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Dealing With Material Thickness6/11/13
I was just curious to how shops deal with different material thicknesses in woods, we use Cabinet Vision 8 Solid Ultimate. Is there certain ways that you have to go about it when using the program we use?
We measure all sheet goods with digital calipers when they come in and enter the actual thickness in the material catalog. Update the job and cv adjusts everything accordingly.
You input a unique thickness for each individual sheet?
one unique material thickness for each type of sheet good....when you get 10 sheets of 3/4" white melamine, measure a couple to find they are actually 0.74. Enter it in the material catalogue and then update the job when you open it....next time you get 10 sheets of 3/4" melamine, measure a couple to find they are actually 0.735....repeat the process for each delivery but not for each individual sheet.
I don't understand why this is necessary. I think you would find at least that much variation in thickness among different sheets in the same unit of material, so why not measure every sheet? Does it matter, engineering wise for wood products, if the thickness varies by .005?
PB & Mdf Cores are easy
We design out products to account for the tolerance in the panel products, so that we dont have to worry about small variances in panel thickness.
All cut sizes go off the ID of the cabinet (cabinets could varry in overall size but this very rarly causes issues) this way all drawer boxes fit and fronts have same overlay.
We use dowel construction and never center dowels, we set all dowels the same distance from the outside of case (puts all variance where it dosnt matter).
Consistent thickness matters if you use dado construction for your cases. We buy calibrated core plywoods that guarantee a thickness variance of no more than .005" per unit. We measure a few sheets on each new unit and input the average into our materials file (Cabnetware). If you use uncalibrated material you're going to get joints that are either too loose or too tight, at least some of the time. We're considering changing to a half dado technique where the size of the dado is predetermined and the mating tenon is sized to match. All the thickness variation falls out at the bottom of the joint that way. The jury's still out, though.
The sheet thickness comes into play much more with Euro frameless cabinetry. With face frame cabinetry you are setting up the opening of the cabinet and the over all size with the frame. Your material could vary by and 1/8" and it would not have an affect on the overall dimensions. For frameless I agree calibrated sheet goods or measure several sheets and average.
I use CV and also update material thickness in the material catalog. For most of the sheet goods we use the thickness is close enough to not matter. Cheep ply requires checking each sheet at the machine (Biesse Rover 27).
I am not nesting and I use dowel joinery. Don't center the dowel holes in the panel (panel DZ/2), instead set then all at a fixed distance from the edge (we use 9mm). It means you have to keep track of which side is "up" for tops and decks but that is normal for us.
If you are using dado joinery in a nest you will constantly have to fine tune the fit. I think if you are using a cnc dado joinery is best left behind. I did it for a few months when I first went CNC; it was a constant PITA. That was on a Thermwood using Ecabs, which I think is the easiest CNC control system for this type of stuff. I cant imagine having to fight material variation in a 12 sheet nest today.
As for material thickness causing issues for Euro cabinets..... Unless you have .5mm variations and bad luck you would never notice it once you align all the gaps during installation.
What problems are you having with material thickness.
we have a multicam CNC, and using cv8. now I think we use to touch off the material then the spoil board and are dados and parts and etc. would cut out at whatever the material thickness was. but we were told that with using cv8 we need to touch off the spoil board and adjust are material thickness? I guess I am just looking on more answers on why do we have to go this route?