Fin alignment: jig, sight, or ?

[Jon Craig]

What's the best way people have found to align fins on a rocket? Have you build (or bought) a jig of sorts? Do you just eyeball it? Or ... ?

I'm getting better, using eyeball method, but I think it's still not perfect, and I always strive for perfection.

 

[stantonjtroy]

I always use my military issued, laser straight, NASA calibrated eyeball.

FWIW

 

[blackjack2564]

Jon, you haven't mentioned what size rockets.....for airframes 2in and up I use homemade jigs made from foamboard or heavy cardboard modeled after this jig.
https://www.vatsaas.org/rtv/construction/finjig.aspx


Simple and easy to make. For estes type rockets I still just eyeball them

It's more of of thrust thing for me. If I do make a smaller high power rocket, like a minimum diam 29mm 0r 38mm I will use a jig.

 

[Jon Craig]

Jon, you haven't mentioned what size rockets.....for airframes 2in and up I use homemade jigs made from foamboard or heavy cardboard modeled after this jig.
https://www.vatsaas.org/rtv/construction/finjig.aspx


Simple and easy to make. For estes type rockets I still just eyeball them

It's more of of thrust thing for me. If I do make a smaller high power rocket, like a minimum diam 29mm 0r 38mm I will use a jig.

Wow - very nice jigs. I haven't the tools to construct one however. I wonder if anyone sells them?

 

[e42]

Wow - very nice jigs. I haven't the tools to construct one however. I wonder if anyone sells them?

While I have not personally used this product, I am told it works extremely well.

Standard Rockets Assembly Tool

Someday I hope to pick one up.

--- Ron

 

[GuyNoir]

Art Rose fin jig, hands down. Your fins will be on perfectly straight using that puppy.

 

[Bravo52]

Art Rose fin jig, hands down. Your fins will be on perfectly straight using that puppy.

Upwards of $500 bones....Ouch! :jaw: If you can find who sells them.

 

[mike_bar]

Jon, you haven't mentioned what size rockets.....for airframes 2in and up I use homemade jigs made from foamboard or heavy cardboard modeled after this jig.
https://www.vatsaas.org/rtv/construction/finjig.aspx
[Snip]

Jim,

Thank you for the link to the Fin Fastening Jig by Rocket Team Vatsaas.

I have made a similar fin alignment jig for model rockets. I use corrugated cardboard. See link below for the pattern sheet.

Estes 3 or 4-Fin Alignment Guide
by Clive Davis
A handy guide to help you align your fins with various size Estes tubing.

Source webpage: Building Tips at Ye Olde Rocket Shoppe

Source website: Ye Olde Rocket Shoppe

 

[Gus]

Art Rose fin jig, hands down. Your fins will be on perfectly straight using that puppy.

Link to Art Rose Fin Jig

 

[Diosces]

Jon, you haven't mentioned what size rockets.....for airframes 2in and up I use homemade jigs made from foamboard or heavy cardboard modeled after this jig.
https://www.vatsaas.org/rtv/construction/finjig.aspx


Simple and easy to make. For estes type rockets I still just eyeball them

It's more of of thrust thing for me. If I do make a smaller high power rocket, like a minimum diam 29mm 0r 38mm I will use a jig.

Like Crazy Jim said a jig made out of heavy cardboard, foam or masoniteo works great.
One of the best fin templates that you can use to make a foam or cardboard one:
BSD Color Fin Template

 

[nxj]

Upwards of $500 bones....Ouch! :jaw: If you can find who sells them.

The high power one is almost $1k...

:y:




Anyway, I just use my eyes and the estes yellow ruler. It helps out with getting it in line.

 

[FatBoy]

The Standard Rockets Assembly Tool (www.standardrockets.com) is the best way to go. It is so simple to set up all fins at one time.... set them up, glue them and forget about them. Its extremely versitile no matter how many fins you have or how thick they are. It even has cradles to lay your rocket flat while doing fillets.

 

[troj]

Hundreds of dollars.... for a fin alignment jig? Wow.

Me? I eyeball 'em. I can rebuild a lot of rockets for what a $400+ jig would cost.

Unless you're a perfectionist, or you have real problems with hands that shake a lot, learn to eyeball 'em and save yourself a lot of money.

-Kevin

 

[AKPilot]

You know, there looks like a tremendous business opportunity here (Vatsass Fin Jig) for anyone that wants to pursue it.

Could make them in all sorts of BT sizes and 3 or 4 fin configurations.

 

[powderburner]

You would also need them (potentially) for different fin thicknesses.

One suggestion: it might be "better" to make the fin guides out of foamcore instead of masonite---it would be much lighter to mail. Foamcore also has a little springy-ness to it, and it grips the fins snugly if you cut it just right.

And foamcore might be compatible with laser cutters?

