Fin Attachment ... Tool

[ezgb59a]

A general question ... but one I'm trying to imagine in my mind on creating a tool to attach fins.

Question - would those in the hobby buy one? Some of you more mechanical and aligned humanoids can probably attach fins, making the straight, while you sit there blind folded.

I've got an idea in my head on how to create one ... that has some flex, from the smaller rockets up to larger rockets ... allowing you to assemble rockets with 3 fins or up to 5 fins.

Just trying to figure out if this could be sold on the market.

Thanks
ez

[TXFergie]

I remember years ago (probably BAR attempt 1 or 2) that Estes made a plastic fin alignment guide. It was a platform that held different sized tubes and had removable plates for the fin alignment. I think it only worked with 3 or 4 fins. I'm sure it isn't available anymore but I really liked mine when I had it. I have the newer alignment/marking guide out now but I REALLY liked the older one. If I could find something like it I may be interested. I'm too impatient to hold it the rocket still until the glue sets.

Rick

[CPMcGraw]

A general question ... but one I'm trying to imagine in my mind on creating a tool to attach fins.

Question - would those in the hobby buy one?

Well, I typically make my own each time I build a model. I use simple pieces of 110# cardstock cut to fit the model, with slots for the fins set to the proper angle. This is flexible for some of my designs, where the fins don't always touch the model at a right angle. I use Corel Draw now to create a very accurate wireframe pattern, then print it out on my cheap inkjet, and cut it out with my X-Acto knife and a steel ruler. Several custom-fit alignment guides can be created on a single sheet of cardstock, each to fit in a different location on the tube. I find using at least two, and preferably three, guides to be sufficient to hold the fins in place until the glue dries. A sheet of cardstock costs, what? A nickel? Works well enough for me...:)

[Bob Kaplow]

A general question ... but one I'm trying to imagine in my mind on creating a tool to attach fins.

Question - would those in the hobby buy one? Some of you more mechanical and aligned humanoids can probably attach fins, making the straight, while you sit there blind folded.

I've got an idea in my head on how to create one ... that has some flex, from the smaller rockets up to larger rockets ... allowing you to assemble rockets with 3 fins or up to 5 fins.

Just trying to figure out if this could be sold on the market.

Thanks
ez

I have the OLD estes one from many years back that did 3 or 4 fins. It only worked for 3/32" fins. Any other thickness and they'd be off center. And IMHO I could align them better by hand than this thing would do. But it was good for kids building, since they could do all the fins at once, and the jig held them in place. Alas, for a building session, you needed a LOT of these jigs.

More recently there has been the yellow plastic trio of tools, 2 marking guides, and an "L" angle for marking lines on the tube and aligning the fins. Again, I could do better by hand / eye than the jig.

Two years ago I finally got talked into buying one of the Art Rose fin jigs. Art is a master craftsman, and this is a wonderful piece of machinery. Of course, I'd do a few things different if I were designing it from the ground up. The biggest one is the dividing head is calibrated with a full 360 degree ring, but only has detent stops at 0, 120, and 240. My old Unimat dividing head has one plate with 24 stops that can do 2, 3, 4, 6, 8, 12, or 24 evenly spaced fins, plus additional plates with 30, 36, and 40 allowing all sorts of combinations. At a minimum, I'd change the 3 detents to 12.

The only downside to the Rose jig is the price. IIRC mine was $425 with all 3 mandrels.

Is there a market? I see two. One for a decent low price unit that is cheap enough for a club to get a dozen for use at building sessions. The other for a high end jig that is both more flexible than the Rose jig, but at a significantly lower price, without decreasing the quality or accuracy. Neither of these will be easy to do.

But...

If you build it, they will come.

[Ltvscout]

The fin guide talked about in this thread was the best inexpensive one made:

http://forums.rocketshoppe.com/showthread.php?t=2249

I've got a few in my collection.

The guy was talking about making these again. He even had a website going for a bit but it looks like he let that die.

[TXFergie]

As luck would have it, I mentioned earlier that I used to have one of the plastic Estes fin guides from about 15-20 years ago. Well, I was cleaning the garage today and decided to go through some boxes I hadn't opened since we moved in here in 2000. I opened one of the boxes and found two things - my old box with launch pad, controller, and some engines( have to rebuild the controller since the batteries leaked) and another box that belonged to my Explorer Aquarius. Inside, were not only my long lost set of decals for the rocket but my old fin guide! It was the plastic one I talked about. I have to make a standoff for the tube while it's in place, but everything else was there. It should take both the 3/32 and 1/8" fin thicknesses depending on which way you turn the guides. I have a Ranger to build and may test it out with that.

[canada]

Just curious if anyone has bought a bmi fin alignment jig (http://www.bmibay.net/finjig.html) and if so, what your evaluation of it is.

[cwbullet]

The BMI Jig is nice. Very useful. Solid construction, but it will not work on thin fins. I had to wait for about 5 months to get it.

[moonzero2]

Just curious if anyone has bought a bmi fin alignment jig (http://www.bmibay.net/finjig.html) and if so, what your evaluation of it is.

One-hundred and fifty dollars!!! :eek: Holy Cow!!! :eek:

[canada]

Come on moonzero2...the starter kit is only $110.00!!! ;)