Head spinner, how big a mushroom to aim for

Hengelo_77

Hengelo_77

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I'm testing a self made head spinner. I did a quick test on some 2mm~5/64" brass roundstock.
(That is also the diameter I use for the middle and back pin on slip joints)
I get an app. 0.35mm~1/64" wider mushroom head on the pin.

Is that a good result or should I try to get a bigger mushroom?

This is the best pic I could take:

20231203-155143.jpg
 
Hengelo_77 said:
I'm testing a self made head spinner. I did a quick test on some 2mm~5/64" brass roundstock.
(That is also the diameter I use for the middle and back pin on slip joints)
I get an app. 0.35mm~1/64" wider mushroom head on the pin.

Is that a good result or should I try to get a bigger mushroom?

This is the best pic I could take:

20231203-155143.jpg
Click to expand...
That's a fantastic result, did you make it on a lathe?

I have not made one yet so take this with a pinch of salt, I would say if its mushrooming its too long a pin length and depending on the handle material could burn it, and leave that horrible looking moat around the pin. Do you anticipate the pin sitting above the handle or buried into it? It looks perfect if you are going to pein into a chamfer on the inside of the liner.
I could be miles off and looking at it from the totally wrong angle.
 
Way-Barney has the proper question - How did it work in a knife handle or test piece of polished wood?

My spinners are just a tad larger than the pin stock.

Watch this video to get how they work.
See next post.
 
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Stacy, is this the video you are linking to?

On YT it shows a bit better with shorter URL.

Another YT video showing the spinner a tad better
 
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I work on folding knives every day. Spinning rivets was developed as a production method.
You can make nicely rounded heads by simply peening properly, then polishing- or you can peen and then finish with cupped punches.
I spin rivets only on knives that were manufactured with spun rivets-sometimes.
Tank (of TBarK knives) recently passed away, and his spinners are no longer available.
Maybe I should make cupped punches and sell them.
 
Bill DeShivs said:
I work on folding knives every day. Spinning rivets was developed as a production method.
You can make nicely rounded heads by simply peening properly, then polishing- or you can peen and then finish with cupped punches.
I spin rivets only on knives that were manufactured with spun rivets-sometimes.
Tank (of TBarK knives) recently passed away, and his spinners are no longer available.
Maybe I should make cupped punches and sell them.
Click to expand...
Hello Bill,
Do you have a different cup for each pin size?

As an aside, I love your knives but sadly they are illegal over here. I thought of you this afternoon when I replaced a flint in my cigarette lighter and how to convert that into a mechanism, its got ma all agogo this knife making lark.
 
Bill DeShivs said:
I work on folding knives every day. Spinning rivets was developed as a production method.
You can make nicely rounded heads by simply peening properly, then polishing- or you can peen and then finish with cupped punches.
I spin rivets only on knives that were manufactured with spun rivets-sometimes.
Tank (of TBarK knives) recently passed away, and his spinners are no longer available.
Maybe I should make cupped punches and sell them.
Click to expand...
Bill, this is kind of a dumb question, but how do you hold the knife, hammer, and punches with two hands?
 
I have made several different cup punch sizes. They don't have to be exact size for the rivet stock.

I only do one head at a time, with the other side supported on an anvil or bench block. Holding the knife with your off hand while holding the punch isn't usually too tricky. You can also use other things to prop the knife into position.

These punches are easy to make from drill rod. You can use a lathe or drill to taper the tips. If you have a lathe, centering the cup is easy. With no lathe, you have to get creative with a Dremel or other rotary tool. Center punch the tip as close to the center as possible, and use a small drill bit to start the depression. Then you can use carbide burrs, diamond burrs, or stone burrs to contour the cup.
Once you have your cup cut, it can be polished with shaped rubber wheels (cones) and final polished with rouge and a hard felt bob. This step should be done after heat treatment. Since these punches will be used on brass or nickel silver and will not be hit hard, heat treatment is not required, but it will make the punches last longer.


I use O-1 rod, and do a simple heat treatment to spring temper.
 
I'll give punches a go as wel.
For now I am testing and seeing what works for me.

I'm impressed with how strong stainless steel is.
Here is a quick 1/64" head on a 5/64" pin that I spun. I hung on it with my 175Lbs and it held!
That is a very small ring of steel holding my body weight!

20231204-112053.jpg


20231204-112059.jpg
 
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Did some testing on stainless. It gets hot but I get a good mechanical bond.
It's hard to take good photo's of but I like it when half the mushroom is in and half is above the material.
Now I'll see if I can get some rubber polishing bits to polish the spinner and pins afterwards.

20231204-202245.jpg


20231204-204835.jpg
 
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Hengelo_77 said:
Did some testing om stainless. It gets hot but I get a good mechanical bond.
It's hard to take good photo's of but I like it when half the mushroom is in and half is above the material.
Now I'll see if I can get some rubber polishing bits to polish the spinner and pins afterwards.

20231204-202245.jpg


20231204-204835.jpg
Click to expand...
Third one looks flipping brilliant,
overall I think that's it just one more thing for me to mess up. I used to do a bit of solid riveting on aluminium panel vans, we used snaps and dollys, much like Bills method, seems far less prone to catastrophic calamity and failure.
Kudos to you for trying to figure it out. :thumbsup:
 
There are Multiple sizes available online under £10 (UK Price), you will need two. they are hardened but not really shaped for "spinning".

Search "Rivet Snap"
 
I spin quite a bit of stainless, use 316 pin stock. It spins easier. Mostly 3/32" stock and get about an 1/8" head.
 
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