# 3D Printed Wa Handles & Sayas



## nakiriknaifuwaifu (Jan 23, 2021)

Hi,

A friend and I have been 3D printing wa handles for a little bit.
It's a cost-effective, beginner friendly, and sleek option that looks good on a wide variety of knives.

One primary benefit (in addition to cost and looks) for 3D printed handles is that I can make the slot exactly to the specifications of the knife, so *don't need any tools or skillz at all to fit the handle*. Just some hot glue gun in the slot, heat up your tang, and it’s good to go - no drilling/sanding/filing needed to replace the handle.

Another plus point is that *I can spec the dimensions and weight to what would be ideal *for the user. The handles do run a little heavier than ho wood, which is great if you're like me and like more balanced knives (perfectly balanced, as all things should be).

Materials will be black PLA and polyurethane sealant - both of which are FDA food safe.

Sayas are printed in a single piece and are strong and rigid. They can be made into friction fit (with splines) or with pin.

PS: It's not slippery


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## Southpaw (Jan 23, 2021)

Great idea


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## Moooza (Jan 23, 2021)

Lovely!


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## BillHanna (Jan 23, 2021)

MY SON!


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## Barmoley (Jan 23, 2021)

Couple of questions; I assume you need tang measurements in order to make the slot fit it, how much precision do you need? Many tangs are not rectangular. For saya, especially friction fit what measurements are required? Great idea to 3D print them I’ve been wondering when people will start doing this, seems like a perfect application for something like this. How much heavier is it vs Ho wood by the way, just to have some reference point.


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## nakiriknaifuwaifu (Jan 23, 2021)

Barmoley said:


> Couple of questions; I assume you need tang measurements in order to make the slot fit it, how much precision do you need? Many tangs are not rectangular. For saya, especially friction fit what measurements are required? Great idea to 3D print them I’ve been wondering when people will start doing this, seems like a perfect application for something like this. How much heavier is it vs Ho wood by the way, just to have some reference point.



Basically I design things a bit bigger (1 - 2mm) than what the client measures at the widest parts for both handle and saya.

This has worked well for a few folks, like @M1k3

Regarding handle weight, I can control how solid and therefore how heavy the handle is. With a 130mm handle I put on my old nakiri, I could probably get it to 90g maximum, maybe around 30g minimum. The most recent one I made was 145mm and 50g. I had mine at 55g and 70g and both were pleasant. The density gives good, solid feedback.

I don't want to give too much away since it took a bit of thinking and I would prefer my idea not get poached, but I'd love to discuss this further in PMs if you're curious (plis don't steal my idea guys).


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## M1k3 (Jan 23, 2021)

Barmoley said:


> Couple of questions; I assume you need tang measurements in order to make the slot fit it, how much precision do you need? Many tangs are not rectangular. For saya, especially friction fit what measurements are required? Great idea to 3D print them I’ve been wondering when people will start doing this, seems like a perfect application for something like this. How much heavier is it vs Ho wood by the way, just to have some reference point.


I measured what I could get of the tang without removing the handle. He made it ever so slightly oversized of my dimensions. In the end the handle slipped on with very little play. Held up fine in the kitchen with only beeswax holding it in place. I wasn't sure if I'd like it or not when I first installed it. Which I ended up liking!


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## Barmoley (Jan 23, 2021)

Great, so even measuring without removing the handle might work if there is no machi. The hole must be deep enough to accommodate most tangs. Very cool.


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## M1k3 (Jan 23, 2021)

Barmoley said:


> Great, so even measuring without removing the handle might work if there is no machi. The hole must be deep enough to accommodate most tangs. Very cool.


I had machi in the way. Hence the guesswork.


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## nakiriknaifuwaifu (Jan 23, 2021)

Barmoley said:


> Great, so even measuring without removing the handle might work if there is no machi. The hole must be deep enough to accommodate most tangs. Very cool.



For @M1k3, his 140mm handle has a 117.5mm slot depth that was around 5mm x 15mm, and I could have theoretically extended that to at least 130mm depth, 10mm width, and 15mm height without compromising structural integrity.

Everything is custom - from overall handle length x width x height, tang slot L x W x H, and weight, so there's nothing that can't be accommodated.


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## Southpaw (Jan 23, 2021)

Can u do heart shape?


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## nakiriknaifuwaifu (Jan 23, 2021)

Southpaw said:


> Can u do heart shape?



