On cast acrylic, I was wondering if anyone has used a McEtcher to cut oramask ? I have a downcut vbit on order from Cadence, but the project needs to be done before it arrives .
I was going to cut grooves using a #502 engraving bit then paint the grooves. I had read the upcut bits lift the oramask, so I figured that precutting with the McEtcher would help.
Any suggestions ?
Because the McEtcher scratches and doesnt cut with a spinning motion, I dont think you will have any luck with it on Oramask.
I wonder if you could cover the Oramask with a piece of wood on top and cut through the wood into the acrylic with an upcut bit to help keep the plastic bits cleared while holding the Oramask down.
The tool for cutting Oramask, or any vinyl would be our Stingray:
Stingray … O boy, another toy to buy !!! Thanks for the heads up.
I will give the #502 a try tomorrow, I have already toasted one piece, why not another.
Worst case I will be doing a bit of scrapping.
No harm in trying but as @Bozo said I doubt it will work without tearing the oramask.
Be sure to use a J roller to really adhere the oramask down. Just placing it with hand pressure is not enough.
Oh boy more toys to buy. Luckily they are not expensive.
Another alternative is adhesive shelf paper you can get at most big box stores. I use the Easy Liner Adhesive Shelf liner I get at Walmart. It is a lot cheaper than oramask and it is likely locally available. You should still use a J roller to adhere it down well.
I will be down to the local HW store for roller. Thanks !
I will try to paint without the mask for this job.
I’ve done several jobs where I use the stingray to pre-cut the Oramask. Works great!!
No goo in your cutter, no pulled up mask.
I use the ramping function to force the toolpaths to overlap a bit, and to get the knife facing the right direction at the start of cut. CC Contour paths don’t compensate for the offset knife in corners, so if you want perfection use a CAM package meant to support drag knives.
Which CAM package are you using @Tod1d ?
It looks like the Dragknife gadget for Vectric is a bit long in the tooth and the plasma/drag knife fillet works great for what I have been using but would not produce nice corners for a mask.
I second @gdon_2003 on the shelf liner from Lowe’s. It’s pretty cheap and I found it much easier to work with.
@Tod1d I remember a thread you commented on that mentioned arcs in sharp corners, where you need the arc to “turn” the knife orientation. I will be using Fusion 360
@CullenS I use CC and NX, neither of which have a drag-knife operation. But for pre-trimming mask I’m OK with small rounded corners. If I’m V-Carving it will pick out the corners. If I’m pocketing the sharp corners will get rounded anyways.
I haven’t used Vectric (or Fusion 360), so I’m not aware of their capabilities.
This is what the plasma/dragknife fillet looks like.
I put a video up of that one on YouTube and will be posting another today or tomorrow on a newer attempt.
You pick the outside corners and pick the radius. The knife does a little loop. Obviously not good on anything other than an outer profile though.
The gadget (which I don’t have) allows you to define a different depth for the corners so that the blade spins but doesn’t cut too deep. That of course is not relevant to the discussion on cutting masks which are thin.
Interesting path, I will have to think about that one.
@Tod1d - NX user Aerospace, Automotive or Power turbines ?
I work for Siemens on NX CAM. Primary jobs are programming postprocessors & creating machine simulations. So pretty much all segments of industry.
Otherwise, I couldn’t afford NX 
And yes, I have a complete post & sim for my HDM
Sadly I lost my access to CATIA when I left Gulfstream and moved to Lockheed. Lockheed has NX, CATIA and Creo but my role changed as well so I don’t have a need for CAD at work anymore.
If only I could go from a PowerPoint to a part I would be set 
You can sort of do that (go from Powerpoint to a part), but you need to:
It’s not really worth it given how limited drawing in Powerpoint is — better to use a better tool such as Serif’s Affinity Designer or even Carbide Create.
More of a joke about how I spend my life in PPT and meetings now instead of CAD or databases.
As my wife will point out, I have no sense of humor, and never understand jokes.
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