18mm cases?

[jsdemar]

They do make for an enticing option, don't they? I thought it would be kinda cool to assemble such a small motor, so I bought the RMS case anyway (and it was cheap!). I may have gotten one of the last 18/20s in Hobbylinc's stock last year, for $17. If I don't lose it, over time it will end up being less expensive to use than the SU 18mm composite motors. IF I don't lose it.

I lost my 18mm AT case on the 2nd flight. D eggloft altitude flight that caught a thermal. Not worth replacing the case for the one D13 load I have left.

 

[JPVegh]

I lost my 18mm AT case on the 2nd flight. D eggloft altitude flight that caught a thermal. Not worth replacing the case for the one D13 load I have left.

If your like me and try to push the limits, any event that has the word altitude in it is probably best launched with an SU motor and the smallest chute you can get away with. Just sayin.

 

[tbzep]

...any event that has the word altitude in it is probably best launched with an SU motor and the smallest chute you can get away with.

That's exactly what I was thinking when I read it.

 

[gpoehlein]

If your like me and try to push the limits, any event that has the word altitude in it is probably best launched with an SU motor and the smallest chute you can get away with. Just sayin.

Personally, the only contest events I might consider using a reload in would be a scale competition (not scale altitude) or a model with RC controls. Anything else is just asking for the case to go bye-bye!

 

[gdjsky01]

Only two different loads... still... What is not to like about D's in a 18mm case? It's not like we BCM at Estes for only 'One kind of D'. :confused2:

Ten dollars for three loads at Value Rockets. :horse: White or Thunder. Sounds good to me. But then I have a load of these loads. So I am bias!

:grin::grin::wink:

 

[New Ocean]

When I first started in the hobby about 13 years ago, I seem to remember seeing smaller 18mm reloads. Maybe it was a dream, but were there ever smaller grains for this case in B or C impulse?

 

[MarkII]

I did both SU and some reloads. The SU are for places where the case might (probably will) get lost.

For the price, I see either as a decent option. The $6 ones at that site, are the only ones cheap enough. Even hobbylinc is a lot more expensive.

Oh I know! At that price it's a "can't lose" proposition. You make out good either way, with reloads and SUs.

 

[jsdemar]

When I first started in the hobby about 13 years ago, I seem to remember seeing smaller 18mm reloads. Maybe it was a dream, but were there ever smaller grains for this case in B or C impulse?

I had some C reloads for the 18mm case about 15 yrs ago. IIRC, they weren't certified. I think I still have them but their swollen and oxidized.

 

[jsdemar]

If your like me and try to push the limits, any event that has the word altitude in it is probably best launched with an SU motor and the smallest chute you can get away with. Just sayin.

I did use a small chute, just enough to recover the egg intact. I used the reload because I had it around for years looking for an excuse to use it. Seemed like the right time. But the mid-day thermals in the NM desert can come out of nowhere, and winds at altitude can be quite different than on the ground. Lost the club's AltimeterOne also. Two were lost that day.

Certain altitude events are better off using trackers.

 

[mwtoelle]

When I first started in the hobby about 13 years ago, I seem to remember seeing smaller 18mm reloads. Maybe it was a dream, but were there ever smaller grains for this case in B or C impulse?

Aerotech used to make the following B and C reloads for the RMS 18/20 case:

B6-2, B6-4, B6-6 (Blue Thunder) (never certified)
C4-3, C4-5 (Moonburning White Lightning) (never certified)
C6-3, C6-5, C6-7 (White Lightning) (only the C6-3 and C6-7 were certified)
C12-4, C12-7, C12-10 (Blue Thunder) (All delays were certified)

All of these reloads were discontinued due to low sales. Another interesting thing to note is that the B and C reloads were 3 packs, but you got only one nozzle to use with all three reloads.

 

[New Ocean]

See that would get me buying the cases again, even if it means sharing a nozzle. Ive never seen small composite motors it must be interesting!

 

[Initiator001]

Aerotech used to make the following B and C reloads for the RMS 18/20 case:

B6-2, B6-4, B6-6 (Blue Thunder) (never certified)
C4-3, C4-5 (Moonburning White Lightning) (never certified)
C6-3, C6-5, C6-7 (White Lightning) (only the C6-3 and C6-7 were certified)
C12-4, C12-7, C12-10 (Blue Thunder) (All delays were certified)

All of these reloads were discontinued due to low sales. Another interesting thing to note is that the B and C reloads were 3 packs, but you got only one nozzle to use with all three reloads.

I'm the one who pulled the plug on the 'B' and 'C' reloads when I worked at AeroTech. Poor sales would be an understatement!

 

[JPVegh]

I hate to keep rehashing this one but that C12 was probably the most useful load for that case. I can't believe the sales on that were worse than the D reloads. I probably used the C12 3:1 over the Ds. It was just such a handy small field load and Big Bertha loved it.

 

[gdjsky01]

I hate to keep rehashing this one but that C12 was probably the most useful load for that case. I can't believe the sales on that were worse than the D reloads. I probably used the C12 3:1 over the Ds. It was just such a handy small field load and Big Bertha loved it.

