This was a really interesting video I saw in instagram of what looks like abrasive grinding wheels being used with a sliding jig to thickness FCS fin tabs.
Super efficient way of accomplishing that task.
This is some Chinese fin-makers Instagram account, some other interesting images/videos in there of their fin making processes
https://www.instagram.com/promaxsurf/
The Instagram post embed doesn’t seem to be loading, so here’s a screenshot of the post for easy context without having to click through
Looks like 2 horizontal grinding wheels with the proper thickness gap between them, then they have a CNC’d holding jig for the fin and the whole jig assembly is on a sliding mechanism so they can quickly slide it back and forth between the grinding wheels to thickness the tabs to an exact spec.
Very efficient, and the whole process only take a few seconds a fin.
Interesting…but it strikes me as kinda complex and awfully specialised. A lot of work to set up something that’s good for only one task that you’re not going to be doing that often.
Now, if I was going to tackle this, I might go with a table saw, a dado blade set and a tenoning jig. Use the spacers that come with the dado set plus some good quality 5/8" washers. Well, that and a low-end digital caliper. For injection molded fins that would be just fine, for fiberglass/composites the grinding wheels for a 5" grinder should work, same 5/8" hole as the dado set.
Now, you can buy the tenoning jig, the Delta 34-184 isn’t bad, good yard sale or Craigslist score used, or you can make your own: Cut Perfect Tenons with this Table Saw Jig! | Woodsmith
Properly tuned and used, can be accurate to 0.01" . Way more versatile too, you can even cut tenons with the thing.
hope that’s of use…
doc…
Insight into how they do things in Chi-Com factories is always an interesting diversion. Just not practical for even the very few that grind their own fins. A couple of passes over a bench planer would do the same.
