AeroTech Open Thread

[jrap330]

I really want to glue some fins onto one. Joe Barnard was able to fly one of the previous versions in his Sprint thrust vectored rocket, and it just burns forever.

Video of Flight- Is all that data and synthesize voice from an altimeter, computer?

 

[Neutronium95]

Video of Flight- Is all that data and synthesize voice from an altimeter, computer?

All of the data is live telemetry from the flight computer, which he designed specifically for thrust vectored rockets.

 

[Arsenal78]

For the 29mm RAS, why doesn’t Aerotech create a spacer to go from 120 to 100? Would it not work in some way? The 29/100 seems very out of place when the system adapts from 120 down to 60.

 

[AeroTech]

The 100 is an oddball case size as it was made to be the same length as a single use G motor and fit in the same motor mount with the motor hook. It’s definitely something to consider, thanks.

For the 29mm RAS, why doesn’t Aerotech create a spacer to go from 120 to 100? Would it not work in some way? The 29/100 seems very out of place when the system adapts from 120 down to 60.

 

[AeroTech]

We brought your comment up in a meeting yesterday. We’ll do some testing.

I hope that the production of 29mm Super Thunder grains will also lead to some fast burning motors. I never got the chance to fly an H410, and I would love to have the option to fly a really fast burning 29mm motor.

 

[AeroTech]

Propellant weight is 116.4 grams, total weight is 202 grams and the length is 8.0”.

Note: The original H13ST total weight was 213 grams, but we lost 11 grams when we switched to the thinner fiberglass case and thicker phenolic liner, because phenolic is lower density than fiberglass.

Very nice! Can I ask how many grams of propellant the motor contains, the length and the full mass?

 

[AeroTech]

I really want to glue some fins onto one. Joe Barnard was able to fly one of the previous versions in his Sprint thrust vectored rocket, and it just burns forever.

13,219 feet at Hamster Dance 9 last year in a 30mm rocket made from Quest parts, with 1/16" plywood fins laser-cut by "Balsa Bill" (Balsa Machining) and recovery components by Top Flight Recovery. Fly-away rail guide by Apogee Components, Telemetrum avionics by Altus Metrum.

 

[AeroTech]

We could do an 840 reload specifically for that application. The only reload without a case

I have the 1080 case and the RAS and it won't work. The 1080 case holds 9 grains @ ~120 ns each... the RAS only comes with 2 grain spacers meaning that you could only adapt down to "840" ns and not the 3 grain spacers that you would need get down to next case lower. (720 ns) I'm not sure if you had yet another spacer or another RAS kit if they recommend using "3" spacers. That might be a good question to ask here.

 

[AeroTech]

I’m hoping by mid-fall if all goes well.

Btw when would the release date be?

(Sorry, it’s just that these are exciting that’s all)

 

[jrap330]

All of the data is live telemetry from the flight computer, which he designed specifically for thrust vectored rockets.

Thanks all that data is cool...

 

[Neutronium95]

We could do an 840 reload specifically for that application. The only reload without a case

It wouldn't be the first. Cesaroni has the 5 grain N2200, but not a 5 grain 98mm case, so it requires spacers. I don't think that making reloads that need spacers makes much sense, unless you're trying to stay within an impulse limit or something.

 

[Retrospace101]

View attachment 429086
13,219 feet at Hamster Dance 9 last year in a 30mm rocket made from Quest parts, with 1/16" plywood fins laser-cut by "Balsa Bill" (Balsa Machining) and recovery components by Top Flight Recovery. Fly-away rail guide by Apogee Components, Telemetrum avionics by Altus Metrum.

Did you put a camera on it?

 

[CarVac]

Any chance of more G138-like motors in the 29/40-120 case? I really enjoy that motor.

 

[3stoogesrocketry]

I have a older black fiberglass 29mm SU motor . 9 inches total length . C slot motor , looks to be about .25 inch square so I'm guessing blue thunder . It is bigger then the H55 motor. Any ideas?

 

[Rocketjunkie]

I have a older black fiberglass 29mm SU motor . 9 inches total length . C slot motor , looks to be about .25 inch square so I'm guessing blue thunder . It is bigger then the H55 motor. Any ideas?

Probably a H90, 240 N-s. Should be printed on the ejection cap like this
IIRC, the H70/140, 200 N-s was about 7" long and the H55/110, 180 N-s was about 6" long. The full H125 was about 12" long. All were C-slot motors with the slot about 1/4" wide. With a flashlight, look into the nozzle and see if you can see the propellant. A white Lightning motor will almost certainly have some white MgO on the propellant, Blue Thunder will be nearly black and pristine looking.

 

[3stoogesrocketry]

Probably a H90, 240 N-s. Should be printed on the ejection cap like this View attachment 429252
IIRC, the H70/140, 200 N-s was about 7" long and the H55/110, 180 N-s was about 6" long. The full H125 was about 12" long. All were C-slot motors with the slot about 1/4" wide. With a flashlight, look into the nozzle and see if you can see the propellant. A white Lightning motor will almost certainly have some white MgO on the propellant, Blue Thunder will be nearly black and pristine looking.

Hey Tom , unfortunately there is no ID tag on this motor. There is zero oxidation on the grain also why I guessed Blue .

 

[AeroTech]

H120?

I have a older black fiberglass 29mm SU motor . 9 inches total length . C slot motor , looks to be about .25 inch square so I'm guessing blue thunder . It is bigger then the H55 motor. Any ideas?

 

[AeroTech]

The G138 is a pretty edgy reload, we could conceivably do one in Super White but I’m concerned it might be too much for the hardware. The point of the G138 was to fit as much power into that case as possible. We were actually trying to make an L1 reload if it would work reliably. We got close...

