Edge Lit Acrylic Blanks

[Xxray]

I set depth between .009 for real fine detail, .014 if fine detail is not required.

If you are "losing" some of it, that means you are out of level or your material is not perfectly consistent thickness [or both].
Very little margin for error, you need to take a level and make sure your cutting area is level, and calipers to check material.

Variations with plexi are not typical, but possible. Most likely a level issue.
Thats my guess anyhow, you can always put more pressure by either setting a deeper depth is software or measuring the Z a bit deeper.
Downside to that is, with plexi, light cuts vs heavy will show up once lit. If you are perfectly level and material is consistent, there is no reason why you should not be able to etch anywhere on the material.

[FixitMike]

Mike,

I've read and reread your post(s), but I am just not getting it.... Sorry

Do I not need to have more depth/pressure than .005" with my drag bit? My spoilboard is flat, so maybe I don't. Guess most of what I have read was to apply 1/4-1/3rd the possible spring retraction of the drag bit.

When using a Pocket toolpath, if I set my depth of cut to more than .005", it does not calculate all the vectors in the tool path.

I do appreciate your help.

It is the tool stepover that I believe needs to be more than the size of the flat on the end of the diamond. 1/4-1/3 depth/pressure sounds right.

[FixitMike]

[quote="Xxray"
Downside to that is, with plexi, light cuts vs heavy will show up once lit. [/quote]

I'm afraid I must disagree. Look at my earlier post where I etched some patterns varying pressure and stepover. The pressure varying did not significantly change the appearance. I assume you are talking about a diamond drag tool that is spring loaded.

[Beltramidave]

I set depth between .009 for real fine detail, .014 if fine detail is not required.

If you are "losing" some of it, that means you are out of level or your material is not perfectly consistent thickness [or both].
Very little margin for error, you need to take a level and make sure your cutting area is level, and calipers to check material.

Thank you both Mike and Xxray. Think I am just going to use the Quick Engrave as I can't explain what is happening, or not happening when trying to use the Pocket toolpath.

My issues are not with my machine. The software (V9) will not calculate correctly (does not include all selected vectors) using a POCKET toolpath unless my cut depth is .005" or less. If I set cut depth deeper than .005", the calculation time is much less as it is not picking up all the vectors.

Mike, maybe it is the stepover setting.. What I would really like to see is screenshot showing 1. Tool setup for a 1/8" 90d drag bit (I have no idea what the tip diameter is) and 2. Using that drag bit in a Pocketing toolpath - NOT Quick Engrave.

Sorry for being so dense. Xxray is saying .009-.014" DOC and Mike is agreeing with me using 1/3-1/4 of the available compression distance on the drag bit. And you both do incredible work!! But I get the feeling that Xxray is using the Pocketing toolpath and Mike is using the Quick Engrave...

I give up! Thanks for trying to help me!!

[Xxray]

Depth setting is not all that critical with a drag bit, obviously you have to enter something.
The rest is on compression, that can be whatever you want.

Can't replicate your problem in my mind, I can say that using very shallow depths often do not show up well if at all in preview, which has no effect on the actual cut. Maybe something was changed/tweaked in V9 that I am unfamiliar with, I've never had issues pocketing plexi with a drag bit.

[FixitMike]

Did your screenshot show the settings that are used when you have the problem? I don't get any problem with the settings shown when I try it with a simple pocket. And can you explain what you mean when you say you lose most of the carving? A screenshot of the preview showing the lost carving would help. You can tile the screen to show both the 2D and 2D views in your screenshot.

[Adrian]

Most likely what is happening is that due to the shape of the bit it can't fit into areas of the pocket that are narrower than the bit is. With a tapered bit the effective width of the bit changes the deeper you cut with it.

Turn on the solid toolpath preview option so you can see where the bit is reaching and then use the measure tool to see how wide the gap is at that point.

[Beltramidave]

Most likely what is happening is that due to the shape of the bit it can't fit into areas of the pocket that are narrower than the bit is. With a tapered bit the effective width of the bit changes the deeper you cut with it.

Turn on the solid toolpath preview option so you can see where the bit is reaching and then use the measure tool to see how wide the gap is at that point.

Adrian, I think that you are the winner here, but I am still confused and hopefully by posting these two screen shots will help with what I am seeing. As far as I can tell, all tool settings and toolpath settings are the same. One shows using the Quick Engrave and the other shows the Pocket toolpath.

How can I determine what the tip diameter is on my drag bit? There was no specs for the tooling.

Thanks again for all the help.

[Adrian]

I don't use the quick engrave toolpath so I'm guessing the way it works by hatching lines isn't affected by the width of the vectors as all it cares about is the hatching.

With the pocket toolpath the effective width of your tool is 0.02" at a cut depth of 0.005" which is wider than your vectors as you've shown in the pictures. The deeper you cut with it the wider the tool gets.

[Beltramidave]

Funny, just did a very similar drawing myself. It is all finally starting to make some sense.

What I am still struggling with, is if I want to use the Pocket toolpath with my spring loaded dragbit (like Xxray does), how do I set my spring preload? Normally when using the Quick Engrave toolpath, I set it at .1". The only reason I set it at .005" in the screen shot above is to see the correct preview. It obviously does not engrave .1" deep.

But using the Pocket toolpath, if I set the depth of cut to .1" (for spring preload), it does not calculate the all the vectors.

Really doesn't matter at this point as I am just going to use the Quick Engrave when using my drag bit. Just trying to understand....