I wondered that too. So I have some inserts for stainless on order.
My biggest concern is that SS inserts may vary considerably in their design and some may be sharper than others.
Tips/Techniques Unique uses for ball bearings
- Thread starter Johnwa
- Start date
Tips/Techniques
I wondered that too. So I have some inserts for stainless on order.
My biggest concern is that SS inserts may vary considerably in their design and some may be sharper than others.
Yes and the material deformed area. This would be a function of the material properties and applied force. From the video, it looks like very little depth of the surface is cold worked to get really good surface finishes. This leads me to believe the forces involved might be comparatively small.
Anecdotally, I occasionally use a ball bearing mounted on a shaft in a tool holder to “bump” stock around to make it run concentric to the longitudinal lathe axis. It does not seem to take much force to burnish the part at all. That is with full width ball bearing outer race contact. Just a ball would be much less force.
Cool! Beats the crap out of tapping it and hoping for a hole shot!
Sort of like a wiggler edge finder. I'm gunna try this asap!
A torus would act like a ball of the same diameter/dimensions - I would think. There would be two of them on a traditional knurling tool so I would expect twice the force compared to a single ball.
I think the long axis would act the same, but the short axis would be much less so overall less. But just a swag.
I wasn't thinking about using both wheels. I was only thinking about how easy it would be to make and use with just one wheel positioned on center.
The idea really depends on being able to find a torrus disk or torroidal bearing the right size.
Overall, I'm still leary of the whole idea..... LOL!
Ok. When is saw “knurling tool” in your post, I thought of the standard two wheel affair and my mind ran with it…
Not sure if on center position is even critical in this application if you are not shooting for a precise dimension. The ball geometry (tangent all around its surface) would be very forgiving to misalignment. Only concern could be lifting forces applied to the carriage/cross slide/compound if above center. (Won’t be any different then running a cut-off tool upside down in a front tool holder - so maybe not even a concern?).
So anyone reading this can see what I mean, this is a balancing arbour made from 1" Hot Rolled 4140. Cut at 600 rpm and 8 thou feed rate and about 3 thou depth of cut (maybe a bit less) using a circular carbide insert for aluminum. If I didn't do it myself I might not believe it. For me, hot rolled 4140 usually ends up chewed and torn up with carbide. There are a few faint lines where the scarf caught here and there. But the scarf was so small that it really didn't affect the appearance much to the naked eye.
And here is the 1/4" insert. I have a bigger 3/8" insert I have not tried yet that might work even better.
I have some round Inserts for SS as well as some Trigon Inserts with bigger radius noses on order.
I confess I deliberately played it safe by saying on-center.
.Your thoughts feel very comfy to my ears.
I thought that too. No way would I try that.
Now you are talking. I wonder if I could just get the wheel!
My exact thoughts too.
If I did, it would be a single wheel like the one @Tom O posted, not a ball.
But. I'm still leery of it.
What is faffing? Is this some new millennial word? How does one go faffing about? Inquiring minds must know.
@6.5 Fan Faffing meaning: from the internet:
If you say that someone is faffing about or faffing around, you mean that they are doing things in a disorganized way and not achieving very much. [British, informal] It was annoying to watch them faffing around when a more direct response was required. [
If you say that someone is faffing about or faffing around, you mean that they are doing things in a disorganized way and not achieving very much. [British, informal] It was annoying to watch them faffing around when a more direct response was required. [
WOW. Agreed. I too thank you @Johnwa for posting the video about the home made burnishing tool. That would be a great project and accessory for my lathe.
Only issue is that i don’t have a lathe.