V-Carve ColorCore?

[rcnewcomb]

For V-carving Colorcore do I V-Carve at the surface of the material or do I start at an initial depth that is the thickness of the top layer? i.e. if I have brown colorcore with a white center do I tell my V-carving to start at 0.1 (or whatever the thickness is of the outer brown layer)?

[jamesgilliam]

Randall, It depends on the look you are trying to get. If the white is just to accent the carving, start at the surface. If it is to be the show of the piece, start at the thickness of the outside layer. If you do start at the surface you can always go back and reset the zero for your Z axis and go back over what you just cut

[jhicks]

We have used a couple of approaches so as James indicates, it depends what you wish to accomplish. Start with the specification that says the top/bottom color layers are APPROXIMATELY 10% of the total thickness. ie .5" overall = .05" color layer on both sides.
Now as you consider a V cut with a serif font, you will definately NOT get the full effect of the inner core on the tips/serifs of the fonts UNLESS you go at least .06" deep as minimum depth for your Z zero. This can be a problem since by doing so, the true tips on the V cuts will extend into the color top layer and may bridge together with the next letter. Thats very frustrating and generally doesn't look very good.
So either space the fonts to compensate or consider another option. Outline the font with a very tiny bit down .062" to create an offset font border and highlight it. Or maybe a .062 or even .031 end mill on the inside profile of the font. Then run your V carve and most of the fonts will come close enough but its a bit risky and not an absolute fix. Unfortunately its a pain to clean up any thin sections with color remaining.
The other option is to use a more acute V like a 60 degree vs a 90 degree but in the end, some art just doesnt work well with this material on a v carve strategy. On the other hand, chamfered borders which expose the core and the top layer on a 90 v for example look pretty nice as do round overs and other edge profiling geometries.
Its all about the look and several tests to achieve the desired effect. The good news is its a cut and invoice sign when you're done so well worth the trial and error tests to dial in your techniques.
Also remember that If you are using 1/4" stock you must be dead flat or you will find cuts clear colors in some areas and leave color on others. Suggest starting with depths of 1.5 to 2X color thickness so you get all the color cleared. The color thickness is not precise so beware and cut a bit deeper than you think you need to. we cut .125" to .150" deep on 1/2" for starters and .080" to .100" on 1/4"

Also remember when drilling to mount to leave room for thermal expansion. Material moves and unless there is room in the oversized screw holes, it will warp.No adhesive works with this stuff so consider mounting plan in your design stage. Also always pilot drill any holes if mounting from the back.
IF you choose to area clear flats with an end mill strategy, get an Onsrud bit with .002" rounded corner radius end mill. (Call Onsrud tech support and they can help you decide because its not obvious in catalogs or web site) It greatly reduces mill marks and produces a much cleaner surface machined area clear.

good luck and have fun.

[chris_booth]

These Onrud end mills with the slight radius are the Series 66-300 (or 66-350 for metric) and can be found by a search on the Onsrud site using the Series number as the keyword.

Alternatively, on the Onsrud site, go to Products > Plastics > Think Mechanical , which opens MechPlastic.PDF where the Series 66-300 and 66-350 are on page 4.