Swivel knife

[mrsbruce]

I need a bit of help with the swivel knife I am making. As posted previously, I have made the main body of the knife ok, but my problem is with the swivel bit itself.

The concept is that your index finger rests on the saddle (stabilising it), and you turn the main body of the knife to cut the shapes in the leather.

I asked someone who made their own, how they made the swivel ‘swivel’, but I just did not ‘get’ it. Could someone here explain in simple language (preferably with a diagram), how to make the swivelling saddle bit, please.

 

[tom2207]

id be guessing theres a straight shaft going into the bottom part from the top , with a grove in it for the retaining grub screw , then just a ptfe bush counter bored into the top of the bottom part , if thats not swively enough , a small thrust bearing , or a couple of ballbearings and make the bush out of brass .
think steering stem on a bike

 

[Ali]

Looking at the mechanism for a cnc drag knife might help you?

 

[tom2207]

just a quick and rough sketch

 

[mrsbruce]

just a quick and rough sketch

Many thanks, chaps.

I’m being bright today, posted my picture, of the swivel knife in action, and never notice that it used a groove and grub screw.


There is another way, as you might be able to see on my knife, the saddle stem screws into the body, with the swivel bit being just under the saddle.

Quite happy to use the groove and grub screw, and it also looks a lot simpler. I have a couple of tiny bearings I might have a play with.

 

[tom2207]

simple is my middle name ,,, lol

 

[gaz1]

now what was you saying that you didnt need a lathe or that you wanted one

so when is that milling machine coming in handy then ?

this forums costly isnt it pmsl

 

[tom2207]

now what was you saying that you didnt need a lathe or that you wanted one

so when is that milling machine coming in handy then ?

this forums costly isnt it pmsl

you need a friend with one , and a passion for beer ,,, barter is the new currency

 

[mrsbruce]

now what was you saying that you didnt need a lathe or that you wanted one

so when is that milling machine coming in handy then ?

this forums costly isnt it pmsl

I’ll have you know that today, I actually got back to making my mini companion set project. Whereas everyone else is mooching about looking for stuff to do, I am up to my eyes in orders. So much for getting a bit time off.
I needed a day off, so now I’ve just got to thread the arms, then paint the stand.

I set up the main bit of the stand in the milling machine, ready to drill, but had a brain burp, and got confused over what size I was drilling the bloomin’ thing. Once I remember, and that’s done, THEN I can work on my new swivel knife, and all the other projects I want to play with.

I came on this forum to learn how to weld, and now look what you’ve made me buy.

It’s funny though, instead of raking through boxes of ‘interesting things’ in the hope of cobbling something together, I now draw a (very) vague plan, and make the bit instead.