20 replies to this topic

[Valkyrie]

This is a project I've been wanting to do for many years now... And I've finally gotten it off the ground! I'd wanted to wait until I had something more significant to show before going public with it, but I figure the sooner I put it out there, the sooner I'll be able to get some feedback on what I'm doing right and wrong. And this way, you all can keep me in check when I start slacking off!

This project is only possible because of the laser engraving machine that my cousin gave to me last year. As far as lasers go, it's a chinese made piece of crap, that'll only run on one (rather flaky) program. But it'll import .DXF files from AUTOCAD, and it's certainly better than nothing! So I'll be using it as much as possible during this build.

To start with, I cut and engraved the deck from .118" thick white acrylic. I had to do it in halves, since my laser's work surface is too small to small to do it all at once.
 001.JPG   49.81K   9 downloads  002.JPG   55.42K   9 downloads
The deck detail is pretty faint in the photos, but it's definitely there.
The holes are where recessed panels will be. I'm going to cut those shapes out of a slightly thinner material, and glue them in the holes. I could cut the recess with the laser, but the result would be pretty rough, and I'd just have to spend more time cleaning it up.

I cemented the two sections together, with a couple more panels on the back to help keep it all flat and rigid. And I need to build up its thickness, anyway.
I'm gluing it with Weld-On 4 acrylic adhesive. It works similar to regular model cement, in that it sort of melts the plastic, then bonds them as it re-solidifies. But it's water thin, so you just clamp the parts together, and flow a little of the cement through the joint.
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[Valkyrie]

The next order of business is the side pods. I needed to make them out of several flat panels, so I drew them up in CAD (based on the 5-view drawings in the DYRL Gold Book), printed them out non-scale, and built one papercraft style as a test.
 papercraft.JPG   94.46K   16 downloads

It worked well, but building it out of acrylic is much more complicated.
I started out by cutting 3 of the main panels.
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And then started dremeling the edges to a 45 degree angle. I shot the edges with some black paint so it would be easier to see how far was too far
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A couple of the walls were too thin, and the dremel tore them out. No biggie, I'll just repair them with sheet styrene later.

Next, I cut the rest of the parts for the port side pod. Once again, some of them had to be split in half. The thin one on top got severely warped during the cutting process. I'll just be replacing that one with Evergreen styrene strips.
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Once again, I'm gluing the sections together with scrap acrylic backing the joints to add support.
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[Valkyrie]

Next, the real fun begins...
I'm going to close up all the openings in the side pods, and add some detail to them. Door shutters and the like. I'd rather do all of that later, but I think it'd be way easier to do it now than after the whole pod is assembled.

I've got some V-groove styrene sheets from Evergreen that should do nicely as bay door shutters. But I'm not sure I want to detail them all the same way, and I'm not sure how else to do it. And really, I'm not sure how many of them are Valkyrie launch bays, or what the rest of them would even be. Missile launchers? Shuttle bays?
Any ideas?

[pfunk]

Cool build!

[Ahab]

Lookin good!

[neptunesurvey]

Will you be bringing the prototype to Wonderfest in May?

[Valkyrie]

Yep. Whatever I have finished will be at Wonderfest

And while I'm posting, a bit of an update.

I put a few hours into it today. But instead of installing the bay doors, I got started building up the basic shape. Pretty much everything except the panels with recessed detail are now assembled.
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I started with the largest piece, and glued some laser cut supports to it.
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That let me glue a couple more panels to it, making alignment way easier.

Then I backed the joints with some Avees Apoxie Sculpt to give it a bit more rigidity (I'll probably be making it solid by the time I'm done, anyway.
And finally, I glues a couple Evergreen strips together, and replaced the smallest panel, which came out of the laser all warped.
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And to finish the day off, I glued some Evergreen strips to the bay panels, which make up the little trench that runs behind the forward vernier clusters.
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That's it for today. More tomorrow, I hope!

[MechTech]

Looks great Valkyrie! I've cut styrene and acrylic on a laser (35W). One trick I learned was to coat both sides with the paper tape that is the same consistency as the paper on plexiglas. Then I got a sponge and dampened the paper. It stops flame ups and minimizes the cleanup after cutting through areas. I wish I had a laser Keep up the great work and posts! - MT

[Valkyrie]

Good tips, thanks!
My laser is 40 watts, but it still takes 2 or 3 passes to cut through the acrylic completly, so it's kind of a pain. The biggest problem I'm having is that the cuts don't always end up perfectly perpendicular to the work surface. So, for example, those bay doors will seem to be cut from a bit of an angle, and I'll have to file them down to get them to 90 degree angles. I'm assuming that the laser is eroding more of the material on the top surface than the bottom because I'm cutting it in multiple passes. But I don't know how I could work around that.

Do you have any good tricks for cutting styrene? Every time I've tried it, the laser seems to melt the plastic, rather than erode it, so I end up with really wide cut lines, and I'd need to sand down the edges afterwards.

[Grayson72]

oooh will you be making this available to the public?

