What weight/engine/length should upgrade to a 3/16 rod? I've had no problems but am trying to figure out why a couple of my rockets corkscrewed that normally fly great. I already use 3/16 launch lugs on most of my rockets since I hate drag on the rod.
When to upgrade a 1/8 rod.
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lakeroadster
When in doubt... build hell-for-stout!
I use a 6 foot long, 5/16" zinc coated steel rod. IMO if you are flying anything with a motor bigger than a D12, upgrading is the prudent thing to do.
The increase in rod diameter helps minimize rod whip and the increase in length helps to guide the rocket longer to gain additional speed.
It's a win - win. About the only issue is you'll need to use BT-3 body tube for launch lug. But that's not really an issue on larger rockets.
Why not go to a small rail? I love using Makerbeam (1.5m x 1mm x 1mm rail) for smaller rockets and it is much more rigid than all but the largest rods. It is also so small that it can work with ring tails.
I typically start using 3/16" rod based on body tube size or weight more than motor. I figure the further the motor is away from the rod and the heavier the rocket the more chance there is for deflection and / or rod whip.
For example, I'll fly a D motor Big Bertha (BT60 1.637") on the 1/8" rod all day but I will use the 3/16" rod for something like the LOC 1.6 Magnum due to the rockets weight. I don't have a hard and fast rule of where I make the switch based on weight as it's pretty much a judgement call at the time I'm building but I'd say somewhere around 7oz.
I'll also move up to 3/16" for fat rockets. Something like the Estes Fat Boy. It's a BT80 kit but only has an 18mm motor (stock). Being BT80 it moves the motor further away from the rod so I have seen issues with rod whip on the 1/8".
That being said, You tend to like to fly large E / F motors in small rockets min. diameter rockets. As long as the rocket isn't heavy and the lug is placed at the CG of the rocket you shouldn't have any issues continuing to fly on the 1/8" rod. If you begin building larger / heavier rockets then it would be a good call to move up to 3/16"
For example, I'll fly a D motor Big Bertha (BT60 1.637") on the 1/8" rod all day but I will use the 3/16" rod for something like the LOC 1.6 Magnum due to the rockets weight. I don't have a hard and fast rule of where I make the switch based on weight as it's pretty much a judgement call at the time I'm building but I'd say somewhere around 7oz.
I'll also move up to 3/16" for fat rockets. Something like the Estes Fat Boy. It's a BT80 kit but only has an 18mm motor (stock). Being BT80 it moves the motor further away from the rod so I have seen issues with rod whip on the 1/8".
That being said, You tend to like to fly large E / F motors in small rockets min. diameter rockets. As long as the rocket isn't heavy and the lug is placed at the CG of the rocket you shouldn't have any issues continuing to fly on the 1/8" rod. If you begin building larger / heavier rockets then it would be a good call to move up to 3/16"
lakeroadster
When in doubt... build hell-for-stout!
Six of one... half dozen of the other. LPR - MPR - HPR designations are based on motor size.
Bigger body tube typically means bigger motor....
More weight typically means bigger motor....
And if your going to upgrade... why just go to 3/16"? That's hardly worth the trouble. Go 5/16".
1.5mx1cmx1cm, I would guess?
I wasn't aware of these. They look great for park flying. What do you use for rail buttons/guides?
Yes that is correct. - 1mm rail would be interesting....1.5mx1cmx1cm, I would guess?
I wasn't aware of these. They look great for park flying. What do you use for rail buttons/guides?
I 3d print rail guides (file on thingiverse i think) and even small buttons. You can also buy micro rail buttons but I forget the supplier.
railbuttons.com ?
Thanks. Had seen the mini buttons there but hadn't investigated the rail. Neat!
I've noticed that kits like the Estes Vapor and Estes Big Daddy come with 3/16" lugs. I think that's a good place to switch to 3/16" rod. These rockets are big enough that with a little breeze they will move a 1/8" rod too much. Also I think it is a good idea to use a thicker and longer rod for anything that has a low velocity off of the rod.
I use the rule of thumb that if its an BT-55 or bigger, go with the 3/16ths size. One thing that helped convince me to go bigger than 1/8" was that my clubs tend to have a fair number of Boy Scouts/Civil Air Patrol groups come through, and they nearly always totally use up all the 1/8" rod positions. Having some rockets that use 3/16" (or 1010 rail) lets me still fly, and usually they like to see bigger rockets going up anyways.
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Anything I can put a decent sized 29mm motor in usually gets both launch lugs and buttons. And, since the mini buttons haven't taken hold like I'd think, they usually get 1010's.
I have frequently had Big Daddy's (or LOC Onyx's) on the high power pad rails where they were basically too small to see at launch from the line, with the RSO commentary.
I have frequently had Big Daddy's (or LOC Onyx's) on the high power pad rails where they were basically too small to see at launch from the line, with the RSO commentary.
After having models tip off when I didn't expect it (even 1 inch diameter models) when flying with C18 and D20 Q-Jets, I'm kind of rethinking when to use something bigger than a 1/8 inch rod. Slow motion video shows that with these motors, even in something the size/weight of an Alpha, one gets significant rod whip, at least on the relatively soft stainless steel rods. Hmmmmmm...maybe it's time for me to revisit carbon fiber rods, at least for those models that don't lend themselves too well to upsizing the lug as a retrofit.
FWIW, I've launched several hundred models up to 6 oz and D power on a 1/8" rod with not a single problem relating to the rod.
Typically, my models are very long, have 3/16" lugs, have big fins and launch in wind condition less than 9 mph.
Edit: Oh, and my rod is cold rolled steel, 44" in length.
Typically, my models are very long, have 3/16" lugs, have big fins and launch in wind condition less than 9 mph.
Edit: Oh, and my rod is cold rolled steel, 44" in length.
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As an old dude the bigger the rod the better. Even on my shorter rockets the RSO wants 1/2" stainless rod.
Still can't convince him rod whip is the rod's fault.
Anything toting a "MIGHTY D" should be at least 3/16".
A 3/16" is a bit small for a Mean Machine.
The dreaded quarter inch rod is banned in places, way too dangerous! Always remember what the RSO says is law. Always remember that any club rule, no matter how stupid, is meant to be followed.
At a club launch someone usually has a spare lug and super glue if rejected at the RSO table.
Straws and bic pen bodys can be used as larger lugs in a pinch. The paper straws from Ted's Montana grill are awesome! "Honey, I am hungry for a Bison Burger...actually I just want some paper straws."
Still can't convince him rod whip is the rod's fault.
Anything toting a "MIGHTY D" should be at least 3/16".
A 3/16" is a bit small for a Mean Machine.
The dreaded quarter inch rod is banned in places, way too dangerous! Always remember what the RSO says is law. Always remember that any club rule, no matter how stupid, is meant to be followed.
At a club launch someone usually has a spare lug and super glue if rejected at the RSO table.
Straws and bic pen bodys can be used as larger lugs in a pinch. The paper straws from Ted's Montana grill are awesome! "Honey, I am hungry for a Bison Burger...actually I just want some paper straws."
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Definitely.
I've seen more than one Ace hardware store selling stainless steel reusable straws (that actually come with a little brush to clean them). I have a little repository for these as launch lugs, and wire conduits. They are very thin and cutting them can leave an edge you need to clean up.
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And this is the correct rail for the Mini buttons? https://www.amazon.com/80-20-Inc-20-2020-Extrusion/dp/B07TJK9ZH8?ref_=ast_sto_dp
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Based on the available references, I believe that is correct.
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