How to compensate for variations in material thickness?

[denver]

Hi,

I have some parts that contain slots that are supposed to be as wide as the material is thick. The outer dimensions of the parts usually aren't too critical, but the width of the slots definitely is. If they're too narrow then the parts won't go together and if they're too wide everything falls apart.

I tried rescaling all the parts, and that will certainly work, but then sometimes there are problems with spacing and fitting all the parts on the sheet. So I'm trying to think of a better way.

Currently the parts are drawn assuming material that's 3/16" thick. If I suddenly find that my material is 15/64" thick, then I would have to make everything 25% larger. Or perhaps keep all the parts the same size and lie about the size of the cutter. In this case, I would have to tell PartWizard (or whatever) that the 3/16" bit was actually 0.046875" (15/64 - 3/16) smaller than it really is. Is this the simplest way to deal with this? Any other ideas or opinions?

Thanks,

Denver

[rick_woodward]

wide belt sander ...

[richards]

Dener,
Would it be possible to mill the edge that fits into the slot? For instance, when I build book cases, I often use stopped dadoes in the case sides to hold the shelves. Usually I cut those slots 5/8-inch wide. Then, when it comes time to insert the shelves, I run a rabbet along the shelf edge that fits into that slot. That way, I don't have to worry about the thickness of the lumber that Home Depot is selling on any particular day.

[denver]

Good ideas, thanks. Here's a picture that might clarify things. The two parts fit together at 90 degrees, forming an "X". Although it's certainly possible to modify the drawings to include additional pocketing around each slot, I'm not sure it's practical - there are a lot of them.

I had also thought of just runnning a surfacing pass over the material to cut it down to specified thickness, but that didn't work very well.


Thanks,

Denver



5099

[rhfurniture]

Denver,
If there are a lot of them, it would be easy enough to write a file using the input command to ask you for the thickness, then cut the slots. If I wasn't so busy at present I might give it a go for you. Check it out in the programming documentation.
R.

[mrdovey]

Easier still to parameterize the slot widths and use your Z-plate to measure the thickness of the workpieces...

[dvanr]

Can you get away with cutting the area behind the slot down to your 3/16th size? ie if the sheet was 15/64 you would have a .047" groove on one side of the part directly behind the slot.

The groove depth would vary from sheet to sheet but all the pieces would be interchangeable.

For this to work you would have to zero off the spoil board

[dvanr]

Ahh.....what Mike said