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Dec 31, 2018, 06:32 PM
Still the "Pro"-crastinator...
Steve85's Avatar
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Cool

Adventures in CNC'ing Scale Pilots


Just before Christmas I upgraded my copy of the Vectric Cut2D CAM program to their VCarve Pro CAM, mostly to gain features like unlimited cutting area and parts nesting for my short kit cutting service, but also to explore 3D milling as a potentially interesting tangent. I successfully milled a couple of Vectric's proprietary 3D clipart files, and then decided to see if I could find and mill scale pilot figures for my models. Thingiverse is a site devoted to shared 3D models intended for 3D printing, where I found an appealing 1/6 scale WWI pilot bust named Manfred 1. It was available in one of the file formats my new CAM program could use, so I downloaded it, imported it and scaled it to 1/9 scale as a potential pilot bust for my rendition of Mike Roach's Sopwith Triplane. Following the very helpful video tutorials available on the Vectric site, within an evening I had modified the Thingiverse model to one that my CNC router might be able to cut, and spent about an hour and a half watching the magic as my CNC deftly carved away all the bits of a styrofoam block that didn't look like a pilot. The photos show the results.

I'm really pleased with how Raymond turned out (Raymond Collishaw, of course...) and have planned a couple of follow-on efforts. First off, I'm going to try painting the foam Raymond to see how he turns out, and next, I'm going to try milling Raymond 2 out of a block of basswood to see how that works. Raymond 1 weighs almost nothing, a gram or two, and Raymond 2 will obviously weigh more, but I'm interested to see if the basswood will support even finer detail than the foam.

Stay tuned...

Steve
Last edited by Steve85; Dec 31, 2018 at 06:42 PM. Reason: Added some URLs
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Dec 31, 2018, 06:57 PM
a.k.a Maltone
Pat Lynch's Avatar
Great result Steve - I have 3d printed Manfred but your version looks infinitely lighter - and the resolution looks good

Pat
Dec 31, 2018, 09:25 PM
Gorilla glue rocks
Spit100's Avatar
Um, holy wow. Looks great. My carved messy foam guys don’t look nearly as great.

The pink foam actually takes flat acrylic paint really well. Will look great with your underlying detail...

Wish I had some at 1:20, ha, ha...

Jon
Jan 01, 2019, 09:37 AM
Still the "Pro"-crastinator...
Steve85's Avatar
Thread OP
1:20? I'll give one a try and see if any detail survives the reduction in size. One thing's for sure, I'm going to order a wider range of cutting bits for more 3D experiments, including some really tiny 1/32" ones, so smaller subjects might be possible.

Steve
Jan 01, 2019, 09:58 AM
Veni, Vidi, Napi
catrancher's Avatar
You might want to give this Balsa Foam stuff a try. It's kind of expensive and I'm not sure how readily available it is but I've seen it used making model railroad scenery and it carves like butter and maintains really good surface detail.

Just a thought. I've never used it myself but it looks pretty interesting. At least to my old, tired eyes.

Tom
Jan 01, 2019, 07:41 PM
Registered User
Honestly? My cheapo 3d printer does 'Manfred' in far better detail.
It's not the best of files tho TBH.
With a CNC gizmo the operating bit, be it rotary cutter or nozzle size determines the resolution. Unlikely to find /fit a .04 mm bit.
CNC router is a Great contraption (wish I had one).. but pilot busts is not it's ideal usage imo.
Jan 01, 2019, 09:31 PM
Still the "Pro"-crastinator...
Steve85's Avatar
Thread OP
Quote:
Originally Posted by catrancher
You might want to give this Balsa Foam stuff a try. It's kind of expensive and I'm not sure how readily available it is but I've seen it used making model railroad scenery and it carves like butter and maintains really good surface detail.

Just a thought. I've never used it myself but it looks pretty interesting. At least to my old, tired eyes.

Tom
Thanks Tom, looks like interesting material - pretty spendy though....

I reworked my cutfiles to resolve the ridge left on Raymond 1's shoulders and now need to cut Raymond 2 to confirm all's well before trying the basswood.

