Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > The Golden Age of Model Rocketry > Model Rocket History
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #21  
Old 05-14-2013, 09:45 PM
Vanel Vanel is offline
Master Modeler
 
Join Date: Jun 2005
Posts: 712
Default

Thanks Carl! Based on this, it appears that staging goes all the way back to the beginning.
__________________
Up next:
Under construction:
Under repair:
In finishing:
In primer: eBay rescue Mark II, Sky Bird II (Estes Rocket Plan #2)
In paint:
Ready for decals:

Bill Cooke
NAR #31312
SAM #0001
Huntsville, AL

My rocket blog
My rocket fleet
Reply With Quote
  #22  
Old 05-15-2013, 08:15 AM
blackshire's Avatar
blackshire blackshire is offline
Master Modeler
 
Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 5,556
Default

Quote:
Originally Posted by Vanel
Thanks Carl! Based on this, it appears that staging goes all the way back to the beginning.
Thanks to Carl seconded! That raises a staging variation (which the Europeans may have introduced many years ago) that Tim Van Milligan (Apogee Components) utilized in the 1990s with his Centrix contest models. Because their 10.5 mm motors had such tiny nozzles, the two-stage version of the Centrix was staged using a length of fuse in the second stage motor's nozzle, which was lit by the first stage motor (it was either a "dash-zero" booster motor or had a very short delay--I don't remember).
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR
Reply With Quote
  #23  
Old 05-15-2013, 10:08 AM
Doug Sams's Avatar
Doug Sams Doug Sams is offline
Old Far...er...Rocketeer
 
Join Date: Mar 2005
Location: Plano, TX resident since 1998.
Posts: 3,883
Default

Quote:
Originally Posted by blackshire
...the two-stage version of the Centrix was staged using a length of fuse in the second stage motor's nozzle, which was lit by the first stage motor (it was either a "dash-zero" booster motor or had a very short delay--I don't remember).
As far as I know, all the 10.5mm boosters had no delay. I have a few in my stash I can check to be sure.

As for the fuses, these were wires which had been dipped in pyrogen. I have some, but have never flown them. In fact, I have been in the process of gettin' around to flying my stash of 10.5's for about 12 years now

I've built several birds to use them, but, alas, it seems the time has just never been right.

Doug

.
__________________
YORF member #11
Reply With Quote
  #24  
Old 05-15-2013, 10:16 AM
blackshire's Avatar
blackshire blackshire is offline
Master Modeler
 
Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 5,556
Default

Quote:
Originally Posted by Doug Sams
As far as I know, all the 10.5mm boosters had no delay. I have a few in my stash I can check to be sure.

As for the fuses, these were wires which had been dipped in pyrogen. I have some, but have never flown them. In fact, I have been in the process of gettin' around to flying my stash of 10.5's for about 12 years now

I've built several birds to use them, but, alas, it seems the time has just never been right.

Doug

.
Thank you! Now that you mention it, the "staging igniters" (fuses--I never got around to building my Centrixes, and gave them and their motors to the Dade County Rocketry Association before I moved to Alaska) looked like Jetex wick and Centuri "Sure-Shot" igniters.
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR
Reply With Quote
  #25  
Old 05-15-2013, 11:07 AM
Carl@Semroc's Avatar
Carl@Semroc Carl@Semroc is offline
Junior ??? Rocketeer
 
Join Date: Mar 2005
Location: Knightdale, NC
Posts: 1,470
Default

The Mabel I engines used Jetex Wick in the upper stage engine to aid ignition. This was dropped with the Mabel II (.5" ID) engines. I remember the "crumbly" Jetex propellant falling away, leaving just the wire hanging in some of the upper stage attempts.
__________________
Carl McLawhorn
NAR#4717 L2
semroc.com
Reply With Quote
  #26  
Old 05-15-2013, 11:29 PM
Gus's Avatar
Gus Gus is offline
7/21/61
 
Join Date: Sep 2005
Location: North of Detroit
Posts: 1,779
Default

I routinely gap stage 10.5 mm motors, both old Apogee motors and European motors. I also routinely gap stage Estes 13 mm motors. I have done a great deal of experimentation and high speed photography and here is what I have learned. (Doug, you and I discussed this in another thread ~4 years ago but I've experimented a lot since then so this info is slightly different)

Contrary to what G. Harry thought, staging, including gap staging has little to do with flying burning particles. In standard, non-gap staging, when motors are taped together booster burn-through results in a jet of flame entering the sustainer nozzle. Ignition depends on the nature of the flame jet and, more importantly, whether the force of the tape holding the motors together is enough to overcome the pressure buildup between the booster and sustainer long enough for the jet of flame to ignite the upper motor. Booster burn-through is an inconsistent process so the jet produced is quite variable.

