Launch Lugs: 1/8" diameter versus 3/16" diameter

brockrwood

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Pet peeve. Dear model rocket companies: Put a 3/16" diameter launch lug into the kit as an option, even if a 1/8" diameter launch lug is all that is required. I often launch a mix of smaller and bigger rockets during the same launch session. It is a pain to have to set up a second pad, with a 1/8" diameter launch rod, when I already have the bigger pad, with the 3/16" diameter launch rod, already set up, just so I can launch that one rocket that has a 1/8" diameter launch lug.

Yes, I know, there is SLIGHLTY more drag from the 3/16" diameter launch lug. This is not an issue for the non-competitive, Saturday afternoon launch at the local park.

I have started putting my own 3/16" diameter launch lug on all of my model rockets, when possible, instead of the 1/8" diameter lug the rocket came with. Sometimes it is not possible, or practical, as the rocket comes with a built-in 1/8" diameter launch lug (sometimes built into a plastic fin can) or there is a spacing or clearance issue.
 
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Pet peeve. Dear model rocket companies: Put a 3/16" diameter launch lug into the kit as an option, even if a 1/8" diameter launch lug is all that is required. I often launch a mix of smaller and bigger rockets during the same launch session. It is a pain to have to set up a second pad, with a 1/8" diameter launch rod, when I already have the bigger pad, with the 3/16" diameter launch rod, already set up, just so I can launch that one rocket that has a 1/8" diameter launch lug.

Yes, I know, there is SLIGHLTY more drag from the 3/16" diameter launch lug. This is not an issue for the non-competitive, Saturday afternoon launch at the local park.

I have started putting my own 3/16" diameter launch lug on all of my model rockets, when possible, instead of the 1/8" diameter lug the rocket came with. Sometimes it is not possible, or practical, as the rocket comes with a built-in 1/8" diameter launch lug (sometimes built into a plastic fin can) or there is a spacing or clearance issue.
Not likely to happen in a low margin business. The solution is to buy a supply of 3/16" lugs and toss out the 1/8"ers from the kits. I mean, I put rail buttons on any 24mm design, for example. With composite 24mm motors, the 24mm rockets originally designed for BP motors can go much higher and faster, so I always kit bash 24mm with rail buttons and TTW fins. I've simmed a 24mm Goblin to near Mach 1 on a D composite motor, for example. Gotta push that envelope...
 

bjphoenix

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Yes, I know, there is SLIGHLTY more drag from the 3/16" diameter launch lug
I'm suddenly seeing this in a different way! I've noticed that even slightly dirty launch rods can cause drag on a good launch lug, a slightly larger lug would eliminate this problem. At a big launch where the pads are busy, the rods can get dirty pretty quickly and might not get cleaned frequently enough.
 

neil_w

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I'm suddenly seeing this in a different way! I've noticed that even slightly dirty launch rods can cause drag on a good launch lug, a slightly larger lug would eliminate this problem. At a big launch where the pads are busy, the rods can get dirty pretty quickly and might not get cleaned frequently enough.
I always clean the rod I'm about to use for a launch unless it's really clean before I get there, which is rare.

Oversized lugs can definitely be a good thing, but they're also kind of ugly so don't necessarily want to go too crazy with them.
 

brockrwood

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I always clean the rod I'm about to use for a launch unless it's really clean before I get there, which is rare.

Oversized lugs can definitely be a good thing, but they're also kind of ugly so don't necessarily want to go too crazy with them.

I keep some extra fine steel wool and a paper towel soaked in 3-in-1 oil in the launch box. Slick up that launch rod real good between launches!
 

Donnager

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I have 1010 rail guides on my Loc park models. I tend to put rails/buttons on everything 29mm and up. 24mm gets 3/16 lugs, and smaller just gets what comes in the kit.

The buttons on a park 1.6 look a little big, but mini rails aren't always available and we usually have one high power pad empty. My small stuff with 1010 guides tends to find its way there.
 

Rory Gin

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Pet peeve. Dear model rocket companies: Put a 3/16" diameter launch lug into the kit as an option, even if a 1/8" diameter launch lug is all that is required. I often launch a mix of smaller and bigger rockets during the same launch session. It is a pain to have to set up a second pad, with a 1/8" diameter launch rod, when I already have the bigger pad, with the 3/16" diameter launch rod, already set up, just so I can launch that one rocket that has a 1/8" diameter launch lug.

I'm starting to think that on all my new builds that I should upsize each kit. 1/8" to 3/16" and 3/16" to 1/4" lugs. I did that for my modified Mercury Redstone, but that was primarily because I went to 24mm motor mount.
 

Bill S

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I have started to put 3/16" lugs on many of my rockets. Sadly I learned the hard way that certain rockets that aren't stable on a 3' 1/8" rod are perfectly fine on a 4' 3/16" rod. But it would really be a pain to retrofit some rockets with another lug, and screw up the nice paintjob.

Some of my club launches, they have Boy Scout troops show up to launch. Needless to say the 1/8" rods are all taken, whereas if you have some rockets that use a 3/16" rod, there frequently is not much of a line for that rod.
 

brockrwood

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I have 1010 rail guides on my Loc park models. I tend to put rails/buttons on everything 29mm and up. 24mm gets 3/16 lugs, and smaller just gets what comes in the kit.

