Estes Fin Guide and similar tools

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Kirk G

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How essential would you say it is to have a "fin guide" whether from Estes or some other source?

The Estes version is a plastic octogon with selectable guides or supports that can be positioned for 4 fins, three fins, two fins, etc, with various motor housings to rest the rocket upon.

Some claim that if working with a young rocketeer, this is the only way to go to assure an even, correctly angled fin attachment. Others say it can be eye-balled by laying on an inverted egg carton, with appropriate books to support fins. Some think if you're working with a cub den or additional kids, you need at least one of these for a production line and to assure that every kid has the proper angle.

What do you think? Is it a worthwhile investment?
 
How essential would you say it is to have a "fin guide" whether from Estes or some other source?

The Estes version is a plastic octogon with selectable guides or supports that can be positioned for 4 fins, three fins, two fins, etc, with various motor housings to rest the rocket upon.

Some claim that if working with a young rocketeer, this is the only way to go to assure an even, correctly angled fin attachment. Others say it can be eye-balled by laying on an inverted egg carton, with appropriate books to support fins. Some think if you're working with a cub den or additional kids, you need at least one of these for a production line and to assure that every kid has the proper angle.

What do you think? Is it a worthwhile investment?


I'd vote that the grey plastic octagon you're talking about is a waste of money. I never was able to get mine to work for me.

I'd say do the foam core/payloadbay.com route for rockets with TTW tabs. And you probably could get away with the (yellow) fin guide that Estes sells for smaller builds.

That said, nowadays, if my rockets aren't minimum diameter, I've been swayed into making them with TTW.
 
Can you expand upon the foam core/payloadbay.com route for us? Some of us newbies have no idea what you're referring to!
 
I have 2 of the gray plastic Estes fin jigs. Use them for some things, not for others.
As for scouts, what was purchased, mailed accross country to me for my son's pack was a plastic fin can, good 1st Rocket. Thanks to a very special member here on the forum a gross box of 25 kits were given to the pack.
There is a thing out there, sold by Apogee, Amazon, and I'm sure on E-bay call the guilitine.
Some guy desinged this thing and patented it, and it's a pretty nice unit.
I built one myself, did a few changes to make it even better.
Really nothin to it once you see it. Last I looked, it was $90 & S&H.
 
How essential would you say it is to have a "fin guide" whether from Estes or some other source?

The Estes version is a plastic octogon with selectable guides or supports that can be positioned for 4 fins, three fins, two fins, etc, with various motor housings to rest the rocket upon.

Some claim that if working with a young rocketeer, this is the only way to go to assure an even, correctly angled fin attachment. Others say it can be eye-balled by laying on an inverted egg carton, with appropriate books to support fins. Some think if you're working with a cub den or additional kids, you need at least one of these for a production line and to assure that every kid has the proper angle.

What do you think? Is it a worthwhile investment?

Fin Alignment is a Very important aspect of building model rockets that you want to fly Straight and True.
There are any number of different schemes, fixtures and jigs available for the novice to BTC (Big Time Competitor) ranging about 20 bucks to over 600.00.

As an Archer: I was taught how to align the fletchings on my arrows to ensure true flight. Sighting down the length of the arrow to see that they are parallel to the long axis of the shaft. A bit latter in mid 1960's my father built a fletching jig to perfectly align our Fletchings. This Jig lead me to the basic design for my Model Rocket fin jig 15 or 20 years later.

Estes Octagonal fin jig is OK for most BT-5 to BT-60 stuff and CAN be altered, improved to work with longer fins and other size bodies (See composite photo below).
I have one I've had for more then 35 years that is used often with Scout groups, and new modelers build sessions.

I also have two fin alignment jigs referred to above, designed and build mainly for competition models but work very well for me on Sport models as well. Neither take much in the way of materials and between the two sizes I can handle models from T2 to BT-101 size body tubes, matching fin thickness spacers they will handle any fin thickness from .005" to 1/2" or more.

There are also any number of other fin alignment jigs out there. One is the Guillotine type Kit, expensive but it does the job. and of coarse the ultimate in precision the ART ROSE fin Jig.
if you do a search I'm sure you'd have a field day just looking at all the different methods.

