AeroTech Open Thread

[CoyoteNumber2]

@ATGM - I see the Raytheon Coyote Block 2 has four 38/240 casings on it. Can you comment on which loads are used in production units?

 

[AeroTech]

@ATGM - I see the Raytheon Coyote Block 2 has four 38/240 casings on it. Can you comment on which loads are used in production units?

We probably shouldn’t go into any additional detail on commercial contracts unless I get authorization from our customers. I can ask.

 

[MClark]

@ATGM - I see the Raytheon Coyote Block 2 has four 38/240 casings on it. Can you comment on which loads are used in production units?

This Coyote is far from the coyote made by Orbital
Sea skimming Mach 2.6 at 15 feet

https://en.m.wikipedia.org/wiki/GQM-163_Coyote

 

[tbonerocketeer]

Question on the plug for the 54mm closure. I'm using a 54mm floating closure, and installed the plug as per the picture below. The delay o-ring doesn't fit, so I assembled with the delay spacer only. First time use - is this the right way?

On a side note - K805G-PS is sold as plugged motor, but comes with delay grain? Confused.

View attachment 474829

That plug is only used on the J99. The other plugged motors use a smoke grain like a delay reload would.

 

[Rocketjunkie]

That plug is only used on the J99. The other plugged motors use a smoke grain like a delay reload would.

I just use an inert forward closure. Ejection well is filled with epoxy.

 

[Sooner Boomer]

Since no one could answer this in its own thread, I'll post it here.

I'm building identical rockets, one (my soon-to-be L2 cert) has a 38mm motor mount, the other, a 29mm. I'm interested in being as frugal as I can. I'm going to try the cert attempt with a DMS, but at some point, I'll need to buy hardware. My understanding is that the RAS will allow me to use shorter-grained reloads than the case would normally use. What's the best case, in both 38mm and 29mm, that would give me the most reload options with the RAS? I already have a 29-180 case, so the lower range in 29mm is taken care of.

AND - don't tell me about one grain, two grain, etc. AT does not list reloads by number of grains!

 

[crossfire]

Unless your going to fly a lot just stick with DMS motors.

 

[Neutronium95]

Since no one could answer this in its own thread, I'll post it here.

I'm building identical rockets, one (my soon-to-be L2 cert) has a 38mm motor mount, the other, a 29mm. I'm interested in being as frugal as I can. I'm going to try the cert attempt with a DMS, but at some point, I'll need to buy hardware. My understanding is that the RAS will allow me to use shorter-grained reloads than the case would normally use. What's the best case, in both 38mm and 29mm, that would give me the most reload options with the RAS? I already have a 29-180 case, so the lower range in 29mm is taken care of.

AND - don't tell me about one grain, two grain, etc. AT does not list reloads by number of grains!

If you want to save money, I'd suggest just building the 38mm version and adapting down to the 29mm motors.

That said, I'd suggest that you get the 29/360 case, it can use spacers to go down to the 29/240, and then your 29/180 can go down to the 29/120, according to this table from Apogee.


For 38mm, I'd just focus on the larger motors, since 29mm gives you a good selection of H motors, and even an I motor. The 38/720 has 4 J reloads, along with a few high impulse I motors. With the spacers, you could fly 38/600 and 38/480 reloads, which would give you a good selection of I motors. The longer 38/1080 and 38/1320 are spaced too far apart to be adapted down with spacers.


I like to use the Balsa Machining Service site to see what reloads are available for each Aerotech case.

 

[tsmith1315]

Since no one could answer this in its own thread, I'll post it here.

Perhaps if you had answered on that thread, someone might have responded with more detailed information like this:

Motors that can be flown with 38/360 case + RAS:




Motors that can be flown with 38/480 case + RAS:




Motors that can be flown with 38/600 case + RAS:




Motors that can be flown with 38/720 case + RAS:





From Aerotech's Master Motor Matrix and the list of Certified Reloadable Motor Spacers on the NAR website.

 

[Sooner Boomer]

Thank You! This was the information I needed to make a good decesion!

