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Agreed. No affiliation, nothing to hide. I wonder how we could chat with them? It would be quite valuable, especially in light of TRA's warning and NAR's lack of notice. If any certifying body has an issue - and some may be see issues others do not - the one entry would propagate to all ThrustCurve users.

Do you know anyone behind the site? If not, I'll just email webmaster and see what comes forth.
John Coker is one of the guys behind ThrustCurve.org.
 
I'll write him, thx.

I’ve corresponded with him already. He’s a good guy and may be willing to help, but I don’t think he wants ThrustCurve to be changed as much as this would be. Before dragging him further into this NAR and TRA need to make some decisions.
NAR and TRA are having a summit meeting in two weeks to talk about several things; this is one of them. When we know more we’ll probably say something on our respective websites or on the Tripoli Forum. It’ll take some time.
 
I recall this notice was issued jointly by NAR, TRA and their respective motor testing divisions. Emails were sent to members I believe, and NAR should have it listed somewhere still.
 
H410 in the Onyx? It looks like a Smoke. LOC says its cardboard is thick, but the Estes tube couldn't be called thick. Maybe if I CA in the 2mm CF rods from MM to NC...

BTW with the new weights the sim says 56G.

You folks wouldn't suggest this if it was irrational, would you? When she was 14, my daughter said "Dad, the word gullible is written on the ceiling over you." And I looked up.

H410 might be a little much. However, if you get the CTI starter set, the 2-grain G250 is an awful lot of fun too. You do need an altimeter to back up the motor deploy, but it's not too long before you have that given how quickly you're moving. Eggtimer has some really nice kits for altimeters, or you can buy them for $40 or so on the low end. The G250 hits my 2-pound LOC cardboard bird with 35+ G on the way to 1600'.
 
One reason to keep thrustcurve out of this- this ban is slightly controversial. It was knee jerk to a single ban event, and supported only by antidotal evidence. ;). The problem was never seen in smaller motors that I’m aware of, and yet it covers them too.

But it I don’t wanna kick that nest again (the above being mentioned only to illustrate why it’s an issue to get involved with these notices)


i think it’s best TRA and NAR maintain a motor notice page.
 
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Some of the very short burn time Warp 9 Aerotech reloads had on the instructions to plug the forward closure or run a plugged closure unit and use electronic deploy.
 
Thanks for looking over my shoulder. That seemed odd to me also, so I simmed the H165R and got an apogee of 1764' at 19G's. Not too far off from yours. Maybe the Smoke's wider NC and transition add enough drag to cause the difference?

No way you'll only get 1764. My Smoke tops over 2,000' on a G64.
 
i think it’s best TRA and NAR maintain a motor notice page.

You fellas obviously know the technical and political factors. Unfortunately, I already write John Coker cuz I'm just that way. Hopefully its politeness isn't seen as "kicking the nest" - which of course was not my intent.

Man, when will I learn to consider an action before taking an action???
 
No way you'll only get 1764. My Smoke tops over 2,000' on a G64.

Aw, I wonder what I'm doing wrong? FWIW I filled the fins with epoxy/microbubbles, increasing their weight from ~28g to ~42g. But still... that doesn't explain this.

If anyone has the time and motivation, here's the OR file.

Thank you for all you're doing for me!

*** Original OR file replaced ***

The ORK file I downloaded had a problem with the Transition that I didn't understand until today - it's fixed. The chute size was 30"; I reduced it to 24". Now it sims to 1971' on the H165R, as swatkat expected.

WRT >2000 on a G64, was that a 3" Estes Nike Smoke?

Updated OR file:

View attachment Estes Nike Smoke v2.ork
 
I ran several of the same motors..they all are in sync. The only thing that really matters is your project weight, .....have you put it on a scale yet? Everything else is just an approximation.

If it does weigh what you have in the sims....they are pretty good altitudes of what you should get.
I have flown many of those motors in similar size/weight rockets & sims seem close to what I would expect, with that weight.

