Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > Work Bench > Building Techniques
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 08-31-2019, 08:27 AM
5x7's Avatar
5x7 5x7 is offline
Sometimes collector
 
Join Date: May 2008
Posts: 1,786
Default Can the Spaceman be built to fly straight?

This is a Semroc xkit Spaceman, built per the original Estes plans. On an A8 it flies usually a spiral but veering off vertical till it ejects pretty far away. Then it’s completely stable but seems to have some lift so it’s veering toward the ground until impact. Is it possible to make it fly straight? I was thinking capping the big main tube at the top to stop the ring fin ahead of the CG might help, then a streamer taped to pthe engine could be put inside. Thoughts?
Attached Thumbnails
Click image for larger version

Name:  3D342D6B-850B-456E-9928-091B88D4D6ED.jpeg
Views: 38
Size:  1.18 MB  
Reply With Quote
  #2  
Old 08-31-2019, 09:02 AM
LeeR's Avatar
LeeR LeeR is offline
Retired with Way Too Many Kits
 
Join Date: Jun 2007
Location: Colorado
Posts: 3,222
Default

I’m building my first Spaceman currently, also a Semroc kit. But it is built stock, using the 13mm motors. I’ve not heard how well they fly normally, but would have to assume converting to 18mm is the issue. Did you use the four weights on the leg braces, or increase their size to counter the bigger motor?
__________________
Lee Reep
NAR 55948

Projects: Semroc Saturn 1B, Ken Foss Designs Mini Satellite Interceptor
In the Paint Shop: Nothing! Too cold!
Launch-Ready: Farside-X, Maxi Honest John, Super Scamp
Reply With Quote
  #3  
Old 08-31-2019, 09:11 AM
5x7's Avatar
5x7 5x7 is offline
Sometimes collector
 
Join Date: May 2008
Posts: 1,786
Default

The mini motor kit from erockets is a bit different from the xkit since it recovers the motor pod by streamer. The xkit is 18 mm ejecting motor. I would love to hear how the flight and recovery go.
Reply With Quote
  #4  
Old 08-31-2019, 09:44 AM
tbzep's Avatar
tbzep tbzep is offline
Dazed and Confused
 
Join Date: Mar 2005
Location: TN
Posts: 11,610
Default

The original Estes version used 18mm motors recommended all the way up to a C6-7, but 1/2A6-2 for first flight. It might be worth it to look at some original plans to see if anything is different. I don't think Estes would have recommended a C motor on something that wouldn't fly at least fairly straight.
__________________
I love sanding.
Reply With Quote
  #5  
Old 08-31-2019, 09:58 AM
ghrocketman's Avatar
ghrocketman ghrocketman is offline
President, MAYHEM AGITATORS, Inc.
 
Join Date: Jul 2005
Location: Nunya Bizznuss, Michigan
Posts: 13,443
Default

Nope; it will only fly straight if you use a hi-thrust motor such as a B14 or D21/24.
__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL
, if you have to ask what is "NORMAL" , you probably aren't !

Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !
Reply With Quote
  #6  
Old 08-31-2019, 02:07 PM
Ez2cDave's Avatar
Ez2cDave Ez2cDave is offline
Banned
 
Join Date: Mar 2005
Location: Raleigh, NC Area
Posts: 1,743
Default

Quote:
Originally Posted by tbzep
It might be worth it to look at some original plans to see if anything is different.


http://www.spacemodeling.org/jimz/estes/k-09.pdf

Dave F.
Reply With Quote
  #7  
Old 08-31-2019, 02:24 PM
5x7's Avatar
5x7 5x7 is offline
Sometimes collector
 
Join Date: May 2008
Posts: 1,786
Default

Semroc released a number of kits around 2008 as xkits - a bag of parts and no plans, the builder would go online and find the plans. Mine was an xkit, so it was built according to the plans above.
Reply With Quote
  #8  
Old 08-31-2019, 02:47 PM
LeeR's Avatar
LeeR LeeR is offline
Retired with Way Too Many Kits
 
Join Date: Jun 2007
Location: Colorado
Posts: 3,222
Default

Quote:
Originally Posted by 5x7
Semroc released a number of kits around 2008 as xkits - a bag of parts and no plans, the builder would go online and find the plans. Mine was an xkit, so it was built according to the plans above.


Ahhh, didn’t realize that was what you were talking about - an xkit is kind of like the BMS clone kits.
__________________
Lee Reep
NAR 55948

Projects: Semroc Saturn 1B, Ken Foss Designs Mini Satellite Interceptor
In the Paint Shop: Nothing! Too cold!
Launch-Ready: Farside-X, Maxi Honest John, Super Scamp
Reply With Quote
  #9  
Old 08-31-2019, 03:08 PM
tbzep's Avatar
tbzep tbzep is offline
Dazed and Confused
 
Join Date: Mar 2005
Location: TN
Posts: 11,610
Default

Quote:
Originally Posted by ghrocketman
Nope; it will only fly straight if you use a hi-thrust motor such as a B14 or D21/24.

Maybe some "accidental" contact between a B4-4 and a small drill bit would help the flight profile.
__________________
I love sanding.
Reply With Quote
  #10  
Old 08-31-2019, 04:00 PM
Ez2cDave's Avatar
Ez2cDave Ez2cDave is offline
Banned
 
Join Date: Mar 2005
Location: Raleigh, NC Area
Posts: 1,743
Default

Quote:
Originally Posted by tbzep
Maybe some "accidental" contact between a B4-4 and a small drill bit would help the flight profile.


Like this ?
Attached Thumbnails
Click image for larger version

Name:  B14_chart_ADJ-2.jpg
Views: 55
Size:  666.5 KB  
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 04:03 PM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024