URRG

General Rocketry => High Power => Topic started by: dbmccann on December 25, 2015, 10:17:43 PM

Title: 2.6" Screech, part II
Post by: dbmccann on December 25, 2015, 10:17:43 PM
So, madcow lets you order just the booster for the 2.6" kits.  lists as 38mm, but a quick email confirmed they'd do them in 54mm as well.

My love for my 38mm screech is the worst kept secret in the world....so here we go again :) 
The longer motor mount is pretty slick, as are the tiny CR's.   Love all if this.

I haven't decided if I'm going to install a kevlar harness, or just attach to the motor bulkhead. 

(https://c2.staticflickr.com/6/5652/23975199395_9897ff6e7f_b.jpg)
Title: Re: 2.6" Screech, part II
Post by: dbmccann on December 25, 2015, 10:24:34 PM
(https://c1.staticflickr.com/9/8804/17656229948_9d449bb994_b.jpg)

I'm not sure how I want to change the paint...but I'd like to subtly indicate a difference in the boosters.  maybe a stripe on a fin or something...
Title: Re: 2.6" Screech, part II
Post by: RKeller on December 26, 2015, 08:27:29 AM
that thing is going to scoooooooooooot! I would use kevlar strap, just to make flight prep easier. it just HAS to be longer than any motor you're going to put in there.
Title: Re: 2.6" Screech, part II
Post by: dbmccann on December 27, 2015, 12:17:53 AM
Patell suggested black.... I kind of like it...a lot.

(https://c2.staticflickr.com/2/1570/23888091892_2e6a0950e0_b.jpg)



I did some math.....  an L1040 in a 54/2800 can technically fit :)
Title: Re: 2.6" Screech, part II
Post by: RKeller on December 27, 2015, 11:30:02 AM
metallic black would be awesome. so would a L1040!
Title: Re: 2.6" Screech, part II
Post by: dbmccann on December 27, 2015, 10:18:42 PM
Little sanding and fitting

(https://c2.staticflickr.com/6/5819/23720168380_a4d299d8ba_b.jpg)

(https://c2.staticflickr.com/2/1683/23907636632_f82b41297d_b.jpg)

(https://c2.staticflickr.com/2/1541/23989765946_446ffe5b5e_b.jpg)
Title: Re: 2.6" Screech, part II
Post by: dbmccann on January 01, 2016, 10:42:30 PM
nothing major, just notched the CR's.   hopefully glue it up tonight...

(https://c2.staticflickr.com/6/5649/23821831880_1579c3e45a_z.jpg)
Title: Re: 2.6" Screech, part II
Post by: dbmccann on January 13, 2016, 07:18:23 PM
and now for the other side of the story!

(https://c2.staticflickr.com/2/1474/24256469072_b207084303_c.jpg)

(https://c2.staticflickr.com/2/1639/24338487076_c2fd8ff3fe_b.jpg)
Title: Re: 2.6" Screech, part II
Post by: RKeller on January 13, 2016, 09:54:17 PM
well that looks fun! I would like something like that with electronics to fly single deploy or possibly cable cutter. I like the short nosecone.
Title: Re: 2.6" Screech, part II
Post by: dbmccann on January 18, 2016, 06:34:00 PM
(https://c2.staticflickr.com/2/1719/24445345365_c6aab1fa0a.jpg)(https://c2.staticflickr.com/2/1681/24385602391_2c0e0636ba.jpg)
(https://c2.staticflickr.com/2/1617/23841213903_bbf1c0bba2.jpg)(https://c2.staticflickr.com/2/1541/23840813004_1d7a3f98dd.jpg)


MMT all glued in.   AP mated right up to the BT.   If I did this all again, I'd likely just skip the kevlar harness.   

Instead of adding epoxy inside the body, I put it on the top of the two CR's and shoved it in and let it run out to make the joint.  Would up making a mess, and nearly glued the aeropack to the BT.     

I took the cap off, cleaned up the epoxy with acetone,  then covered the aeropack in vaseline and and screwed it back on.    It seems to have done the trick,  but next time, I'm just putting the epoxy in the tube like i've always done before.
Title: Re: 2.6" Screech, part II
Post by: dbmccann on January 24, 2016, 05:35:28 PM
and the push and smoosh begins :) aeropoxy ES6209

(https://c2.staticflickr.com/2/1634/24562713156_1db3340f8a_c.jpg)
(https://c2.staticflickr.com/2/1706/24221117169_7d83037138_z.jpg)
Title: Re: 2.6" Screech, part II
Post by: dbmccann on January 25, 2016, 07:26:16 PM
All three up.  :)   Proline 4500 will be used for fillets.

