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  #1  
Old 11-19-2017, 09:44 PM
ScottM ScottM is offline
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Default So how do you manage dimensions?

One of the things I am trying to figure out is how to manage creating a project or using an existing one that has set, for instance, the material Z height to .75, and all the pieces are setup for that for height, rabbets and dadoes etc..., but the material is actually significantly smaller, for instance, .682 versus the .75 is almost .070 difference.

Do you go back in and rejigger every panel height and all the cuts so that you actually get a snug fit or ?

I guess the this goes along with if instead of using 1" material you want to use 3/4" instead, the same technique would apply I would think. I just don't know what that is.

Any one be able to help a newbie out?
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Old 11-20-2017, 09:07 AM
TimPa TimPa is offline
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I'm so new I don't even have my machine yet. but I would be looking for a z offset capability for the difference.
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  #3  
Old 11-20-2017, 09:25 AM
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Gary Campbell Gary Campbell is offline
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What design software are you referring to?
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Old 11-20-2017, 10:01 AM
Ger21 Ger21 is offline
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It depends on the specific project, and the desired results. And how much difference you are talking about. If you are changing the thickness by 1/4", then you likely need to make considerable changes with your CAD/CAM.
If you are talking about 1/32", and you are not too concerned about the fit, you can leave it like it is.
For example, I cut a lot of plywood framing components for reception desks. These parts are not seen, so I'm not concerned about loose dadoes. I program everything as if it were 3/4", but it ranges from 11/16" to 23/32". If you zero the Z to the spoilboard, the only issue you'll have is loose dadoes.
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Old 11-20-2017, 10:33 AM
jjwdawg jjwdawg is offline
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Mozaik (cabinet design/cnc software) has a joinery option called qualified tenons. If you zero to the spoilboard, then you can mill a tenon on the end/edge of any piece that needs to fit into a milled rabbet/dado. Since you're referencing off the bottom of the workpiece, you can accurately set the resulting thickness of the tenon, regardless of the actual material thickness. You could use this same technique in VCarve or most any other cad/cam software.

This would obviously add to the complexity of your design work, but it might be worth it for a job that you plan to run repeatedly.
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  #6  
Old 11-20-2017, 08:34 PM
ScottM ScottM is offline
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Thanks for the responses.

Software I thought wouldn't matter, but then I realized for some things you could set some allowance offsets that would help if the vectors were broken out to manage that.

I am using Aspire, and know that can be done there.

I was just thinking about things for instance like furniture where loose joints would be a significant. As well anything with butt joints would throw everything off in height or width dimensions as well.
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  #7  
Old 11-20-2017, 09:03 PM
rcrawford rcrawford is offline
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In Aspire it's easiest to use offsets to adjust for tight fitting dados and rabbets. Just be sure to design in such a way that using offsets will work with your design.

And zero off the spoil board, so there will be less effect of substrate thickness on your finished product.
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  #8  
Old 11-20-2017, 09:36 PM
ScottM ScottM is offline
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Yeah, I figured that would be done for those.
Again, more about pieces that have a lot of butt joints.

For instance, I created this in Aspire and was going to use some 3/4 ply I had, but then decided I would first do it in MDF. I guess I'll see how it turns out as MDF is close to the correct thickness, whereas the ply is dimensionally smaller of course.
Attached Images
File Type: jpg ShakerFirewoodBox.jpg (13.7 KB, 36 views)
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  #9  
Old 11-29-2017, 09:04 AM
ScottM ScottM is offline
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So I was able to finish this piece.
I used the material thickness, which was average .71, 3/4" blondewood plywood from Lowes

All butt joints so for this project no issues with variable material thickness.

Only one piece had issues and I think that might have been my miss-measure off the drawing (bottom of top compartment.

Here are some final pictures, and the final nested DXF from Aspire if any are interested.
Attached Images
File Type: jpg IMG_2088.jpg (87.5 KB, 26 views)
File Type: jpg IMG_2091.jpg (93.4 KB, 27 views)
File Type: jpg IMG_2092.jpg (96.9 KB, 25 views)
File Type: jpg IMG_2090.jpg (80.6 KB, 26 views)
Attached Files
File Type: dxf Shaker Firewood Box.dxf (85.7 KB, 2 views)
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  #10  
Old 11-29-2017, 09:14 AM
ScottM ScottM is offline
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Just a bit more history of project parameters.

Used a 3/8" downcut from Amana using 100 ipm, at 18k.
https://www.toolstoday.com/solid-car...ywords=46420-K

I was conservative and took 3 passes leaving the last pass at .030 before cutting out. I had both vacuums on the Hurricane going. I tabbed the smaller pieces, and some of the larger waste that would have come loose to prevent it being tossed about and maybe moving my material and ruining some cuts.

~21minutes for cut time

Overall the cut came out good, but because of the grain at different layers of the ply there wasn't as smooth as a cut as I would have liked and I ended up having to sand the edges, I'm thinking slowing down just a bit might not have pulled the end fibers as bad.
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