Steve
Jan 01, 2019, 09:59 PM
If it flies, I can crash it.
rocketsled666's Avatar
Get a 3D scanner and make pilot busts of yourself...

I did this a few years ago, with a Kinect for PC and some freeware called "ReconstructMe". I put the Kinect on top of my computer monitor and just spun around in my desk chair to capture a 360ļ scan of my head and upper torso. Then I printed it on my Form1 laser/resin 3D printer. The level of detail is limited by my Kinect, which isn't very high resolution 3D scanner-wise. And my beard and mustache gave it fits. But it's not bad considering this bust is only about 3/4" high...

I agree that CNC isn't the best for something like this (I have a Taig CNC - if you used a ball-end mill you might try a square cutter if you have one that's smaller than the ball-end. It should give you "sharper" features). 3D printing really is best, but I recommend a resin-type vs. extrusion. I own both of these types of printers, too (A Robo and 2 FormLabs printers). Resin printers produce a much better surface finish.

The biggest problem with CNC is that it's more involved (you have to either make a front/back and glue together or you need to do a two-sided cut which is a PITA to fixture/align) and it wastes a lot of material. Subtractive is good for stuff that needs to be strong and I CNC most of my structural parts (ABS or Aluminum), rather than 3D print. But for anything with a complex shape that doesn't need to bear a huge load, 3D printing generally produces better results with less effort...

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Jan 01, 2019, 11:02 PM
Gorilla glue rocks
Spit100's Avatar
What we can’t loose sight of, is the fact that Steve85’s pilot weighs 2 to 3 g painted.

The 3D printed resin ones must weight 20g or more.

I think the CNC foam details are perfect for painting at 1:10 scale, considering some planes need 4 exposed crew members which would only add 10g to the overall plane weight. In3d resin we might add 80g or more....

Jon
Jan 01, 2019, 11:31 PM
If it flies, I can crash it.
rocketsled666's Avatar
Quote:
Originally Posted by Spit100
The 3D printed resin ones must weight 20g or more.
Both resin and FDM prints can be printed as hollow shells (or with extremely "sparse" infill). The example above was solid, and yeah it probably weighs close to an ounce. The cured resin has a density similar to Lexan. But weight wasn't my objective here, it was just a trial to convince myself I had a process that worked. But I'm sure I could get it down to a few grams if I printed it cored-out.

I decided I needed a higher resolution 3D scanner and nothing has come on the market yet with resolution and a price point I like so I've shelved this project for now...
Jan 02, 2019, 03:34 AM
Registered User
For really small pilots, 1/20th sort of size, I just use soft balsa, a scalpel and a pin. Itís quite therapeutic carving heads!
Jan 02, 2019, 09:47 AM
Still the "Pro"-crastinator...
Steve85's Avatar
Thread OP
Pete,

If I could carve like that, I'd leave the CNC machine alone!

Steve
Jan 02, 2019, 10:09 AM
Still the "Pro"-crastinator...
Steve85's Avatar
Thread OP
Quote:
Originally Posted by Bare
Honestly? My cheapo 3d printer does 'Manfred' in far better detail.

CNC router is a Great contraption (wish I had one).. but pilot busts is not it's ideal usage imo.
Quote:
Originally Posted by rocketsled666

I agree that CNC isn't the best for something like this... 3D printing really is best...3D printing generally produces better results with less effort.

Attachment 11507517
Well, obviously a machine that's tailor-made for creating 3D shapes will probably do a better job than a CNC router, but I don't have a 3D printer. And I'm certainly not advocating anyone run out and buy a CNC and its software to carve pilot busts, I'm just exploring the possibilities of the tools I own. Lots of libraries and makerspaces have CNC routers, and if I can inspire someone else to try them, I'll be happy.

Steve
Jan 02, 2019, 03:37 PM
Gorilla glue rocks
Spit100's Avatar
Pete, what a super shrunken head. I could never carve with that detail.....

Jon
Jan 02, 2019, 05:24 PM
Registered User
Quote:
Originally Posted by Pete1978
For really small pilots, 1/20th sort of size, I just use soft balsa, a scalpel and a pin. Itís quite therapeutic carving heads!
Thanks for raising the bar! Gonna have to that a go.

Phil


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