After you have 2 flights [different motors, doesn't matter any 2] then adjust the drag slider in OR till the sim flights match the actual. Comparing the 2..till you get close. It may take several sim flights....so what..it's fun!

Rest of your sims can be as close as 2-3% of actual with a bit of simple tinkering. [sport flying]

When you start doing big motor/mach flights at high altitude, then things change quite a bit, as other factors must be considered.

So first things first...you have actual weight of rocket, ready to fly, sans motor?
I would guess you do the same or similar, with your gliders for pre-flight check on distance covered in various conditions... rate of climb...etc.
 
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So first things first...you have actual weight of rocket, ready to fly, sans motor?
I would guess you do the same or similar, with your gliders for pre-flight check on distance covered in various conditions...

Thanks for looking, CJ. The v2 file is much better. No... I don't have an actual weight yet, but I should by tomorrow.

We can't really glide-test the Smoke, but otherwise the R/C world is similar. Build it, find your personal CG, adjust it to slightly forward of mid-range, glide-test, then yell "Maiden!" and launch.
 
Agreed. No affiliation, nothing to hide. I wonder how we could chat with them? It would be quite valuable, especially in light of TRA's warning and NAR's lack of notice. If any certifying body has an issue - and some may be see issues others do not - the one entry would propagate to all ThrustCurve users.

Do you know anyone behind the site? If not, I'll just email webmaster and see what comes forth.

Just a thought... Maybe a new thread for everyone?

Possible Titles :
Motor verification
Motor Recall
How to check your motor
Manufacturer Recalls / Alerts.

I think you would get a lot of different opinions and reach some who are already in the know.. The trick is going to keep the data neutral so that it cant be taken as a slight against one manufacture or the other, or even another.

And if it was kept as "flyers motor info" it should also keep everyone clear of lawyers..

Would the mess report data be helpful also?

Just some ideas.

Great idea by the way!!!!
 
You fellas obviously know the technical and political factors. Unfortunately, I already write John Coker cuz I'm just that way. Hopefully its politeness isn't seen as "kicking the nest" - which of course was not my intent.

Man, when will I learn to consider an action before taking an action???

i wouldn’t lose any sleep lol. It’s not a terrible suggestion. It’s fairly logical in most ways.


Back tonthe smoke.... H238T is a reaaaalllllly cool motor, if you ever grab AT 29/180 hardware
 
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Just from looking at ThrustCurve, it seems it's driven by a SQL database. This makes it organized and searchable, free of clutter and opinions. If only NAR/TRA/CAR certification reps were granted access to the additional field, they would be posting documented issues that are traceable and verifiable.

If this was done as a thread or sub-forum here, it would be full of stories and rumors with no accountability. We're talking about lawndarts and other dangerous potentials, so I don't want chatter or potty-mouthing.

Depending on how ThrustCurve is implemented, since a NOTAM filing would be to a specific motor, the database could fire off a notification to the manufacturer. I'm sure TRA/NAR does something like that, but this is (a) redundancy, and (b) a legal positive.

The issue of attorneys is real. My wife is an attorney for the CA AG so I see a lot of things. There is some issue of liability for misuse of the system, but I believe it's overriden by two facts. The posters are personally authorized by NAR/TRA, and the public benefit outweighs the potential for misinformation. Courts do a "balance of justice" test when there are competing motivations. Here, with the right safeguards, mfr notification and public safety benefits, I believe any litigation from disputed entries would lose, perhaps in an MSJ.

On another note, geez Louise, who came up with this OR file? My goodness, the NC weight and dimensions were wrong, as was the BT, and the fins weren't the right size. When all the mods are made, it's now showing 0.99 - 1.05 cals stability with an empty mass of 550g. Better sims, too. Here's the file, but I'm done with it until I can measure the Smoke.