 

[DaHabes]

Unless your going to fly a lot just stick with DMS motors.

Or unless you want to fly propellants that aren't available in DMS or at the impulse you want to fly.

Do build the 38mm and adapt down. If money is an issue there are plenty of examples of how to build adapters here on TRF. If you can swing it, the Aeropack adapters are what I use. You can nest adapters all the way down the size chain. For example, you can build a minimum diameter 54mm and adapt down to 38mm with one adapter or combine the the 54-to-38 and 38-to-29 adapters to go to 29mm. As long as you don't lose the rocket, it's a long term investment.

For what you save in building one rocket vs. two, the Aeropack retainer and adapter(s) are mostly paid for.

 

[AeroTech]

If you want to save money, I'd suggest just building the 38mm version and adapting down to the 29mm motors.

That said, I'd suggest that you get the 29/360 case, it can use spacers to go down to the 29/240, and then your 29/180 can go down to the 29/120, according to this table from Apogee.
View attachment 476798

For 38mm, I'd just focus on the larger motors, since 29mm gives you a good selection of H motors, and even an I motor. The 38/720 has 4 J reloads, along with a few high impulse I motors. With the spacers, you could fly 38/600 and 38/480 reloads, which would give you a good selection of I motors. The longer 38/1080 and 38/1320 are spaced too far apart to be adapted down with spacers.
View attachment 476799

I like to use the Balsa Machining Service site to see what reloads are available for each Aerotech case.

Actually the 38/1320 can be adapted down to use 38/1080 reloads with two spacers, right?

 

[AeroTech]

Also, it’s not just about being frugal. You may not want the extra weight or there may be a length constraint in your rocket.

 

[crossfire]

Or unless you want to fly propellants that aren't available in DMS or at the impulse you want to fly.

Do build the 38mm and adapt down. If money is an issue there are plenty of examples of how to build adapters here on TRF. If you can swing it, the Aeropack adapters are what I use. You can nest adapters all the way down the size chain. For example, you can build a minimum diameter 54mm and adapt down to 38mm with one adapter or combine the the 54-to-38 and 38-to-29 adapters to go to 29mm. As long as you don't lose the rocket, it's a long term investment.

For what you save in building one rocket vs. two, the Aeropack retainer and adapter(s) are mostly paid for.

Isn't he talking about AT grain spacer system?

 

[Reinhard]

Actually the 38/1320 can be adapted down to use 38/1080 reloads with two spacers, right?

The tables look like they are from Apogees website, which seems to contain a couple of errors in that regard in addition to the example you've pointed out.


Shouldn't it be possible to adapt down to the 29/60 from the 29/120 and 29/180?



I don't think there is a 54mm 5G casing. So adapting down with a single spacer from the 54/2560 wouldn't work and 2 spacers would work with 54/1760 reloads.
Also, the 54/2800 would require shorter spacers that I haven't seen yet.

Can you confirm that? In this case, someone should point that out to Apogee, because their site seems to be one of the most cited resources regarding spacer compatibility.

Reinhard

 

[AdAstraPerAspera]

The tables look like they are from Apogees website, which seems to contain a couple of errors in that regard ...
Shouldn't it be possible to adapt down to the 29/60 from the 29/120 and 29/180?
...
I don't think there is a 54mm 5G casing. So adapting down with a single spacer from the 54/2560 wouldn't work and 2 spacers would work with 54/1760 reloads.
Also, the 54/2800 would require shorter spacers that I haven't seen yet...

The 29/100 case is an odd length that doesn't work with spacers. There is no 5 grain case for 29mm or 54mm either. 38mm jumps from the 6 grain 720 case to the 9 grain 1080 case, then the 11 grain 1320 case.

The short spacer for 54/2800 to 54/2560 does exist. It was released after the rest of the adapter kit. I want to say the new version of the kit includes it, but I'm not sure.

 

[user 30299]

Here is a picture of the 29mm and 54mm Reload Adapter Systems - along with their configuration drawings. The 29mm and 54mm systems come with three spacers, while the 38mm system comes with two spacers.



