Why Don't They Want Us Going Supersonic???

A few years ago I flew a FlisKits Thing-a-ma-Jig with one of my two remaining G55's. I waited until the end of a launch when only three or four people were at the field, and I flew it from a high power distance. It would've been more fun had it all worked, but it was fun as it was! Got about 100 ft before the fins disintegrated and the body tube folded in half.

cerving said:

The 3G F240 looks like a fun motor...

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It is. Sims had it breaking Mach at 100-150' or so; it went zero to 43g worth of parts in about 80ft. Photo taken about 60' AGL.


I have four more F240s in my box, along with a couple of E75s, for when (if) I get the CF version completed.

Initiator001 said:

The AeroTech F32/F72 and G55 motors came out before Rocket Vision.

The F72 was just a F32 motor with Blue Thunder propellant substituted for White Lightning. The goal was to get a full 80 n-sec motor in 24mm diameter.

The G55 and G110 were again similar motors with one having White Lightning propellant and the other using Blue Thunder. Not possible to get 160 N-sec
with 62.5g of propellant. Had to settle for around 120 n-sec.

Of course, there were differences in nozzles.

Sales were low so the motors were discontinued.

That G110 would make a great Mach-buster motor today. :wink:

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Hi Bob

I know AT developed the motors before Rocket Vision started. AT was the major APCP model rocket motor manufacturer of the time and RV wasn't going to develop motors so it make economic sense for everyone to have AT private label the motors for RV. Unfortunately it didn't generate enough sales to justify continued production....

Getting 120 Ns from 62.5 g of propellant was really good 20+ years ago. Today you can squeeze ~150 Ns from 62.5 g of propellant (Isp ~243 seconds) if everything is optimized but there's nothing more to get at any reasonable price.

Unfortunately while the hobbyist wants everything for next to nothing, the manufactures need to make a profit so if a motor type doesn't sell, no matter how great it is, they go OOP.

Bob

JordanT said:

It is. Sims had it breaking Mach at 100-150' or so; it went zero to 43g worth of parts in about 80ft. Photo taken about 60' AGL.
View attachment 262217View attachment 262216

I have four more F240s in my box, along with a couple of E75s, for when (if) I get the CF version completed.

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Very nice rocket to flame ratio

I'm surprised CJ didn't highlight the G107 White Dual Thrust ..that is a motor you don't find in every bracket !

Kenny

https://bayarearocketry.com/24mm-hardware_c125.htm Here is 1 source for the hardware with prices. Launch it twice and don't loose it and you're even, 3 times and you are ahead. Mach 24mm didn't even thick of it. Might be a project for June launch.

Pfffft, AeroTech D21T or IF you can find one then a 18mm E25T(I think it was) in a old Zinger....use a silver Mylar streamer if you want a chance to find it again... The D24T reload weighs 6 gm more loaded. I don't know the empty weight of the single use 18mm. If you don't mind losing an 18mm case the D24-10T will get you there.

accpool said:

https://bayarearocketry.com/24mm-hardware_c125.htm Here is 1 source for the hardware with prices. Launch it twice and don't loose it and you're even, 3 times and you are ahead. Mach 24mm didn't even thick of it. Might be a project for June launch.

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Thanks for the heads up. Those prices seem fair enough.
Before I order, am I correct in assuming that all I need is a case and a rear closure? Will I need a delay drilling tool too?

TopRamen said:

Thanks for the heads up. Those prices seem fair enough.
Before I order, am I correct in assuming that all I need is a case and a rear closure? Will I need a delay drilling tool too?

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There is a Pro24 Starter Set which includes a 1G, 3G and 6G casing, a rear closure and a DAT adapter. The list price is $66.95 and you can find them discounted. A 2G casing is $12.99. You will need a PRO38 DAT which is $15.35 and works with Pro24, Pro29 and Pro38 motors.

Bob

bobkrech said:

There is a Pro24 Starter Set which includes a 1G, 3G and 6G casing, a rear closure and a DAT adapter. The list price is $66.95 and you can find them discounted. A 2G casing is $12.99. You will need a PRO38 DAT which is $15.35 and works with Pro24, Pro29 and Pro38 motors.

Bob

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Cool, thanks.
Is there a "First Timer CTI Pro24 3G Case Use" thread anywhere to get me started?
You know that I'll start one if there is'nt.

Buy the case
Buy the reload
Adjust the delay
Screw the reload into the case
Install in rocket
Launch rocket

As far as I know all CTI reloads require Hazmat shipping charges, so you really need a local dealer to make them practical cost wise. You need a large mail order to bring the required $28.50 shipping charge down to a reasonable amount on a per motor basis. I either get them from a local on site vendor or order them in a large group order on "Wildmans" Black Saturday sale.