View attachment Estes Nike Smoke v3.ork
 
BAR's L1 cert deal does sound nice. I'm committed to the H115DM at this point, primarily for the spark shower and single-use DMS simplicity, but it also has a nice thrust curve; 12.1 Gs and apogee almost 2000'. Funny thing, the H128 pushes 15.4Gs but only 1650' apogee. I don't want to sim my life away, but it's extremely interesting to see how thrust curves relate to performance.

The CTI starter 29mm start set with 3- and 6-grain cases, etc., is also high on my list. Having Mike come to the launches makes CTI affordable in small quantities.

Hey, not to bring this thread back on-topic, but at some fields, on some days, sparky motors might be restricted on account of fire danger. Not sure if it is a consideration where you are planning to fly, but when I was choosing a motor for L1 I picked the H182R DMS over the H115DM DMS so that I wouldn't have to worry about it.

I just had this funny thought about base drag while assembling the MM. Given this equation:

BaseDrag1.png

...we can reduce base drag in the coast phase by "extending the tail cone". I'm visualizing an iris diaphragm as an example, but something conical that a servo could extend when a G meter detects MECO. Triangular "teeth" hidden within a typical tail cone, retracted until coasting begins, then extended until they mesh with each other. If they converged to zero diameter, according to the equation we'd have zero base drag (in a perfect world). Remember Dd is base diameter, Db is Diameter of Body.

It should work and maybe help set altitude records. The longer the coast time, the greater the benefit. If someone likes this idea and tries it, please let me know. I won't be in that build space for a while.

I like it. A self-boosting boosted dart.
self_boosted_dart.png

I am imagining something like the spring-loaded fins on breech-launched rocket flares -- but in reverse.

https://aeroconsystems.com/cart/rockets/the-flippifin-breech-launched-model-rocket/

3 or 4 spin-fins that close up to make a Haack-Sears fairing on motor burn-out.
 
Just from looking at ThrustCurve, it seems it's driven by a SQL database. This makes it organized and searchable, free of clutter and opinions. If only NAR/TRA/CAR certification reps were granted access to the additional field, they would be posting documented issues that are traceable and verifiable.

If this was done as a thread or sub-forum here, it would be full of stories and rumors with no accountability. We're talking about lawndarts and other dangerous potentials, so I don't want chatter or potty-mouthing.

The trouble with motor issue reporting, is the most reliable method we have is the MESS report. people have an issue, they fill it out with as much info as possible. The "powers that be" review these and make choices about when action needs to be taken.

However. The manufactures refuse to release production numbers. The two certifying organizations refuse to release the MESS report data to the public.

Basically, you have statistically worthless information. The only real check on manufacturers is that they all provide a warranty against defect, and replace load and case in the event there is an issue. People are highly likely to report a malfunction to Estes, AT or CTI. MESS reporting is spotty at best. People benefit from reporting to the manufacturer. There is zero reason to file a MESS report, and you don't even get data back from it. Like pissing into a black hole.

The most accurate way to be aware of issues, is direct observations, and watching the forums here for reported issues. Manufacturers will only make adjustments if it affects the bottom line, NAR and TRA do not have the data to make any kind of supported choices, and rumor and chatter are the best options for fliers to listen to.

*dons fire retardant suit*

The only way we as fliers could get significant data, is if all clubs recorded all flights and the results (most do) and reported all flights to a database (none do)
 
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The trouble with motor issue reporting, is the most reliable method we have is the MESS report. people have an issue, they fill it out with as much info as possible. The "powers that be" review these and make choices about when action needs to be taken.

However. The manufactures refuse to release production numbers. The two certifying organizations refuse to release the MESS report data to the public.

Basically, you have statistically worthless information. The only real check on manufacturers is that they all provide a warranty against defect, and replace load and case in the event there is an issue. People are highly likely to report a malfunction to Estes, AT or CTI. MESS reporting is spotty at best. People benefit from reporting to the manufacturer. There is zero reason to file a MESS report, and you don't even get data back from it. Like pissing into a black hole.

