S8D for noobs?

madcow rocketry
rocket sok
The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Doug Holverson

Doug Holverson

Well-Known Member
Joined
Jul 4, 2012
Messages
655
Reaction score
595
A friend is asking me about S8D out of the blue. I mainly know that it exists. Where does anyone begin?
 
This has good background on coverting for both S8E and S8D, Note S8E will be transitioning to S8D/P with a slighly larger minimum wingspan than S8D which does not have the precison aspect as the senior class.
Also, both the D2.3 and C3.4 are only being maybe yearly produced, Balsa machining has a few C3.4's... I do still carry D2.3's The new S8D/P may require a new 18mm D motor with a higher average thrust maybe...

 
Last edited:
MANY S8 flights flown today at the World Spacemodeling Championships near Austin. If I hadn't been so busy wrangling altimeters and data for the S1 flyers, I'd have watched some. Brian Muzek is among those participating today.

Really challenging conditions with gusty winds.

S8D would be S8 flown on D impulse motors.
 
I came down to the WSMC for Wed afternoon and Thursday. I enjoyed seeing a number of the Jr S8D flights and the two fly off rounds Wed afternoon for S8E. Meant to be here sooner, but life is plan B.

During the fly off rounds, the top 5 (if I recall correctly, might have been 6) models were launched in rapid succession and flew more or less together. From my viewpoint, they all boosted up and transitioned in front of a big white cumulus cloud. A beautiful sight!

At the event now. The scale activity had a little rain after lunch, but is is beautiful again, a little cooler and things are about to resume.

There were some “exciting” scale flights this AM during Jr S7….:) Not to worry: everyone survived, no injuries.
 
Last edited:
BEC said:
MANY S8 flights flown today at the World Spacemodeling Championships near Austin. If I hadn't been so busy wrangling altimeters and data for the S1 flyers, I'd have watched some. Brian Muzek is among those participating today.

Really challenging conditions with gusty winds.

S8D would be S8 flown on D impulse motors.
Click to expand...
Yes, there would be S8D for juniors and S8D/P for seniors with .9 meter and 1.1 meter wingspan requirements respectively I believe.
 
tab28682 said:
I came down to the WSMC for Wed afternoon and Thursday. I enjoyed seeing a number of the Jr S8D flights and the two fly off rounds Wed afternoon for S8E. Meant to be here sooner, but life is plan B.

During the fly off rounds, the top 5 (if I recall correctly, might have been 6) models were launched in rapid succession and flew more or less together. From my viewpoint, they all boosted up and transitioned in front of a big white cumulus cloud. A beautiful sight!

At the event now. The scale activity had a little rain after lunch, but is is beautiful again, a little cooler and things are about to resume.

There were some “exciting” scale flights this AM during Jr S7….:) Not to worry: everyone survived, no injuries.
Click to expand...
If you come out again tomorrow for S2/P stop by the altimeter tent and say hello (if we're not swamped with business at the time).
 
Keenly interested as well. Zero background experience, but one of my Jrs wants to do S4A next year and the other S8D.
 
Learning to control the S8D ( S8, too, for that matter ), during powered flight, is probably the most difficult obstacle to overcome . . .

99% + of S8-type models will not Boost "Hands-Off", successfully, to Apogee.

Also, "S8-type" models are not launched vertically, but at a much shallower angle.

Dave F.

 
Last edited:
Ez2cDave said:
Learning to control the S8D ( S8, too, for that matter ), during powered flight, is probably to most difficult obstacle to overcome . . . 99% + of S8-type models will not Boost "Hands-Off", successfully, to Apogee. Also, "S8-type" models are not launched vertically, but at a much shallower angle.

Dave F.
Click to expand...
It is important to have a nearly vertical boost. The rules state that the model’s ascent trajectory must be within 30 degrees of either side vertical. It is difficult for the Range Safety Officer (RSO) to accurately judge the +/-30 degree “cone” when stationed near the launch site. Therefore, it’s important to have a smooth, near vertical boost to avoid being disqualified. Models that have jerky “stair stepping” trajectories
 
burkefj said:
It is important to have a nearly vertical boost. The rules state that the model’s ascent trajectory must be within 30 degrees of either side vertical. It is difficult for the Range Safety Officer (RSO) to accurately judge the +/-30 degree “cone” when stationed near the launch site. Therefore, it’s important to have a smooth, near vertical boost to avoid being disqualified. Models that have jerky “stair stepping” trajectories
Click to expand...
Agreed . . . I edited my previous post and inserted this video.

 
BEC said:
If you come out again tomorrow for S2/P stop by the altimeter tent and say hello (if we're not swamped with business at the time).
Click to expand...
Alas, could only be there Wed/Thur. Kept an eye out for you (saw you were going to be there via your posts). Ran in to a few folks I know.

Sure enjoyed what I was able to see.

Highly unlikely to ever be another WSMC within a 2.5 hour drive from my house in the remainder of my lifetime….:)
 
Last edited:
Yeah, but none of them look like the Space Shuttle, fighters, or the Klingon Deep Space Fleet.

:eggnog:

Joking aside, this has been very helpful.
 
tab28682 said:
Alas, could only be there Wed/Thur. Kept an eye out for you (saw you were going to be there via your posts). Ran in to a few folks I know.

Sure enjoyed what I was able to see.

