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Imaging Physicist @danielr33187703.bsky.social

Apr 23, 25 tweets

1. Developing a new weapon is hard so why not just copy another company’s design? Fibre optic drones are a hot product and part 4 of this series looked at a company (Skywalker) who developed their own. Other companies have rushed to make similar weapons.

2. Here are two fibre optics kits made by the Chinese company, Skywalker. Opening the boxes is the likely owner of PGI Technology, which operates in China but is effectively russian. Initially, this photo was confusing. Was Skywalker collaborating with PGI Technology? Nope.

3. PGI bought these two Skywalker kits with the goal of copying the technology and selling their own version. The following photos are very unusual since they show the design process. Here is the Skywalker canister with a large drone frame.

4. Very interesting image (from a video) showing the electronics & fibre optics. The circuit board has been removed from the base station but there isn’t a good view of it. Here a short fibre optic is being used instead of an entire spool. Note the russian & Chinese flags.

5. This is the optical transceiver board used on the drone (it mounts inside the fibre bobbin). Unfortunately, there is only a blurry image of the board’s underside. The PGI logo is the most interesting aspect since it indicates this is a custom board.

6. The housing for the base station is machined from aluminum. This is just a copy of the Skywalker design. The large slot holds an off-the-shelf battery pack. The circuit boards would have been trivial to obtain or copy.

7. One thing that is very unusual and interesting is PGI shows the design cycle for the fibre canister. Their first step was to make a simply copy of the Skywalker design. This drawing looks like a preliminary design.

8. The fibre optic canister is somewhat complicated because PGI chose to use injection moulding. Software is Siemens NX with plug-ins by Yanxiu for mold design. This is the filthiest computer display I have ever seen. Yuck.

9. It is likely 3D printing was used to make mock-ups since this translucent white resin is common on stereolithography printers. It also looks like the canister warped, which also a common problem with thin-walled prints.

10. The canister was redesigned to include ribs on its sides. It also has more taper on the hole end. The bobbin for the fibre is also shown. (“bobbin” is used here to differentiate it from the large spools of bare fibre)

11. The design was further optimised by replacing the guide tube with a simple insert. The insert is likely to prevent the fibre from being scuffed as it leaves the canister.

12. Here are the 2 halves of the mould cavity (they require more machining). Oddly, they didn’t clean the metal shavings off the mould before taking this photo. The canister and bobbin are injection moulded at the same time.

13. Here are the corresponding cores for the canister and bobbin. The bobbin has a noticeable taper.

14. Here are the parts as they are being ejected from the mould. The cores are shown half-way out. This process is much faster than 3D-printing.

15. Here are the injection-moulded canister and bobbin. The notches on the end of the bobbin are used when winding the fibre optic onto the bobbin. The purpose of 4 holes in canister is unknown.

16. Weight is important to drones and the PGI canister is 60 grams lighter than the Skywalker version. Note the name written on the background wall. Portions of this name are also visible in #9 and in a few videos. From these, it was possible to piece together the entire name.

17. The circuit board shown in #5 fits inside the bobbin and is held in place with one of these covers. Note that the company name & logo are visible on the door in the background.

18. An employee posted a video to social media showing a similar door with the same sign & logo 东莞市米泰动漫玩具有限公司. This is Dongguan Mitai Animation Toys (23.09543, 113.95446). I think 米泰 (Mitai) is phonetically close to “Mattel”. It makes plastic toys (and weapons for russia).

19. Optical fibre is supplied on large spools and must be wound onto the bobbins. PGI may have had problems with fibre breakage as there were at least 4 different models of rewinder machines. Their building is large and looks like it is shared with other companies.

20. There isn’t a good photo of the rewinder they use. These video stills show the tension control uses counter weights. The tension from the supply spool is isolated from the tension of the fibre going onto the bobbin. The translation stage is massive.

21. PGI has at least 3 of these rewinder machines (they claim 6 machines total). Here, they programmed the rewinder machine so the fibre optic is tapered towards the end of the bobbin. This should allow the fibre to more easily exit the canister.

22. These weapons are not hard to make. Total capital investment by PGI was probably about US$100k. Production is likely limited by availability of bulk fibre and time required to rewind fibre onto the bobbins. With 6 rewinder machines, PGI can make about 100 kits per day.

23. Fibre is dyed to improve performance in water & reduce visibility. Here are the boxed kits ready to ship to russia. The signs on the steps are familiar. This is the shipping company 3188 Kapro (23.145953, 113.245767) that was described in part 6 of this series.

24. This photo illustrates how this series fits together. It shows russians in occupied Starobilsk, Ukraine (49.305965, 38.9269716) with fibre optic kits produced by the two small companies described in this series, specifically Skywalker and PGI who are both based in China.

25. Fibre optic kits are very effective and easy to make but are any EU countries helping Ukraine by manufacturing these?

If you found this thread interesting, please repost as a quote. Also see my previous threads shown under “Highlights”. Respectful comments are always welcome.

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