I could not see the value in duplicating B6's or C6's. Nor, given the average heavier weights of the current crop of commercial model rockets, the C4.


But yes, I could see the value of a C12. I know the Estes C11-3 is a nice small field load for a 3 or 4 ounce BT60 sized rocket. I could see the C12 being a nice load for rockets that liked the C5 as well.

 

[New Ocean]

I guess the majority of people flying A-C motors don't want the complexity of loading rms motors for each flight.

 

[foamy]

I guess the majority of people flying A-C motors don't want the complexity of loading rms motors for each flight.

Certainly true in my case. Though, I'm glad this thread came up. I've been considering re-loads for my Centurion and Big Bertha. The Centurion is a little heavy after a re-build and I'd like to see it fly with a little more authority. This thread has been informative.

So, now the question is... a case or single use?

 

[accooper]

I love my 18mm cases. I ordered 2 more with my Christmas money. I make adapters for them with old Estes D12 and C11 casings to fit in my smaller 24mm rockets. According to Aero-tech the D24 has the highest chamber pressure of all their reloads except the G138 or some such number.

The D24 is also very loud for such a small package.

Not hard to clean. Lots of fun.

Andrew

 

[thobin]

The problem may be availability. I have to drive a long way or order the 18mm reloads. The reloads are getting way cheaper than Estes motors.
I'm moving to them almost entirely. I would love to see a C12 or the like.

Hobby lobby is sucking it up for motors I'm lucky if I can find one pack of D's at any given time.

TA

 

[accooper]

What I wouldn't give for and E 18mm load...man! Hey Aero-tech I'll trade you Jeff if you come out with an E 18mm load!

Andrew

 

[qquake2k]

What I wouldn't give for and E 18mm load...man! Hey Aero-tech I'll trade you Jeff if you come out with an E 18mm load!

Andrew

Sounds like a fair trade to me!

 

[Initiator001]

I could not see the value in duplicating B6's or C6's. Nor, given the average heavier weights of the current crop of commercial model rockets, the C4.

It's all about marketing.

The C6-5 is the most sold model rocket motor type. More rockets list the C6-5 as being an usable motor than any other. The B6-4 comes next.

AeroTech didn't have any kits which could really use the RMS-18 motors so we went after the market which already existed. Plus, White Lightning propellant in a 'C' motor is pretty cool.

 

[MarkII]

AeroTech didn't have any kits which could really use the RMS-18 motors so we went after the market which already existed. Plus, White Lightning propellant in a 'C' motor is pretty cool.

Excellent point!

 

[Johnny1Eye]

What I wouldn't give for and E 18mm load.

There used to be an 18mm single use E, back in 1995-6 or so.

 

[accooper]

Nah, I wouldn't trade Jeff. He's the only guy in our group with fingers small enough to do Micro-Max. Every group needs a Micro-Max guy!

Now my wife might trade me if I don't find room for some of these rockets I've built!

Andrew

 

[JPVegh]

There used to be an 18mm single use E, back in 1995-6 or so.

There was also an 18mm E reload. It was the E27-4, it was barely an E at just over 20n and the short delay made it impractical for an 18mm rocket.

 

[New Ocean]

I have to say single use for 18mm motors, since I rarely feel the need to fly 18mm kits on D motors. I have a box of 50 or so 18mm motors that I got for free, so I consider them basically a free resource at this point. Only above D does reloading seem worth the time and initial capital investment. Only the availability of many reloads would change this for me, including different propellants like T or J in small motors. I get very bored of white lightning. One concern is that, with bigger and somewhat clumsy hands, I may have a hard time building 18mm motors!

 

[JPVegh]

Nah, I wouldn't trade Jeff. He's the only guy in our group with fingers small enough to do Micro-Max. Every group needs a Micro-Max guy!

Now my wife might trade me if I don't find room for some of these rockets I've built!

Andrew

Andrew, I'm not the only one in our group who builds MMX but I do like the title of MicroMaxx guy.

 

[accooper]

You ARE the MicroMaxx guy!

Andrew

 

[RocketRick]

There was also an 18mm E reload. It was the E27-4, it was barely an E at just over 20n and the short delay made it impractical for an 18mm rocket.

And, the reason it was barely an E, and only available in a short delay, was simple: they simply put a bit more propellant in the space where the longer delay would have gone. I know that they were trying to maintain size compatibility with the 18mm Estes motors, but I would have loved for AT to have come out with a double-long 18mm casing, with a couple of loads for it.

An 18mm full E (or minimal F) would have been freaking COOL! Can you say BT-20 Machbuster?

Hmmmm.... neglecting erosive effects (which you can't in such a long, thin reload, but still), if you increased the nozzle throat to about 1.4 times the original diameter, and simply used two of the grains that would have gone into the D13W or D24T reloads, you'd have roughly an E26W and an E48T.

In reality, to keep erosivity from completely killing you, you'd probably have to at least double the nozzle diameters to keep the Kn under some control. You'd probably also have to switch from a C-slot to a BATES grain geometry, with stepped core diameters (smaller near the top) to keep supersonic flow from tearing the lower grain to pieces. Still, it'd be a cool motor!

 

[New Ocean]

Warp 9 endburner?