The most accurate way to be aware of issues, is direct observations, and watching the forums here for reported issues. Manufacturers will only make adjustments if it affects the bottom line, NAR and TRA do not have the data to make any kind of supported choices, and rumor and chatter are the best options for fliers to listen to.

*dons fire retardant suit*

I don’t think you need a fire retardant suit, David. You hit the nail on the head with respect to MESS data. If we NAR and TRA) has production data, I would be in favor of releasing MESS reports as long as we could do it without disclosing proprietary data or business sensitive data. I don’t know how that would work, but I think it would be better than what we have now.
The problem is that right now all we have is partially complete and woefully inconsistent numerator information. If we have 30 people reporting catos with the Shannon G-66 Motor, it makes a difference whether there were 5,000 sold or 50. And really it’s not even so much the number sold as it is the number flown. If we could get accurate and comprehensive data from all the flight cards we could probably have a meaningful conclusion. But we’d need an army of data wranglers.
I wish I had the answers.
 
I love data, so I'd love to see all the flight cards standardized and entered. That'd be ideal. Having been part of running a club, I realize how hard it is just to get enough people around just to hit the button.

Realistically, I think what we do now is the best we can. I do think it'd be nice if the manufacturers released production and warranty data... but understand the hesitation.
 
Thanks Dave and Steve for your thoughtful, insightful accounts of how things are.

As a new viewer of the hobby, I see two processes that are related but independent. What you've addressed Steve is the "hard problem" of deciding when to make a mandatory directive. It was great to read your logic, and statistically spot-on.

From my point of view - known to be new and limited - the process of notifying the public once a decision has been rendered is what I'm discussing. After reading your info, it may be the case that "the field" needs to be N fields for N certifying agencies. Again, the goal is disclosure that otherwise is difficult to find. N fields let each certifying agency make a decision that need not require similar behavior from others, but users could still see the merits of the agency's decision and choose how to proceed.

While shopping for groceries, I had this attorney-thought. This thinking happens by osmosis when you live with an attorney. So, just let me be devil's advocate, what if ThrustCurve recommended a motor for a rocket, in this instance, an H410. The rocket lawndarts, kills Schrodinger's cat in the process, and Schrodinger sues ThrustCurve because it was a recommended motor.

Forgive me. I don't like devil's advocate stuff. I'm a one-man shop and sometimes have to consider these things even though I don't like them. I bring it up only in the spirit of helpfulness.
 
Aw, I wonder what I'm doing wrong? FWIW I filled the fins with epoxy/microbubbles, increasing their weight from ~28g to ~42g. But still... that doesn't explain this.

If anyone has the time and motivation, here's the OR file.

Thank you for all you're doing for me!

*** Original OR file replaced ***

The ORK file I downloaded had a problem with the Transition that I didn't understand until today - it's fixed. The chute size was 30"; I reduced it to 24". Now it sims to 1971' on the H165R, as swatkat expected.

WRT >2000 on a G64, was that a 3" Estes Nike Smoke?

Updated OR file:

I haven't weighed mine but the 26oz empty weight on your file seems a little pessimistic. I won't be able to weigh mine for another four days. Additionally, the launch lugs on your file show a .6" inside diameter and .67" outside diameter, which is too big and probably adding drag in the sim.
 
Thanks Dave and Steve for your thoughtful, insightful accounts of how things are.

As a new viewer of the hobby, I see two processes that are related but independent. What you've addressed Steve is the "hard problem" of deciding when to make a mandatory directive. It was great to read your logic, and statistically spot-on.

From my point of view - known to be new and limited - the process of notifying the public once a decision has been rendered is what I'm discussing. After reading your info, it may be the case that "the field" needs to be N fields for N certifying agencies. Again, the goal is disclosure that otherwise is difficult to find. N fields let each certifying agency make a decision that need not require similar behavior from others, but users could still see the merits of the agency's decision and choose how to proceed.

