'Nother minimum diameter Q - How to attach rail buttons/

[Sooner Boomer]

54mm dia. airframe. How do I attach rail buttons when I can't go through the body tube? I was thinking of gluing a "spar" on the side, and using T-nuts under it.

I *think* that's the last question. I think I can do the fins w/o trouble (surface mount w/substantial fillets).

Also - this will be cardboard/phenolic body, 1/4" ply fins. I'll bevel the leading edges of the fins on the table saw, using a jig to hold each.

 

[tim cubbedge]

You can always use rail guides. I think Giant leap sells an aluminum set. Wildman sells a 3D printed set. Or you can also use fly away rail guides.

 

[tsmith1315]

I think Giant leap sells an aluminum set

Yep, ACME conformal rail guides.

Also - this will be cardboard/phenolic body, 1/4" ply fins

Can’t wait to see that! Please post some pics.

 

[Sooner Boomer]

Rail guides sounds like a good idea. I'll see what I can find. There's Airfest in a couple of months. Lots of vendors there.

This is a project for next year. I'm trying to get the parts together early.

 

[jmasterj]

You could also use a tower instead.

 

[SolarYellow]

Can you just glue tee-nuts on the inside and have enough room left for your motor to slide in?

 

[Donnager]

You could also use a tower instead.

Or fly-away guides.

 

[tfish]

54mm dia. airframe. How do I attach rail buttons when I can't go through the body tube? I was thinking of gluing a "spar" on the side, and using T-nuts under it.

I *think* that's the last question. I think I can do the fins w/o trouble (surface mount w/substantial fillets).

Also - this will be cardboard/phenolic body, 1/4" ply fins. I'll bevel the leading edges of the fins on the table saw, using a jig to hold each.

single use motor? CTI? AT? Research launch?

Tony

 

[rfjustin]

54mm dia. airframe. How do I attach rail buttons when I can't go through the body tube? I was thinking of gluing a "spar" on the side, and using T-nuts under it.

I *think* that's the last question. I think I can do the fins w/o trouble (surface mount w/substantial fillets).

Also - this will be cardboard/phenolic body, 1/4" ply fins. I'll bevel the leading edges of the fins on the table saw, using a jig to hold each.

https://giantleaprocketry.com/products/acme-rail-guide-3-00in?variant=37741098401964

 

[MClark]

Tower

 

[Rocketjunkie]

Tower. Scale down this. This was built for LDRS XI in 1992, Minimum diameter O.

 

[mtnmanak]

These are the best fly-aways I have found:

https://www.additiveaerospace.com/products/fly-away-rail-guides?variant=2599394476069
I have one set of each that they make. For the most part, I have just stopped using rail buttons on 4" rockets and smaller. These are easier.

 

[CoyoteNumber2]

I thought this thread was going to be about a minimum diameter rocket on a Q motor.

 

[Neutronium95]

If you don't care about optimizing every last detail of the rocket fo altitude, go with the conformal rail guides. If you're building with cardboard tubes and 1/4" plywood fins, you're in this group. Some clubs don't like the possibility of galling from the aluminum ones, so you might want to look at the resin ones from PML.

If you do care about maximum performance, get or build a tower. IMHO flyaway rail guides are a poor compromise option that can cause additional problems. I've seen pictures of them getting hung up on a rockets fins all the way to apogee.

 

[bjphoenix]

Can you just glue tee-nuts on the inside and have enough room left for your motor to slide in?

That's what I was thinking- should be able to fit them tightly enough inside the tube for the motor to still fit. It might take a little bit of work to get them to fit just right.

 

[David Schwantz]

I like to use blind nuts. I will lay them across open vice jaws and tap them to give them a concave surface. Then I will grind out a small, thin spot to glue them into. Insert motor into tube with saran wrap to protect it while glue dries.

 

[SDramstad]

I used the plastic conformal rail guides on a minimum diameter 54mm rocket at last years airfest. Stuck an L1090 in it and melted the guides all to bits.... Dont know if it was just the speed or if friction going up the rail did it but they were trashed and it took thousands of feet off my apogee......

 

[charrington]

54mm dia. airframe. How do I attach rail buttons when I can't go through the body tube? I was thinking of gluing a "spar" on the side, and using T-nuts under it.

I *think* that's the last question. I think I can do the fins w/o trouble (surface mount w/substantial fillets).

Also - this will be cardboard/phenolic body, 1/4" ply fins. I'll bevel the leading edges of the fins on the table saw, using a jig to hold each.

I really like the fly away rail guides from additive aerospace. Easily survived a 38mm Mach 2 flight!