54mm to 38mm MD ISC

Discussions for scratch builders. For the enthusiast that builds from the ground up. Tell us what you've built and what projects you working on in the space race.

Moderator: Moderators

drew
Southern fried goodness
Southern fried goodness
Posts: 928
Joined: Sat Aug 01, 2009 10:20 pm
Location: Perth

54mm to 38mm MD ISC

Postby drew » Tue Feb 06, 2018 6:25 pm

So to support my plans at THUNDA in 2019 I'm going to hopefully test a top lit staging stack at WWW2018 in June. I've got a 54mm booster sorted (my 54LB from last year). I just need an ISC and 38mm sustainer. So I've been in planning and production modes at the moment. Below are most of the parts required to make this sucker a reality along with a drawing of the planned final ISC.

Image

Comments?
Andrew Hamilton
AMRS 28 L3
AMRS Records Committee Chairman
Max Alt AGL - 23,908ft - K300 - Balls 22
Max V - 2,488 ft/s, ~Mach 2.2 - M2250 - THUNDA 2015

Oldboy
Rocket Flyer
Rocket Flyer
Posts: 188
Joined: Sun Oct 28, 2012 10:51 am
Location: York WA

Re: 54mm to 38mm MD ISC

Postby Oldboy » Tue Feb 06, 2018 8:29 pm

All this time I surmised you measured in "Freedom" increments.
WARS 005 AMRS 98
"I GOT IT"

drew
Southern fried goodness
Southern fried goodness
Posts: 928
Joined: Sat Aug 01, 2009 10:20 pm
Location: Perth

Re: 54mm to 38mm MD ISC

Postby drew » Wed Feb 07, 2018 10:34 am

Oldboy wrote:All this time I surmised you measured in "Freedom" increments.


I like the accuracy of mm and I do not like fractions. I've been converted.
Andrew Hamilton
AMRS 28 L3
AMRS Records Committee Chairman
Max Alt AGL - 23,908ft - K300 - Balls 22
Max V - 2,488 ft/s, ~Mach 2.2 - M2250 - THUNDA 2015

User avatar
RainierWolfcastle
Parachute Packer
Parachute Packer
Posts: 46
Joined: Wed Sep 02, 2015 11:29 am

Re: 54mm to 38mm MD ISC

Postby RainierWolfcastle » Wed Feb 07, 2018 11:31 am

drew wrote:
Oldboy wrote:All this time I surmised you measured in "Freedom" increments.


I like the accuracy of mm and I do not like fractions. I've been converted.


One down, 325,853,998 to go!
- Ben

AMRS #174 L2
WARS #037

 "If I have seen further, it is by standing on the shoulders of giants." - Sir Isaac Newton, 1675

strud
Engineer
Engineer
Posts: 917
Joined: Thu Oct 02, 2008 7:37 am
Location: Central Tablelands, NSW

Re: 54mm to 38mm MD ISC

Postby strud » Wed Feb 07, 2018 10:33 pm

Hi Drew,

Head end ignition will definitely reduce the complexity of the whole assembly process on the pad and eliminate those pesky wires that would either come down from above or into the coupler....

What are you going to use to drive the ignitor on the sustainer? ie electronics. You really want a solid electrical isolator for the ignition circuit, some of those screw type switches might be the ticket.

Will you be using a time post booster shutdown for triggering the event?

Do you hope/expect that the booster will drag separate immediately upon shutdown?

Staging is interesting, it adds more complexity but more fun too I think.

drew
Southern fried goodness
Southern fried goodness
Posts: 928
Joined: Sat Aug 01, 2009 10:20 pm
Location: Perth

Re: 54mm to 38mm MD ISC

Postby drew » Thu Feb 08, 2018 6:12 pm

strud wrote:Hi Drew,

Head end ignition will definitely reduce the complexity of the whole assembly process on the pad and eliminate those pesky wires that would either come down from above or into the coupler....


Indeed, especially in the case of MD rockets. Jim Jarvis's TaperWire technique has never really been high on my list. I've always had a spool of it on the "to buy someday" list but never got around to it. I'm glad I didn't.

strud wrote:What are you going to use to drive the ignitor on the sustainer? ie electronics. You really want a solid electrical isolator for the ignition circuit, some of those screw type switches might be the ticket.


I'll be using an EasyMega as I'll build an AV Bay just above the motor and my airframe will be carbon fibre. GPS just won't work there.

strud wrote:Will you be using a time post booster shutdown for triggering the event?


Currently my plan is to PM or email Jim and Kip on TRF and try to wrangle Keith from Altus into the conversation for their latest advice. I suspect I'll configure it to inhibit motor ignition if the tilt is over 15% off vertical and it's not at a baseline desired altitude. And BENCH TEST multiple times.

strud wrote:Do you hope/expect that the booster will drag separate immediately upon shutdown?


100%. I don't believe it's an issue when you stage from a larger diameter booster to a smaller diameter sustainer. The two attempts I flew SpeedStack with both drag separated immediately after booster cutoff.

strud wrote:Staging is interesting, it adds more complexity but more fun too I think.


Can confirm!
Andrew Hamilton
AMRS 28 L3
AMRS Records Committee Chairman
Max Alt AGL - 23,908ft - K300 - Balls 22
Max V - 2,488 ft/s, ~Mach 2.2 - M2250 - THUNDA 2015

drew
Southern fried goodness
Southern fried goodness
Posts: 928
Joined: Sat Aug 01, 2009 10:20 pm
Location: Perth

Re: 54mm to 38mm MD ISC

Postby drew » Thu Feb 08, 2018 6:15 pm

Also, if I have issues with the EasyMega I'll revert back to a Raven. Here's Adrian's advice on staging with them from TRF in 2013.

Image
Andrew Hamilton
AMRS 28 L3
AMRS Records Committee Chairman
Max Alt AGL - 23,908ft - K300 - Balls 22
Max V - 2,488 ft/s, ~Mach 2.2 - M2250 - THUNDA 2015

Oldboy
Rocket Flyer
Rocket Flyer
Posts: 188
Joined: Sun Oct 28, 2012 10:51 am
Location: York WA

Re: 54mm to 38mm MD ISC

Postby Oldboy » Thu Feb 08, 2018 9:47 pm

Forgot to add to my original post,
As usual most excellent project.
Any assistance required consider the "Recovery Crew" in.
WARS 005 AMRS 98
"I GOT IT"

drew
Southern fried goodness
Southern fried goodness
Posts: 928
Joined: Sat Aug 01, 2009 10:20 pm
Location: Perth

Re: 54mm to 38mm MD ISC

Postby drew » Fri Feb 09, 2018 3:49 pm

Oldboy wrote:Forgot to add to my original post,
As usual most excellent project.
Any assistance required consider the "Recovery Crew" in.


Cheers bud! Looking forward to it. Hopefully this time we'll have GPS coordinates to assist!
Andrew Hamilton
AMRS 28 L3
AMRS Records Committee Chairman
Max Alt AGL - 23,908ft - K300 - Balls 22
Max V - 2,488 ft/s, ~Mach 2.2 - M2250 - THUNDA 2015


Return to “Scratch Built”

Who is online

Users browsing this forum: No registered users and 3 guests