PDA

View Full Version : Burnishing on a lathe?



IOWOLF
12-30-2005, 05:22 AM
Can anyone tell me how to do it In a simple way,As I am simple minded. http://bbs.homeshopmachinist.net//wink.gif

------------------
The tame Wolf !

Your Old Dog
12-30-2005, 07:47 AM
Not sure if the question is more complicated than I'm thinking of if you think the process is more complicated than it is. I've always just rubbed the metal/wood/ivory to be burnished with something harder than the item and poliched to perfection. My burnishers have a slightly rounded surface so that means you get higher concentration of force but if too tight a radius they leave dent in the finished project.

I likely made an ass of myself but I wanted to get to you before someone dropped.....

1. What do you want to burnish?
2. How hard is the material? (will it flow)
3. What kind of lathe do you have?
and of course,
4. What did you have for breakfast?

.....on you http://bbs.homeshopmachinist.net//biggrin.gif

[This message has been edited by Your Old Dog (edited 12-30-2005).]

PTSideshow
12-30-2005, 09:41 AM
Engine turning, the circular swirls used in auto custom work can be as simple as a pencil eraser chucked in a drill motor or press. to the store bought kits with sized heads and media to achive the effect your want. What is neat about the eraser idea is by using different types of erasers pencil, ink gum hard and soft differing effects can be had.
in sign work on leafing of different materials. A silkswatchfilled with cotton and twisted to form a little ball will work. on the foil vinyl the above over the head of an appropriate sized wood dowel will work.
For lathe work a flat paint paddle type stick covered with leather( the 5 gal type from home depot works good). To hold the media of choice waxes,Bon Ami soap, baking soda, pumice,blasting media finer sizes and oils or grits(lapping type). The most important thing is to have a stiff backing behind the material used for burnishhing. Another thing that has worked on flat surfaces is small suction cups like they use to hang dust catchers on windows. the ones with a hole in the back center that will fit over a dowel are great. as you use the they may wear down but you can pitch them and use a new one.


------------------
Glen
Been there, probally broke it doing that

mochinist
12-30-2005, 10:10 AM
Are you talking about roller burnishing. If so this may help you.

http://www.manufacturingcenter.com/tooling/archives/0300/0300tp.asp

IOWOLF
12-30-2005, 01:34 PM
Y O D, thats it,You did good.
1.steel
2.4140
3.several
4. oatmeal

PT, thats jeweling,but thanx.

Mo, thanx for the link.

------------------
The tame Wolf !

Your Old Dog
12-30-2005, 02:26 PM
Well then if I'm on the right track then I should also tell you this:

When burnishing to eliminate a deep scratch you burnish with the scratch and not perpendicular to it like you would if you were trying to sand it out. I think when you "burnish" on other than metal such as wood or ivory it's called boneing and in days of yesteryear was supposedly done with whale bone. With that you have the limits of my vast knowledge on burnishing http://bbs.homeshopmachinist.net//biggrin.gif I could talk a little more on boneing but nothing anyone would probably want to read here !!

tattoomike68
12-30-2005, 02:29 PM
A simple way...

With a scissor type knurling tool you can change the rollers to some that are smooth, like a <1-4 micro finnish with a slightly rounded surface like YOD said and it will make a very nice finnish.

I have seen the roller burnishing types on multi spindle screw machines doing ID and OD roller burnishing, the cost of the tool was insane but works good for 50,000-1,000,000+ parts orders.

I Know you could make some smooth rollers for a knurling tool that would give a good finnish for seals, orings and roller bearing surfaces.

burnishing is nothing more than forcefully shoving the hills into the valleys.

Sprocket
12-30-2005, 07:18 PM
Does burnishing increase surface hardness (work harden)?

jburstein
12-30-2005, 07:24 PM
Cogsdill is the name I've heard most in roller burnishing tools, if that helps. Their tools are ~$3-400, if I remember right. I haven't done any of it though, so I'm not much help.

-Justin

bobbybeef
12-30-2005, 10:37 PM
Iowolf,
Britten's Watch and Clockmakers Handbook:dictionary and Guide.
Says;
" BURNISHER.-A hard polished surface,generally steel,which is rubbed against metal to smooth it.The surface to be burnished must be free from scratches,which the burnisher would not remove,but render more destinct by contrast,and the burnisher must be kept highly polished,for the surface burnished can never be smoother than the burnisher."
Clockmakers burnish pivots to make them harder and run more sweetly.
Regards,

bobby.

Norman Atkinson
12-31-2005, 01:25 AM
As Bobbybeef rightly explains about the finish imparted by a burnisher, we used to polish things like galvanised pails with a chain mail burnisher- by hand.

If you want the origin of the Three Bees- Bull**** Baffles Brains- this is it.

Oh, and it's a Happy New Year from me.

Norm

IOWOLF
12-31-2005, 05:35 AM
Thanx Norm, Happy New Year to you also.

And same to all the rest of the guys on here.

------------------
The tame Wolf !