I think I have a G55 left over from my brother in my vintage collection. G42s are 24mm SU as well. I think they were about 90ns or so. I bought a bunch in an auction, but due to their age, some work, some chuff / don't light, some don't have the delay / ejection work correctly. Fun for saucers at least.

both AT and CTI reloads come with reasonably good instructions, though having someone to 'walk' you through the assembly is helpful. as an overview, this video will give you an idea of how it goes; https://youtu.be/gAkYdnVkz5Y
I've run across two videos (including this one)...the other is 15 seconds long showing a complete cti build(they didn't adjust the delay ). in comparision there are more than a few videos showing an AT motor build.
Rex

Rex R said:

both AT and CTI reloads come with reasonably good instructions, though having someone to 'walk' you through the assembly is helpful. as an overview, this video will give you an idea of how it goes; https://youtu.be/gAkYdnVkz5Y
I've run across two videos (including this one)...the other is 15 seconds long showing a complete cti build(they didn't adjust the delay ). in comparision there are more than a few videos showing an AT motor build.
Rex

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Thanks Rex.
If a Brit can figure it out I'm sure I'll do just fine.

to answer your question about the delay adjustment tool, one could probably adjust the delay w/o the tool* but, it is lot easier( and quicker) with it.
*CTI might squawk about a warranty claim if the tool wasn't used.
Rex

Cracked open the collectors vault (a UN0339 40mm Ammo Can) and found this, an 18mm E-45 Blue Thunder:



Would be a lot of fun in a MD rocket. Here are some motor details and a thrust curve: https://www.aerotech-rocketry.com/c...s/NAR/single-use/18mm_mr_su/e45t_nar_cert.pdf

Anybody flown this bad boy? I've got an 18mm F motor as well. Let me dig that one up and I'll post a pic.

pyrobob said:

Cracked open the collectors vault (a UN0339 40mm Ammo Can) and found this, an 18mm E-45 Blue Thunder:

Would be a lot of fun in a MD rocket. Here are some motor details and a thrust curve: https://www.aerotech-rocketry.com/c...s/NAR/single-use/18mm_mr_su/e45t_nar_cert.pdf

Anybody flown this bad boy? I've got an 18mm F motor as well. Let me dig that one up and I'll post a pic.

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Try that in a baby bertha!

Nate

Ohh!! And I thought I was lucky because I still have an F101 lying around. Cool motor.

pyrobob said:

Cracked open the collectors vault (a UN0339 40mm Ammo Can) and found this, an 18mm E-45 Blue Thunder:

Would be a lot of fun in a MD rocket. Here are some motor details and a thrust curve: https://www.aerotech-rocketry.com/c...s/NAR/single-use/18mm_mr_su/e45t_nar_cert.pdf

Anybody flown this bad boy? I've got an 18mm F motor as well. Let me dig that one up and I'll post a pic.

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$9? SOLD! LOL.

cavecentral said:

$9? SOLD! LOL.

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I was wondering if anyone would notice the price tag. It's a pretty sweet deal indeed!

AT also used to make an 18mm F55. It was about 50 n/s IIRC.

Syclone said:

AT also used to make an 18mm F55. It was about 50 n/s IIRC.

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https://www.reocities.com/CapeCanaveral/Hangar/6017/rocket_motor_info.htm has a lot of oop motor info.

The AT 18 mm x 138 mm SU F55-4,8,12 Blue Thunder motor is listed as a 60%F = 64 N/s with a 0.9 second burn time according to the above reference. If the burn time is correct however, the Total Impulse would be around 50 N/s which is what you remember. If it was a 64 N/s motor the burn time should be ~ 1.15 seconds so there is a typo somewhere.

Bob

TopRamen said:

Cool, thanks.
Is there a "First Timer CTI Pro24 3G Case Use" thread anywhere to get me started?
You know that I'll start one if there is'nt.

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Here's a video by TVM; it covers the 29mm cases and such--same process for the 24mms. Hope this is of use...


https://youtu.be/vwV8QMV1lD0


Later!

--Coop

markkoelsch said:

Try the f85 white thunder- fun little motor.

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F85 should be an L1 motor. Over 80n average thrust by its designation. But I'm strictly going by its designation. The OP said he's not L1 certified.

Kruegon said:

F85 should be an L1 motor. Over 80n average thrust by its designation. But I'm strictly going by its designation. The OP said he's not L1 certified.

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Yes, the F85 is a high power motor. It is not a model rocket motor because the average thrust exceeds 80 N, therefore it is a high power motor that requires high power certification to launch.

Bob

Kruegon said:

F85 should be an L1 motor. Over 80n average thrust by its designation. But I'm strictly going by its designation. The OP said he's not L1 certified.

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Yeah, if I was L1 I would'nt be complaining about the lack of Mach 1 ready motors available to me.

TopRamen said:

Yeah, if I was L1 I would'nt be complaining about the lack of Mach 1 ready motors available to me.

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I feel ya man. I'm not L1 yet either. It's coming. I may have to wait till the fall. Depends on what magic I can pull out of my rump. I can try an L1 if I can keep it under 3650' at the local launch. Perhaps I can try Southern Thunder. But I'm not sure how to coordinate that anywhere but a local launch.

In the mean time, I've got a build I'm working on that sims over mach 1. And it's L0. But add an altimeter and it'll be too heavy to break mach lol. It's so riding the edge.

Here we go, the 18mm F-55 Blue Thunder (a little pricier at $9.75 ):

If you're looking for L1 under 3500', you can build a basic scratch rocket around a 54mm LOC tube, a 29 or 38mm motor mount, and a standard LOC nose cone. It won't be a machbuster, but it'll fly nicely on a baby H motor. Both my daughter and me certed with this configuration on the 3-grain Cesaroni motors, topping out around 3000'. I'm sure there's AT motors that work as well, and you could also ballast a bit to keep the altitude down. There's probably a kit, but this will get you a cert relatively cheaply.