I can see it now--sets of jigs (for BT20, BT50, etc), with pairs of guides for 3 fins 1/16th thick, 3 fins 1/8th thick, 4 fins....

 

[Pat_B]

I have the Art Rose fin jig and am extremely satisfied with it. However, it is expensive and I've noticed that the price has increased quite a bit since I bought mine.

The mandrel cost is way out of line considering that you can buy dimensioned metric rods that would just need to be cut down and center drilled. The mandrels supplied with mine were made out of Delrin which is pretty inexpensive stuff (~$1/ft in 2" diameter).

Nonetheless, it works really well and I'm glad I have mine, but it is high priced.

 

[Adrian A]

Here's what I do to glue on my fins straight. The granite/marble floor tiles cost about about $3 each at Home Depot.

This way, you use the nice uniform thickness of the floor tiles to ensure that the fins are parallel to the body tube, which is the most important part to get perfect. To make sure that the fins stick straight out from the tube, I set the tube on end over a piece of paper with 120 degree markings, and adjust while the glue is soft. I also like to save time by taking the fins using this jig with CA, and then I go back with epoxy for fillets.

 

[foose4string]

I usually just eyeball 'em. A jig would be nice but I get along pretty well without.

However, if I were to spend dinero on a jig, I think it's hard to beat Lyle Merdan's, Standard Rockets Assembly Tool. Very clever design and solid. Cost a fraction of the Rose jig.:2: I think you can pick one up through Sirius-Standard Rockets Jig.

 

[JRThro]

I use the gray plastic Estes Fin Alignment Guide that someone gave me a few years ago. Works like a charm for most single-engine model rockets.

 

[Stymye]

annother vote for the estes fin alignment guide.

 

[FatBoy]

However, if I were to spend dinero on a jig, I think it's hard to beat Lyle Merdan's, Standard Rockets Assembly Tool. Very clever design and solid. Cost a fraction of the Rose jig.:2: I think you can pick one up through Sirius-Standard Rockets Jig.

This is worth every penny.

 

[BobH48]

The Standard Rockets Assembly Tool (www.standardrockets.com) is the best way to go. It is so simple to set up all fins at one time.... set them up, glue them and forget about them. Its extremely versitile no matter how many fins you have or how thick they are. It even has cradles to lay your rocket flat while doing fillets.

I saw these at NARCON last year and I'm kicking myself for not picking one up.

 

[jeff_in_AZ]

BMI CAD also used to make and sell a machined Aluminum fin jig:

https://www.bmibay.net/finjig.html

I'm not sure what their status is right now, the fin jig is not
listed on the BMI home page anymore.

I think the answer to what is needed for fin alignment
depends a lot on what the rocket is used for. If it is
a contest rocket, fin alignment will be important. If it is
for park flights with your kids, then line of sight alignment
is fine.

jeff

 

[spacecadet]

I always use my military issued, laser straight, NASA calibrated eyeball.

FWIW

In the RAF they call it the Mk. 1 eyeball.

 

[j.a.duke]

I saw these at NARCON last year and I'm kicking myself for not picking one up.

Bob,

You can order one still-it's never too late! And you get the newer version to boot.

Cheers,
Jon

 

[Moldie]

Eyeball and lots of double checking.

 

[rocketsmith]

You know, there looks like a tremendous business opportunity here (Vatsass Fin Jig) for anyone that wants to pursue it.

Could make them in all sorts of BT sizes and 3 or 4 fin configurations.

Anyone interested, contact me : [email protected]. I have been making acrylic fin alignment jigs and they work great. I will include instructions on use and I can make any size body tube/ fin thickness/ number of fins you want. I will post a picture when I can. Cost is pretty minimal as the material is less than 10 dollars a square foot. Epoxy doesn't stick either.
David B. Smith (tra #11892)

 

[Viperfixr]

Anyone interested, contact me : [email protected]. I have been making acrylic fin alignment jigs and they work great. I will include instructions on use and I can make any size body tube/ fin thickness/ number of fins you want. I will post a picture when I can. Cost is pretty minimal as the material is less than 10 dollars a square foot. Epoxy doesn't stick either.
David B. Smith (tra #11892)

Would really like to see this for HPR application, like on a 38mm min diameter build I am about to start. Any pictures? $$$?

 

[luke strawwalker]

As most rockets I build have four fins, I usually put them on in opposing pairs and clothespin a scrap piece of balsa (usually "L" shaped) or a steel ruler across the two fins to keep them straight...

Works like a champ... I may need to come up with something with a 120 degree angle for 3 finned rockets though... OL JR

 

[Scott Evil]

For LPR-ish sized rockets, I've been known to round up some choice LEGO's from my sons extensive selection and make jigs out of them. It actually works fairly well with a little creativity.

(It's also a great excuse for a grown man to play with LEGO's a bit :blush: )