R142:Aerotech C3.4 and D2.3 Certification

[billspad]

The following motors have been certified by NAR Standards & Testing for
general use as Model Rocket Motors effective July 19, 2013.




*************************************
Aerotech:
C3.4-P
18mm x 72mm
8.96 Newton-seconds Total Impulse
9.08 Newtons Peak Thrust
3.14 Newtons Average Thrust


Propellant mass: 5.2 grams






D2.3-P
18mm x 72mm
17.21 Newton-seconds Total Impulse
10.14 Newtons Peak Thrust
2.12 Newtons Average Thrust


Propellant mass: 10.7 grams


*************************************

 

[GregGleason]

Well. These look interesting. They look like they are long-burners.

Any idea when they will show up on the NAR S&T approved motors list?

Greg

 

[5x7]

Are these single use or reloads?

 

[GregGleason]

Answered my own question*:

6.10 Approval for Use in NAR Competition
Model rocket motors which are granted NAR certification will also be listed by S&T in official NAR motor
certification lists as “approved for use in NAR competition”, if the motor is available to dealers and/or
consumers from the manufacturer and is therefore available for purchase by any consumer in the U.S.

6.10.1 The approval for competition must be made effective by S&T no less than 60 days after the date of
publication of the notice of certification of that motor by S&T.

Greg

* Source: National Association of Rocketry - Standards & Testing Committee Motor Testing Manual - Version 1.4

 

[billspad]

Are these single use or reloads?

Reloads using a plugged casing.

If someone can tell me how to post a pdf I'll put the engine data sheets here. I think I've done it before but I can't remember how I did it.


They're approved right now for sport flying. Competition certification just requires S & T knowing that they're generally available.

 

[5x7]

Thanks! What is the propellant?

 

[GregGleason]

Bill, for adding .pdf's (or any file), do the following:

Click "Go Advanced", then look for the "Manage Attachments" button.

Click it, then click the "Add Files" button. Navigate to where the file is and select it. Then click "Upload Files".

Add another as needed.

Then click "Done" when you are finished.

Greg

Note: There is a file size limit of 1.91 MB per .pdf on the forum.

(I just walked myself through the process)

 

[accooper]

I wish they would come out with some other 18mm reloads. It's fun tinkering with those small cases!

 

[chadrog]

Reloads using a plugged casing.

A plugged casing? I suspected that's what the "-P" meant. So a glider only motor?

 

[billspad]

Okay, there should be a couple of engine data sheets here. The page with the RASP data isn't done yet but I attached a couple of unofficial ones. Jack usually goes through them to make sure the ones he puts on the data sheet are typical. I picked these at random but the motors were consistent so the real files won't be much different.

The propellant is Blue Thunder. That's pretty much all I know so you should direct any other questions to Aerotech.

View attachment ATC3 4-PT.pdf

View attachment ATD2 3-PT.pdf

View attachment at130702.eng

View attachment at130721.eng

 

[GDJ]

Well, even for a LPR with a small altimeter plugged motors shouldn't be a real issue, unless we aren't allowed to run a separate ejection charge in LPR flying. The smallest altimeter with deploy features are light enough nowadays.

 

[Rocketjunkie]

Well, even for a LPR with a small altimeter plugged motors shouldn't be a real issue, unless we aren't allowed to run a separate ejection charge in LPR flying. The smallest altimeter with deploy features are light enough nowadays.

Glider motors. Don't see much other use. Way too likely to lose case and altimeter. Probably not enough lifting power to add a tracker.

 

[GregGleason]

Thanks for posting those Bill.

I did notice that on the X-Y axes of the thrust curves were not marked with any values.

Greg

 

[GDJ]

Glider motors. Don't see much other use. Way too likely to lose case and altimeter. Probably not enough lifting power to add a tracker.

I dunno. A lightly built rocket with BT-55 tubing should work.

That or it would make one heck of a upper stage motor (since it doesn't have to work to lift the rocket up and it's flying fast already). Kind of like the E9.....but with WAY more burntime.

 

[chadrog]

They're making rocket motors that are not very good for rockets - ???. I think it would make much more sense to make these 18mm loads use the current hardware, the hardware that everyone ALREADY HAS, that way the ejection charge is optional. These won't be around long if their only effective use is in small boost gliders. Why would they bother to develop and produce something that has such a small market? Sure electronic deployment is a possibility, but how many people would actually go to the trouble?

 

[GDJ]

Sure electronic deployment is a possibility, but how many people would actually go to the trouble?

I would, if the results were worth the effort.

 

[billspad]

Thanks for posting those Bill.

I did notice that on the X-Y axes of the thrust curves were not marked with any values.

Greg

We noticed that too. We wanted to make sure the certification got done so that if Aerotech wanted to demo one at NARAM there wouldn't be the hassle of getting approval to fly an uncertified motor. As a result the paperwork isn't as nice as it should be. Here are a couple of curves that will give you a better idea.





These were made from a data set that had a lower sample rate than was actually collected.

 

[shreadvector]

Internats motor.

 

[5x7]

Monocopters! These will be really great.
https://www.artapplewhite.com/monocopters.html

The copters for 18mm are only 10 dollars. They would be amazing on the D.

 

[patelldp]

Monocopters! These will be really great.
https://www.artapplewhite.com/monocopters.html

The copters for 18mm are only 10 dollars. They would be amazing on the D.

I'd go so far as to say they love the D.

 

[kenstarr]

but how many people would actually go to the trouble?

I did. Have an 18mm carbon fiber rocket with modified adept22 and featherweight magnetic switch itching to be flown in a couple weeks!
Probably not a lot of others doing that I suspect...
-Ken

 

[TheAviator]

Nope, but I just built a glider that would go crazy on the D motor.

 

[Rocketjunkie]

I did. Have an 18mm carbon fiber rocket with modified adept22 and featherweight magnetic switch itching to be flown in a couple weeks!
Probably not a lot of others doing that I suspect...
-Ken

Got room for a tracker? It will be a hissyfit to infinity :wink:

 

[mwtoelle]

Internats motor.

The FAI still does not allow reloadable motors in international competition. Only single use motors in nonmetallic cases are allowed.

 

[JPVegh]

The lack of ejection will limit the use of these even as a glider motor. So much for my plans to use these in BGs, oh well.

 

[Peter Olivola]

The continued miniaturization of components makes these ideal for RC boosted gliders.

The lack of ejection will limit the use of these even as a glider motor. So much for my plans to use these in BGs, oh well.

 

[TheAviator]

I flew a couple of these motors last week, and I have to say that they are a blast. The reason they have no ejection charge is that they are end burners, which doesn't play well with composite delays. I flew both the C and the D in a ~95g RC glider and it got nearly out of sight on the D. Keith Vinyard flew them in a ~50g RC glider and boosted to a speck in the sky. The nice thrust kick at the beginning is due to a deep slot in the grain, and makes the motor suitable for light (probably <100g) models with electronic deployment.

As far as why AT would develop these motors, I think this is essentially the internats D3 in a reloadable case, so not that much legwork on AT's part, but a cool new product.

 

[Rocketjunkie]

The single use D3's Apogee sold had delays. I never had a delay problem with them.

 

[Peter Olivola]

Some of us loved them (and NARAM trophied with them.) Some never figured out how to light them. Never saw a delay problem with, not that it mattered in NAR contest flying at the time.

The single use D3's Apogee sold had delays. I never had a delay problem with them.