Clear Plastic Fin Material

[BigRIJoe]

What is everyone using for clear plastic fin material on scale birds these days?

[chrism]

What is everyone using for clear plastic fin material on scale birds these days?

Here are a couple of suggestions about clear plastic material for fins. One is to use clear sheet styrene such as the stuff from Evergreen Plastics. Here is a link to their site:

http://www.evergreenscalemodels.com/Sheets.htm#Clear Sheets

Another idea came from Chris "Hans" Michielssen who use the plastic "glass" from oridnary picture frames that you would find at Wal-Mart or any dollar store.

[hcmbanjo]

Here are a couple of suggestions about clear plastic material for fins. One is to use clear sheet styrene such as the stuff from Evergreen Plastics. Here is a link to their site:

http://www.evergreenscalemodels.com/Sheets.htm#Clear Sheets

Another idea came from Chris "Hans" Michielssen who use the plastic "glass" from oridnary picture frames that you would find at Wal-Mart or any dollar store.

In the end, the clear plastic fins I used popped off on landing, much like the fins did on the early Estes Thor Agena B and Gemini Titan.
Attaching the plastic using clear dope (as in the old instructions) felt like a good bond at first. In a few days, the joint got weaker.
Unless I found a good, compatible plastic and glue, I'd probably go with through the wall clear fins next time.

[blackshire]

In Europe, plexiglass (perspex) is often used as clear fin material.

[Bill]

In Europe, plexiglass (perspex) is often used as clear fin material.


I have always heard that plexiglass (acrylic) is brittle; my experience is that clear polystrene is as well. Lexan (polycarbonate) is better in that department, but Carl told me that his laser cutter does not cut Lexan efficiently.


Bill

[chrism]

I used to have the R2-D2 rocket a long time ago and the clear fins used a small screw to attach to the legs. I don't remember what type of plastic that was but it was not that durable and cracked.

[mwtoelle]

All transparent plastics tend to be brittle. I think that it has something to do with the chemistry involved in making the plastic see-through in stead of opaque. I think that the classic Estes kits with clear fins (the Gemini-Titan (K-21), the Thor-Agena B (K-28), Saturn V (K-36) and the semi-scale Saturn V (K-39)) used clear butyrate for the fin material. Lexan that is thick enough may work well, but it would have to cut with a blade. Just my $0.02.

[tbzep]

The clear slotted fins that came with my Centuri Saturn V were flexible. They worked great, but because of the way they attached, they gave the Saturn a slow roll. They never came off in flight, and I don't even recall one popping off on landing.

[blackshire]

I have always heard that plexiglass (acrylic) is brittle; my experience is that clear polystrene is as well. Lexan (polycarbonate) is better in that department, but Carl told me that his laser cutter does not cut Lexan efficiently.


BillTwo thoughts: The laser cutter's beam might not be impeded enough by the transparent Lexan to heat the intended cut line enough, but maybe if the beam hit it at a shallower angle that might improve the heating of the cut line? Also:

Polycarbonate is also commonly used by European model rocketeers for making clear fins, but another possible material (that I have never heard of being used for clear fins) is clear polyurethane, which at least some of the polyurethane casting resin suppliers offer. SynAir Corporation, the initial producer of the Por-A-Kast polyurethane resin, also sold a clear version of the resin that their product specifications said would not yellow over time. Other polyurethane resin makers such as PolyTek, Ciba-Geigy, and Alumilite might also have clear resins. In addition:

If clear polyurethane resin is physically similar to the opaque formulas (quite stiff even in thin sections, but not brittle, and having just a bit of "give"), it should work well for making durable clear fins. As well, maybe a laser cutter would work well enough on clear polyurethane resin to cut it well?

[naoto]

IIRC the substrate material of CD and DVD is a polycarbonate. I usually end up with a pair of "blanks" (disc of substrate material w/o any of the foil recording surface) on the ends of a spindle pack (as I usually go through a spindle or two every few months, I've accumulated a stack of these "blanks"). The material is quite resilient compared to clear styrene (you can bend a disc almost to a point where it resembles a taco shell -- which requires a fair amount of force to apply). At a certain point you'll start noticing a cracking noise, and eventually followed by a rather spectacular shattering of the material (might not be a significant problem as rocket fins -- it takes considerable amount of flexing before this happens -- and probably would require several hard landings before such a failure would occur -- by then the rocket is probably toast anyway). I haven't checked to see what adhesives work on this material. The other downside that I can see is that the size of fins you could cut out of this material is somewhat limited.

