Estes fin alignment jig

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Has anyone had any problems with the fin jig not aligning the fins properly? Specifically with a four-finned rocket? Of course it could be me.
 

Tobor

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Two things to keep in mind:

1) make sure the airframe is centered in the jig.

The best cheap way to insure that is to use spent motor casings. The hole in the center of the jig will accept 13mm BP case, like an Estes A10-3T. If your rocket uses 18mm motors, Estes B's or C's, then fit a 18mm casing over the 13mm casing. If your rocket uses 24mm motors, Estes D's, E's, F's, then fit a 24mm casing over the 13mm-18mm combo.

2) The uprights of the jig are marked with offsets for 2 different fin thicknesses, 1/8 & 3/16 IIRC, depending on which side you have facing the fin. When viewed from above, the fins should be situated to the right, counter-clockwise, of the uprights.
 

Scott_650

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My results with the Estes fin jig are hit or miss. Typically, if my Macklin guillotine fin jig is occupied, I attach the fins by eye and use the Estes jig to hold the rocket while the adhesive sets. Using the Estes jig to attach/align the fins can be inconsistent - it’s just not very precise for me.
 

LithosphereRocketry

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I've had spotty results with mine as well. What I do now is just put the rocket in a vise very lightly (a drill press vise works great) and eyeball- I've found that to work pretty well, though you can only do 1 at a time.
 

dhbarr

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I've had good results essentially only with the smallest birds. Good for Scout groups, but a Macklin or homebrew is much better.
 

T-Rex

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Mine always has one fin slightly off, and always the same way. Lately, I have gone back to using the MkII eyeball and seem to have better luck.
Sometimes I also use a piece of foam board cut using a guide from the tools section of payloadbay.com .
I like dr wogz' idea of a spent motor and a toothpick or skewer, but you have to be able to get the rod straight on the casing.
 

LithosphereRocketry

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I'll spout about my little jig till the cows come home..

I've wanted the Estes style fin jig until I figured there had to be a better way (and the Estes jig was either not to be found, or un-affordable..)

If you still want one, I somehow ended up with two and I never use them...
 

Tobor

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Oh I forget to answer your question in my previous post.

I have never had an issue with my Estes jig. Purchased back around 00'~01'. Started using it again 2 summers ago on kits ranging from a Semroc Sprite to the Estes V2. V2 flew straight as an arrow on every flight, with zero roll around the Z axis, until a CATO last summer put it into forced retirement. Sprite won't fly, just got it to have it.
 

K'Tesh

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I bought one, and was never really happy about it. When the rear of the fins extend behind the body tube, while the root edge was located at the back of the body tube, I'd always end up with one or more fins being pushed up slightly while the glue was setting up. Perhaps I was doing something wrong, but keeping that body tube reliably up high enough to attach the fins was always a problem. Mine ended up being use primarily as a stand to keep rockets that can't stand up on their own, upright.

Nowadays I use fin guides made from the tool at payloadbay.com, and have been very happy with the end results.
 

ThirstyBarbarian

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I only used mine once and didn’t like it. The rocket was a Big Bertha. The fins extend so far beyond the body tube that it didn’t work well at all. Soon after that, I moved on to bigger rockets, and the Estes guide wasn’t big enough for those rockets.

Anyone want it?
 

snrkl

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I bought one, but had niggling issues (to my eye..) similar to those mentioned by the OP and others.

These days, I only use it for the kid's rockets if I don't already have a foam core jig the right size, as little fingers that don't quite have the needed fine motor skills for sub millimetre alignment can work it pretty easily...

For my rockets that aren't TTW fins, I print and cut a foam core jig from payloadbay.com (https://www.payloadbay.com/index.php?page=Tools&action=FINGUIDES)
 

flyingeagle

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The Macklin Fin Guillotine jig isn’t a bad idea but not enough thought went into it. You have be careful that the adjustable aluminum guides are dead on from one end to the other. If you don’t measure it exactly your fins will be off from the lower ones if the rocket has fins above the other. I found this out the hard way on Estes Nike-X. When I received the box dissembled I used a square to put it together while I glued it. No matter how hard I tried, from corner to opposite corner it was an 1/8 inch off. I had to compensate 1/16 of an inch off on each side to make it work. This is a big deal when gluing a fin above the other at an distance it’s is way off. I also found out after gluing, the fin was tilted. Not sure what’s causing this yet, still working on that.This might be because of the box is not being square. $132.00 plus TAX & S&H I expected better.

The Estes fin guide jig isn’t that bad but as mentioned above make sure the air frame is centered and no play where the body tube moves around. I have used them for years but it’s a good idea to check the fins before they set rock solid. I found the Quailman guides are the best to check your work or to use alone. A lot of extra thought went into Quailman guides.. I purchased all sizes from him and couldn’t be happier. Multiple fin arrangements and marked very well.
 
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I got one as a present and tried it on two rockets and it didn't work for either one of them as far as being able to grab the fins, so we sent it back the next day
 

flyingeagle

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I haven’t used the Estes fin jig in quite some time. I did find it a little bothersome at times to get the fins just right but it’s not an expensive fin jig. It’s geared more towards kids. Occasionally I will use it on small builds. I did purchase every size of card stock fin alignment guides from Apagee Components and the work well. I was using my Quailman card stock guide last night for 3/32 fin stock on a BT 60 tube and I noticed that I had one for a BT 70 tube and last BT 80. I never knew there was a BT 70 tube? I was looking over the Quailman guides as to how well they were made. Not only giving the tube sizes but the degree angle also, Cool.
 

jqavins

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I love mine. But I seem to be in a small minority.