The top of an Estes booster motor is simply the upper end of the pressed propellant slug. If you view it from above at ultra high speed burn through may occur in the middle, or closer to an edge. It may resemble a cross burning out from the middle of where the bars cross or be more like a widening circle. The variability of this burn through is completely random resulting in very different jets being produced. A booster that burns through closer to the edge will produce a flame jet which may not be centered near the sustainer nozzle opening. As the booster continues its burn-through the flame jet widens. If the tape can hold the motors together long enough for the flame jet to reach and enter the nozzle, then sustainer ignition will occur. In most cases taped together motors do a fine job and ignition occurs.

In gap staging, the tube between the booster and sustainer motors acts like fireworks Quick Match, propgating a ball of flame from booster to the sustainer almost instantaneously. A pressure wave of gas precedes the flame by milliseconds and, if not vented out the upper sides of the tube, will push the sustainer motor off the tube before ignition occurs. But what travels up and ignites the sustainer is not little burning embers, but a ball of flame that envelops the aft end of the sustainer motor causing it to ignite. Part of the flame ball also exits the vent holes. The ball of flame is long (in milliseconds) gone before noticeable flame begins exiting the sustainer nozzle.

This is why it is possible to reliably ignite gap staged European sustainer motors with VERY tiny nozzles, without any wick. Be aware, though, that European competition 10 mm booster motors are slightly different from Estes or old Apogee motors. Euro booster motors have a forward cap with a very tiny hole in the middle. When the booster motor burns through it is only a very tiny spurt of flame that exits the top end of the motor. Euro booster motors are designed to be augmented with a pinch of black powder on top that serves as the flame propgator for sustainer ignition.

The fact that gap staging depends on a moving ball of flame, rather than burning embers, allows you to do interesting things. You can actually gap stage around gentle corners. The sustainer motor does not have to be located in a straight line directly above the booster motor. My daughter's Little Joe 1A which she flew in Slovakia used this technique to have one of the 4 18mm booster motors located at their scale outward locations in the booster to ignite a 13 mm motor in the center of the base of the Mercury capsule (to simulate the escape motor). Photo of the LJ1A internals below. This system used standard Estes motors, no augmentation. Very reliable.

Final note. Wick is useful in a sustainer nozzle when you are trying to delay ignition by a second or so. The wick fills the sustainer nozzle preventing the ball of flame from directly igniting the sustainer. Instead, the wick ignites and then takes a second or so to ignite the sustainer. Useful if you are going for altitude, but it adds a whole extra failure mode and can be tricky.

Hope this info is useful,

Steve
Attached Thumbnails
Click image for larger version

Name:  LJ1A internals.jpg
Views: 44
Size:  351.9 KB  Click image for larger version

Name:  BoosterBottom.jpg
Views: 34
Size:  119.7 KB  Click image for larger version

Name:  BoosterTop.jpg
Views: 43
Size:  112.8 KB  
Reply With Quote
  #27  
Old 05-16-2013, 12:03 AM
Gus's Avatar
Gus Gus is offline
7/21/61
 
Join Date: Sep 2005
Location: North of Detroit
Posts: 1,779
Default

Bill,

I know the thread is about the history of clustering and staging so I appologize for the tangent. But I want to share another photo which does a good job of showing what happens at the top of a gap stage tube, or what you would see at the top of a booster motor if it didn't have a sustainer motor taped on top.

The photo below shows three frames of a movie I did of a test trying to determine how much powder to use in a 1/8" diameter by one foot long gap stage tube for European booster motors. At the left end of the tube is an Estes igniter held in place in the tube by a tiny ball of Kleenex. I held the tube vertically and sprinkled a very tiny pinch of black powder down on top of the Kleenex.

The 3 frames are consecutive and were shot at 30 frames per second.

The first frame shows immediately before the igniter lights. Igniter and black powder to the left.

Second frame shows the small white spot at the left of the tube as the igniter lights.

Third frame shows the volume of flame at the other end of the tube 1/30th of a second later. Note the lack of flame at the left end of the tube where the igniter was.

The gap stage tube effectively works like fireworks "quick match", virtually instantaneous propogation of a ball of flame to the other end of the tube.

It's not burning embers.

Jerry Lee Lewis had it right: "Goodness gracious great balls of fire!"

Steve
Attached Thumbnails
Click image for larger version

Name:  S1FuseTest.jpg
Views: 71
Size:  156.5 KB  
Reply With Quote
  #28  
Old 05-16-2013, 01:55 AM
Royatl's Avatar
Royatl Royatl is offline
SPEV/Orion wrangler
 
Join Date: Mar 2005
Location: Atlanta, GA
Posts: 2,244
Default

Quote:
Originally Posted by Vanel
My time line and notes so far - I welcome any comments/corrections/additions!




