[roc-chat] Re: 4" Goblin on K2045
- From: Wedge Oldham <wedgeoldham@xxxxxxxxx>
- To: roc-chat@xxxxxxxxxxxxx
- Date: Mon, 2 Apr 2012 15:14:21 -0700
My Goblin had 2 layers of 6 oz glass on each side. BUT....I cut off the
fin tabs, and all three fins were surface mounted.
I wouldn't worry too much about grain colapse; or even a shred. When we
started teh idea of a 4" goblin drag race Andy and myself tried to shred a
STOCK goblin, and had a very hard time. Only when we steped it up to the 6
grain 54mm motor could we get it to shred.
The hard part is finding the Goblin after you're done.
Wedge
On Mon, Apr 2, 2012 at 11:47 AM, Lakestake Rocketry <lakestake@xxxxxxxxx>wrote:
> Dok and I outflew Wedge at the first 4" Goblin drag race. We were on the
> 75mm K and Wedge was flying the 98mm. That is the 1499 and 1999 IIRC. No
> problem with either of the flights going up.
>
> Mike's notes 1, 2 and 4 are quite relevant.
>
> Our goblin had stock fins, a OEM fiberglass Nike nosecone and some CF on
> the airframe. (And a custom-machined slimline retainer of course.)
>
> Wedge, what were you flying that day?
>
> Matt
> On Apr 1, 2012 7:47 PM, "Mike & Nancy Kramer" <kramer@xxxxxxxxxxxx>
> wrote:
>
>> Launched a heavily modified 4" goblin on a K2045, no grain collapse, but
>> the chute never came out, when i dug it out of the crater (yes crater)
>> there were shreds of the nosecone at the bottom of the of the carnage. I
>> never did figure out why the nose never ejected. The motor case was
>> 'significantly distorted' after the landing, the entire front of it was
>> flared back over the back of the motor. Bought Jack a new case that day,
>> it was a loaner.
>>
>> Couple of things;
>>
>> 1) Get a tracker, it was impossible to see it going up
>> 2) Beware of whiplash
>> 3) Come up with a cool name, we went with the Shred Zeppelin
>> 4) Can I watch
>> 5) Doc tried a near stock goblin on a K1999, it re kitted about 50 feet up
>>
>> Mike Kramer
>>
>>
>> On 4/1/2012 6:32 PM, Leslie Stephens wrote:
>>
>> I remember a drag race at ROC with 4" goblins on K-1999'z after seeing
>> that i believe a K2045 should be ok
>>
>> Andy H
>>
>> On Apr 1, 2012, at 6:16 PM, Steve Trammell wrote:
>>
>> Forgot about grain collapse. Looks like some more research is in
>> order. It is rocket science after all :-)
>>
>> Thanks all,
>>
>>
>> On Sun, Apr 1, 2012 at 5:44 PM, Gene Engelgau wrote:
>>
>> At 92 g's You could collapse the propellant grains and make a big boom!
>> Fiber glassing the fins will not help in that case.
>> --
>> - Regards
>>
>> Gene Engelgau
>> KI6IBL, NAR 86770 / TRA 12243 - L3
>> *http://fruitychutes.com* <http://fruitychutes.com/> - Consumer and
>> Aerospace Recovery Solutions
>> *Like us on Facebook!* <http://www.facebook.com/fruitychutes>
>> *Follow us on Twitter!* <http://twitter.com/fruitychutes/>
>> 408-499-9050
>>
>>
>> On Sun, Apr 1, 2012 at 5:21 PM, JACK GARIBALDI < *JackGaribaldi@xxxxxxx*>
>> wrote:
>> Maybe glass the fins and I think it will work
>> Jack
>>
>> Sent from my Mil Spec IPhone 4S
>>
>> On Apr 1, 2012, at 5:11 PM, "Steve Trammell" < *stramm8235@xxxxxxxxxxx*>
>> wrote:
>>
>> I'm thinking of flying a 4" Goblin (stock build + fin fillets) on a CTI
>> K2045. I've flown this rocket on a number of K motors including 2
>> successful K1100 flights. The K1100 flights pulled 40g's and reached 1,000
>> MPH. A K2045 flight sims to 92g's and 1100+ MPH. Any thoughts?
>>
>>
>>
>> Also, does CTI V-Max propellant use standard delay charges or are
>> electronics needed like AT Warp9 propellant?
>>
>>
>>
>>
>>
>>
>>
>>
>>
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