From other threads, I've learned that there was a manufacturing change at some point. I have grey ones, which work great for me, and there are yellow ones, which apparently are of inferior quality. But that's all second hand.

The advice in post # 2 is important, if a smidgeon incomplete:
1) make sure the airframe is centered in the jig.

The best cheap way to insure that is to use spent motor casings. The hole in the center of the jig will accept 13mm BP case, like an Estes A10-3T. If your rocket uses 18mm motors, Estes B's or C's, then fit a 18mm casing over the 13mm casing. If your rocket uses 24mm motors, Estes D's, E's, F's, then fit a 24mm casing over the 13mm-18mm combo.
The jig comes with a set of 13 mm, 18 mm, and 24 mm "blank" casings (never loaded) that are meant for this purpose. The 18 mm and 24 mm work better than spent motors because their insides are not charred.

Also, to ensure the rocket is vertical as well as centered, push the four (or three) sliding vanes firmly against the body tube.
2) The uprights of the jig are marked with offsets for 2 different fin thicknesses, 1/8 & 3/16 IIRC, depending on which side you have facing the fin. When viewed from above, the fins should be situated to the right, counter-clockwise, of the uprights.
Yes, this; very important.

There are three degrees of freedom in attaching a fin to a body tube. The fin (usually) must be vertical (i.e. not canted), it must be perpendicular to the surface, and there must be the right spacing between fins. Most of the other suggested other jigs, the Qualman cards, the guillotine type jigs, and others, get you only one or two of those; the Estes jig gets you all three.

There are also some 3D printed jigs that wrap around the body tube that also give all three. I know people print those for themselves, but I don't know where to buy them. Also, they have no versatility; one needs a dedicated set for every tube diameter, fin thickness, and fin count combination. They probably work better than the Estes jig, but one would spend a lot and end with a drawer full to do the same jobs (which might be worth it).
 

Tobor

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...... The jig comes with a set of 13 mm, 18 mm, and 24 mm "blank" casings (never loaded) that are meant for this purpose. The 18 mm and 24 mm work better than spent motors because their insides are not charred.

I've had my fin jig since the 80's iirc. The blanks disappeared many many moons ago...
 

BABAR

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I'll spout about my little jig till the cows come home..

I've wanted the Estes style fin jig until I figured there had to be a better way (and the Estes jig was either not to be found, or un-affordable..)

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Love the simplicity and the cost.

wonder, don’t you need an offset? Otherwise seems like the fins would be eccentric one toothpick width and one 1/2 fin width from plumb? But your results look perfect. What am I missing?
 

dr wogz

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Love the simplicity and the cost.

wonder, don’t you need an offset? Otherwise seems like the fins would be eccentric one toothpick width and one 1/2 fin width from plumb? But your results look perfect. What am I missing?
the tooth pick is thru the center of the motor caseing. you line up the fin to the width of the pick. it is behind the fin, teh fin does not touch teh pick. it is a visual guide to ensure it is perpendicular
 

BABAR

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the tooth pick is thru the center of the motor caseing. you line up the fin to the width of the pick. it is behind the fin, teh fin does not touch teh pick. it is a visual guide to ensure it is perpendicular
I like it. What do you do for fins that extend below the end of the tube? I guess you can just not put the motor casing in all the way.
 

BABAR

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Something that augments the Estes fin jig are “cheaters” aka balsa fillets.

draw your marker lines.

cut 1/16” balsa strips 1/16” wide and the length of (or slightly shorter than) the fin root.

figure out which side of the fin will be up against the base plate of the Estes jig (I think looking down from nose to tail it is counterclockwise, but check to make sure.

glue a cheater along the line where the fin will go, with the cheater edge directly against the line on side opposite the baseplate of the jig side. Since the cheaters are extremely light weight, they attach easily and don‘t usual shift with gravity while drying. Allow to dry enough to be fixed. I prefer wood glue, so this usually takes a couple hours. I use a double glue joint (apply liberally, put part in place, take part of, wipe off excess, wait about five minute, and reapply.)

Use a double glue joint to place the fin against the OTHER side of the line you drew, so butted up against the fillet. NOW use your Estes fin guide Or fin guide of choice. This also works without a guide, use your mark 1 eyeball or @dr wogz guide to make sure the fin is perpendicular to the body.

once completely dry, the 1/16” fillet is often completely covered by a thick glue fillet.

for symmetry and/or extra strength you can add one on the other side of each fin when dry.

advantages?

1. assuming your lines are straight and fillets are straight and glued on straight (all pretty easy to do), your longitudinal fin alignment should be as close to perfect as you can get.

2. Provides a larger bong surface area, so the glue ”tack” itself is a bit faster. (edit with thanks to @astronwolf , please change that to “bonding surface”. At least I didn’t call balsa “ball sack” this time:rolleyes:)

3. The same larger surface area provides a stronger bond to surface mounted fins
 
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