OK boys, what methods are you using to align rail buttons/guides/lugs, etc

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Well-Known Member
May 10, 2009
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Looking for opinions/tips. I have used several methods before. I have extra pieces of rail that I have used to align them, have used the old door frame trick, have used 90 degree aluminum and a couple other ways I cannot think of right now.

What are you guys doing. This is always the hardest part of putting them together, haha.

I am sure this post will help me, along with others as well.

What size rail and buttons are you referring to?
How large an airframe and how far apart would the buttons be?

(I ask this because your post is in the HPR section.)

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I tape a piece of thread on the butt end of the rocket. I pull the thread over the rear of the rocket and pull it taut up to the nose cone. Keep the tread line exactly in the middle of the fins. Then I tape it to the tip of the nose cone. Then, using a pencil or whatever writing utensil that has the finest point, I make two tiny dots directly underneath the thread at the exact places I want them.
I've used this technique on a rather large rocket that due to its size, I felt that it needed a third button. I worried that it would be off but was pleasantly surprised that it was a very smooth fit with no tightness.

Also, when figuring out placement for the rail buttons, I try not to put the forward button way too far forward. I want the rocket on the rail for as long as possible in order to build up speed.

Good luck.
Another vote for 1" 90 degree aluminum. No issues yet.

I mark with a good-sized piece of metal angle stock, like several others have already described.

When assembling, I install the lugs as carefully as I can but I only use a preliminary dose of a very tiny wipe of glue for the initial assembly. I use the old Mk 1 eyeball to sight through each lug to line it up with the other, while the glue is still wet. After I am happy with placement, and the first glue is dry, I use a small paintbrush to apply a few drops of water around the base of the joint (to help the next dose of glue to penetrate the joint) and apply the main dose of glue to the joint and work it in, then smooth the outside with my finger.

Don't forget to scuff-sand the outside of the BT where the lug is going to be seated, and the inside of the lug.
Size could be anywhere from 2" to 8", this is meant for HPR.

When you guys use the aluminum angle, do you just set the tube in the V of the aluminum and draw a line along the tube? Or what method are you doing when using the aluminum angle?
Fast, easy and cheap way!

Use any door jam in your apt or house, open the door, insert airframe, and draw a line. Do make sure is a good and straight look door edge first.

When you guys use the aluminum angle, do you just set the tube in the V of the aluminum and draw a line along the tube? Or what method are you doing when using the aluminum angle?

You pretty much got it.

Sounds like you've never done this, no problem.
I have a short length of scrap aluminum angle about a foot long.

I just hold the airframe tube in one hand and place the open side of the angle on the tube with the other. The tube and angle piece will self align.

At that point you can hold the whole deal in one hand.
align one side of the angle along where your rail buttons or lugs will go and draw a pencil line down the side.
Take a look at it, is it what you want? If not just draw another line.

If you still can't visualize this go to your local Home Depot or Lowes.
In the hardware isle they will have the angle stock.
Grab a piece and go over to plumbing.
Find some 2" or so PVC pipe and do the above, you'll understand.

I have a couple of aluminum angle,, on is 3/4" and one is 1.5" (I think) I use the 1.5 for 4" and larger, both are 4ft or so long. I draw a line the length of the airframe, drill the holes for the rail guides before paint, then attach the guides after paint.

For real small estes stuff,, door frame.

Add me to the list of aluminum angle.

I lay it against the body tube and draw a line down the edge.
For launch lugs I'll hold the lug against the edge while the glue/epoxy dries.
Yessir....alum. angle in various dimensions & lengths depending on rocket size.