small part question

Dave McPherson · Post by **Dave McPherson** » Thu, Sep 07 2006, 12:46PM

Hi everyone!
We make alot of curved reception stations. We have been cutting the 2\"wide curves for the frame on the CNC. They always seem to move, so we have been leaving the skin thickness on and then cutting with a hand router. does anyone have any tips to cut small or thin parts on the machine. Is it possible to sink a screw on each end of the curve rail into the \"wasteboard\" to prevent movement. The frame is made out of flakeboard and then we veneer after.

Thanks,
Dave

Forrest Chapman · Post by **Forrest Chapman** » Thu, Sep 07 2006, 1:33PM

Dave,

We cut small parts all the time and when allowed we will brad nail the parts on the ends. It sound like this is the fastest method for you.

Forrest

Dave McPherson · Post by **Dave McPherson** » Thu, Sep 07 2006, 1:34PM

Thanks for the reply Forrest!

Brian Shannon · Post by **Brian Shannon** » Thu, Sep 07 2006, 2:26PM

I do the same as Forrest suggests, using a 23 guage headless pinner.

David Hall · Post by **David Hall** » Wed, Sep 13 2006, 7:51AM

Dave,

We too resort to screws or brads when necessary but for these parts I would first try:

1. Change my outline tool to a down cut spiral.
2. Add \"additional part clearance\" of about 3/4\"
3. double pass/onion skin all.
4. turn off dust collector during second pass.
5. Use a freshly machined waste board.
6. Add a couple of extra parts to the nest.

Regards,
Dave

Ryan Hochgesang · Post by **Ryan Hochgesang** » Wed, Sep 13 2006, 9:34AM

You can also run a couple pieces of double sided tape, that run underneath and intersect all ends of the curved parts and possibly a piece through the middle, this may also help secure your parts. This will provide additional hold down but will not make it such a pain to remove cut parts, as it would if you were to put double face tape covering entire bottom surface of part.

Dave Burtchell · Post by **Dave Burtchell** » Wed, Sep 13 2006, 5:17PM

Dave,

Dave has a good list of things to try.
We successfully cut a nest of 10 parts 0.75\" wide by 95\" long in 1/2\" AC ply on a regular basis. Like Dave says, onion skin all and \"perform all thru cuts last\". I don't need to use \"additional part clearance\" on these, but I had to manually alter the code so the machine cut the parts in order starting from the edge of the sheet. Since we cut these parts on a regular basis, I just run it from the .CNC file. If I had to renest this every time, I'd go crazy. It doesn't matter which combination of \"Outline Order\" and \"Nest Direction\" I choose, it doesn't want to cut from outside in.

Let us know when you have a pile of good parts.

Dave

David Hall · Post by **David Hall** » Wed, Sep 13 2006, 6:29PM

Dave B.

For DXF files you can control the order in which the parts are cut by manually nesting the sheet.

The sheet goes on the outline layer.
The part perimeter is cut with the chain compout1, chain compout2, ... layers.

There are a few downsides: Chain compout on parts smaller than your double pass size is broken. You will get the code for the first pass, but not the second pass. (i.e. set your double pass size really small or you will not get a through cut)

We do the double pass either by drawing it in the DXF file, slightly offset(.002\") from the first pass. Or if the whole sheet needs to be double pass, then just run the same CNC file twice with different z shift.

RN will still insert the code for the outline (perimeter of the sheet) but this is easy to edit out, or skip over.

Your chain compout tool needs to be set-up to do \"rout\" operations. Chain compout will not use the \"outline\" tool.

Regards,
Dave

Nick M Singer · Post by **Nick M Singer** » Thu, Sep 14 2006, 12:04AM

Hi Dave. We have a similar problem mainly because we stupidly bought a Vac pump that is a tad under spec. however we generally get away with adjusting our wasteboard thickness so as to leave a film of material holding the parts together. You should not need to rout the parts just knock off the excess by hand or a light sand will do the trick.