[roc-chat] Re: 4" Goblin on K2045
- From: Lakestake Rocketry <lakestake@xxxxxxxxx>
- To: roc-chat@xxxxxxxxxxxxx
- Date: Mon, 2 Apr 2012 16:38:42 -0700
Yeah, I surface mount all my fins now. It makes repairs so much easier.
IMHO TTW fin mounting is just about never needed if you have good build
skills though I can see why manufacturers recommend it as they have no
control over who buys and builds their kits.
Matt
On Apr 2, 2012 3:14 PM, "Wedge Oldham" <wedgeoldham@xxxxxxxxx> wrote:
> 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?
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>
Other related posts:
