Transparent Plastic Fins

My latest how-to is on making transparent fins from plastic: Plastic Fins video.

JohnCoker said:

My latest how-to is on making transparent fins from plastic: Plastic Fins video.

Click to expand...

John:
Very nice Video:
While not wanting to hi-jack your thread I find you've left something out that should not be overlooked by the majority of Model Rocket building public. Many who do Not fly HPR but use Polycarbonate Clear fins on their LPR, MPR and PMC conversions DO NOT want or use TTW fin tabs. The preferred Alternate mounting method is called the "Epoxy Rivet" method.
This method is every bit as strong as TTW without having to slot the tube(s).

Generally using a 1/16" +/- drill bit, two lines of staggered holes are drilled along each side of the fin location lines on the model body allowing for the thickness of the Polycarbonate fin. Depending on the fin Thickness Holes are drilled in the root edge of the fin itself approx. 3/16" to 1/4" up from the root edge. Fins are then butt-on attached with 30minute Epoxy with addtional epoxy fillets (which can be colored or clear). This attachment method can be used on all sorts of body/fin combination.

This is the method used on My current 5-D12 Clustered 4" diameter Crayon which I've been flying for almost 3 Decades now without a single Fin problem. Further this method can be used on ANY size rockety from Micro to 3.3lb MPR's.

This method and a ton of other information on "Working with Plastics" can be found by visiting the narhams.org wedsite in the library section (Left Hand menu) under Tech Tip-017. This text and extra pictorial file info is downloadable for everyone covering the wide range of Plastic substrates used in Model rocketry and their suitable adhesives in great detail.
Hope this helps.

Nice looking Crayon rocket, John. Thanks for the link to the NARHAMS paper, I added it to my page.

Thanks for the info! Those are some very nice videos & tutorials on your site. Thanks also for the LPR application, Micromeister! I hope to employ it soon.

Very nice crayon bank rocket, JohnCoker...

Your choice of TTW resulted in a very clean design...

Much cleaner than the "preferred" alternate epoxy rivet method...

Much stronger and easier than the laborious drilling and time consuming epoxy...

I just updated the video to include a new section on flame polishing. (Thanks Crumb fire for the nudge.)

KidRockET said:

Very nice crayon bank rocket, JohnCoker...

Your choice of TTW resulted in a very clean design...

Much cleaner than the "preferred" alternate epoxy rivet method...

Much stronger and easier than the laborious drilling and time consuming epoxy...

Click to expand...

Kidrocket: It's obvious you have never used the Epoxy Rivet method. You might want to actually give it a try before poo-pooing a proven fin mounting method.
Epoxy rivet method requires much less time to layout, cut, drill and install then TTW tube Slots, cutting and installing tabbed fins.
Further Epoxy Rivet Attachment with small Radius fillets have proven to have a much stronger Structural bond then simple TTW attachments on LPR, MPR, PMC and Scale models. Since both methods require the same use of epoxy its time of use are moot.
While TTW attachment is a vaild HPR technique as mentioned many times is totally unnecessary for LPR, PMC, Scale and much of the MPR model construction. It's nice to have alternate methods for given structural requirements. but Over building is not the answer to model rocketry construction. Build Light and Strong...not bullet Proof!

As for Cleaner appearance; Well that's in the eye of the beholder; Personally I perfer the look of small radius Fillets over square Draggy butt joints. That said; Small radii fillets are unquestionably more aerodynamically superior Hands down.

Micromeister said:

Kidrocket: It's obvious you have never used the Epoxy Rivet method. You might want to actually give it a try before poo-pooing a proven fin mounting method.
Epoxy rivet method requires much less time to layout, cut, drill and install then TTW tube Slots, cutting and installing tabbed fins.
Further Epoxy Rivet Attachment with small Radius fillets have proven to have a much stronger Structural bond then simple TTW attachments on LPR, MPR, PMC and Scale models...

Click to expand...

The only thing obvious is...

that you've spent too much time sniffing epoxy...:grin:

I second the rivet technique as an alternative to slotting and TTW mounting.

Cosmetically it can be just as clean, or cleaner, using the rivet approach compared to slotting.