Aerotech F44 "Econo-Max" 24mm x 70mm ???

Anyone have certification news on these? They have appeared on some online retailer websites as 'coming soon'.

https://www.hobbylinc.com/htm/aro/aro64408.htm

Nothing on the NAR S&T website or the combined cert list.

If nobody here has heard about them I might just have to call or e-mail Aerotech later today. I'm waiting and posting this here to see if I was asleep and missed previous discussion or news about this motor.

Thanks!

And let's add the G74 29mm Econo-Max to this query as well........

I noticed these too but haven't seen anything on the Aerotech Facebook page, which is often where things like this show up.

I don't know, but they look very aggressively and nicely priced!

Yeah, that's great pricing!

I still have a few of the OLD F44s left, from 1988.. Unfortunately they are F44-0. I am not sure if they would reliably stage w/o thermalite.

OLD F44... Now THAT's a "F" motor... I miss the old Aerotech motors, except for the lack of tracking smoke. Performance wise they were excellent. I really liked the F20.

Posted a question on their Facebook page. Now we wait...

"We aren't ready to release anything publicly yet, but hopefully in a few weeks."

patelldp said:

...they look very aggressively and nicely priced!

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They do, but it's hard to see how they can avoid hazmat charges for shipping (the F20 is already at the 30g limit and the G certainly will be over) so mail order will be less favorable.

The F44 could very easily be 30 grams or less of propellant - if so, it will have less than 80 N-s of total impulse.

The F32 does quite nicely.

I remain curious if the length of this 24mm motor is correct (70mm) or if it will be longer like the F32.

Either way....see previous link.

mikec said:

They do, but it's hard to see how they can avoid hazmat charges for shipping (the F20 is already at the 30g limit and the G certainly will be over) so mail order will be less favorable.

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Is the Econo-Max the same fuel composition as the old Econo-Jet's , or is this there "new" flavor . It must be their way of competing with CTI's I-Max . I bet they are slightly chaper too lol .
I still think the Old F20's are my favorite LPR motor .

Eric

3stoogesrocketry said:

Is the Econo-Max the same fuel composition as the old Econo-Jet's , or is this there "new" flavor . It must be their way of competing with CTI's I-Max . I bet they are slightly chaper too lol .
I still think the Old F20's are my favorite LPR motor .

Eric

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Yes, I certainly miss the 'old' Econojets, as first released by AT back in the '98 time frame. Those had the 'crackling white lightning' effect, with darker smoke, and more total impulse as well. The F20 had like 64n-s, while the G35 had just over 100. That's when I made a butt ton of gliders specifically for each of those, until I ended up with a bunch of the infamous 'bad batch' of G35s, and that was that.

Todays Econojets are really lesser versions with standard WL effects. Would love to see the old stuff return, especially the 24mm F21 in this new 'flavor'!

Econojets are all 30 grams of propellant to make them mailable (by those with legal permission), and the 30 gram propellant fits into the new molded casings. So, they have less total impulse. There are a fairly wide variety of propellant types in the Econojet line, so I am not sure why you are claiming they only exist in white lightning. There is FJ, R, T and W.

The speculation about cometing with CTI motors is silly since these are single use and CTI reloads are generally pricey AND all CTI motors are CSFM Classified as "High Power Rocket Motors" for California. The Aerotech single use motors will almost cewrtainly be CSFM Classified as "Model Rocket Motors", so buuying them and flying them in CA will be easy.

There is no information on the specific fuel type of these new "Econo-Max" motors beyond what we can "infer" from the letter designation in the leaked 'coming soon' listings that the online vendors have on their websites. It looks like they jumped the gun listing them before they are ready. Hopefully they get S&T testing and approval soon.

AstronMike said:

Yes, I certainly miss the 'old' Econojets, as first released by AT back in the '98 time frame. Those had the 'crackling white lightning' effect, with darker smoke, and more total impulse as well. The F20 had like 64n-s, while the G35 had just over 100. That's when I made a butt ton of gliders specifically for each of those, until I ended up with a bunch of the infamous 'bad batch' of G35s, and that was that.

Todays Econojets are really lesser versions with standard WL effects. Would love to see the old stuff return, especially the 24mm F21 in this new 'flavor'!

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Yes, all we can do is speculate. But I am very exited and curious about these. Extremely aggressive pricing! I am most curious about the F44's propellant composition, which isn't noted. I would *speculate* that it is also White Lightning.