Estes B14 discontinued in 1980 due to safety concerns; Centuri B14 advertised until 1981.
B8 introduced in 1980; discontinued 1997
B14 - peak thrust of 7 lbs. 0.35 sec duration; B8 - peak thrust of 5 lbs, 0.6 sec duration.
C5 introduced by Centuri in 1977; discontinued by Estes in 2001 (C5-0S went away with Centuri in 1983).
C5 peak thrust of around 5 lbs (21.8 newtons)



My measurement of later "B14" motors show them to be almost identical to the first "B8" motors. It seems to me that this was the first example of a redesign (from drilled core to pressed core) where they attempted to keep the same designation, but then had to change (probably when the motors came up for re-certification after a three year term).
__________________
Roy
nar12605
Reply With Quote
  #29  
Old 05-16-2013, 01:26 PM
ghrocketman's Avatar
ghrocketman ghrocketman is offline
President, MAYHEM AGITATORS, Inc.
 
Join Date: Jul 2005
Location: Michigan
Posts: 8,687
Default

Somebody with a set of STONES should give MAMBY-PAMBY safety a LONG RIDE on a LARGE BOOT off a SHORT PIER and start DRILLING the core of motors to make REAL B14's on an AUTOMATED (non-manned) machine. If an 'incident' occurs, nobody is hurt and presents no real safety issue anyway. If distributed through normal 'discount' channels such as Hobby Lobby and Michaels, I would venture the B14-0 and B14-5 would out sell any other B motor except the B6-4 ! Remember Bigger (14 vs. 6 or 4) numbers ALWAYS sell better from an as-inine yet true marketing standpoint. That's why idiots randomly buy D12-7's and C6-7's when they don't know which to pick. Any way one slices it, as long as the price is competitive, the B14 will sell. Short of that even a B8 would be a VAST improvement over the engines we get now.

I still have a supply of both drilled-core and pressed-core B14's in my OOP motor supply. While the pressed-core motors do provide a pretty good liftoff punch, the drilled-core ones have a much more vigorous 'kick'. I have all flavors of the pressed-core B14 left but only have B14-0's and B14-7's with drilled-cores. Have B8's in all flavors but the Centuri-only B8-3, which I have NEVER physically seen in-person. Have seen several photos of that one that existed only one year.
__________________
When in doubt, WHACK the GAS and NEVER touch the brake !!!
No Harm=NO Foul advocate

If you are NOT FLYING LOW in the left lane, you need to GET THE #$&@ OUT of it !

Yes, there is such a thing as NORMAL
, if you have to ask, you probably aren't
!
Reply With Quote
  #30  
Old 05-16-2013, 02:13 PM
blackshire's Avatar
blackshire blackshire is offline
Master Modeler
 
Join Date: Jan 2009
Location: Fairbanks, Alaska
Posts: 5,556
Default

Quote:
Originally Posted by ghrocketman
Somebody with a set of STONES should give MAMBY-PAMBY safety a LONG RIDE on a LARGE BOOT off a SHORT PIER and start DRILLING the core of motors to make REAL B14's on an AUTOMATED (non-manned) machine. If an 'incident' occurs, nobody is hurt and presents no real safety issue anyway. If distributed through normal 'discount' channels such as Hobby Lobby and Michaels, I would venture the B14-0 and B14-5 would out sell any other B motor except the B6-4 ! Remember Bigger (14 vs. 6 or 4) numbers ALWAYS sell better from an as-inine yet true marketing standpoint. That's why idiots randomly buy D12-7's and C6-7's when they don't know which to pick. Any way one slices it, as long as the price is competitive, the B14 will sell. Short of that even a B8 would be a VAST improvement over the engines we get now.
I've seen it (and heard it, via conversations in hobby shops) happen--"This one's better, it's a 'see-six-SEVEN!'--while they were buying an accompanying rocket kit that required shorter-delay motors...
Quote:
Originally Posted by ghrocketman
I still have a supply of both drilled-core and pressed-core B14's in my OOP motor supply. While the pressed-core motors do provide a pretty good liftoff punch, the drilled-core ones have a much more vigorous 'kick'. I have all flavors of the pressed-core B14 left but only have B14-0's and B14-7's with drilled-cores. Have B8's in all flavors but the Centuri-only B8-3, which I have NEVER physically seen in-person. Have seen several photos of that one that existed only one year.
Although I can't speak for him, of course, there is a potential future supplier for such motors. John Wickman, the President of Wickman Spacecraft & Propulsion Company, is a former Aerojet engineer. He and Hermann Oberth's son developed a new, low-cost solid propellant that uses phase-stabilized ammonium nitrate, and he teaches amateur rocketry courses and sells publications on making these rocket motors (see: http://www.space-rockets.com/ ). Unlike G. Harry Stine, who categorically stated "There is no safe way to make a rocket motor of any type," Mr. Wickman counters (and has demonstrated numerous times, through his motor-making courses) that anyone who takes prudent safety precautions can make his or her own successful--and reliable--rocket motors (his students static fire and flight test their motors as the "final exam").
__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR
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 09:52 AM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe 1998-2018