Start of Mod on large Insingo

[victorf]

Having tooling shipment delay until 11/18 from MSC - so, slight delay to start project. I wasn't gonna start a new thread on my Insingo until modding completion. Posting to share, what is new to me. Maybe others already knew, the fact of a small subtle discovery on the Sebenza's grip.

Been brainstorming, fondling knife, to weight in, on several options, regard to surface machining/finish and pretty much settled on the one design. It will have simple milled dimples in accordance to my grip impression for an enhance grip, polished then flame anodize - hopefully to highlight the design.

Through multiple handing, discovered lower handle, both RIL lock bar/presentation side, lower edge appears to be straight. Measured, using machinist precision scale, by the clearance cutout for the RIL access, 1/2" away from the cutout, there is an subtle peak then gradual drop back to the rear - an almost invisible middle finger groove!

Anyone notice that subtlety?

 

[Muaddib1116]

I didn't really notice till reading this, but once I knew, it's really easy to feel and see. I wouldn't go so far as to call it a finger groove though.

 

[Zeta33]

Your picture doesn't show up for me

 

[kidcongo]

Sounds like an exciting project. Really looking forward to seeing your results.

 

[biggerjon]

Good luck! Can't wait to see progress pics.

 

[victorf]

I didn't really notice till reading this, but once I knew, it's really easy to feel and see. I wouldn't go so far as to call it a finger groove though.

Yea, I called it "an almost invisible middle finger groove!". Maybe better term should have been an depression for the middle finger.

Your picture doesn't show up for me

Sorry. I hope you can get the idea from my description. I can not easily see the difference with the actual knife, but it is certainly one I can feel by rubbing finger over the lower handle edge. Once realizing its there, now I can see the tale tale bump.

Sounds like an exciting project. Really looking forward to seeing your results.

I do like to work with titanium alloys, made parts for my road racing bicycle, motorcycle and car projects. Especially how magically it transforms with heated flame on some applications.

Good luck! Can't wait to see progress pics.

Once project started, I don't know if I can take progress pictures. But maybe in between work stoppage after my hands are cleaned. No promise.

***

One more week before anticipated tooling from MSC. Mean while, I am planning to disassemble Insingo, for fun, to machine a concave radius onto the standoff. Measure thickness of the stand off, to make one shouldered titanium barrel to fit, in place of the lanyard w/existing floating lanyard pin. Also based on the standoff dimension, make a aluminum spacer, drill/tap to clamp the two handle scale together, along with another backing plate, to mount one scale at a time, for the eventual machine work.

 

[Twat]

Anyone notice that subtlety?

I did, and I believe it to be the result of bad drafting.

If anyone wants to change my mind on this point, I'm all ears.

 

[Haze]

Why don't you make the effort to present your point ? We're all ears too......

I did, and I believe it to be the result of bad drafting.

If anyone wants to change my mind on this point, I'm all ears.

 

[Twat]

Why don't you make the effort to present your point ? We're all ears too......

1. I spent many years drafting and have seen this type of a mistake made countless times. Someone makes an arc or a line that looks straight or as if the arc follows the appropriate curve, but when zoomed in and the view regenerated, you can see a distinct point. When this CAD point is then converted to a machined process, the computer is going to follow the drafted point, but now matter how close the lines or arc might flow, the machine can only cut to whatever tolerances it's capable. That point will show up in the machined product.

2. I see no functional purpose for this small point in the knife. It doesn't make sense from a machining perspective, design perspective, engineering perspective, or efficiency perspective. From any perspective I think of, I can't account for the slight bump.

3. Prior to presenting my hypothesis I took the knife to a couple of mechanical engineers and machinists, asked them why it would be there, and they came to similar conclusions.

Now, I am the first to admit my fallibility, and am open to correction in any area. So with that being said, I've presented my rationale, and like I said prior, I'm all ears.

 

[Haze]

I'm not saying you're wrong and you do present good points now you have been asked for them.

I also have a background in design engineering and machining. I know many designers, my self included, use the same angles, radiuses and so forth in all my designs and for a number of reasons. I think that may well be a purposful design feature of some sort or a carry over from previous design rather than a genuine mistake.

To give an example, the Classic/21 handle shape has the same radius to the spine but it is reversed on the Regulars. One will notice they sit together perfectly spine to spine with the convex spine of the Regular Sebenza fitting splendidly into the concave spine of the Classic/21 Sebenza.

I can't speak for CRK and their design procedures but knowing the background Chris has as a die/tool maker and machinist I have to give him the benefit of any doubt.

1. I spent many years drafting and have seen this type of a mistake made countless times. Someone makes an arc or a line that looks straight or as if the arc follows the appropriate curve, but when zoomed in and the view regenerated, you can see a distinct point. When this CAD point is then converted to a machined process, the computer is going to follow the drafted point, but now matter how close the lines or arc might flow, the machine can only cut to whatever tolerances it's capable. That point will show up in the machined product.

2. I see no functional purpose for this small point in the knife. It doesn't make sense from a machining perspective, design perspective, engineering perspective, or efficiency perspective. From any perspective I think of, I can't account for the slight bump.

3. Prior to presenting my hypothesis I took the knife to a couple of mechanical engineers and machinists, asked them why it would be there, and they came to similar conclusions.

Now, I am the first to admit my fallibility, and am open to correction in any area. So with that being said, I've presented my rationale, and like I said prior, I'm all ears.

 

[Twat]

I agree with all you said.

I also think it's most probable that it is a carryover from a previous design.