I wonder if the propellant composition in the Gs (and these Fs, if they're WL) is the "New White Lightning" that the E20W/E15W uses. It's my understanding that there are many WL formulations but this one is easier to light it seems. Looks a little different too.

And I concur with all, the old F20Ws were the bomb diggity. I understand the reason for the darker smoke and cracking flame was because of the full diameter delay grain, which I also heard was/is similar to Black Jack propellant. All 'what I heard somewhere' though.

As someone relatively new to this, what in general is different between the Econo-jet line and other AT single-user motors?

24mm you say? That would fit into my Crossfire DX....

Regular motors are usually pretty close to the full total impulse of 80 N-s for F and the 60 to 62.5 gram limit for G motors. Econojets are shorter and use less propellant, so they have less total-impulse, but they are sold in twin packs and are cheaper per motor. Fine if you do not want to fly too high if using the regular motor would make the model fly too high.

Also fine if you are in TARC and need a 47 N-s motor because a 35 N-s motor is not enough and an 80 N-s motor is too much.

Zeroignite said:

As someone relatively new to this, what in general is different between the Econo-jet line and other AT single-user motors?

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Perfect, thanks

I wanna see pictures before I wet my pants over these motors.

Andrew

Let the pants wetting begin, my friend.

https://www.facebook.com/pages/AeroTech-Consumer-Aerospace/159005948954

Perhaps they're star core or something like that.

Let the science based speculation begin. We'll assume the pants wetting has already occurred....


Since they are "W", they are White Lightning propellant.


If we assume the molded casing are the same as the existing molded casings, then something interesting has been done to get us from the 35 N-s E20 to some kind of F motor which would start at 40.01 N-s.
https://www.nar.org/SandT/pdf/Aerotech/E20.pdf

So, perhaps at a minimum they have no liner which would free up more internal space for propellant.

And maybe the casing is slightly different and the nozzle is more efficient.

I guess we'll find out sometime soon when the time is right.

The best thing to do now is to burn up all of those "old" motors we might have on hand so that we can have room for the "new" motors when they arrive.

My latest Hobbylinc order just shipped yesterday so I will have a bunch of F32 and F23 motors as well as more F35 reloads very soon.

J Blatz said:

Let the pants wetting begin, my friend.

https://www.facebook.com/pages/AeroTech-Consumer-Aerospace/159005948954

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If no liner, then it is most likely a BATES grain. (and that is all caps, unlike 'cato'....)

Very clever.

Are these a 100% F?

Also, is it just me or in general is there about a 10% weight penalty to using reloads versus comparable single-use?

Liners in these little motors are probably a waste. Due to how volume works, casting propellant in the old liner (or maybe even directly in the case) adds a surprising amount of propellant and therefore impulse. The thrust curve on these should tell the tale.

shreadvector said:

If we assume the molded casing are the same as the existing molded casings, then something interesting has been done to get us from the 35 N-s E20 to some kind of F motor which would start at 40.01 N-s.

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Re: 40.01Ns : That's what I'm thinking, that, at best, these will be baby F's. Kinda hard to get much more impulse in that (24x70mm) form factor without resorting to propellant with a lot higher Isp, such as liquids

I'm thinking 45Ns, max.

Doug

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CarVac said:

Perhaps they're star core or something like that.

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That's an interesting thought. Having a star core would allow the overall core volume to be reduced, thus making more room for propellant, while still allowing enough surface area for a good initial thrust spike.

But the challenge is how to do it. Trying to use a cookie cutter sort of die would require constant sharpening and be prone to several problems such as alignment and crushing/tearing.

I wonder if the grains could be molded around a core, but I can see lots of problems with that, too.

Drilling (round holes) and slotting seem to be much more straightforward and reliable processes.

Doug

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plano-doug said:

That's an interesting thought. Having a star core would allow the overall core volume to be reduced, thus making more room for propellant, while still allowing enough surface area for a good initial thrust spike.

But the challenge is how to do it. Trying to use a cookie cutter sort of die would require constant sharpening and be prone to several problems such as alignment and crushing/tearing.

I wonder if the grains could be molded around a core, but I can see lots of problems with that, too.

Drilling (round holes) and slotting seem to be much more straightforward and reliable processes.

Doug

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They did say on their FB page that "we used every trick in the book and invented some new ones" in order to do it.