[Valkyrie]

Of course, it'll be a kit when it's done

[MechTech]

The only good advice I can give is trila and error. Thick styrene (.060) gets gloppy and burns with the right speed pass to cut through. I got .040 to cut, but also got a bevel on it (what's up with that)! I got thinner plastic to cut clean (.020) for skinning frames (made big things lighter). The thin can be cut without burning or marring. You just need to adjust the speed and power settings to get it work.

The acrylic (because of its properties) should cut clean through. I cut 1/4" acrylic with paper covered sheets and made trophies or plaques. Then there's adding LED light to the edges for affect...

Try the moistened paper tape. I also found sometimes on straight plastic (regardles of thickness) that a second/third pass could cause flameups/fire. But paper lined could take the power on a single slow/hot pass with minimum flame. The paper also protects the plastic from marring and you only have to peel the tape up afterwards.

The attached photo object was a rectangle cut from 3/16" acrylic (rastor etching and vector cutting used). Clean, glossy edges. You could make some REALLY awesome stands for your models with that laser! - MT

Edit - why does my camera warp all straight edges!!??

Attached Files

•  CIMG4897.JPG   899.8K   7 downloads

Edited by MechTech, 27 March 2012 - 03:15 PM.

[Major Focker]

Edit - why does my camera warp all straight edges!!??

perhaps because you're shooting at the extreme wide-angle range of your zoom? try backing away and zoom a bit.
strange though, since the verticals look straight.

[Valkyrie]

Thanks for the advice, Mech. I still need to do some experimenting with that tape trick. And styrene cutting, also.
But I've been finding out that my laser cuts PETG plastic cuts way cleaner than it does acrylic. And it's not as dense as acrylic, so you can still cut it with an xacto. If I wasn't so far along, I'd be tempted to start over, switching materials.

I haven't made too much progress the past few days. Most of the time put into it was spent fixing geometry mistakes that was preventing one of the side pod's panels from going on correctly.
I glued on the bottom piece, and puttied the seam, giving it more rigidity.
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And I did some experimenting with the bay door paneling. I cut the doors out of .060" PETG, then skinned them with Evergreen's V-groove siding sheets. I tried them with both types I had, .040" and .050" spacing. I think the 040 looks good for the larger door, but too big for the smaller one. I need to pick up a sheet of the .030" stuff tomorrow
 020.JPG   96.6K   4 downloads  021.JPG   88.42K   4 downloads

[MechTech]

What glue works with PETG? I've never used that before (I think). Looking good! - MT

[Valkyrie]

Regular plastic cement seems to work ok for gluing styrene to PETG. But I suspect I'd need to use my Weld-On acrylic cement to bond PETG to itself. It's really great stuff, but it was hard to find. And it's super runny, so it tends to get everywhere if you're not careful.

[Valkyrie]

Minor update. I got some of the finer V-groove paneling today and worked on cutting out and skinning a few doors. It's coming along well, but I'm thinking I need a couple more door designs to vary it up a bit.
For the smaller ones, I'm trying to skin them with resin copies of one of Kaiyodo's mecha detail photo-etch sets. I'd use the real thing, but they're out of production now.
 022.JPG   128.13K   14 downloads

[Ignacio Ocamica]

Great project!!! It's coming along very nice.

[Zinjo]

Minor update. I got some of the finer V-groove paneling today and worked on cutting out and skinning a few doors. It's coming along well, but I'm thinking I need a couple more door designs to vary it up a bit.
For the smaller ones, I'm trying to skin them with resin copies of one of Kaiyodo's mecha detail photo-etch sets. I'd use the real thing, but they're out of production now.
 022.JPG   128.13K   14 downloads

You might consider using paint to vary the doors as well. Different schemes for different doors can denote specialized uses.

Just a thought...

coming along great.

I was wondering what you used to control your laser cutting? If it is a program, is it possible to simply invert the process and then turn the piece over to be cut from the other side? I'm just guessing having never used such a tool myself...

[Valkyrie]

Things are coming along, but slowly... I got most of the doors done on the center panel, but I had a few breakage issues that slowed me down. And the whole process is way more tedious than I had anticipated.

I'm using literally the only software possible with this laser, a piece of crap called NewlyDraw. As I think I mentioned earlier, if it didn't accept .DXF files from AutoCAD, the machine would be almost completely useless to me.
All it does is take the lines I've drawn in CAD, and draw with the laser. In the process, it vaporizes about 0.01" of acrylic as it cuts. So I need to manually adjust the drawing of each individual door to get it to fit the opening. And I still usually need to tweak the size one way or another to get a good fit.
Like I said... tedious.

[Valkyrie]

I'm not quite dead yet!
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So that's as far as I've gotten so far. It's still tedious and slow going. I really don't know how Moscato does it!
The bottom two panels are just about ready for assembly, except for a bit of repair work. They'll still need some detailing, but that can come later. The X's on the panels are placeholders for raised panels that'll be added later. I figured I'll just end up cutting those panels out of clear plastic, so I'll just be able to line up the corners of the panels with the endpoints on the X's, and that'll make proper placement a breeze.

At this point, I'm really anxious to move on to other areas. Probably the underside of the main hull next. But I need to concentrate on one thing at a time...