(https://c2.staticflickr.com/2/1501/24588382146_105ba72915.jpg)
Title: Re: 2.6" Screech, part II
Post by: RKeller on January 25, 2016, 09:07:07 PM
this thing is going to rip. curious to see if it has no spin like the 38mm one.
Title: Re: 2.6" Screech, part II
Post by: dbmccann on January 25, 2016, 09:52:05 PM
I usually spend a good bit of time setting fins.... I'm literally going crazy checking these to try and match the performance of the 38. 
Title: Re: 2.6" Screech, part II
Post by: dbmccann on January 26, 2016, 07:55:59 PM
(https://c2.staticflickr.com/2/1452/24340370040_2645f8fa92_b.jpg)
Title: Re: 2.6" Screech, part II
Post by: dbmccann on March 06, 2016, 12:54:07 PM
Got another order of Proline 4500 in,  so I started into fillets last night.     25 gram to 4 gram batch size.  Had a good bit left over to glue up some other assorted items, but not so big that I could have reduced size easily.   

Fillets pulled with a 3/4" PVC pipe.

I taped over the side of the proline can here to avoid getting any in the rim and making the lid a mess.  (though the new batch of 4500 I just got in can in a plastic screw cap tub... ungh.  Gonna have to transfer that to a bottle.)

First two sets are done.   Probably lay the third in later tonight.   I used regular masking tape on this.  Laid the epoxy in immediately after mixing, pulled the fillets out, and then pulled the tape off.   Smoothed out the front and back edges (bumps occur outside the pull line, I'm too lazy to tape that detailed) with a paper towel soaked in acetone.   I'm going to be sanding and painting these so I'm not too concerned with making it look pretty.   I wait until each set has cured before doing the next.

(https://c2.staticflickr.com/2/1642/24930191354_c3917ab693_z.jpg)(https://c2.staticflickr.com/2/1644/25442141022_ea76bdcefc_z.jpg)
(https://c2.staticflickr.com/2/1477/24933988363_3fee8311d3_z.jpg)
Title: Re: 2.6" Screech, part II
Post by: RKeller on March 07, 2016, 12:43:18 PM
those look perfect. Hope the rest of them look that good :o
Title: Re: 2.6" Screech, part II
Post by: dbmccann on March 07, 2016, 12:58:30 PM
Thanks :)


There's a small void 1/4 of the way into the first one.  I'll Sand them all up and fill it in when I do fillets on the dual optima :)
Title: Re: 2.6" Screech, part II
Post by: dbmccann on May 24, 2016, 01:55:21 PM
I test fit the 54/2550 I got from AG71 and filled with guts from Dan.    It fits... :)

(https://c2.staticflickr.com/2/1665/25841370075_da213b4357_b.jpg)


At this point, I'm not going to be flying for awhile,  so I'm considering getting another Av-bay, NC, and payload tube for this. 


I'm not entirely happy with the amount of epoxy on the CR to BT joint.  When I drill rail buttons I think I'll inject a bit more on top.
Title: Re: 2.6" Screech, part II
Post by: rocketcrazyperson on May 24, 2016, 04:45:49 PM
Very nice!
Title: Re: 2.6" Screech, part II
Post by: dbmccann on May 24, 2016, 07:48:14 PM
Thanks!  Should be a fun ride
Title: Re: 2.6" Screech, part II
Post by: dbmccann on June 22, 2016, 01:48:47 PM
And we're rolling again!

(https://c2.staticflickr.com/8/7566/27739919802_ca04bdf425_b.jpg)

It wound up being a split shipment from Madcow.  USPS was here in 2 days.  FedEx took a week :)
Title: Re: 2.6" Screech, part II
Post by: dbmccann on June 29, 2016, 12:42:56 AM
I love these two side by side.

(https://c2.staticflickr.com/8/7735/27689812650_05f419160f_c.jpg)

(https://c2.staticflickr.com/8/7353/27867740932_33dc7c8b79_c.jpg)
Title: Re: 2.6" Screech, part II
Post by: RKeller on June 29, 2016, 12:04:55 PM
so is the new nosecone one of them newfangled composite tip ones?
Title: Re: 2.6" Screech, part II
Post by: dbmccann on June 29, 2016, 12:53:16 PM
It is indeed.  Going to screw the coupler in.  :)