Quantcast

Homemade Fin Alignment Guide Version 2

The Rocketry Forum

Help Support The Rocketry Forum:

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
33
I made a bigger fin alignment guide for larger rockets. This one should take up to 3" body tubes no problem, maybe even 4". I made it from 2x6 redwood. I used screw hooks for the rubber bands/elastic instead of dowels, and used Brian Guzek's idea of using bolts and wing nuts.

fin_guide_v2_1.jpg


fin_guide_v2_2.jpg


fin_guide_v2_3.jpg


fin_guide_v2_4.jpg


fin_guide_v2_5.jpg
 

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
33
Some more photos. I know the carriage bolts are way too long, but they're what I had.

fin_guide_v2_6.jpg


fin_guide_v2_7.jpg


fin_guide_v2_8.jpg
 

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
33
It works just fine with 4" body tubes. Here are photos of my LOC-IV and Integrator.

LOC-IV_build29.jpg


integrator20.jpg


integrator22.jpg


integrator23.jpg
 

Attachments

Winston

Lorenzo von Matterhorn
Joined
Jan 31, 2009
Messages
8,772
Reaction score
957
That is a _great_ idea and I _will_ be making one of those.

Here's a TTW fin slot cutting alignment jig I made from 1/4" MDF and scrap wood, just glued together with Titebond. The white hooks are the screw type wall hangers. The side blocks were glued in place with a 2.56" body tube in between. This has been used with up to 4" tubing on a laser-guided compound miter saw. Rubber bands hold the tube in place.

Fin slot jig 1a.jpg


Fin slot jig 2a.jpg
 

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
33
That is a _great_ idea and I _will_ be making one of those.

Here's a TTW fin slot cutting alignment jig I made from 1/4" MDF and scrap wood, just glued together with Titebond. The white hooks are the screw type wall hangers. The side blocks were glued in place with a 2.56" body tube in between. This has been used with up to 4" tubing on a laser-guided compound miter saw. Rubber bands hold the tube in place.
Yeah, it's worked out great. I've used both the large and small versions several times. I can't take credit for the idea, though, but I think I did improve upon it.

I like your slot cutting jig. I'm assuming it holds the body tube parallel to the blade, and you just plunge the blade in as far as you need, correct?
 

Andyd103

Active Member
Joined
May 15, 2010
Messages
28
Reaction score
0
wow thats such a good idea i use something like this but 1/10th the size good idea
 

Pyropetepete

Well-Known Member
Joined
Jan 27, 2014
Messages
901
Reaction score
8
Sorry too dig an old topic up but what length are good? I've a fin that's 12''
 

Micromeister

Micro Craftman/ClusterNut
TRF Lifetime Supporter
TRF Supporter
Joined
Jan 19, 2009
Messages
15,074
Reaction score
41
Location
Washington DC
Sorry too dig an old topic up but what length are good? I've a fin that's 12''
Really the fin Length isn't that important as you can hang the length over the end of the fin platform. I don't know how big qqake2ks fin Platform is but my flatbed similar fin attachment jig has an 6" x7" long platform and handles body tubes to BT-101 (3.938").
Since we clamp the fin to the platform while the glue dries Long fin hang over shouldn't be a big deal.

Lg Fin Jig-g1_4Pic Page 1of2 11-13- 09_rework-11-05-13.jpg


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

enderw88

New to the game
Joined
Feb 24, 2014
Messages
230
Reaction score
0
It isn't clear to me from the description, but it looks like there is a spacer between the two pieces of dimensional lumber that needs to the the same thickness as the fin being aligned. Am I misreading the pictures?
 

Micromeister

Micro Craftman/ClusterNut
TRF Lifetime Supporter
TRF Supporter
Joined
Jan 19, 2009
Messages
15,074
Reaction score
41
Location
Washington DC
It isn't clear to me from the description, but it looks like there is a spacer between the two pieces of dimensional lumber that needs to the the same thickness as the fin being aligned. Am I misreading the pictures?
You are absolutely correct. The Spacer automatically centers the fin on the body tube at the desired location in perfect alignment with the long axis of the body tube.
Once you have spacers made they last a good long time. I just replaced a few of the original 2009 spacers a couple months ago. I think qqacke2k's jig uses elastic or string to hold the body in place. Mine uses leather straps held be an Aluminum bar back pressure plate secured with a couple thumbscrews.
These jigs are a joy to use I have an all aluminum smaller one for Micro to about bt-50 size as well.

Lg Fin Jig-d_5.625in top & StrapClamp 11-09_rework 11-05-13.jpg


Lg Fin Jig-e_45° bevels & new Straps 11-09_Rework11-05-13.jpg


Lg Fin Jig-f_Strapped Test w fin on table11-09_rework11-05-13.jpg


MM Fin Alignment Jig-b7_3rd fin on T3 model (no clamp)_02-04-11.jpg
 
Last edited:

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
33

Pyropetepete

Well-Known Member
Joined
Jan 27, 2014
Messages
901
Reaction score
8
So i got my wood @ 6X2 Redwood, have 2m of it.

What length do i make the base?
How much should i give for my fin?
These spacers ever one is referring to, is this spacer to be the same thickness of the fins your fitting and is fitted between each block in the middle? Have not see it n use in any photos.

Have ordered 1'' wide elastic as this won't mark the tubes and some 1'' screw eyes.

Am building a 4'' dia bird with my booster section being 30'' long and the fins 12'' at the max, so what size should i do
 

tfish

Well-Known Member
Joined
Dec 8, 2009
Messages
2,600
Reaction score
598
I made one of these jigs. check out about 3:20 in this video.

[video=youtube;EwvKR5Lfolk]http://www.youtube.com/watch?v=EwvKR5Lfolk[/video]

Tony
 

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
33
Here are some detail shots without a rocket in the way. The bottom board is 24" long, and the top board is 18" long. You can see the spacers clearly. They're just scrap pieces of the same stock I used for the fins, in this case 1/4". The spacers keep the fins centered to the body tube, and are very important. I've used the wrong thickness spacers by mistake, and it will make your fins crooked. Probably not enough to make it unstable, but definitely noticeable. As you can see, I use two 1/4" carriage bolts and wing nuts to hold the two boards together. This makes it easy to change the spacers. I keep telling myself that I'm going to make a set of nice, marked spacers, but haven't gotten around to it yet. (I'm fresh out of "round tuits"!)

Let me know if you need clarification on anything, and/or more photos of any details.


fin_guide1.jpg


fin_guide2.jpg


fin_guide3.jpg


fin_guide4.jpg


fin_guide5.jpg


fin_guide6.jpg


fin_guide7.jpg
 

tfish

Well-Known Member
Joined
Dec 8, 2009
Messages
2,600
Reaction score
598
It's only clean where you can see. Believe me.

By the way thanks for posting this jig build thread. The jig makes it really easy to align and glue on fins. I just got done building a "modified" Estes Super Alpha (29mm, Raven and Tx) and used the jig on the fins

Tony
 

Pyropetepete

Well-Known Member
Joined
Jan 27, 2014
Messages
901
Reaction score
8
Thanks for the help everyone. Will post photos soon as it's finished.

Cut the wood today @45*. Made the base section 24" and the top was 15". Drilled 3 holes evenly spaced @10mm and used 3 M10 coach bolts to hold sections together. 1" eye hooks and elastic on there way, might arrive tomorrow.

Need too add some feet too the base. Just got to work out the best height, thinking 6".

Have some 6mm MDF at work so will cut some of this too make a spacer. Plan to make one full size like the gentleman in the video with a section cut off more when fitting the fin (my build is using 6mm thick fins.

Just need to give it a light sand to dress the cuts.


Sent from my iPhone using Rocketry Forum
 

Pyropetepete

Well-Known Member
Joined
Jan 27, 2014
Messages
901
Reaction score
8
Built mine at last. Will use it on this upscale project

6X2 24'' and 15'' sections
2X2 X2 for the feet
X3 M10 140mm coach bolts
X3 M10 wing nuts
1'' wide elastic
6X 1'' screw hook
MDF spacer

The MDF spacer is 6mm, same as the fin thickness. I've cut the end closest to the fin at an angle to allow me some extra space. Feet are wood glued on (PVA). I'm happy with it and so are the kids.

Shown with a template fin size and 4'' od poster tube











 

ChrisAttebery

Well-Known Member
Joined
Feb 16, 2014
Messages
2,450
Reaction score
58
Very nice job Pyropetepete.

I need to build one of these this weekend.
 

enderw88

New to the game
Joined
Feb 24, 2014
Messages
230
Reaction score
0
I ghetto'd one of these together using 2x4s and C-Clamps over the weekend. Works a charm. Thanks for the great idea!
 

majordude

Swimsuit Model
Joined
Apr 5, 2013
Messages
1,320
Reaction score
5
That's pretty neat! Do you have to use a specific fin thickness or with this work for any material?
 

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
33
That's pretty neat! Do you have to use a specific fin thickness or with this work for any material?
The center spacer has to match the thickness of the fins. I've used it with 1/8", 1/4", and now 3/8" fins.
 

ChrisAttebery

Well-Known Member
Joined
Feb 16, 2014
Messages
2,450
Reaction score
58
Here's mine. I made it from scrap melamine board. This stuff is great for fixtures and jigs since it is really flat and generally stays that way. I originally made it so that there was able 8" between the tips of the V. Then I realized that the straps wouldn't be able to hold the tube against the jig. After I cut it down I realized the right thing to do would have been to cut slots into the legs of the V so that the straps could hold anything from BT5 and up. :facepalm:

Oh well, it'll work fine. I might go back and dado the slots into the jig later on.

Fin Jig 1.JPG


Fin Jig 2.JPG
 

Scott231

Well-Known Member
Joined
Oct 7, 2011
Messages
145
Reaction score
11
FYI - I would think it best to NOT put the three (or four) bolts together in a straight line (see Pyropetepete's pictures) as that can make the jig begin to rotate on the axis of the bolts. Shouldn't matter for fin alignment, but will wallow out the bolt holes that have been drilled in the main pieces.
 

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
33
FYI - I would think it best to NOT put the three (or four) bolts together in a straight line (see Pyropetepete's pictures) as that can make the jig begin to rotate on the axis of the bolts. Shouldn't matter for fin alignment, but will wallow out the bolt holes that have been drilled in the main pieces.
I'm not following you.
 

qquake2k

Captain Low-N-Slow
Joined
Jan 26, 2010
Messages
13,573
Reaction score
33
Here's mine. I made it from scrap melamine board. This stuff is great for fixtures and jigs since it is really flat and generally stays that way. I originally made it so that there was able 8" between the tips of the V. Then I realized that the straps wouldn't be able to hold the tube against the jig. After I cut it down I realized the right thing to do would have been to cut slots into the legs of the V so that the straps could hold anything from BT5 and up. :facepalm:

Oh well, it'll work fine. I might go back and dado the slots into the jig later on.
That looks nice!
 
Top