Laser Engraver/Cutter for Custom Masks

[Jesse6669]

I was thinking of ways to do an SP bloody nose or other masking jobs in T scale (bloody small, if you pardon the pun) and thought about all the custom-made masks available to aircraft modelers.  These must be laser cut--  from some CAD artwork I suspect. 

I started searching and found a YouTube video by a guy who does custom masks for his Matchbox cars with a cheap USB engraver.  Similar to this one I found on Amazon for less than $150.   Basically he's laser cutting Frog tape and using frisket film to transfer the mask to the model.  They look pretty good, too--sharp with fine lines.  His example was some flame work and frankly the paint job was heavy and would've been a lot nicer if he'd used an airbrush.   Also, 8cm x 8cm is the working area for the masks, which may be small but it would work for my small scale models.

Has anyone tried making masks like this?   I couldn't find any threads about making masks specifically.  I don't want to spend a lot of money on a really nice laser cutter for an occasional job, but $150 would be ok.  I suppose if it cuts wood the occasional structure might be of interest.

Jesse

[Chris333]

Couldn't you cut it with one of those Cricut machines?

[Ed Kapuscinski]

I've always been curious to try this for masking DPM windows.

[AlwaysSolutions]

I've done it recently although in a rather crude way and not likely applicable to T scale.  Did a warbonnet and "Santa Fe" lettering on the side of an N scale test shell using Tamiya tape.  I lasered the stencil on the model  because 1) I was just testing a concept, 2) wanted to do it quickly to see if it was even worth pursuing, 3) the shell was a throw-away 3D print I had done earlier - I have tons of fails laying around for just this type of abuse and 4) "on the model" because I didn't have time to think of a clever way to actually transfer the stencil from point A to the shell without wrecking the whole thing.  Results were decent but I'd really like a way to do them independent of the model, then apply later because aligning the shell w/the laser is a giant pain.  So my findings are the concept will work, just need to find a way to refine it.  Will have to look into frisket film to see if that's the direction I need to go...

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Cheers -Mike

[peteski]

I've done it recently although in a rather crude way and not likely applicable to T scale.  Did a warbonnet and "Santa Fe" lettering on the side of an N scale test shell using Tamiya tape.  I lasered the stencil on the model  because 1) I was just testing a concept, 2) wanted to do it quickly to see if it was even worth pursuing, 3) the shell was a throw-away 3D print I had done earlier - I have tons of fails laying around for just this type of abuse and 4) "on the model" because I didn't have time to think of a clever way to actually transfer the stencil from point A to the shell without wrecking the whole thing.  Results were decent but I'd really like a way to do them independent of the model, then apply later because aligning the shell w/the laser is a giant pain.  So my findings are the concept will work, just need to find a way to refine it.  Will have to look into frisket film to see if that's the direction I need to go...

Cheers -Mike

Frisket film is relatively stiff and doesn't stretch much.  Sort of like wax paper.  I doubt you would be able to burnish it like more stretchy masking Tamiya) tape.  That would be problematic over raised surface details.

I'm also not sure what benefit is using a laser engraver/cutter vs. one of the cutting machines using a knife (like Cricut).  I guess if you have laser cutter, that's what you use.

As far as transferring masking tape stencils after being cut, I always save the backing paper from pressure-sensitive stickers which are all around us.  They can be found on some prescription  receipts or invoices, postage, postage labels, and all sort of stickers, or you can even buy ink jet label sheets and just use the backing sheet.  Then stick your masking tape to one of those sheets, cut it, then peel  and apply to the model.

While collecting the backing sheets I have found out that there are many different types, some are very slick (so masking tape will barely stick to them, while others are less slick, so masking tape will actually stick enough to be handled.  Sometimes it pays to be a packrat. 

[Spades]

I've always been curious to try this for masking DPM windows.

I just photo copy the walls.  Cut out the window/now mask/place and airbrush.  I also use a razor saw to score the back of the wall to put in a checkrail/sash ( the part that splits the window into two.)
You do need to fill the cut on wall ends. 

Truth be told I have gotten rid of every DPM building

[Jesse6669]

Couldn't you cut it with one of those Cricut machines?

I suppose that is an option.  I hadn't considered it either;  The price is roughly the same as the laser engraver/cutter.

Ideally these would take vector graphics for the input (SVG files) but it seems they have some proprietary software to control them. 

On a side note, one wonders how powerful a laser would need to be to cut through .015mm brass sheet....  probably pretty powerful (expensive) --but this would make a nice alternative to chemical etching..

[Chris333]

If the price is the same then I'd get sharks with fickin laser beams.