If you'd like to build one similar to my alignment jig I have a scale drawing that could be e-mailed or posted here.

Estes Fin Alignment Jig-h_7 pic Pg_11-05-06.jpg

MM 406uc02b_FletchingJig applied Feathers_09-06-14.jpg

MM Fin Alignment Jig-b6_Fin on rest_02-04-11.jpg

Lg Fin Jig-g2_2Pic Page 2of2 11-13- 09_rework-11-05-13.jpg

FinJig-a3_Art Rose_Crop2-279x201_10-07.jpg
 
To answer the OP's question: Yes. It doesn't cost much, relatively cheap in fact, and it works on most LPR rockets. I can't think of a good reason not to have one.

Like 'Meister, above, I've had one since they were introduced. Sometimes I use it—sometimes I don't, but it is certainly worth having. Particularly if you're new to the hobby.
 
I am a fan of the Macklin jig sold by Apogee. Even the kids (ages 5 and 7) can use it to attach straight fins without help.
 
Can you expand upon the foam core/payloadbay.com route for us? Some of us newbies have no idea what you're referring to!

Go to Dollartree and buy a sheet of foam core (price $1 (plus tax presumably)). Go to Payloadbay.com -> TOOLS -> Fin Guide Tool, enter in the required info (e.g. number of fins, width of fins, body tube diameter), and print the resulting .pdf file. Then you glue the printout to the foam core, and cut out the designated material, and you've now got a fin guide that will work for you.

The reason I say TTW for that style of guide is due to my failures in keeping that kind of guide aligned properly while sliding fins in place (and thus smearing glue all over the place). Now that I'm older, and have more practice, I do think I could make it work for a surface mount using the double-glue method.

One nice thing about this method, is it's a lot cheaper than many other types of jigs out there, and you're only limited by the size of the foam core you buy and the paper you print on.
 
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I'm going to second (or third) the opinion that the Estes jig is mediocre at best. I don't think it was user error, although failure is always an option.

Seriously, the construction of the one that I bought was not particularly sturdy, or was it necessarily straight/perpendicular. I have one particularly vivid memory of attaching all four fins on a rocket using that jig, then later finding I needed to cut two of them off and reattach, because they were not aligned with the body tube.

I've recently purchased a guillotine jig from Apogee, put it together, and have not had time to use it yet - pending cross-country move getting in the way.

There's another member that has a fin guide that's configured like the Estes but is machined rather than plastic: www.ultimaterocketfinguide.com His stuff can be pricey, but it looks like it wouldn't suffer from the deflection issues I encountered with the Estes jig. If I hadn't just bought the one from Apogee, I would have seriously considered this one when it went on sale. You only need the BT-5 and BT-20 mandrels, as long as you install the MMT first in your kit. You can then handle anything with a 13mm or 18mm MMT, which is a huge chunk of LPR.
 
I build only low and mid power. In the low power side, my builds are almost never simple 3 or 4 fins at the rear of the tube. An Estes-type alignment guide is of limited use to me.

I also find that the guillotine-type jig does not work very well for me. I don't know why it is, perhaps it is my aging vision, but it seems that there is always at least one fin where the alignment line is not directly lined up with the slot in the metal angles. (remember, I am often dealing with complex number of fins and/or non-traditional configuration).

For the mid power that is TTW, I don't have the alignment line issue and can use a simple "Kuhn jig" style of tool to ensure the fin projects straight from the tube. I use the V-slot at one end of the Estes tube marking guide to wedge the fin in place, and tape the guide to the airframe while the epoxy sets (you have to remove the sliding piece to use it this way)

Back on the topic of low power, using surface mounted fins, I needed something that supported non-traditional configurations. I found that with the Qualman Rocketry fin guides. Because they support a large number of fins in up to 12 different alignment locations, and are not constrained to the be used with a motor mount, they work best for my kind of builds. Not only do they ensure that a fin projects away from the tube correctly, but they also ensure that each fin is properly aligned with all the others. They are reusable, inexpensive, and save me the hassle of making new Payloadbay.com guides for each new build. And even when the fins cannot project through the slots, I can still use the printed lines on geometric shape of the guide as an alignment template.

