Sun burst

[MADDOG]

I am trying to regain the sun burst effect on a watch case. What can I use that will give me the best result.

[.olli.]

To do a perfect job, you need a lapping machine. Not really an option for the diy'er!

Short of this, it is possible to achieve a reasonable finish with abrasive sticks. A basic jig will help you keep the grain straight and concentric. There is an excellent thread on thewatchsite describing one approach to this. I have included a link below.
I would practice on a scrap case first, be very careful when you reach the edges of the case to avoid rounding them

http://www.thewatchsite.com/21-japan...added-how.html

[walkerwek1958]

To do a perfect job, you need a lapping machine. Not really an option for the diy'er!

Short of this, it is possible to achieve a reasonable finish with abrasive sticks. A basic jig will help you keep the grain straight and concentric. There is an excellent thread on thewatchsite describing one approach to this. I have included a link below.
I would practice on a scrap case first, be very careful when you reach the edges of the case to avoid rounding them

http://www.thewatchsite.com/21-japan...added-how.html

Certain cases need a lapping machine, whilst others can be done by hand. I've done a few and I don`t use a jig, I have a technique which gives excellent results but it does require a steady hand. I use the edge of a Garryflex block, but the edge has to be sharp. I`ve also used a narrow strip of coarse wet and dry glued to a thin rubber block, followed by the Garryflex block to soften the finish slightly.

I think I spent more time trying to devise a way to do this (designing a jig etc) than finishing my first attempt! In the end I gave it a go using an old case and was surprised how good a result I got. After that I practiced and eventually got it right.

Practice makes perfect, get an old case to practice on.

Paul

[Arie Kabaalstra]

To do a perfect job, you need a lapping machine. Not really an option for the diy'er!

Short of this, it is possible to achieve a reasonable finish with abrasive sticks. A basic jig will help you keep the grain straight and concentric. There is an excellent thread on thewatchsite describing one approach to this. I have included a link below.
I would practice on a scrap case first, be very careful when you reach the edges of the case to avoid rounding them

http://www.thewatchsite.com/21-japan...added-how.html

if you look at what a lapping machine basically is..you'd be surprised how easy it can be to make one.

Last week i looked up what it would cost me to buy one.. well.. somewhere in the regions of €7K to start.. and then €3K to get a fixture to attach your cases to..

then.. i looked on "Marktplaats" a dutch website for trading second hand stuff.. and i found a woodworking lathe for only €25,-
if it is a popular model, you can get faceplates for it.. bolt on a slab of aluminium, and stick some sandpaper on it.. and you're done.. any cheap lathe will suffice.

the fixture is the expensive part.. well.. you could use a magnetic base, for dial indicators.
You'd only have to fabricobble some sort of clampingdevice, i have a lathe and a mill.. so i made a set of collets (yes.. i'm quite a "DIY-er") and..



well.. you get the point.. i have an old cheap lathe i use for all kinds of work..

a future project will be a detachable beltsander that will be driven from the main spindle, and the attachment can be clamped on the machinebed..

[.olli.]

It looks like a nice setup. I am planning to have a go at making my own at some point.
What is the red articulated attachment you used here if you don't mind me asking?

[Dave S]

Looks like an indicator stand. Used to hold dial indicators when setting pieces up on machine tools ( amongst other uses)

Dave

[Arie Kabaalstra]

Looks like an indicator stand. Used to hold dial indicators when setting pieces up on machine tools ( amongst other uses)

Dave

Yup.. it is exactly that.. :)
as said before, i have more machines in my "pretty little workshop", namely a CNC Mill and a CNC lathe ( i have two more CNC lathes, but not enough room to set them up.
with those machines, i made the ColletChuck to clamp the case.