Receiving "Nested" designs from clients.

[dubliner]

I cut the occasional referral & while I always ask for a 1:1 scaled dxf, sometimes they take it upon themselves to "nest" the parts also. They are trying to squeeze the last square inch out of a sheet. I'm wondering what I should set as minimun part & edge clearance on a sheet so that if they do nest their own parts, they observe those limitations. What are your thoughts? TIA Dubliner

[dlcw]

Part and edge clearance will depend on the bit you use for outline cutting and how good your holddown method is. When cutting cabinet parts out of plywood I tend to use .125 clearance between parts accounting for the bit width. So if I'm cutting with a 3/8" MC bit, I will specify 1/2" between parts. If a 1/4" bit, then 3/8" between parts.

I have a vacuum holddown system that will hold the parts in place pretty well. If I don't think this will be enough (small parts) I will specify tabs that are 1/4" long and 1/8" high.

[bill.young]

Hey Nev,

I would recommend leaving a small border around the edge of the sheet as well...the factory edge of plywood can be pretty dicey and you're better off cutting all the edges of the part rather than ending up with a factory edge in the part.

You don't need much of a border allowance but sometimes the edge of a sheet can have some pretty nasty dings in them...I try to keep all parts at least 1/8" in from the edge of the sheet if I can.

Bill

[knight_toolworks]

it also depends on the size of the parts. the smaller they are the more space I leave. say they are 4"x4" and I am cutting them with a 1/8" bit. I would do 1/8" plus say .5 or a bit less. that leaves a web of material and the sawdust in place to hold the part.

[dlcw]

I believe SBLink defaults to an outside parameter (sheet edge) of half the diameter of the bit specified for outline cuts.

Someone please correct me if I'm wrong. I don't want to give out bad info here. :eek:

[Gary Campbell]

Don...
You are correct. The default nest is 1/2 bit diameter from sheet edge. Plus any collar amount. In my case that is 1/2". I use the larger collar amount for Bill Y's reason above AND I can usually hold a couple inches more vac when none of the bit tracks can go to the edge of the sheet.