Cheap And Cheerful Home-Made Swivel Knife

[Renoir]

I made myself a swivel knife

I also wrote-up how I did it if anyone else is interested.

http://renoirsrants....ade-swivel.html

They aren't that expensive, but I find it interesting to make your own tools .

TBD:

Find/make a proper 'flat' blade.

Surface finish on wood - stain/varnish.

Also, I'm looking out for one of the aluminium cheap knives - may be a bit sturdier than the plastic one.

[shtoink]

I must commend you on a very unique approach. Aside from wanting a bit thicker material for your blade and something other than plastic, how are you liking it?

I'm not sure about places outside the U.S., but sourcing bearings from a shop that specializes in RC cars, boats, and such is a good place to start. It could allow for more flexibility in the size of your yoke, if you wish. I have talked to a few that are local for me and purchased new bearings for pretty cheap. I imagine that you might be able to talk someone out of their used bearings that are too worn for racing, but that's a never a guarantee.

I'll agree that the aluminum craft knives might yield a sturdier knife, but the method you used for the plastic handle might not work as well. I'm only referring to the cutting, drilling, and tapping threads into the aluminum as the rest of your process would be largely unchanged.

I can't help but wonder if drilling a hole into the jaws for holding the blade might allow it to clamp and hold a standard swivel knife blade. This whole thing is intriguing and thank you for sharing it with us.

[Renoir]

Thanks for reading

Yep, in my UK experience, there are two 'commonly' available ball bearings : the RC size, and the larger 8mm id/'skate' bearings used for skateboards and in-line skates. I happen to have a couple of dozen of the former lying around from an old project. Of course, you can always order from the 'net.

I'm still getting started, so I don't know how this compares to a 'real' swivel knife - but it does the job and is a lot more controllable than the knife on its own. Definitely an improvement - still learning the cutting and tooling skills. The slight angle to the scalpel actually seems to help a lot - you can hold the knife vertically and it cuts nicely. According to the tandy videos, some swivel knives have angled blades too, or you hold them at an angle.

I've done a bit of home drilling/tapping before and I'd be happy doing the same thing with an aluminium rod - it's relatively soft and metals are fine with a nice sharp drill and some cutting fluid - just go slowly and cool frequently to avoid work hardening.

Nice idea about using a standard blade. The plastic mount is actually pretty shoddy - it hardly tightens at all (it's possible to pull the original blade out with your fingers, almost just a friction fit). A slightly more substantial holder would probably nicely drill and hold a standard blade.

In fact... using the brass collar from the plastic knife, it would be possible to thread a mild steel rod and probably form your own blade holder... maybe time for an update..

Edited August 30, 2013 by Renoir

[Northmount]

Another source for small bearings is the guide bearings for router bits. Go to your local power tool store.

Tom

[Renoir]

http://www.iilg.net/tmp/LGOC/ShopTalk_SwivelKnife.pdf

more than I ever knew about swivel knives

[Renoir]

In theory, since the standard swivel knife blades are 7/32 inch (5.56mm) then it should be possible to drill and insert a standard blade.

[TwinOaks]

Kudos to you for innovation and making your own tools! One thing to consider is that the scalpel blade may be TOO sharp, an you could inadvertantly slice through the leather, so be attentive to your downward pressure. Other than that, I'll yield to Shtoink's experience.

[Les No6]

You could can get everything from eBay they have a very wide selection of bearings and round bar in brass, aluminium, stainless steel, but i would advise silver steel which is a tool steel that comes in precision ground round bar it's in it's annealed state so can be cut drilled taped filed then hardened and tempered its excellent for cutting tools even steel cutting so you can make the blades, it do's rust but but no ware near as readily as mild steel but you could hot blue the body.

[Renoir]

Thanks - I'd used ebay for bearings and similar, but I'd not thought of trying it for stock. There's quite a variety of suppliers on there now!

[Leatherbaron]

10pcs 681 Miniature Bearings

ball mini open bearing 1.5 x 4 x 1.2mm

on ebay from China for $ 10 for 10 bearings

Regards Terry