[w1vt]

I've cut sheet polycarbonate several times with a sheet metal shear--works great if you have something like that available.

[sbs0011]

Hi im new here and i Thank Scott for helpimg me get here!

Well Thank You for helping me to find something in the clear fin stock. I hope i can find it thin enough for a wrap around the body tube as in the origional Titans

First off im new here but i have been doing model rockets sinc i was 14.
I have built many of Estes rockets including the Saturn 1B and the Saturn V over time but took a break for many years.

I decided to build a challenging 2 for this year the Gemini/Titan GT3 and the Titan 3E since they are close in build material! The plans i have aquired and at least with Semroc i have gotten almost all the parts for the Gemini/Titan and figuring the body tubes for the Titan 3E has worked out! I Think!!!
I have found the Decals for both so that was good.

But finding the nose cones for the Titan 3E is a challenge so that is my job for now!
If any of you know where to find them i Thank You in advance. Some of them are odd and no parts numbers and some were made in plastic but if i have to i can improvise making them somewhat different.

I finall have a grandson old enough to enjoy this hobby with me so its time to sharpen my building skills and the we can build and fly our rockets together.

Thanks again for this forum and the help out there

Mike

[tbzep]

I believe somebody here or on TRF made slip-on clear fins and described how he did it. You might try a search at both sites and see what he used. I remember thinking I was going to make a few sets when I got my Gemini Titan clone built, but I haven't even come close to that project yet.

[jharding58]

In determining that my money was worth less than my time I have had several sets of Gemini Titan clear fins laser cut. They are shipped to me with the paper and plastic overlays intact so they come out of the bag looking blue. Strip off the paper and the film and you have a crystal clear fin made from PETG. Now to get that fin can wrap and see how they adhere.

[jharding58]

Just to add some clarity, here are the fins cut and assembled to an ABS band. The fins are cut by Pololu in Las Vegas. This method takes me about 10 minutes to assemble the can; few touches with Tenax to set and hold them, then a fillet run of Plastruct to lock them in place. Not sure how long they will hold up to landings but I suppose this would be a fielders choice launch anyway.

These are about 1/16th thick clear PETG and require a CDR file for the most economical submission. There are a minimum number to cut, but it makes this process so much easier. I have a file with 19 on a sheet if you would like to copy that.

http://www.pololu.com/catalog/product/1268

[jetlag]

Just to add some clarity, here are the fins cut and assembled to an ABS band. The fins are cut by Pololu in Las Vegas. This method takes me about 10 minutes to assemble the can; few touches with Tenax to set and hold them, then a fillet run of Plastruct to lock them in place. Not sure how long they will hold up to landings but I suppose this would be a fielders choice launch anyway.

These are about 1/16th thick clear PETG and require a CDR file for the most economical submission. There are a minimum number to cut, but it makes this process so much easier. I have a file with 19 on a sheet if you would like to copy that.

http://www.pololu.com/catalog/product/1268

That looks about as professional as I have ever seen! Really nice work.
Where to get the ABS band, if I may ask?

Thanks,
Allen

[jharding58]

The ABS sheet was some old stock which I had. You can purchase PET sheet from the LHS or Tower as the K&S Engineering product. Given the material of my fins it will probably make for a better adhesion (or cohesion I guess).

SIG used to have ABS sheet on their website butnow has "Clear Plastic Sheet", not sure of the material but there it is. I used this to build fin cans using the .030 and .008 sheets for fins and wrap respectively. Navigate to building material, plastic, and clear sheet.

http://www.sigmfg.com/cgi-bin/dpsmart.exe/MainMenuFV5.html?E+Sig

[ghrocketman]

Sheet Butyrate.
Bonded/Welded with Dope thinner or Tenax 7R.
Good ENOUGH then and Good ENOUGH now.

[jharding58]

Sheet Butyrate.
Bonded/Welded with Dope thinner or Tenax 7R.
Good ENOUGH then and Good ENOUGH now.

http://k-mac-plastics.net/cellulose-acetate-sheet.htm

[ghrocketman]

Prices seem quite reasonable on that site, but some thicknesses are only available in UNreasonable moronically large quantities.

[jetlag]

Is the butyrate plastic the polymer that yellows with age so badly?

Allen

[jharding58]

Is the butyrate plastic the polymer that yellows with age so badly?

Allen

That was what I found to be the case. That is why I went with PETG; supposedly more stable and does not become brittle with UV exposure.