 

[Muaddib1116]

1. I spent many years drafting and have seen this type of a mistake made countless times. Someone makes an arc or a line that looks straight or as if the arc follows the appropriate curve, but when zoomed in and the view regenerated, you can see a distinct point. When this CAD point is then converted to a machined process, the computer is going to follow the drafted point, but now matter how close the lines or arc might flow, the machine can only cut to whatever tolerances it's capable. That point will show up in the machined product.

2. I see no functional purpose for this small point in the knife. It doesn't make sense from a machining perspective, design perspective, engineering perspective, or efficiency perspective. From any perspective I think of, I can't account for the slight bump.

3. Prior to presenting my hypothesis I took the knife to a couple of mechanical engineers and machinists, asked them why it would be there, and they came to similar conclusions.

Now, I am the first to admit my fallibility, and am open to correction in any area. So with that being said, I've presented my rationale, and like I said prior, I'm all ears.

I think I understand what you're saying in your first point, but I think that the double arc of the handle slaps is too pronounced for it to be accidental due to misaligned drafting arcs. As far as not being able to come up with a reason to purposefully include such a profile, I don't feel like that is a very strong argument. Just because you (and/or others) don't know why it was put there, doesn't mean it wasn't intentional. I am continually impressed with how thoughtfully Chris Reeve knives are designed and manufactured. Maybe during the design Chris looked over the drafter's shoulder and didn't quite like the handle shape with a single arc, and said, "hey, push this part of the handle out a bit by making a second arc". There may not be a particularly compelling reason for that profile to exist, but it strains my belief to think that it was an accident that nobody has bothered to fix.

I think the most I would be able to believe would be that it was an accident of some sort on the first prototype slabs milled, but that it was discovered and they decided that they liked it.

 

[Twat]

Regardless, it's not stopping me from buying more of my favorite knife... Sebenza 21.

 

[bhyde]

First, the small inconsistency is very likely an artifact of the previous design as Haze stated. In a CAD assembly, this would have been very obvious. Ahh..the power of 3d CAD..Lines, arcs, splines and nurbs all become very obvious. ( I have one sitting next to me )
One element that may or may not be so obvious is the industrial design aspect of these things. Very large arcs are easier on the eyes than straight lines and reflect light differently as one example.
By the way, industrial design engineering isn't an element a mechanical engineer or a machinist would be naturally exposed to..We do have a few of those Engineers in this area...Just a thought..I have many years of experience in machining and almost as many in CAD and alot of CAD packages..Not to mention alot of CAM packages..Which brings me to my second point;

In my opinion, the mark you are seeing ISN'T a point dwell from the machine at all, at least not from a point existing in the CAD model..It's an entry/exit point of the tool itself. ANY pause at the machine tool, no matter how slight, creates a witness mark in the material. Many CAM programs have entry/exit options and this one appears to be centerpoint/centerline midpoint/midline of a line entry/exit.

To sum it up,. It may be intentional, it may not,..But I wouldn't call it "bad drafting". I know the guy that does most of the drafting and I would call him very proficient. By the way, converting a point to a machine process, it's simply an endpoint...Nothing more and nothing less. It's no different than generating an arc to a line..There is a start point, a G2 or G3 command and then an endpoint.

 

[victorf]

Well, first off, thank you Mr. Haze, very gentlemanly turning the "Bump" into an intelligent pursuit! Very interesting/knowledgeable responses.

As a retired Nuclear ToolMaker with 39 years under my belt. Had the pleasure, worked along with a few Nuclear Engineer as well as Industrial Tool Design Engineer and Tool Design Draftsman - few, with great minds, in all areas involved designing/revising/improving/manufacturing special tooling, in accordance with high Nuclear standard demands. I don't believe Mr. Reeve, had a 15 years stint in Tool & Die, would continue making the 21 and not knowing the "bump'S" existence. Not saying it can't be true! But who knows other than Mr. Reeve, right?

I do know a little on differences between conventional and CNC programming/machining. One particular stand out, is transitional point. Where tangent point dwell during an transition - if program/configure properly with the known correct/precise tool radii, in relation to initial tangent point set up/touch off - resulted seamless transition becomes flawless, certainly a thing of beauty - where the best skilled/experienced ToolMaker can only dream, after employing the best equipment.

I do come away learning from all these civil response - Mahalo all!

Please don't hesitate contributing further intelligent pursuits!

 

[loon#r]

What's missing here? I see one image and it's that of a plain looking insingo. What is going on in this thread?

 

[nyefmaker]

Knowing Chris Reeve. EVERY aspect of his knives, every little nook and cranny has a reason and a purpose. Some obvious and some not so obvious.

I never doubt the Man Himself.....!!!

 

[victorf]

Knowing Chris Reeve. EVERY aspect of his knives, every little nook and cranny has a reason and a purpose. Some obvious and some not so obvious.

I never doubt the Man Himself.....!!!

Some real Tool & Die Maker are a different breed - especially those with true passion. But not all his product line I like. But it all boils down - to each his own, right?

I do agree large Seb21 Insingo stands out among his other style and it is the only, I selected to own. Other style/design not so much.

I started on "lightening" the stand off and machine floating titanium shouldered barrel to replace lanyard/pin yesterday. I will try take some pictures later today as I am just about out of the door for my appointment. Interesting as found, both standoff/stop pin bushing are same thickness but pivot bushing is .0002" less thick. There is, on the OD, a dent already on the stop pin bushing, on an one month old knife. it is non magnetic, I will make one replacement out of 17-4PH and heat treat it to take the contact impact a little better.

 

[victorf]

Here shown the "Lighten" stand off and replacement of lanyard/pin with one piece shouldered titanium pin:

They will also be flame treat along with, after finishing the rest, on skeletonize handle scale internal, as well as external dimples to personalize for finger locations.

 

[bhyde]

Those look great! Any plans for more mods?

Keep 'em coming!