LDRS multistage Stage F50SS-0 challenge

[Scott S]

Registered LDRS Flyers,

I've had some Rocketflite F50SS-0 motors in my magazine for a while now with the intention of building a 2 or 3 stage rocket. I just don't have the time so I'll provide 4 F50SS-0 motors to an LDRS registered flier to design, build and fly the motors at LDRS. Here's a thread showing a 5 stage rocket using the larger G motors.

Here's the rules:
- Must be a registered flier when you submit your design
- Must attend and fly the rocket Saturday (weather permitting)
- Designs posted to this thread with rocksim / openrocket available upon request
- obviously, stable flight a must
- discuss recovery method in your post
- it must be at least a 2 stage rocket.
- at a minimum it must use all 4 F50SS motors

other than that it's up to the design builder, coolest project gets the motors. I'll entertain opinions on the best project from the forum but I decide the winner. Winner will be selected Sunday Feb 12, 2017.

Disclaimer - winner understands these are 1994 motors and any damage or loss of the rocket is not my responsibility. It's just part of the fun!

Let's see those design, Scott

 

[rstaff3]

This should be fun to watch. How about 4 canted F50s to 4 F15s to....

 

[Scott S]

Dick - I was hoping to see what you would come up with, are you in? Scott

 

[MClark]

These motors are well over a decade out of certification.
I don't think they can be used at a regular launch

M

 

[blackbrandt]

But given that LDRS is a research launch, I believe they are able to be flown.

 

[Scott S]

Let me check into this, want to be sure we are following TRA guidelines.

These motors are well over a decade out of certification.
I don't think they can be used at a regular launch

M

 

[BigDuphis]

2 F50 to 2 F50 to 2 F15?

 

[rstaff3]

Dick - I was hoping to see what you would come up with, are you in? Scott

I wish. Not much time to build between now and then. Probably will just watch on Saturday.

 

[rstaff3]

2 F50 to 2 F50 to 2 F15?

I say keep all the sparks as close to the watchers as possible. Cant them to spread the out.

 

[Scott S]

But given that LDRS is a research launch, I believe they are able to be flown.

I'm hearing Matt is correct with one possible exception, US Rocket motors. So I think we are good to go.

 

[rstaff3]

That would be a weird exception, indeed.

 

[rstaff3]

If it doesn't happen, maybe some other MDRAers will reply and it can go up in the the summer.

 

[BDB]

This might fit well with a project that I've been planning, and it would give me a good reason to attend LDRS. (Honey, a guy I met online is going to give me four awesome motors. The trip practically pays for itself!)

I have never flown these motors, so can you provide a little more information about them? I know they are 29 mm, but what is the length? Is it true that Rocketflight booster motors burn through like an Estes D12-0, or are they plugged? Thanks.

 

[Rocketjunkie]

The previously mentioned video was mine. Note that they are not a true zero delay, the G's were 2-3 seconds. The 'delay' is the same propellant and produces a few sparks. The front of the motor has a clay bulkhead with a hole. You run a piece of quickmatch from the hole up into the next motor. There will not be burning chunks blown forward like Estes motors. If you cluster them, you must assume they will not all burn through at exactly the same time. You must allow each stack to stage separately, either independent sustainers or boosters.

 

[Scott S]

This might fit well with a project that I've been planning, and it would give me a good reason to attend LDRS. (Honey, a guy I met online is going to give me four awesome motors. The trip practically pays for itself!)

I have never flown these motors, so can you provide a little more information about them? I know they are 29 mm, but what is the length? Is it true that Rocketflight booster motors burn through like an Estes D12-0, or are they plugged? Thanks.

The motor is 7" long. The clay bulkhead mentioned below is recessed about an inch into the motor. I searched for a thrust curve but was unable to find one.

The previously mentioned video was mine. Note that they are not a true zero delay, the G's were 2-3 seconds. The 'delay' is the same propellant and produces a few sparks. The front of the motor has a clay bulkhead with a hole. You run a piece of quickmatch from the hole up into the next motor. There will not be burning chunks blown forward like Estes motors. If you cluster them, you must assume they will not all burn through at exactly the same time. You must allow each stack to stage separately, either independent sustainers or boosters.

Thanks for the info Tom. That would have been a disappointing over site.

 

[MClark]

Form Combined CAR/NAR/TRA Certified Rocket Motors List, https://nar.org/SandT/pdf/CombinedList.pdf

"This list may indicate that a motor is "expiring" on a given date. This means its certification for general use will be withdrawn on the indicated date. The expiration date is three years after the motor is deemed de-certified, to give flyers time to use up any motors they have already purchased. After the expiration date passes, the motors can no longer be used....."

Maybe Bob K can give us an official call.
Better to find out now than from the RSO.

M

 

[rstaff3]

The way I read the TRA research code is that any motor that has ever been certified can be flown at a reseach launch. But, if it were me I'd rather hear that from the TRA overlords. Afterall, we MDRAers generally aren't worried about that.

 

[Steve Shannon]

The way I read the TRA research code is that any motor that has ever been certified can be flown at a reseach launch. But, if it were me I'd rather hear that from the TRA overlords. Afterall, we MDRAers generally aren't worried about that.

I'm still learning as a freshman board member, so I'm not speaking for the board, but that's how I understand it also. The only exception would be a motor that had its certification revoked for some reason (safety or legality come to mind).


Steve Shannon

 

[rstaff3]

I'm still learning as a freshman board member, so I'm not speaking for the board, but that's how I understand it also. The only exception would be a motor that had its certification revoked for some reason (safety or legality come to mind).


Steve Shannon

Thanks for the feedback and the last two issues (in parens) need to be ruled on. My mind tells me the Rocketflite motors have been used at TRA events in recent history. But, my mind tricks me regularly.

The fallback solution is easy. The person that wins should agree, if the motors are disallowed and they can't attend a later MDRA event, that they leave their rocket with Scott and he will fly it

 

[Steve Shannon]

Thanks for the feedback and the last two issues (in parens) need to be ruled on. My mind tells me the Rocketflite motors have been used at TRA events in recent history. But, my mind tricks me regularly.

The fallback solution is easy. The person that wins should agree, if the motors are disallowed and they can't attend a later MDRA event, that they leave their rocket with Scott and he will fly it

A brief email consultation with the other board members confirmed that motors with certifications that have expired rather than being decertified for cause may indeed be used at Tripoli Research Launches. That's official.

I'd like to also put in a plug for the Tripoli Forum as the best place to request interpretations of current rules.

Steve Shannon

 

[rstaff3]

Good to know. Some of us in the peanut gallery don't have access. Doesn't stop me from speculating Looking forward to crazy and or wonderful rockets to burn those sparlies!

 

[Scott S]

Looks like this is a bust, thought there would be more interest. Going to scrap this.