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Old 07-31-2012, 04:01 PM
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mycrofte mycrofte is offline
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Default Moving up to 3/16 rod.

With the addition of two new rockets, I am moving up to mid power.

Having never flown them, I have no idea how long to make the launch rod. They have 3/16 launch lugs so I bought a 3/16" piece of rod (6 foot long). So, what length should I cut it?
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Old 07-31-2012, 04:42 PM
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GregGleason GregGleason is offline
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Run some simulations of what you want to fly and the motors to get what your lower acceptable range is (how far does the rocket need to travel to get up to about 40 feet/second).

That said, was is the max range your vehicle will accept.

Then you might split the difference.

That is just one approach though.

I'm not sure I would cut it less than 3 feet though.

Greg
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Old 07-31-2012, 05:01 PM
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Doug Sams Doug Sams is offline
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Quote:
Originally Posted by mycrofte
With the addition of two new rockets, I am moving up to mid power.

Having never flown them, I have no idea how long to make the launch rod. They have 3/16 launch lugs so I bought a 3/16" piece of rod (6 foot long). So, what length should I cut it?
The useful length of 3/16" rod is about 4 feet. After that, the flex/whip will make it iffy. Given that most 1/8" rods are already around 3', most folks opt to cut their 3/16" rods at 4'.

If you want to go longer, I recommend going up to 1/4", which can be used reliably up to 6', but storage and transport can become problems - they tend to get bent when they're longer than 4'. I've seen folks have them cut in two and machined so that the halves screw together, but getting a perfect alignment is iffy - there tends to be a slight step due to misalignment at the joint.

BTW, for mid-power (E-F-G), I like to start with 1/4".

Doug

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Old 07-31-2012, 05:42 PM
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mycrofte mycrofte is offline
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I was thinking 4' would do, but wanted to be sure. And if I use my wood launch pad, 4-6" will be under it hitting the ground.

The first rocket, I won in a raffle, came with 3/16" lugs and a D/E dual engine mount. The next one, a 2X Goblin, I just went with the same size launch lug.
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Old 07-31-2012, 07:30 PM
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Jerry Irvine Jerry Irvine is offline
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Move all the way to 1/4". The standards for rods going forward should be 1/16" x 12" (Micromax and similar), 1/8 x 36" (1/4A-D) low mass rockets under a pound. 1/4" x 47" for higher power and higher mass rockets up to about 5 pounds or an H. 1/2" x 70" for larger rockets or motors.

Standardization of launch pads and equipment is an important thing. By intentionally forsaking 3/16" and 3/8" it simplifies things greatly.

Just a suggestion form the people at Jerry
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Old 08-01-2012, 01:31 PM
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Best bet is a 1/4"x 6' stainless steel rod.
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