Minimum diameter rocket rail buttons

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FlyBy01

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So Wildman on the Black Friday sale had a Carbon Mach 2 for a price I didn't resist. I have no experience with minimum diameter rockets other than low power and my idea is to use a PEM nut to mount the aft rail button. Idea 2 is to use a blind nut without the teeth and epoxy inplace.

If you have some experience and picture prefered; please post
 
Apogee also makes rail guides you can epoxy onto the exterior of the airframe if you don't want to risk anything hanging up the laundry from the inside.
Giant Leap Rocketry also sells the Acme aluminum rail guides that you use JB Weld to attach to your minimum diameter airframe. They are more aerodynamic than rail buttons.
 

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All the above pretty much nailed it!

I have a Mach 2 and my basement is the semi-permanent home to @rfjustin 's launch tower. So, I use the tower. :)

Also, you will love the Mach 2, it is a wonderful rocket, really simple but devilishly complex given that it is minimum diameter.

I have removable motor adapters for mine that allows me to launch it on 29mm and 38mm motors as well.

It's so light (even the FG version) that you can fly it on G motors with an adapter (below) or go full send on an L1090W......or somewhere reasonable inbetween.

Let me find those pics.....

20221105_110317.jpg20221105_110411.jpg20221105_110520.jpg20221105_110605.jpg20221105_110739.jpg
 
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Those motor adapters are made simply with a LOC motor adapter kit, a centering ring that you will grind down to act as a thrust ring, an aeropack retainer, some 1/8" kevlar, and some #6-32 hardware.
 
Towers are the most effective thing to use if you are looking for max altitude. Downside is they are big and you have to build them, haul them out to the launch site and set them up. If you are heading out to the desert and really want to crank up the altitude, it is a good trade off.

For regular club launches, especially on the East coast where it is virtually impossible to max out most minimum diameter flights, due to the lower max waivers, fly-away rail guides are way easier.

I finally bit the bullet last year and invested in a full set set of these rail guides from Additive Aerospace:

https://www.additiveaerospace.com/products/fly-away-rail-guides
They are not cheap, but they work perfectly every time and are very well built. I have started using them on all my rockets, 4" diameter and below. Slap a fly-away guide on out at the pad, slide it on the rail and done. I have a few very tall rockets/oddrocks they aren't well-suited for, but they work great on the vast majority of my rockets.
 
I have used rail buttons on several minimum diameter rockets. You can still use screws, but you need them to be short enought to not go any further than the inside of the body tube.
 
So Wildman on the Black Friday sale had a Carbon Mach 2 for a price I didn't resist. I have no experience with minimum diameter rockets other than low power and my idea is to use a PEM nut to mount the aft rail button. Idea 2 is to use a blind nut without the teeth and epoxy inplace.

If you have some experience and picture prefered; please post
For your consideration, very similar concept to @Rocketjunkie, on perma-loan to @StreuB1
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So Wildman on the Black Friday sale had a Carbon Mach 2 for a price I didn't resist. I have no experience with minimum diameter rockets other than low power and my idea is to use a PEM nut to mount the aft rail button. Idea 2 is to use a blind nut without the teeth and epoxy inplace.

If you have some experience and picture prefered; please post

Wildman has some nice 3d printed conformal rail guides. I epoxied them in place, and used a very short screw that didn't extend through the wall of the tube.

https://wildmanrocketry.com/collections/rail-guides/products/conformal-rail-guides-2pk

Here is one installed on my 38mm MD LaserLoc.

https://www.rocketryforum.com/threa...-on-level-1-motors-with-modifications.159420/
(I don't know why I can't get that link to work....)
 
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I think I am going to go with the flyaway rail-guide on Wildman's website. Thank you for all of the input; very impressive stuff posted.

Those are made by Additive Aerospace (link I posted above). Regular price is pretty much the same between WM's site and AA's site, so if you are ordering from WM anyway, good thing to throw into your order.

AA periodically has very good sales. Their Black Friday sale was 20% off on these fly-away guides and I took advantage to complete my set of them. If you think you would use more than one size of these, get the one you need now at regular price then stock up next time there is a sale. These are expensive items - the discount saved me about $100 on 5 fly away guides.
 
I use 'srewed' on rail buttons. They are easy to replace..as needed. I've seen several glued on rail buttons pop off..while being placed on the pad. I have towers but hate tower tip.
I'll take the altitude hit associated with buttons.

An upper button.

Tony
 

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Towers are the most effective thing to use if you are looking for max altitude. Downside is they are big and you have to build them, haul them out to the launch site and set them up. If you are heading out to the desert and really want to crank up the altitude, it is a good trade off.

For regular club launches, especially on the East coast where it is virtually impossible to max out most minimum diameter flights, due to the lower max waivers, fly-away rail guides are way easier.

I finally bit the bullet last year and invested in a full set set of these rail guides from Additive Aerospace:

https://www.additiveaerospace.com/products/fly-away-rail-guides
They are not cheap, but they work perfectly every time and are very well built. I have started using them on all my rockets, 4" diameter and below. Slap a fly-away guide on out at the pad, slide it on the rail and done. I have a few very tall rockets/oddrocks they aren't well-suited for, but they work great on the vast majority of my rockets.
I plan a first flight of a Blackhawk38 next week using an AA guide, so your endorsement is encouraging! A question for you: how do you position the hinge relative to fins, say on a 3 fin rocket?
 
I flew a 29mm and 54mm minimum this weekend with 1010 rail buttons. I flew them with rail buttons but madden sure the screw did not go all the way through the airframe. I also added a little JB weld to keep the screw in there.
 
I plan a first flight of a Blackhawk38 next week using an AA guide, so your endorsement is encouraging! A question for you: how do you position the hinge relative to fins, say on a 3 fin rocket?
I put the hinge in the valley between 2 fins.

The hinge ends up being opposite the rail buttons and the rail buttons need to end up between the fins, so, if it is a 4 fin design, both the hinge and the buttons would be in the valley between the fins, if it is a 3 fin design, the hinge would have to be over one of the fins in order to ensure the buttons are in the valley opposite. If you put the buttons over a fin, you wouldn't be able to get the rocket on the rail.

TL;DR - it is the buttons that determine the fly-away guide placement, not the hinge.
 
I plan a first flight of a Blackhawk38 next week using an AA guide, so your endorsement is encouraging! A question for you: how do you position the hinge relative to fins, say on a 3 fin rocket?

Re-reading this, I think maybe you are asking where to put the guide along the length of the rocket? I like to put the guide so it is pretty much sitting just forward of the fins, just touching the fins. This gives you two benefits - first, you want to take advantage of as much of the rail as you can - once the first button leaves the rail, you don't have any flight control. Second, especially with a fast burning motor, if you place the guide high on the rocket, the rocket will slide through the guide and the fins will slam into the guide. I made this mistake a while back using the plywood guides you can get from Apogee. The fins slammed into the guide and the guide shattered and broke two of the fins. The rocket did go sideways (it pinwheeled along the ground for a bit), but, luckily, it was an MPR flight and a relatively lightweight rocket, so it didn't go very far. I was lucky to learn the lesson without creating a huge safety issue and I have not repeated that mistake. I bet the additive aerospace guides would hold up well, which means they would probably shear the fins off a minimum diameter rocket. The additive aerospace guides do have a nice rubberized cork lining that sticks well to the rocket tube, which makes for a safe flight when the guide starts resting on the fins.
 
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