Any chance of more G138-like motors in the 29/40-120 case? I really enjoy that motor.

 

[AeroTech]

No, I didn’t want the extra weight or drag.

Did you put a camera on it?

 

[AeroTech]

Since this is an AeroTech thread, I was speaking in that context.

It wouldn't be the first. Cesaroni has the 5 grain N2200, but not a 5 grain 98mm case, so it requires spacers. I don't think that making reloads that need spacers makes much sense, unless you're trying to stay within an impulse limit or something.

 

[Retrospace101]

Btw, just curious, is there an available .eng file for the H13? Just curious to see how some rockets would react to that motor.

 

[DeltaVee]

Yesterday in preparation for our club launch, I decided to assemble an F63 24/60 motor. When I opened the package (which I got sometime around 8-9 months ago) I was rather dismayed at the condition of the propellant grains that I extracted... the following photos show what I mean...
Here is a photo of the kit with the rather scary looking grains... note that the one on the right hand side, was in what appeared to be far worse shape:



The next image is the right hand grain closer up:


This image is the other end of the same grain:



THIS end looked like a funnel or that it was reamed with a countersink!


Is this *normal* for redline propellant... it was growing WHISKERS!. Ive seen white lightning bloom... but this seem like a degenerative effect!

It took *thermalite* to light this motor....

I haven't had this reload kit all that long but is this *normal*??? Seems the shelf life of redline isn't so good... The bag was sealed prior to these photos being taken.

 

[OverTheTop]

Redline does get hard to start if it is a bit old. Seen that many times at launches, going for second or third igniters. If you scuff the core a little to take the oxide layer off it will light easier.

 

[DeltaVee]

Redline does get hard to start if it is a bit old. Seen that many times at launches, going for second or third igniters. If you scuff the core a little to take the oxide layer off it will light easier.

Yup, used 150 sand paper to clean it up. Still wasn't enough for the standard igniter... So it goes. The question I have is: What constitutes "old" for redline? The 24/60's are relatively recent I believe. The grains are far nastier looking than white lightning ones that I got at about the same time. I didn't expect redline to be worse.

 

[swatkat]

first experience with the RAS kit today on a 38mm load. I launched a 38/360 motor earlier in the day and wanted to do a 38/240 later. Put it all together just fine, but learned something new the hard way. The RAS forward closure is smaller in diameter than the standard closure for the well, so the red cap Aerotech includes does not fit. No problem, just tape it right? The well is also deeper and actually holds more powder than the standard forward closure, so when the rocket gets to apogee and goes horizontal, the powder follows gravity and distributes itself along the "side" wall of the forward closure and apparently does not light 100% of the time. The result... you get unburned charge still in the well, but burnt tape on the top... and no ejection. Lawn dart (my first ever) from 2300 feet into the playa and my son's favorite rocket, the night fury/loc hi tech (and a nice JL alt) reduced to powder... I've never seen a nose cone invert like this one! Solution, put some dog barf/wadding in the extra space in the well and tape it. Aerotech might also consider a smaller cap included for the floating closure or perhaps more powder/or instructions to help mitigate the same issue I had.

 

[JDcluster]

Can you please add a plugged option for the 40-120 G 138 loads?
I think the delay is causing the casings to heat up. Mine have more discoloration.
I cover the casting tube/ liner in green high adhesion painter tape.and it is still happening.

No blisters but, they have lost allot of the discoloring around the end of the case that is screwed into the forward closure. A AL plug or some type of end burning style closure. I like flying them, just don't want them to turn into SU casings. Mine have about 2-4 flight on them and still holding up.

 

[CarVac]

If you don't want the delay to burn as long, then just drill it out to 8 seconds or so. The 14 second delay is pretty long, after all.

 

[AeroTech]

https://www.aerotech-rocketry.com/resources.aspx?id=8

Btw, just curious, is there an available .eng file for the H13? Just curious to see how some rockets would react to that motor.

 

[AeroTech]

We could consider a plugged closure for the 40/120. With or without 1/4-20 bulkhead retention?

Can you please add a plugged option for the 40-120 G 138 loads?
I think the delay is causing the casings to heat up. Mine have more discoloration.
I cover the casting tube/ liner in green high adhesion painter tape.and it is still happening.

No blisters but, they have lost allot of the discoloring around the end of the case that is screwed into the forward closure. A AL plug or some type of end burning style closure. I like flying them, just don't want them to turn into SU casings. Mine have about 2-4 flight on them and still holding up.

 

[AeroTech]

Like I mentioned on FB, we’ll look into the issue. We had not heard of this happening previously.

first experience with the RAS kit today on a 38mm load. I launched a 38/360 motor earlier in the day and wanted to do a 38/240 later. Put it all together just fine, but learned something new the hard way. The RAS forward closure is smaller in diameter than the standard closure for the well, so the red cap Aerotech includes does not fit. No problem, just tape it right? The well is also deeper and actually holds more powder than the standard forward closure, so when the rocket gets to apogee and goes horizontal, the powder follows gravity and distributes itself along the "side" wall of the forward closure and apparently does not light 100% of the time. The result... you get unburned charge still in the well, but burnt tape on the top... and no ejection. Lawn dart (my first ever) from 2300 feet into the playa and my son's favorite rocket, the night fury/loc hi tech (and a nice JL alt) reduced to powder... I've never seen a nose cone invert like this one! Solution, put some dog barf/wadding in the extra space in the well and tape it. Aerotech might also consider a smaller cap included for the floating closure or perhaps more powder/or instructions to help mitigate the same issue I had.