While shopping for groceries, I had this attorney-thought. This thinking happens by osmosis when you live with an attorney. So, just let me be devil's advocate, what if ThrustCurve recommended a motor for a rocket, in this instance, an H410. The rocket lawndarts, kills Schrodinger's cat in the process, and Schrodinger sues ThrustCurve because it was a recommended motor.

Forgive me. I don't like devil's advocate stuff. I'm a one-man shop and sometimes have to consider these things even though I don't like them. I bring it up only in the spirit of helpfulness.

The Devil’s Advocate is a necessary part of vetting a pope or saint. I’m neither, but I thoroughly enjoy hearing various opinions.
Schrödinger would have a difficult time proving the rocket killed his cat because he can’t say for sure that the cat was alive.
Mandatory rules need to be minimal in a hobby, but when needed we must do them. I don’t think this is one of those instances.
I’m not sure I understand the use of “N” fields, even though I’m also a sucker for a good relational database. Please explain or maybe provide an example.
Thanks for the great discussion!
 
Hi Folks,
Just planning ahead for an L1 attempt much later in the season, quick question....Is there any significant difference between the Madcow Super DX3 kit and the Torrent kit that Madcow makes exclusively for Apogee Components? I'm pretty much settled to the DX3 or variant, but just wondering if one is better/more durable/easier to build and set up than the other? I plan on building a ship for L1 cert. and flying it on smaller engines first to dial in the recovery system (gonna use a JLCR and drogue), then hopefully fly a L! cert. flight before the end of the year....
Any advise or suggestions would be appreciated!
Thanks!
Franz in NJ
 
I think the DX3 looks a lot like the HyperLOC 835 I'm working or.

Sent from my VS988 using Tapatalk
 
Schrödinger would have a difficult time proving the rocket killed his cat because he can’t say for sure that the cat was alive.

You have an umlaut, good for you. I agree, from the time the rocket should have impacted the ground until the time Herr Schrödinger observed the cat, the cat was in a superimposed state of 99.99999% alive and 0.00001% dead. To be honest, I have never understood why the cat's consciousness didn't collapse the wave equation, but for now it seems you have to be human or degreed to do so.

I’m not sure I understand the use of “N” fields, even though I’m also a sucker for a good relational database. Please explain or maybe provide an example.

For each
motor in the database, there are data points unique to the motor (e.g. thrust curve) and data points that related to other motors (e.g. 29mm vs. 38mm). The latter are "relational" fields, thus "relational database". Some of the fields in a motor's database entry are unique to the motor.

At first I suggested each motor have a field for NOTAMs (for lack of defined word). When I later said "N fields", the idea was there would (for each motor) be a NOTAM field for NAR, TRA, CAR and other agencies ("N agencies"). This lets each agency state or not state an opinion on a motor, and the user could see all of them to decide for hirself. This leaves no room for preference, rather, it leaves room for a difference of opinion. Each agency is not bound by any others' decisions, but each agency can remark if they wish.

Thinking about what I wrote, this implies the automatically generated notification to a manufacturer should be also be sent to all participating agencies, or they're behind the power curve. This is where we get to what you talked about, the "hard problem" of de-cert or issuing a warning. In this scheme, TRA would know if NAR dissed a motor, and then could take any action it deemed appropriate - which includes no action. By having "N fields", the decision not-to-decide is clear, giving the user a bit of thinking space.

Thanks for the great discussion!

Thank you for your respect of a complete rookie. This hobby is full of gentlemen.
 
Herr VonRektofen,

Lies diesen Thread ... die DX3 ist sehr komplex. Behalte es einfach, dann halte den Daumen.

Schoenen guten Abend,

Steinhund
 
An often overlooked factor with cat is even if it was proven the cat was alive before impact and dead shortly after, the transgressors would only be 1/9th liable.


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