On a knife edge

Strap, buckle, and box making, reviews, and more
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Phaedros
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On a knife edge

Post by Phaedros »

Since I had some stressful events just lately I felt I needed something to rest my mind upon.
My Cali build ( viewtopic.php?f=8&t=6315 ) is on hiatus waiting for parts, so I expanded into a detail I really enjoyed a lot. This will be loads of work, text and a lot of revealed „trade secrets“ of mine but I found this board to be about sharing and the exchange of knowlegde so here goes:

- the knife edge buckle -

Having to fill a minimum order with my laser cutting service I ordered some blanks. I have to thank [mention]Emilio[/mention] (again) for giving me any help needed to work out the dimensions of the original 27mm buckle. Loosely based on these I drew up a design for a 26mm and a 24mm as well.

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I went entirely from my own preferences and ended up with a slim 26 and a fat 24. If anyone needs a raw fusion file he can alter to his needs, feel free to drop me a pm.

Now firstly there are two main problems, each posing it‘s own little set of challenges. Repeatable bevels and a uniform finish.

If you search the archive you’ll find many different bevel angles. I personally like the flat ones better than the steep ones so accordingly I built a jig (pictured a bit later) to hold the blank to my beltsander in all five positions necessary.

I found it easiest to first establish two opposing bevels and then blend in the others.

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Note: using a fresh belt (3M Trizact 160) for this, that is strictly limited to brass will minimize a lot of problems in plating later on ([mention]binbin[/mention] lesson learned from your hint on the anodizing thread - thanks again!)

A lot of thought went into how and when to finish the 13 surfaces of the buckle (not counting the pin). I couldn’t clamp to a finished surface without marring it so the largest - front and back - would go last. First I roughed in the hinges and then I started the bevels. To get a super straight brushing I had to limit movement to one axis and came up with this:

I used the bevel jig...
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...and an L-shaped piece of aluminium clamped in the vise against a piece of aluminum composite material.
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The sanding paper would be held in the vise inbetween and could be moved up and down to use every last inch of it - quite economic 😬

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All bevels done I went for the in- and outside with diy sandpaper files.

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They are made up of aluminium composite (dibond), double stick tape and sanding paper. I can make them to have dull or cutting edges and bang out different shapes in a minute. The coating makes it easy to peel off the tape and replace... an evolution from my popsicle stick file.

From this...
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...to this
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Now for the large front and back. There’s no more surfaces to clamp to and pushing with my fingers would result in losing fingertips and not finishing buckles.
I made a little block with a non-scratching fiber surface, that would catch the blank from the inside. A little jig - holding a strip of acrylic glass, again with double stick tape and sandpaper - that would pose a ridge for the sanding block and buckle to ride on. This would again limit the movement to one direction. I also used a little aluminium dice with double stick tape to pick up the buckle from the paper, not to mar the surface.

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All that fiddling led me here:

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They were starting to look a bit like jewelry :angel:



Third issue was plating. I jumped a lot of hoops and was lucky to have most of the equipment at hand. I‘ll skip the basics - there’s so many tutorial on youtube, it would be redundance to go into detail.

So what’s special here?

I got a dirt cheap, used lab heating/ stirring plate. This way all emerging bubbles were drawn from the parts immediately and I could maintain a solid temperature around 40°C. Current was 3V DC, time was 90 minutes each.

https://vimeo.com/541382188

[mention]hako[/mention] reminded me of a very nice publication from the german copper institute that held a recipe for breaking up oxide layers before plating. Brass is super reactive and will oxidize quickly so if you don’t plate right after sanding you‘ll get a dull plating that needs polish afterwards.
A twenty second dip of the part in 10% sulphuric acid!
To me this was a game changer. No residue on the parts post plating. Shiny buckles straight from the bath. Neutralize and dry... done.

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Right, no pics of the finished buckles yet - there’s a catch.

Since I had two whole sets of buckles so six pieces to be precise, in the making I wanted to get the opinion of some dear members of the board and sent out five for appreciation. I asked specifically for their private opinion and harsh critique and left open if they wanted to join this thread publicly so I wont disclose any identities unless they choose to themselves.

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If it turns out they are any good, I might make a batch for sale every once in a while but would like to wait if they are up to par yet or if some tweaking is due. Of course I left a little dent or a scratch on every last buckle (f@#€&ck) and already found a little mistake I made - just after sending them out (double-f&€#@ck) - but that’s the purpose of a prototype, right?


I very much know I can’t replicate the impeccable work [mention]Elias Livadaris[/mention] has made with his rendition but maybe this can be a „homage to his homage“ after he stopped making them.


Thank you for reading - well appreciated!
„I asked her for gasoline, she gave me water...“

Me, side of the road, pushing my bike.
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toofsy
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Re: On a knife edge

Post by toofsy »

:cool: super nice post. Thanks for sharing the pics, the process, the tips...and a buckle... :)
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Superspark69
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Re: On a knife edge

Post by Superspark69 »

Super effort here :)
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Emilio
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Re: On a knife edge

Post by Emilio »

It's looking great. We wish you good luck on this journey [emoji1783]
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straps68
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Re: On a knife edge

Post by straps68 »

Really nice work :thumbup: I like your jigs and setup. Thanks for the write up and the pics.
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NortON
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Re: On a knife edge

Post by NortON »

Great work!
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binbin
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Re: On a knife edge

Post by binbin »

I love these kinds of posts. :thumbup:

Great work.

Sometimes figuring out how to hold the part is harder then actually making the part. :)
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Re: On a knife edge

Post by tafari »

great job [emoji106]
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Phaedros
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Re: On a knife edge

Post by Phaedros »

[mention]toofsy[/mention] you are very welcome! I really am excited about this - making those buckles is a super fun challenge.

[mention]Superspark69[/mention] thank you!

[mention]Emilio[/mention] as I said, great fun as well.I am super grateful for your help there!

[mention]straps68[/mention] thank you - you set a benchmark in finishing quality that makes me really struggle to get even close! Now I really know what you mean by hours of finishing 😅

[mention]NortON[/mention] thank you very much!

[mention]binbin[/mention] thank you too! Your advice about contamination of parts in the early stages really helped a lot. My first buckle had so much strange residue on itself after plating... working all clean from the start resolved this nicely.

[mention]tafari[/mention] thanks a lot!
„I asked her for gasoline, she gave me water...“

Me, side of the road, pushing my bike.
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TimemiT
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Re: On a knife edge

Post by TimemiT »

Great job Chris! ... this homage hobby inspires new talent and innovation!
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