Bit selection

[TomJ]

Hi everyone. Just to start I am rather new at this so sorry for asking such a simple question.

I am looking to create some wooden crosses for my church. About 5 inches wide and 8 inches tall. Using simple pine.

I have never use my CNC Shark to cut anything out, just engraving. If I want to do a full cutout of a cross using pine with a thickness of one inch what type of a bit would I need to purchase (and where)? Thank you very much for any help you can provide.

Also, is there somewhere online that provides a new user guides to which bits to use for what.

Thanks again. Tom

[BillK]

There ar a lot of posts on this if you search, but here are a few tips. I would try a 1/4" downcut bit with pine to keep chipout on the board face to a minimum. Use the profile cut, outside the line, conventional, and add ramps, 1/2" to 1" long is good. Make sure the bit's cutting section is long enough to cut through the entire part.

Personally I don't like using tabs. Make sure you have a waste scarf board underneath that you can cut into. If you have speed control on your router, you don't have to use the highest speed, but one notch higher than a pocket or V-cut.

Where to buy? I found a couple of good ones at Lowes Snd Home Depot, amazon, or really good ones at precisebits.com.

[TomJ]

Thank you very much for taking the time to reply. I do appreciate it.

One last questions if I may...If you don't use tabs on a cut-out how do you anchor your cut-out piece?

Thanks again.

Tom

[BillK]

Tom, here's an excerpt from another post that I did on an anchor cut out http://www.cncsharktalk.com/viewtopic.php?f=4&t=3889 I use this method for most of my work and it gives me great results. Others use tabs, double sided tape, a few mention vacuum clamping but that is very few and far between.

"Joe,

I used to have issues with using tabs. I did a project 1.5" thick as a cutout. On either side of the tabs I got indentations the size of the tool over the full width. After much filing and sanding I tried a different method.

I measure the wood's thickness, for example .730 at the thinnest, then subract .015 and so set the depth of cut to .715. This leaves a very thin, but strong layer of wood holding together the part and the waste. As a result, I no longer cut into my scarf board and I cut the edge finish sanding time down to next to nothing. Later, I read somewhere that this is a technique called "skinning" leaving a thin skin to connect the part to the waste. Sometimes I use my scroll saw to cut through the skin, or a coping saw or utility knife. The remainder can be taken off with a file or a flush trim router bit. This works great for inlays for me which I do a lot of.

The anchor size is approximately 8" x 10"."