[Jesse6669]

I've done it recently although in a rather crude way and not likely applicable to T scale.  ..  So my findings are the concept will work, just need to find a way to refine it.  Will have to look into frisket film to see if that's the direction I need to go...

I think the frisket is definitely the way to go, then just apply the masking.  I'm curious if you can post a close-up photo of the edges on a piece of paper or Tamiya tape--how "crisp" of a cut does the laser make?  That's the critical factor for me. There's one out there (brand name "Wainlux" that claims .05 mm accuracy but it still only uses JPG or PNG bitmap files for input so this will inherently have "fuzzy" edges. 

The Cricut looks interesting, although the proprietary software and web-enabled interface again makes me go ..eh maybe not.

Hummm maybe I can 3D print a thin layer of a flexible/rubbery resin material on a carrier attached to the build plate..  (although slicer files are also also layers of bitmaps)..

[JeffB]

On a side note, one wonders how powerful a laser would need to be to cut through .015mm brass sheet....  probably pretty powerful (expensive) --but this would make a nice alternative to chemical etching..

Depends on the type of laser...  Copper alloys tend to require a considerable amount of laser power.  But being that thin (about 0.006"), you could probably get away with 400-500W if it was the right type of laser.

JB

[peteski]

I think the frisket is definitely the way to go, then just apply the masking.  I'm curious if you can post a close-up photo of the edges on a piece of paper or Tamiya tape--how "crisp" of a cut does the laser make?  That's the critical factor for me. There's one out there (brand name "Wainlux" that claims .05 mm accuracy but it still only uses JPG or PNG bitmap files for input so this will inherently have "fuzzy" edges. 

The Cricut looks interesting, although the proprietary software and web-enabled interface again makes me go ..eh maybe not.

Hummm maybe I can 3D print a thin layer of a flexible/rubbery resin material on a carrier attached to the build plate..  (although slicer files are also also layers of bitmaps)..

I have an old Graphtec CraftROBO cutter.  Yes, it has proprietary (vector-based) software, but mine also came with a Corel Draw plugin which allows you to design your artwork in Corel Draw, then send the job directly to the cutter.  I have not used it for few years, but I believe the proprietary software can also import vector-based artwork from other graphic software.

Do you really think that frisket mask will "hug" the surface details on the model's surface?  I have tried frisket once probably 20+ years ago, and as I remember I found  it useless for tightly masking any uneven surfaces.

[AlwaysSolutions]

Lots of questions here...  1) laser vs cutter:  if I had an operating cutter laying around I think I'd prefer to use that rather than the laser.  The cutters are just easier to use for this kind of thing.  I have a craft robo from way back in the day but I don't know if it works anymore.  Haven't used it for well over a decade but it was/is a good machine.  2) How crisp is the laser cut?  Good enough for larger masks, not good enough for fine detail imo.  It works by burning the material so depending on speed, power and material the cut quality is going to vary.  3) Can the laser cut metal?  When I first read that question my answer would have been you'd have to buy a CO2 or fiber laser.  Then, as YouTube's algorithm got all pre-cog, a video showed up in my feed a little while ago flipping that notion on its head:

The laser this guy is using is a 20 Watt diode laser that combines four 5W diode lasers into a single beam.  Like the guy in the video, I wouldn't have believed diode lasers could cut metal because that's what we've been told over and over and over.  For those unable to watch the video at this time, brass and aluminum didn't cut for this guy, but he was cutting steel all day long up to .5mm.  That's crazy.  The laser I use combines two 5W diodes.  The four diode lasers are the latest generation only out for a month or so and based on the video above I'd say are worth looking into.  I'm now curious if my 10W laser can cut steel.

I'm new to the laser thing so my knowledge is limited to my own experiences and what I'm learning from other users.  I got it just to see what kinds of things I can do with it - I'm learning I can do more and more every day.

Cheers  -Mike

[JeffB]

Cutting steel with low laser power is clearly possible.  I'll have to watch the video and see how he did it.  I use a disk/fiber optic laser to cut 0.5mm steel with Nitrogen as a shield gas.  For this I use about 400-450watts.  Cut speed is about 1m/min.

My guess is that he's using oxygen as a cutting gas, and a fairly low feed rate, but again, I have to watch the video...

Brass (an alloy of copper) is a different story though.  Copper alloys don't laser cut easily (depends on the type of laser) and generally need a good amount of laser power to do so.

But if you're going to use steel, that's going to make your life a lot easier.

JB

[Chris333]

Robert Ray used his laser to cut what looks like brass. I think what he did was just trace over the same pass again and again until it cut all the way through. The results looked a little bit crispy so I doubt it was ideal.

 Sorry it is a "short"   
https://www.youtube.com/shorts/3MV3dBSsq4M

[Chris333]

In fact Robert just uploaded this video today: