grease - hinge and high pressure grease - to hold the blade washers/bushings and coil springs in place. The knife functioned great with this grease in place after reassembly, but I washed it out with Strike Hold - a dry film lubricant that won’t attract as much pocket lint and dust as the hinge and high pressure grease does. The knife functions just as well with that as it did with the light grease, and just as well as it did from the factory.
Found remnants of blue Locktite upon disassembly and reassembled with the same.
The Buck 591 Paradigm Shift Auto:
Observations:
The blade shape and opening/closing mechanism is obviously related to the 293 Inertia. They both use the same coil springs to open the blade.
The blade washers/bushings are notched so they stay fixed relative to the blade, so the smoothness of opening closing is between the bushings and the liners - interesting choice since the liners are likely less precisely machined than the sides of the blade. Mine was sticky upon closing. Opened perfectly, but when you released the lock and started pushing the blade closed, you had to overcome some stick before it would move freely. I tried a drop of oil before disassembly but that didn’t solve it. While apart, I rubbed both sides of each washer in circles (approximately 20 each side) on an old Buck hard Arkansas stone. That fixed it - and helped me resist the temptation to drill the three rivets securing the liners to the backspacer so I could smooth the inside of the liners on a stone as well. If I had drilled the rivets, it appears M2x8 pan head bolts would fit for reassembly with just a couple thousandths filed off the length to fit the recesses in the G10 scales. The M2 hex nuts I have would need the peaks files down in order to fit in the recesses. Maybe another day, but not tonight.
The cross pin that locks the blade both open and closed is actuated by a ramp in the rotating bolster. It is greased from the factory with a heavy good old fashioned machine grease - something that will stay put. I reassembled with similar.
During reassembly I used a lighter grease - hinge and high pressure grease - to hold the blade washers/bushings and coil springs in place. The knife functioned great with this grease in place after reassembly, but I washed it out with Strike Hold - a dry film lubricant that won’t attract as much pocket lint and dust as the hinge and high pressure grease does. The knife functions just as well with that as it did with the light grease, and just as well as it did from the factory.
Found remnants of blue Locktite upon disassembly and reassembled with the same.
