[NRV Rocketry] Kentland farms update
Maier.chris
maier.chris at gmail.com
Mon Aug 15 15:50:34 CDT 2011
38 mm I - get the cert done dude, and go big or go home :P
Seriously though, I recently underpowered a little Estes model - package recommended an A, it flew, but the 5 second ejection charge went off about 10 ft AGL...
I promise I'll never make that mistake again
Chris
On Aug 15, 2011, at 3:13 PM, Tweeks <tweeks at rackspace.com> wrote:
> [Mark, I'm moving this thread over to the NRVR mail list.. ;) ]
>
> This is a useful discussion that me and one of the VAST rocket guys are having
> about the maiden flight of my Talon-3, and what I should launch it on (a 29mm
> H motor, or my 38mm motor casing with an *I* impulse motor):
> http://theweeks.org/rockets/TALON-3/Talon-3_m.JPG
>
> On Monday 15 August 2011, Mark Miller wrote:
>> Of course, it's ultimately your call since it's your bird. I just wanted
>> you to know that H motors in [your talon-3] rocket are doable. As long as
>> it passes RSO muster (as far as motor goes it's normally based on a minimum
>> of 5:1 thrust-to-weight ratio) you are literally good to to go.
>
> I'm still learning here.. but I was considering the 5:1 thrust to weight ratio
> when asking my question about which motor to use.
>
> My thinkinf was that with a 6lb loaded bird (call it 8 with a 2lb motor) will
> need to clear an average thrust of around 176 N.. right? (8lb * 4.4N/lb *
> 5:1 ) Unless I just punch it with a VMax or the like (really high initial
> thrust to get it to stable flight)...
>
> VMax excluded... doesn't that point to an I motor?
>
>
>> It looks like we will be flying in some type of crop regardless of whether
>> it's corn or the remaining silage, so I would suggest either some type of
>> tracking device or at the very least an audio beacon to aid in recovery.
>
> Yeah.. I have a 120dB alarm that I've been saving for something like this. :)
>
> Tweeks
>
>
>> A
>> stand of corn like that can swallow a huge rocket and defy you to find it.
>>
>> Take care,
>>
>> Mark
>>
>> On Mon, Aug 15, 2011 at 3:01 PM, Tweeks <tweeks at rackspace.com> wrote:
>>> I'm doing ground tests now (getting my sheer pin hardware set up.. making
>>> sure
>>> I have good charge volumes, good reliability, etc).
>>>
>>> I'm a little hesitant to go as low as an H in the Talon-3, as it's only
>>> rated
>>> for I-J.
>>>
>>> Tweeks
>>>
>>> On Monday 15 August 2011, Mark Miller wrote:
>>>> Tweeks,
>>>>
>>>> Just running a quick sim in RASAero for a rocket of that general
>>>> configuration and weight of 6 lbs, I come up with a bit over 1000' for
>>>> an H400 flight and a bit over 1200' for an H399. In I motors Harry has
>>>> in stock, there is the I287 @ ~2550', the I297@ ~3000', and the
>>>> I350@~3300'. If you choose to go with a 29mm motor, hardware is no
>>>> problem since if
>>>
>>> you
>>>
>>>> don't want to buy it from Harry right away, you are welcome to borrow
>>>
>>> what
>>>
>>>> you need in hardware and/or adapters.
>>>>
>>>> Now that you have your dual deployment set up, that gives you more
>>>> flexibility as far as altitude. Have you had a chance to do some
>>>> ground tests to get your charge sizes worked out?
>>>>
>>>> Take care,
>>>>
>>>> Mark
>>>>
>>>> On Mon, Aug 15, 2011 at 12:44 PM, Tweeks <tweeks at rackspace.com> wrote:
>>>>> Haven't got all the finishing touches just yet.. but probably around
>>>>> 6lbs..
>>>>>
>>>>> Tweeks
>>>>>
>>>>> On Monday 15 August 2011, Mark Miller wrote:
>>>>>> Hey Tweeks,
>>>>>>
>>>>>> What is your empty weight on the Talon 3? In other
>>>>>> words, ready to fly other than the motor.
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>> Mark
>>>>>>
>>>>>>
>>>>>>
>>>>>> -
>>>>>> On Aug 15, 2011 11:49 AM, Tweeks <tweeks at rackspace.com>
>>>>>> wrote:
>>>>>>
>>>>>> You guys recommending a large H over an I on the Talon3?
>>>>>>
>>>>>> I'm equipped for 38mm (just bought my Pro-38s casings).. and have
>>>>>> nothing for
>>>>>>
>>>>>> 29mm. I'm AM set up for dual deploy...
>>>>>>
>>>>>>
>>>>>>
>>>>>> Tweeks
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Sunday 14 August 2011, Mark Miller wrote:
>>>>>>
>>>>>> > Tweeks,
>>>>>>
>>>>>> >
>>>>>>
>>>>>> > Harry from The Dragon's Hoard is scheduled to be there both
>>>
>>> days.
>>>
>>>>>> Here is
>>>>>>
>>>>>> > the link to the motor page on his website:
>>>>>>
>>>>>> > http://www.thedragonshoard.com/motors.php
>>>>>>
>>>>>> > Don't forget that your Talon 3 should also be able to fly on
>>>
>>> some
>>>
>>>>>> of the
>>>>>>
>>>>>> > higher average impulse H motors as well, like the H399 in the
>>>>>> Pro29 series.
>>>>>>
>>>>>> > If you don't have adapters for 38 to 29mm, you are welcome to
>>>>>> borrow one
>>>>>>
>>>>>> > from me if you like.
>>>>>>
>>>>>> >
>>>>>>
>>>>>> > Take care,
>>>>>>
>>>>>> >
>>>>>>
>>>>>> > Mark
>>>>>>
>>>>>> >
>>>>>>
>>>>>> > On Sun, Aug 14, 2011 at 1:55 AM, Thomas Weeks
>>>>>>
>>>>>> <tweeksjunk2 at theweeks.org>wrote:
>>>>>>
>>>>>> > > **
>>>>>>
>>>>>> > >
>>>>>>
>>>>>> > > BTW..
>>>>>>
>>>>>> > >
>>>>>>
>>>>>> > > Who's the motor vendor? And how do I connect with them?
>>>>>> I'm
>>>>>
>>>>> going
>>>>>
>>>>>> to need
>>>>>>
>>>>>> > > some Pro-38 Is.
>>>>>>
>>>>>> > >
>>>>>>
>>>>>> > > Tweeks
>>>>>>
>>>>>> >
>>>>>>
>>>>>> > This email may include confidential information. If you
>>>>>> received it
>>>>>
>>>>> in
>>>>>
>>>>>> > error, please delete it.
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> This email may include confidential information. If you received it
>>>
>>> in
>>>
>>>>>> error, please delete it.
>>>>
>>>> This email may include confidential information. If you received it in
>>>> error, please delete it.
>>
>> This email may include confidential information. If you received it in
>> error, please delete it.
>
>
> _______________________________________________
> NRVR mailing list
> NRVR at nrvr.org
> http://nrvr.org/mailman/listinfo/nrvr
More information about the NRVR
mailing list