Custom 3mm CNC machined pivots for Alox mods

[crackout]

I was wondering how many of you are interested in getting some of these because I'll have to come up with a number in the machining shop that makes them.

Also, the overall length should be discussed. I guess it's no problem to machine them in different lengths already, so there is no more grinding needed. One problem might be the drilling of the threading. If the pivot is longer than the effective cutting part of the drill, you will have to drill from both sides meeting in the middle. That's so problem as long as you don't grind off too much. In this case it might be better to have them made in the right length already.

I use 12.1mm length for 3 layers (blade, scissors, caplifter). If you guys plan on doing plier mods, there must be more pivot flesh.

Materialwise, I'll go with 303 AISI steel.

Throw in some numbers!

[lowtech]

Me! Mainly for doing strange things to  108 vics and maybe some 91s.

I think 10 mm would be a sice i can grind down to fit on 1 and 2 layer 108s.

[tattoosteve99]

Just 3mm???  How about 2.5mm to have a complete set? I'd be in for a few sets that way

[clickstop]

Just 3mm???  How about 2.5mm to have a complete set? I'd be in for a few sets that way

I wouldn't mind 2.5mm either, that would make modding so much easier for people who don't have drill presses! I'd be interested in some sets 

[crackout]

If you want to use M2 threading, a 2.5mm pivot is too thin to be halfway stable.
And believe me, you don't want to go with M1.

Those who don't have access to drill presses will have a hard time disassembling the Alox in the first place.

Anyways, I'll ask in the shop if it's still okay to drill a M2 threading inside a 2.5mm pivot.

[Nikos]

... or even 4mm. Then we could change the pivots in and play lego with Vic Spirits! Plus, they only come in one length.

[tattoosteve99]

Oh this thread is getting   Do you know how long we have all been waiting for these pivots. Super!

[ICanFixThat]

... or even 4mm. Then we could change the pivots in and play lego with Vic Spirits! Plus, they only come in one length.

+1 I like this idea... this might be fun; we don't see many Spirit mods, this might help get the ball rolling.  Although it's perfect the way it is.... but maybe then I could have the RT handles on an S-type....

Of course pivots for the regular SAK would have to be very popular 2.5mm or 3mm I'd just do a bunch... just get a price for 200, 500, and 1000 and see what is economical that might help people decide.  Get the exact spec for the steel to be used. I'd definetly be in for some no matter what size you make.

[Syph007]

It would certainly make 93 mods easier for standard configuration fiddling.  You'd still have to drill any donor parts from 91 saks as they will be 2.5 mm pivots instead of 3.0 though.   

If you use all 3.0 pivots then you'll run into the same issue I did with the center hole.  The end holes are nicely countersunk already, but if you drill out the center to 3.0 you will have to countersink it (if you want flush screws).  You can get away with this on silver alox as you wont notice the rougher edge around the screws, but on colored it will stand out.  This is how I learned I needed to countersink and drill those center holes before anodizing.

I gave up trying to work in metric do to lack of availability and high cost of metric carbide bits in this part of the world.  The spring tempered pivots I get are very tough and cheap when you buy in quantity so I just committed to those.  They are $1.35 when you buy 50 or more.  I keep meaning to ask if they could give me a deeper discount for a higher volume.

[crackout]

You can't go much higher than 3mm for the central hole on 93s.
I hope I get info on Monday.

[tattoosteve99]

I don't pay but about $12 per carbide bit. I found a guy who sells them to me at cost. I get 3mm and 2.5mm. Not to bad I guess.

[crackout]

That guy doesn't happen to be in Europe somehow?

[tattoosteve99]

That guy doesn't happen to be in Europe somehow?

Nope but if you need some on the cheap let me know and we can work something out . I have no problems shipping overseas. Oh btw I use endmills to drill out the holes. This requires a drill press.

[Syph007]

I cant remember if I shared this place yet. but its the cheapest Ive found.

http://drillbitsunlimited.com/New-Drill-Bits-C291007.aspx?sid=25472

I can get a 10pack of 1/8 carbide bits shipped to my door for $22.    They arent the spade type I prefer, but they work fine.

[papercut]

If you want to use M2 threading, a 2.5mm pivot is too thin to be halfway stable.
And believe me, you don't want to go with M1.

Those who don't have access to drill presses will have a hard time disassembling the Alox in the first place.

Anyways, I'll ask in the shop if it's still okay to drill a M2 threading inside a 2.5mm pivot.

Any new info on the 2.5mm pivots?

[crackout]

It's possible to make them but not with a M2 threading which kills the purpse for me.
Aside from that I stepped back from modding 93mm simply because drilling out tools is too much hassle for me. I can't find the right drill bits and I have the feeling that even the slightest deviation from the perfect diameter makes to tool wiggle.
I focus on 84mm mods because of the ease of assembly. Also it's more fun to hunt down rare tools.

[papercut]

Would threading (and screws) smaller than M2 not be strong enough? 

[crackout]

I have my doubts. Also I don't like having screws of different sizes on one knife.

[papercut]

After a couple avenues of inquiry of 3mm and smaller pivots not panning out, I have asked a knife shop that custom orders butterfly knives in China to make a inquiry about pivots. We shall see, also asked a South Africa firm too. If all this flops My final trump card is to ask a contact at a heavy steel fabrication firm. He is also a bit in the tech industry so it might be a go.


