Engraving on both sides of plywood

Has anyone tried to engrave on one side of the plywood & then flip the sheet over & engraving on the other side and still have the paths match up with each other?

I’m thinking the pass on the first side could drill a hole & then I’d use that hole on the other side to register the home base point to start from on the other side. Anyonw have any better suggestions?

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I have not done this on the Maslow yet but other equipment. This is called using indexing pins . You typically use 2 offset from each other. I have a frame design around this function.

Thank you

depending on how big our work piece is, you might be able to set up a frame around it and place the work piece inside to register the position.

example here -

Thank you

Cool thanks for the tips.

To add on to what’s already been said, there are some techniques that I’ve used on the machines work that should work with the Maslow as well. One is to use locating pins like you mentioned. The other way, which i prefer, isto make a fixture to locate the part. After engraving the first side and cutting the outside profile of your part, nail a scrap piece of plywood to the machine. Cut an L-shaped profile into the plywood from the origin. This should go both the entire length and width of the part. The origin should be at the right angle of the L. That corner should be dog-boned so that the tool radius doesn’t throw off your cut. Then you can position your part in the fixture you just made, and have it located EXACTLY on the origin.

We do this all the time for cabinet parts that need operations done on both sides :wink:

Hope this helps.

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Am I correct is saying that it only works on rectangular parts? So if I had something like the Millenium Falcon I did, I couldn’t use the method, correct? Just making sure I understand what you are proposing.

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On the desktop-cnc I clamp the cut-sheet to the spoil-sheet and make a .nc file to drill 4 holes, symmetrical to the centre and outside of the the final product. Then I glue 4 ‘pins’ in the spoil-sheet and can flip the cut-sheet precisely. The outside cut profile is the last in the workflow, so I see it working with the

as well.
IMAG1223

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The particular fixture I was describing would work best for rectangular parts, yes. However, you could make a fixture to fit the Millennium Falcon :wink: You’d just need to take the outer profile and cut that into the scrap piece instead. Luckily, the Falcon has the forward cargo protrusions, so you could use those to locate the part. If it was straight-up circular, a locating dowel fixture would work much better. Otherwise you can’t guarantee that you will be at the right rotation.

Quick illustration, with the Falcon as our (fantastic) example. The green outline would be your plywood fixture. For the Maslow it would also help to put a couple of scrap pieces into the open area in the upper left for the sled to ride along.

EDIT: The location of the origin isn’t as important as both the fixture origin and the part origin being the same. The point of the fixture is to have an accurate locator for the part.

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And don’t forget to mirror/flip your files for non-symmetric products :wink:

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I was thinking I could make a rectangular “frame” around the piece (piece attached to the frame using tabs) and use the maslow to drill the holes into the workpiece. I could then manually drill through those holes into the spoilboard (1/2" foam) and a possibly a little into the backboard (3/4-inch ply). When I pull it, I can insert the dowels and then flip it. After I’m done, I cut the tabs off the piece holding it to the frame.

This is a very good point! I hate when I forgot silly things like that :upside_down_face:

Both of our solutions will work well. I personally prefer using fixtures, but it’s entirely up to the machine operator as to which method to pursue.

I would likely use your method with smaller sheets of plywood… and probably will use your approach so I don’t drill holes all over my spoilboard.

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That would work well. Pins are great for doing multiple copies of items, but may be overkill for your needs. I think that going with the frame that I suggested, which is similar to @MeticulousMaynard’s suggestion of cutting a plywood piece.

As you’ve shown your image above, you could just use 2 to 4 scraps of plywood each with a straight edge that can be placed against an edge of the work piece and fastened to the backer board with screws. This would allow you to flip the piece and place it back where it was with the origin in the same location.

That’s a very good point and wasn’t something I was thinking about. The fixture is probably best suited to smaller parts. The pins would work well on large panels that would either need a big sheet of plywood to make a fixture or be too awkward to place accurate in the fixture.

Sorry Keith, I missed your earlier post!

no worries. Your idea is a good one. Best to have options to choose from and potentially combine. For instance, if you used the L to define the origin as you suggest, it allows you to use a smaller board later… for whatever reason.

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