The buttons on a park 1.6 look a little big, but mini rails aren't always available and we usually have one high power pad empty. My small stuff with 1010 guides tends to find its way there.

I have never used a rail type launch pad. I will have to investigate that.
 

brockrwood

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Do you do this at club launches? when there is a line of people waiting to fly?

No. What I do at club launches, especially when a Cub Scout Troop or other kids’ group is launching, is I carry some sandpaper and an “emery board” fingernail file in my pocket. After a few launches none of the kids can launch because the igniter clips on each pad are covered in engine exhaust residue. I clean up the igniter clips on my pad and the pads near me to help out the bewildered Cub Scouts.
 

brockrwood

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So it turns out I did not have any 3/16" launch lugs here at my girlfriend's house. (I need to stock her house with an ample supply of rocket building parts. I am sure she won't mind the spare bedroom being turned into the "Vehicle Assembly Building".)

I did find a left over 1/4" paper drinking straw from Ted's Montana Grill. It was pressed into service as an "upgraded" launch lug.

Hmm. Looks a little fat on the BT-50 body tube. Like the rocket has a growth that needs to be removed.

BUT. BUT! I can launch this sucker on any sort of rod now - 1/8", 3/16", and 1/4". :)

IMG-5780_cropped.jpg
 
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Scott_650

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Heavy duty paper drinking straws from the Dollar Tree/Dollar Store - I bought a pack of Halloween theme straws after the 31st for $.50 and haven’t used them all up after a couple years. Not sure of the exact size but they fit fine over 3/16” rods 😉
 

BABAR

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So it turns out I did not have any 3/16" launch lugs here at my girlfriend's house. (I need to stock her house with an ample supply of rocket building parts. I am sure she won't mind the spare bedroom being turned into the "Vehicle Assembly Building".)

I did find a left over 1/4" paper drinking straw from Ted's Montana Grill. It was pressed into service as an "upgraded" launch lug.

Hmm. Looks a little fat on the BT-50 body tube. Like the rocket has a growth that needs to be removed.

BUT. BUT! I can launch this sucker on any sort of rod now - 1/8", 3/16", and 1/4". :)

View attachment 477149
If you were going for altitude, you’d ditch the lug and go with a tower. Embrace the Mega Lug. Incorporate it into the paint scheme! A sensor array? An escape pod? A Hyperpace Injection Port?
 

brockrwood

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Dry sanded. Second coat of primer on. Someone somewhere said to make the second coat of primer a contrasting color so you can see if you have covered the first coat completely. Good idea. Wet sanding begins in about 15 minutes. God, what a lot of work. I hope I don’t lose the rocket in the weeds on the first launch. First launch will be an A8-0 and A8-5. I want to get it back at least once.

image.jpg
 
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Dry sanded. Second coat of primer on. Someone somewhere said to make the second coat of primer a contrasting color so you can see if you have covered the first coat completely. Good idea. Wet sanding begins in about 15 minutes. God, what a lot of work. I hope I don’t lose the rocket in the weeds on the first launch. First launch will be an A8-0 and A8-5. I want to get it back at least once.

View attachment 477452

I hate to tell you this but I haven't had luck with a similar rocket. The first DCSAM on a B6-4 floated away in the wind. The 2nd on a A8-0/A8-5 angled and floated away, not enough booster power perhaps. The third on a B6-0/A8-3 angled and floated away, perhaps needed NC weight. That being said, good luck!

I might suggest some NC weight and C6-0/A8 whatever.

 
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Pet peeve. Dear model rocket companies: Put a 3/16" diameter launch lug into the kit as an option, even if a 1/8" diameter launch lug is all that is required. I often launch a mix of smaller and bigger rockets during the same launch session. It is a pain to have to set up a second pad, with a 1/8" diameter launch rod, when I already have the bigger pad, with the 3/16" diameter launch rod, already set up, just so I can launch that one rocket that has a 1/8" diameter launch lug.

Yes, I know, there is SLIGHLTY more drag from the 3/16" diameter launch lug. This is not an issue for the non-competitive, Saturday afternoon launch at the local park.

I have started putting my own 3/16" diameter launch lug on all of my model rockets, when possible, instead of the 1/8" diameter lug the rocket came with. Sometimes it is not possible, or practical, as the rocket comes with a built-in 1/8" diameter launch lug (sometimes built into a plastic fin can) or there is a spacing or clearance issue.
And so we can appreciate today the genius and foresight of Oliver Carlisle, who put a giant launch lug on the first commercially practical model rocket, the Rock-A-Chute Mark II.
Able to accomodate 1/8", 3/16", 1/4" rods and then some.
0814212019[1].jpg
(Semroc retro repro).
Heh.
Actually I think the lug was a motor casing and the rod was a wooden stick, IIRC.
The nose cone was a plastic pencil sharpener.
 

Daddyisabar

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I almost had that happen on a down scale trebuchet I built as a high school project in 1984. The sling slipped off early sending the projectile straight up like a rocket! It landed next to the engine and spun backwards a bit, passing next to me. I think it was only the third test shot and already had a heads up flight.
 
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