YMMV
 
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The BIG flaw with the grey Estes jig is keeping the body tube high enough to mount the fins. As it stands, body tubes tends to want to sit on the plastic, and if the fins are too long, it can result in them sliding up the body tube. You can solve that by sliding the dummy engine on a dowel (or replacing the dummy engine with a dowel) and cutting the dowel to length.

I also have problems with the guides (the parts that are supposed to hold the fins steady) being too loose in their slots, and so you can induce a cant (which would cause a spin or roll) into the fins.

Mine just ended up being a glorified base for a rocket that couldn't stand on its own.
 
For the mid power that is TTW, I don't have the alignment line issue and can use a simple "Kuhn jig" style of tool to ensure the fin projects straight from the tube. I use the V-slot at one end of the Estes tube marking guide to wedge the fin in place, and tape the guide to the airframe while the epoxy sets (you have to remove the sliding piece to use it this way)

It was the Estes tube marking guide that I used on my L1 build that resulted in my fins all being 1/16" off from perpendicular (at the tip of the fin). I've since retired it.
 
I have never had much luck with the Estes guide. For one thing, mine cants the fins a little. It just isn't straight.

As I said above, even my kids can handle Ted Macklin's guillotine jig:
photo.jpg

I use a combination of the jib (to hold the fins on straight while the adhesive dries/cures) and a paper template for indexing. Short of a Rose fin jig, I think it's a great solution.
 
As I said, "YMMV"

No offense meant, or taken. I was just trying to explain why I no longer care for that tool (the Kuhn jig).

That said, I really wish that Estes would modify (and expand upon) the circular marking guides. IIRC It's lacking the BT-56, BT-70, BT-80 tubes. I'd like it to include a 29mm, and 38mm guide, as well as the new 2", 2.5", 3", and 4" Pro Series II tubes, as well as have a special line between two of the 90° fins to mark the logical location for a launch lug. I've modified my existing guides to have that line (and marked it in red)

All The Best!
Jim
 
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I have never had much luck with the Estes guide. For one thing, mine cants the fins a little. It just isn't straight.

As I said above, even my kids can handle Ted Macklin's guillotine jig:
View attachment 187687

I use a combination of the jib (to hold the fins on straight while the adhesive dries/cures) and a paper template for indexing. Short of a Rose fin jig, I think it's a great solution.

The guillotine is a nice jig. I got one as an anniversary gift this year. :) My only issue is that if the BT is too short to reach both ends of the box, its kind of hard to use. Found that out on the batrock I built a few weeks ago.

I wish I had this when I built my mini darkstar. One set of the split-fins is ever so slightly out of alignment. (I think the craft sticks I used as alignment splints were slightly warped.)
 
The guillotine is a nice jig. I got one as an anniversary gift this year. :) My only issue is that if the BT is too short to reach both ends of the box, its kind of hard to use. Found that out on the batrock I built a few weeks ago.

I wish I had this when I built my mini darkstar. One set of the split-fins is ever so slightly out of alignment. (I think the craft sticks I used as alignment splints were slightly warped.)

You can always extend the tube by using a 2nd one and a tube coupler (or a suitable dowel)
 
You can always extend the tube by using a 2nd one and a tube coupler (or a suitable dowel)

basically what I did - I didn't have any appropriatley sized coupler tubes, but I did have a spent motor and extra BT. the fit was kind of loose, so I had to beef it up (friction fit) with tape. it worked well enough.
 
The guillotine is a nice jig. I got one as an anniversary gift this year. :)


Why does the name "guilotine jig" fill me with dread? :facepalm: I must not understand how it works, since I've never seen one...
 
Why does the name "guilotine jig" fill me with dread? :facepalm: I must not understand how it works, since I've never seen one...


[video=youtube;lDutfGhAbcA]https://www.youtube.com/watch?v=lDutfGhAbcA[/video]
 
Could one not use two short BT20 tubes with interior centering rings to make a BT5 tube fit, one at each end of the jig? Lots of companies have centering rings, I know BMS sells a wide variety.
 
