Estes 2231 Fin Alignment Guide Model Kit , Color Varies

Cheap and effective. I wish I had this when I was a kid. 90% of the time when I had a problem with model rockets as a kid it was because of fin alignment, and this goes a long way towards eliminating that problem with model rocket kits that need balsa wood fins attached to a cardboard tube. I have built several kits with my son and have had no problem with fin alignment. You still have to be careful, but this eliminates the guessing and trying to line up measurements on a curved surface so everything is straight and spaced evenly.

Works as described

Works well, helps grandson line up fins correctly.

I was unsure how useful it would be based on some of the reviews, but I tried i immediately today on a Big Bertha very successfully. the technique is basically to let one fin set up first and then attach the others. not perfect, but does what it says. recommended if you build a lot of rocket kits.

This is kind of pricy for what it is, but it is very nice when it comes time to put the fins on a kit such as the V2. For kits that have grooved placement of fins, this jig makes it way easy. For kits that directly glue balsa to the body tube, there is some technique involved with getting one fin aligned and held at a time. This would involve patience to let the fin set up a little more before using the included clips. The alignment plates are helpful, but you really need to read the instructions on which side of the plate to use depending on whether the rocket is using 2mm (common) or 3mm thick fins. This jig also uses the motor mount to line things up, so you may need to change your order of building to get the motor mount in first before the fins get put on. This jig has helped me on the V2 and Magician build that uses D-E sized (24mm) motor mounts. It can be used on 18mm (ABC) motor mounts and micro motor mounts. There is nothing included for 29mm motor mounts. But, you can probably rig it to take larger motor mounts. This is definitely my "go to" fin jig now that I have it. I plan to use it on all my future 18mm and 24 mm motor builds.

Worked great to help align the fins and act as my 3rd and 4th hands

I purchased this after reading about it on TRF and YORF forums, knowing its limitations, which I can verify exist. The main issue is that plastic doesn't cut it. A well-done aluminum version of this would be awesome. But anyway. This tool is best used for attaching one fin at a time until the glue has dried. As long as you trust the alignment lines on your body tube, it does a good job holding fins in precise position. Some of the alignment plates are more loose at the base than others, so there is excess play (some, not all of them) so you will have good ones to use. After fin 1 goes on, you rotate the body tube to bring the next mount line in position (this instead of instead of having all of the fins pre-aligned and ready for group gluing ... not gonna happen). One fin at a time until dry and you are good to go. Since the body tube mount is the worst part of the design, you'll be moving the tube around a bit to get fin-tube alignment right for each fin (thus why you can't glue all of the fins at the same time after lining them all up. Also, since many fin designs extend beyond the end of the body tube and/or the motor mount with retainer is in position, you have to raise the body tube by nesting the provided mounting tubes (sizes A-D, I believe). A piece of painter's blue tape to lock them in position (key), and you will at least have a sturdier mount. This may not be all too clear if you haven't seen the rig up close, and for that I apologize. But, I do use it on every project.

Grand kids built rockets on rainy days. For sunny days .

I'd have given it a star or two more if one of the backets on the three fin arrangement wasn't loose. Causes these rockets to fly with bit of a wobble. The four fin arrangement works great, but I seem to be on a 3 fin kick.

Viele Jahre habe ich die Flossen meiner Modellraketen mit Augenmaß und Flosse für Flosse angeklebt, was doch recht mühsam und Zeitaufwändig war. Jetzt geht es in einen rutscht. Ich habe das Teil auf ein Brett montiert was ein umkippen vermeidet. Die mitgelieferten Adapter passen gut bei normalen Flossen, ich habe mir noch eigene Adapter aus alten Motoren gebaut um noch flexibler zu sein, mittlerweile möchte ich das Teil nicht mehr missen.