Highly unlikely to ever be another WSMC within a 2.5 hour drive from my house in the remainder of my lifetime….:)
Click to expand...
Well, as frantic as it was in the altimeter tent on Friday it is just as well. I wouldn't have been able to give you more than 10 seconds. We expected 39 competitors in S2/P but four members of the Chinese team were added, so we had 43 people, each trying to get a flight in during a one hour round, then getting their Adrels read, results documented, then swapped with another altimeter (ad a topped up cell) for the next round. And we started the morning with 37 good Adrels (and two more released after a Romanian protest over a couple of S5 flights on Thursday was denied). Then repeat again for a third round, and after that they all wanted their deposits back. Avis, Dan, Will and I, even with some assistance from Rachel Nowak and Chris Kidwell, were swamped pretty much until the third round was over at 11:15.

We just got home — a one hour drive, four hour flight, then 20 minute drive.
 
Last edited:
BEC said:
Well, as frantic as it was in the altimeter tent on Friday it is just as well. I wouldn't have been able to give you more than 10 seconds. We expected 39 competitors in S2/P but four members of the Chinese team were added, so we had 43 people, each trying to get a flight in during a one hour round, then getting their Adrels read, results documented, then swapped with another altimeter (ad a topped up cell) for the next round. And we started the morning with 37 good Adrels (and two more released after a Romanian protest over a couple of S5 flights on Thursday was denied). Then repeat again for a third round, and after that they all wanted their deposits back. Avis, Dan, Will and I, even with some assistance from Rachel Nowak and Steve Kidwell, were swamped pretty much until the third round was over at 11:15.

We just got home — a one hour drive, four hour flight, then 20 minute drive.
Click to expand...
The UK team would like to thank all of the Adrel operators for your service
 
I agree with Will — thanks for being such great folks to work with.

And since I can't edit the quote, I need to note it was Chris Kidwell who was helping during the round 2/round 3 crush yesterday....not Steve.... :oops:
 
Ez2cDave said:
Learning to control the S8D ( S8, too, for that matter ), during powered flight, is probably the most difficult obstacle to overcome . . .

99% + of S8-type models will not Boost "Hands-Off", successfully, to Apogee.

Also, "S8-type" models are not launched vertically, but at a much shallower angle.

Dave F.

Click to expand...

They are near vertical, not at a “much shallower” angle.
 
These photos are probably within 10 degrees of vertical from the latest WSMC, you cannot go more than 30 degrees during boost or get disqualified in FAI S8 no matter what the safety code allows and since it is so hard to judge this and the risk associated is is preferred to boost more or less vertical. Slight angle away helps in pulling vertical after leaving the pad since it is often more difficult to push a model away than pull up and can avoid getting behind you and getting disqualified due to angle. Due to pitch down or wind I don't think anyone would really risk starting at a pad angle of 30 degrees in any case.

This is the official guidance in the NAR webpage on S8 competition: "It is important to have a nearly vertical boost. The rules state that the model’s ascent trajectory must be within 30 degrees of either side vertical. It is difficult for the Range Safety Officer (RSO) to accurately judge the +/-30 degree “cone” when stationed near the launch site. Therefore, it’s important to have a smooth, near vertical boost to avoid being disqualified.

There are advantages with heavier models to boosting at more of an angle letting the wing do the lifting instead of the motor and letting the motor build up speed, but not in this case as much due to the restrictions of the rules.

356415555_10159691765929542_5945386854981325771_n.jpg358393956_10159707097574542_7196159208576919596_n.jpg
 
burkefj said:
These photos are probably within 10 degrees of vertical from the latest WSMC
Click to expand...
Can confirm that everyone was launching at about a 10-degree boost angle. Any closer to the 30-degree limit than that and you're giving up precious altitude and flirting with a DQ, any closer to vertical and you will have perspective challenges on boost.

Of particular note is the fact that this event was operated under an FAA-issued waiver to the 400' AGL altitude limit imposed upon UAS systems by Section 44808 of the Federal Aviation Regulations. The team at the Academy of Model Aeronautics guided us through the process, which allowed flights to the base of Class E airspace over the launch site, or 1.200' AGL. This was one of the first waivers for these operations ever issued.

In addition all S8 pilots, both US and foreign, had all of the proper registration documentation to fly legally in the US.
 
James Duffy said:
Can confirm that everyone was launching at about a 10-degree boost angle. Any closer to the 30-degree limit than that and you're giving up precious altitude and flirting with a DQ, any closer to vertical and you will have perspective challenges on boost.

Of particular note is the fact that this event was operated under an FAA-issued waiver to the 400' AGL altitude limit imposed upon UAS systems by Section 44808 of the Federal Aviation Regulations. The team at the Academy of Model Aeronautics guided us through the process, which allowed flights to the base of Class E airspace over the launch site, or 1.200' AGL. This was one of the first waivers for these operations ever issued.

In addition all S8 pilots, both US and foreign, had all of the proper registration documentation to fly legally in the US.
Click to expand...
So, under unwavering conditions contestants have to do some pretty fancy flying to stay within the 30 degree cone and under the 400 foot limit?:rolleyes:
 

Similar threads

S
Flight Systems motors
Replies
0
Views
148
skaffgeorge2
S
COSTransplant
Syracuse Blue Spray Paint
Replies
5
Views
458
tsmmiller
tsmmiller
K
Best Practices -- Featherweight AV-Bay -- Active End Up or Down ?
Replies
8
Views
488
manixFan
manixFan
billeblurzz
Estes Black Brant XII
Replies
6
Views
401
billeblurzz
billeblurzz
Buckeye
How long is your booster stage?
Replies
15
Views
960
cls
C

Latest posts

Back
Top