You want to follow the drawings carefully, and use in conjunction with the motor reload assembly instructions - especially when a seal disk is part of the assembly.

 

[jimzcatz]

Since no one could answer this in its own thread, I'll post it here.



AND - don't tell me about one grain, two grain, etc. AT does not list reloads by number of grains!

Maybe not, buy those of us who fly regularly can tell you how many grains a motor has just by its designation!!

 

[Walter Longburn]

Maybe not, buy those of us who fly regularly can tell you how many grains a motor has just by its designation!!

Some times... how many grains would you guess a J520 to have?

 

[Theory]

Question, which nozzle does the H220 use?

the chart on page 112 of this thread looks to show a .266” throat, however, I do not see that nozzle on the RCS site.

thanks all!

 

[Reinhard]

Question, which nozzle does the H220 use?

the chart on page 112 of this thread looks to show a .266” throat, however, I do not see that nozzle on the RCS site.

thanks all!

0.266" is right.

http://www.aerotech-rocketry.com/cu...gs/29mm_hp_rms/29-240/29-240_h220t-m_assy.pdf
Reinhard

 

[Theory]

0.266" is right.

http://www.aerotech-rocketry.com/cu...gs/29mm_hp_rms/29-240/29-240_h220t-m_assy.pdf
Reinhard

yes, ok.

is this nozzle for sale via RCS?

 

[Neutronium95]

Yes, but you have to drill the throat to size yourself.

https://www.rocketmotorparts.com/2938mm_Nozzle_0180__Throat/p1577809_7762949.aspx

 

[Rocketjunkie]

.266" is 17/64". Use a 17/64" drill bit to drill out a .180 nozzle. If you plan to do a lot, get a carbide tipped drill. The nozzle material wears down HSS bits in a hurry.

 

[Sooner Boomer]

Thanks again to everyone that pointed me to references.

I've done research, and I've found what I think will work for me. I think a 29/360 case and RAS, and a 38/360 case and RAS should cover just about any load I will fly (and the usual field can handle). I already have a 29/180 case. These three tubes and associated hardware will allow me to choose from over 30 loads, from a G25W to an I357T, with a bunch of badass H motors in there, too. If I *really* need to fly another case/load, there are plenty to borrow.

 

[mtnmanak]

For everyone's benefit, wanted to relay that I got a call from Karl from Aerotech and he said I can use one of the brown fiber discs on top of the seal disc to make up the 1/16" gap. Makes sense. He is sending me a couple discs. Good solution and quick response from Aerotech.

Just wanted to follow up on this issue.

Karl did send me the phenolic discs and I used them to assemble and fly the K1103X this past weekend. Wanted to report that the solution worked great and the motor flew with no issues.

To recap since this thread was from a few weeks ago, if you end up with a short liner, alert Aerotech and they will send you the correct liner. If you already bonded the grains like I did, adding a phenolic seal disk above the metal seal disc works to close the gap.

 

[AdAstraPerAspera]

Just wanted to follow up on this issue.

Karl did send me the phenolic discs and I used them to assemble and fly the K1103X this past weekend. Wanted to report that the solution worked great and the motor flew with no issues.

To recap since this thread was from a few weeks ago, if you end up with a short liner, alert Aerotech and they will send you the correct liner. If you already bonded the grains like I did, adding a phenolic seal disk above the metal seal disc works to close the gap.

Is grain bonding required for this motor?

 

[Wayco]

I found a note to check up on an M1955 Dark matter load that fits in the 75/7680 casing, I seem to remember this was supposed to be a demo load at last years Airfest. Does anyone have info?

 

[AeroTech]

I found a note to check up on an M1955 Dark matter load that fits in the 75/7680 casing, I seem to remember this was supposed to be a demo load at last years Airfest. Does anyone have info?

This motor is still in development. We ran into some issues that need to be resolved.

 

[rharshberger]

This motor is still in development. We ran into some issues that need to be resolved.

Looking forward to that one, was hoping to fly the M1955DM two years ago in my GLR Nuclear Sledgehammer, instead I flew a M1550R, cool..but not as cool!