I'd be willing to try


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## toddnmd (Jan 24, 2021)

Please, please, please make a phallic one for @ian ’s Dalman!!! (Just make sure it will fit in that box)


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## Alder26 (Jan 24, 2021)

This is a really good idea. Having well fitting sayas for that price is awesome, not to mention if some crud gets in there you could just blast it with dish machine sprayer and let it dry. No need to worry about wood getting wet


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## tostadas (Jan 24, 2021)

Will it melt if you try to remove it by placing in a warm oven (to soften the hot glue)?


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## nakiriknaifuwaifu (Jan 24, 2021)

tostadas said:


> Will it melt if you try to remove it by placing in a warm oven (to soften the hot glue)?



I'd recommend immersing boiling water at 100 C/212 F; the melting point for the filament is around 185 C/360 F.

While I've never tried the oven method (with 3D printed stuff or otherwise), I'd probably stick with the hot water as I wouldn't want to risk getting filament all over my oven.


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## 9fingeredknife (Jan 24, 2021)

toddnmd said:


> Please, please, please make a phallic one for @ian ’s Dalman!!! (Just make sure it will fit in that box)


Maybe in peach color?


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## Bensbites (Jan 24, 2021)

I have used it it to prototype handle shapes, works great. I didn’t get much interest when I offered it for rehandles.


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## ian (Jan 24, 2021)

toddnmd said:


> Please, please, please make a phallic one for @ian ’s Dalman!!! (Just make sure it will fit in that box)



It’s ok, you can just send it to me in an additional separate kiri box. I may want to store the handle on its own in my bedroom.

Can you please put some ridges on it? I really like my handles to be grippy.


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## Robert Lavacca (Jan 24, 2021)

These sayas look awesome. I would love some eventually. I’m a huge fan of 3D printing.


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## AT5760 (Jan 24, 2021)

The sayas seem like a really smart idea. Good luck with the testing and production!


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## M1k3 (Jan 24, 2021)

nakiriknaifuwaifu said:


> I'd recommend immersing boiling water at 100 C/212 F; the melting point for the filament is around 185 C/360 F.
> 
> While I've never tried the oven method (with 3D printed stuff or otherwise), I'd probably stick with the hot water as I wouldn't want to risk getting filament all over my oven.


I was going to ask you about this today. Glad I didn't just stick it in the oven! I'll just heat the tang.


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## M1k3 (Jan 24, 2021)

Robert Lavacca said:


> These sayas look awesome. I would love some eventually. I’m a huge fan of 3D printing.


They do look good. And durable. And at a price point I won't stress over a scratch or ding.


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## home chef (Feb 27, 2021)

nakiriknaifuwaifu said:


> I'd recommend immersing boiling water at 100 C/212 F; the melting point for the filament is around 185 C/360 F.
> 
> While I've never tried the oven method (with 3D printed stuff or otherwise), I'd probably stick with the hot water as I wouldn't want to risk getting filament all over my oven.



A word of caution: even though the melting point on the PLA is higher than 100 C, the glass transition temperature is lower. above the glass transition temperature allows the PLA to become more flexible and be molded so if putting in boiling water be careful not to load the handle or it could deform. A better method may be to use gloves and hole the blade in the boiling water to heat the blade up to temperature and directly melt the glue instead to minimize risk of handle deformation


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## M1k3 (Feb 27, 2021)

home chef said:


> A word of caution: even though the melting point on the PLA is higher than 100 C, the glass transition temperature is lower. above the glass transition temperature allows the PLA to become more flexible and be molded so if putting in boiling water be careful not to load the handle or it could deform. A better method may be to use gloves and hole the blade in the boiling water to heat the blade up to temperature and directly melt the glue instead to minimize risk of handle deformation


I just used my oven at 170°F. I wrapped the handle in aluminum foil because I'm a freak and figured protecting it from direct heat was a good idea.


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## da_mich* (Mar 16, 2021)

I also thought about it for a minute to print handles because it´s fast and easy but something inside of me sayed nooooo. A plastic handle is against my principles. I only build handles with natural materials. But yes it´s very beginner friendly and cost effective. If you like plastic too it´s perfect.


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## Williamchan87 (Mar 21, 2022)

woo single piece 3D printed saya, when I was thinking in my head I thought it would be more practical to make it 2 pieces with one side having pins and the other side having holes so when you glue it you can use a mallet to put them tightly together.

Now that said, please help me build a 3D model I can use to print, or teach me, or make some for me


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## nakiriknaifuwaifu (Mar 21, 2022)

Williamchan87 said:


> make some for me



alright, send me a PM with what you'd like and I'll see if I can do some fancy fabricación


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## ptanks15 (Mar 28, 2022)

Interesting. Great idea.


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