I'm not a big fan of the Estes Fin Alignment guide. I tried it once and it didn't really help. But, as simple as it is, I really like the Estes Ultimate Tube Marking Guide. It's a big chunk of plastic that helps you draw straight lines down a body tube. I find it more convenient than searching the house for a drawer sill or whatever that is just the right size for a specific tube. And, since it is designed for Estes body tube sizes, the resulting lines are more accurate.

-- Roger
 
I'm not a big fan of the Estes Fin Alignment guide. I tried it once and it didn't really help. But, as simple as it is, I really like the Estes Ultimate Tube Marking Guide. It's a big chunk of plastic that helps you draw straight lines down a body tube. I find it more convenient than searching the house for a drawer sill or whatever that is just the right size for a specific tube. And, since it is designed for Estes body tube sizes, the resulting lines are more accurate.

-- Roger

I took one look at the Ultimate Tube Marking Guide ($12.00), and decided not to get it. My concern is that since it is made of plastic, it was no good for cutting slots for TTW fins, it'd get notched too easily.

I ended up buying a piece of aluminum angle bar ($5.67) from Home Depot, and cut that into two pieces (one 20" long, one 28").
 
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Thanks to all who have purchased my Guillotine Fin Alignment Jigs. I hope you will have many years of use and enjoyment of this tool. I will attempt to answer some of the questions in this thread.

The name "Guillotine" resulted from the way in which the sliding end panels interact with the fixed end panels thereby creating a variable square aperture for various tube diameters. The vertical sliding feature resembles the gruesome device used by the French to make fries. See https://en.wikipedia.org/wiki/Guillotine and https://www.securitybosspetdoors.com/Kennel-Clad-Insulated-Guillotine-Doors-p/kc-ins-guill.htm

The pair of extruded aluminum rails which span across and are attached to the sliding end panels provide a means to align the fins in the longitudinal direction, much like a visual gun sight on a rifle barrel. These rails are adjustable for fin thickness in or out from the theoretical center line and are referenced to a V-notch formed at the center line of the cleats along the top edge of each sliding panel. The length of the original device evolved from the fact that most Estes body tubes are sold in 18 inch lengths and allowing an overhang of about half this length made for a device of about nine inches long. On smaller rockets or short booster sections, a coupler and extension tube can be used as has been described, or a section of aluminum angle can be laid in the belly of the 90 degree V-cuts in the fixed end panels. (This workaround requires that the user cut out the radiused corner left by the router, which can be done using a razor saw.)

I recently subcontracted the task of fabricating the end panels to Nat Kinsey of Upscale CNC and have been delighted by the quality of his work. As a result of this change I have also created written instructions for the user which are now included with each kit sold through Apogee. See attachment hereto.

View attachment Guillotine_User_Guide.pdf

If you are building a rocket which is already slotted for the fins you are pretty much stuck with the fin slots. This applies to manufactured kits as well as tubes that have been slotted by the hobbyist. As long as the fins are aligned in both the radial and longitudinal directions, your rocket should fly reasonably straight regardless of any esthetic considerations. Believe it or not, nothing made by man is perfect. :wink:
 
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The guillotine is a nice jig. I got one as an anniversary gift this year. :) My only issue is that if the BT is too short to reach both ends of the box, its kind of hard to use. Found that out on the batrock I built a few weeks ago.

I wish I had this when I built my mini darkstar. One set of the split-fins is ever so slightly out of alignment. (I think the craft sticks I used as alignment splints were slightly warped.)

My solution to that problem is two-fold. I either use a spare section of tube and a coupler to give the body tube more length, or I lay a section of aluminum angle the length of the jig and clamp the shorter tube into it.
 
yep - the aluminum angle in the jig is something I'm going to try. tmacklin also suggested it. don't know why I didn't think of it myself.

I did end up using a coupler and spare tube for the batrock, but the fit was loose, so I still had a bit of play in the tubes. I solved it by adding a couple of wraps of blue painters tape around the joint.
 
Here a few pics showing how an aluminum angle can be used to support a short body in lieu of using a coupler and additional body tube extension. A third shim pressing on the short tube holds the tube down yet allows it to be rotated.

IMG_0963.jpg

IMG_0964.jpg

IMG_0965.jpg

IMG_0966.jpg
 
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