Rails or rods..which to use for launching

Using rails to launch has many advantages over rods.
Our club rule for which to use needs to be updated.

Would you tell us what your club policy is about rails vs. rod use.

Thank you

What do you need a rule for?
Fully supported rails or towers are better than end-held-rails which are better then rods...but each has it's place.

It's one of those things that is hard to codify. I learned my lesson the hard way after I tried to launch a lightweight rocket on a 1/4" rod while the wind was blowing about 15 mph. Between the rod whip and needing a higher thrust motor, it went up about 50 feet, then took a 90 degree turn and went ballistic. The rocket ended up in flames.

Launch lugs are usually glued to the surface, whereas rail buttons are normally screwed in; so buttons have less chance of breaking off, too.

Since then, I have put rail buttons on all my MPR and HPR. I think the rule should be, "If you can see the rod bending in the wind, don't use it."

That being said, I think the RSO should make the final judgment call on whether or not rods are allowed in a given set of circumstances.

My personal opinion is that I don't use rods for anything above lightweight, 1/8" sizes. Anything that needs 3/16 or 1/4" rods gets buttons of one size or another, depending on the situation. I'm even leaning toward replacing 1/8" lugs with micro buttons, the only thing holding me back is that the 1/8" rods are usually close by on the mod-roc pad, whereas if I want to use my 10mm rail, I have to put it on my tri-pad, which is typically out near the 1010 button pads. So little rockets are hard to see that far away, and thus photograph. I might want to build a second pad to use that rail closer in...

You should accommodate your members.

At CMASS we have a micromax padhead, 1/8", 3/16" and 1/4" rods and 10mm and 1" rails for the model rocket pads, and 1/4", 3/8" and 1/2" rods and 1" and 1.5" rails for the high power pads.

Bob

Bob, no offense, but I think you missed the point. Tom didn't ask "What should you have?" He asked, "What should the rules be?" You can have every size and length rod and rail in the known universe, but is it always safe to use rods just because someone wants to?

Before I burned up my Ascender, I wish someone had said to me, "You shouldn't launch that on a 1/4" rod in this kind of wind." I was new and dumb.

In my experience, MARS (same club that the OP is part of) doesn't allow the use of 1/4" rods to begin with. I'd had to adopt buttons to fly heavier rockets with them that had been using 1/4" lugs. This was kind of tricky on my Jayhawk and my upscaled Advanced Target Drone. OTOH, URRG allows the use of the 1/4" rod - and I even have a carbon fiber rod that's pretty stiff - but now that I've changed over, given the choice, I don't fly with the rod anymore even though the rocket in question still had the lugs on it. I'm curious as to what about the current club rules that Tom feels need revising. I wasn't at the last launch, so I wonder if something came up.

The only rules I can think of is no excessive rod whip, properly sized and attached lugs or rail buttons. Not using 1/4" rods does not make sense. Ban 1/4" rods at our club and you will be ridden out of town on a rail!

Bat-mite said:

Bob, no offense, but I think you missed the point. Tom didn't ask "What should you have?" He asked, "What should the rules be?" You can have every size and length rod and rail in the known universe, but is it always safe to use rods just because someone wants to?

Before I burned up my Ascender, I wish someone had said to me, "You shouldn't launch that on a 1/4" rod in this kind of wind." I was new and dumb.

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No, I didn't miss the point. My policy is to accommodate the members.

There are plenty of rockets where a 1/8" rod may not be sufficient, but a 3/16" or 1/4" rod is more than adequate. Sorry, but I don't believe it's the job of the club to tell a rocket builder how to build his rocket. If it's too windy to launch a certain rocket design then it's the responsibility of the flier not to launch it, and for the RSO to make the decision for him if the flier doesn't recognize it.

Bob

This is from the MARSclub.org web site...in the section Local MARS rules.

MARS requires all High Power rockets to use rail buttons for launch guidance, unless they will fly to no higher than 800 feet.

I fly at 3 clubs and you can use a rod or rail for any H or I motor.

Our club has no restrictions on rods or rails, but.... We have all rail pads except the LPR rack with 1/8" & 3/16" rods and a 1/4" rod in a side pad. We also have one pad on the HPR rack with your choice of 1/4" to 5/8" rods. If you want to fly a HPR from a rod, the RSO may let you, but you have to wait for the one pad to be available and you have to change out the rod to the size you need which isn't always easy.

We pretty much discourage rods for anything not LPR and don't feel bad at all about making it very difficult for you to fly HPR from a rod. Rails are HIGHLY encouraged, although not "required".

TOM C said:

This is from the MARSclub.org web site...in the section Local MARS rules.

MARS requires all High Power rockets to use rail buttons for launch guidance, unless they will fly to no higher than 800 feet.

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This is fine for a general safety guideline but I hope the RSO can make exceptions. What if someone showed up with one of these?



Or lord forbid one of these:



The Cosmodrome Vostok in the photo was initially launched on a 3/8" rod and it had a bit of rod whip. The flyer was reprimanded by the RSO (who keeps a very sharp eye on those rods) and all subsequent flights have been off a 1/2" rod. The flyer would say the oddrocs max out at about 800 feet so I bet they would easily get a pad assignment.

Sometimes only a thick, stiff rod will do.

You can have all the rule making you want but in the end it comes down to RSO adjudication. Spare the rod and you spoil the flyer.

I'm not sure that MARS keeps 1/4" rods in the trailer, I've always just been told that they don't use them and they aren't available. That's why I've had to adapt the buttons to my models that had the 1/4" lugs. I've got an upscale of an Estes Hawkeye that there isn't a practical way to get a rail up through it. Its heavy enough to probably need the 1/4" rod, but its built with 3/16" due to rod availability. I have not, however, tried to launch it yet - the guide size has me concerned. I may retrofit it with 1/4" anyway, and only fly it in Potter...

Spare the rod and you spoil the flyer.

Click to expand...

- that's clever, BTW.

EXPjawa said:

I'm not sure that MARS keeps 1/4" rods in the trailer, I've always just been told that they don't use them and they aren't available. That's why I've had to adapt the buttons to my models that had the 1/4" lugs. I've got an upscale of an Estes Hawkeye that there isn't a practical way to get a rail up through it. Its heavy enough to probably need the 1/4" rod, but its built with 3/16" due to rod availability. I have not, however, tried to launch it yet - the guide size has me concerned. I may retrofit it with 1/4" anyway, and only fly it in Potter...

- that's clever, BTW.

Click to expand...

Definitely retrofit with a 1/4" lug and fly it at the other club. Or if you are a member of the club ask why the 1/4" ban is in effect, maybe they had a bad experience, but I doubt it was a 1/4" rod's fault. Or bring a 1/4" rod with you and see what they say. Flying off a 3/16" when it should be on a 1/4" total invalidates the silly rule.

There does seem to be some high power rod-rail bias and misconception out there. I have seen it in action and it ain't pretty, but that is a story left to discussing over beers.