Would M1.6 screws be too small?  I think that would be the right size for 2.5 pivots.

[papercut]

Ok, the knife shop was a flop and the South Africa contact seems to have lost interest.  I still can inquire with my industrial friend, but want to save that for the last resort.  Another alternative is to try Aliexpress.  There are several vendors who do precision lathing with not too crazy minimum orders and cheap prices (100 pivots for $50?).  I hope to have pivots made for 3.0, 2.5 and 2.2mm.  Screws can be acquired rather easily I believe.

So before approaching them, I would like to confirm the best spec for what we are looking for:

1.  3.0mm pivots with M2 thread all the way through, Stainless Steel 304, heat hardened
2.  2.5mm pivots with M1.6 thread all the way through, Stainless Steel 304, heat hardened
3.  2.2mm pivots with M1.4 thread all the way through, Stainless Steel 304, heat hardened

What would be the ideal length?  12mm?  15mm? Longer?  They can always be shortened by cutting or grinding. 

Is 304 good enough?  What would be better w/0 being overkill?

http://www.aliexpress.com/item/SELL-Precision-Stainless-Steel-Shafts-cnc-machining-part-cnc-machined-part-cnc-lathe-shaft-steering-shaft/575325252.html

http://www.aliexpress.com/item/Brass-CNC-Lathe-And-CNC-Precision-Machining-Part/629275321.html

http://www.aliexpress.com/store/product/Good-Quality-and-Low-Price-for-CNC-Machined-Parts/212511_640038068.html

If these pivots can be fabbed, the next step is fabbed Wenger 85mm and Vic 91mm CF scales, then a mix with a Wenger handyman and a Super Tinker for some good lovin!

[crackout]

For a Farmer with scissors you need around 15mm and for a Pioneer with scissors around 12mm.

[Syph007]

Id get them as long as you possibly can.  Most of the mods I do now, the 0.5 inch pivots I have aren't long enough so I end up doing the pin splice trick more often than not now.  I know threading something that small all the way though will be tough, but whatever the max length is, go for that.  I always leave them long when I build, dont put the final scale on, but instead put on a scrap liner and use that as a guide to grind the pivots down to correct length, use compressed air to blow out debris, the pop on final scale and add screws.

$50 for 100 is a good price if they work out well.

[papercut]

I figured longer is probably better, some of the 4 and 5 layer saks are pretty thick, and the ones on up can get crazy thick.  Splicing is always an option but probably not ideal. 

With prefabbed Cf scales, one could do easy brakedown of the cellidor models (no need to save the bushings or pins), lay down the the Cf scales with the pins already in and stack away.  That is the theory at least... :p 

(This would be for the folks without the workshop necessary to do the more delicate operations that Syph, Steve, Mosquito and others are pulling off!)

[papercut]

Put out inquiries with two suppliers, we shall see if they bite.  I asked for 22mm pivots with the general spec above (not sure if 300 grade SS can be hardened though).  Alternative acceptable grades listed 302,316, and 440.  303 seems a bit suspicious due to its lower corrosion resistance.

What sort of treatment should I request (acid, etc)?

[papercut]

One price quote so far on the spec I provided.  304 steel (I don't believe it can be hardened actually, it is quite hard).  The supplier in question said he tested an 1/8 drill bit in one continuous thread for 35mm so 22mm is doable.  He quoted his unit price when ordering 100 (minimum order) is $0.66 USD per barrel.  22mm is actually long enough for 2 pivots for many mods :p.  Or should I ask for 25mm?

There is another firm that is considerably cheaper, they seem to be a big industrial firm, but it seems that the longest continual thread they can do is 10mm with this possible from two sides.  This is not as ideal as the pivots need to be cut to order and matching threads is not easy.  Plus they offer 303 steel which is more susceptible to corrosion.  Their minimum order is much larger, but due to low unit price- the final price is similar.

A third supplier requires drawings, which I do not have at the moment and based on the simple spec, should not really be required.

With three pivot sizes and using the first supplier it would be $192 for 300 (or 600 if frugal) pivots.  I could probably front the money, but I would only be interested in a third of the order.  Does anyone else want in?  I need to confirm the shipping charges as well. 

Cheers!

[papercut]

Er, $198 not 192 :p.

Shipping to my current country would be free, to the USA would be about $25.  As I will be coming stateside next month, I could bring some over for cheap domestic shipping.

[papercut]

Doesn't seem to be much interest in these pivots at the moment.  I suppose the established modders already have their own working method.  In that case I might just have the 25mm pins fabbed up first as they are the right size for Wenger 85mm mods (x4), and that is what I would like to start to tinker.   

Cheers!

[Tabasco]

I would be willing to front half of the cost, if that estimate is close to correct. Sorry for the late reply, I don't spend a lot of time on-line anymore. 

[papercut]

Thanks for the heads up.  One guy on BF says he wants about a tenth of the order.  So:

1/2 + 1/3 + 1/10 = 28/30!

I guess that is close enough!

Cheers

[papercut]

Looks like a second BF member wants the last 3/30, so it seems to be a go!

Uh oh, no worries though, my portion could be cut a few thirtieths without any issue. If anyone else wants in let me know in the next day or so, I can make the order larger or shrink my portion a bit.