Has anyone done 3D printing to put an aftermarket stab to an armie fuse ?
Thanks
I’ve thought about this in the past. It’s difficult to solve for Armstrong due to the threads being in the stab and the hole spacing being different to most.
Given that we will need threads in the adaptor itself, I don’t think 3D Printing will be strong enough.
I could machine something in G10 with stainless steel threaded inserts, but would like to see a bit of interest before I bury a lot of effort into this. I’ll check back on this post to see if there is enough interest and then I’ll have a go at something.
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I’m waaaaayyyy too easily distracted. I couldn’t help myself. The thickness is dictated by the standard Armstrong screw length and also the need for decent screw engagement to bolt down the aftermarket stab (will need 12mm long M6 CSK). The fore/aft position of the stab is dictated by the need to avoid the required Armstrong screws and not create too much of a stress concentration.
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Why not M5 barrel nuts?
I did consider this, but discounted the idea for the following reasons:
- Hard to get in torx and even if I could it wouldn’t be T30
- Would need 2 tools to assemble
- More loose and non-standard parts
- It doesn’t change the overall thickness since I still need engagement of the M6 screws assembling the stab
Unless I’m missing something?
I made a quick 3D print to test the geometry. All looks good. I’ll machine one in G10 when I am cutting a proto stab later in the week.
If anyone is keen for one let me know (here or via crispfoils.com contact form or @crisp_og on insta).
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The G10 version came out nicely.
I omitted the helical thread inserts for my prototype, but I’ll probably include these for others to save the risk of stripped threads.
Below it’s shown as assembled with a Crisp Flex 130 for AFS or other generic bottom mount brands.
I gave it a quick spin winging and it felt nice.
Feel free to get in touch via crispfoils.com, @crisp_og on insta or Crisp Foils on Facebook. I’m not planning to add these for sale on the website just yet.
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Very impressive mate. Hey how did you model the underside of that adapter? From memory Armstrong have a few contours going on. Ah, actually, I’ve just realised you probably have access to their files or something?
I was making Armstrong compatible stabs long before I was working for them and have always used my own CAD model. Same goes for all the other brands - I get hold of a fuselage (and sometimes a stab) and make a bunch of measurements, use a contour gauge, take photos and use a combination of those to build a representative CAD model. Then I test the fit with scale printed templates, or more recently, 3D printed parts. Tweak and repeat until I’m happy. Sometimes I get a head-start if the brand has released CAD files for shims.
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Yeah nice, I actually love doing that sort of thing!
It’s a bit of topic, but have you tried photogrammetry to get a 3d model of an interface? It seems that you could nail an accurate model on the first go.
I’m working with Agisoft and Pix4d for coastal science but they are expensive.
Meshroom is an opensource software that could work.
Yeah interesting thought. I’ve always found that Photogrammetry and Laser Scanning is only as good as the software used to interpret the point cloud into nice geometry. That said, I haven’t used it seriously for 10 years. It’s worth having a fresh look, thanks.