Estes 2020 Catalog Online

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Thrustcurve shows slightly higher total impulse for the C5 (9.1 vs. 8.8 N-s), slightly shorter burn time (1.7s vs. 1.9s), slightly higher average thrust (5.3 N vs. 4.7 N), and significantly higher max thrust (21.9 N vs. 14.1 N). Yeah, I'm too lazy to create a table.

So basically, it's stronger than the C6 in all regards, with only slightly shorter burn (assuming the Thrustcurve data tells an accurate tale). I would probably use it instead of C6's in all my larger/heavier 18mm rockets, since I would *always* like to get more speed off the pad to reduce weathercocking.

Does anyone know why the C5 was discontinued instead of the C6 in the first place?
 
neil_w said:
Thrustcurve shows slightly higher total impulse for the C5 (9.1 vs. 8.8 N-s), slightly shorter burn time (1.7s vs. 1.9s), slightly higher average thrust (5.3 N vs. 4.7 N), and significantly higher max thrust (21.9 N vs. 14.1 N).
Click to expand...

At first I was wondering if the C5 is to the C6 what the B4 is the B6. It is close, but not quite. In an end burning configuration, if the nozzle and BP opening were the same, the only difference would be thrust duration, but there are some other differences. The B4 and C5 start increasing thrust at similar rates, but the C5 continues to a higher peak thrust, so somehow the geometry allows for more BP exposed surface area. In each case, the higher peak thrust motor (B4 and C5) continues the tail of their burn at a lower thrust than the B6 and C6. Another situation where the lower average thrust motor has a higher peak thrust at lift off.

But yeah, the C5 looks like a good motor:

C6C5_compare.png
 
We need to start a new thread for the C5 engines and get this one back to talking about the 2020 catalog itself.
 
neil_w said:
Thrustcurve shows slightly higher total impulse for the C5 (9.1 vs. 8.8 N-s), slightly shorter burn time (1.7s vs. 1.9s), slightly higher average thrust (5.3 N vs. 4.7 N), and significantly higher max thrust (21.9 N vs. 14.1 N). Yeah, I'm too lazy to create a table.

So basically, it's stronger than the C6 in all regards, with only slightly shorter burn (assuming the Thrustcurve data tells an accurate tale). I would probably use it instead of C6's in all my larger/heavier 18mm rockets, since I would *always* like to get more speed off the pad to reduce weathercocking.

Does anyone know why the C5 was discontinued instead of the C6 in the first place?
Click to expand...

year code X failed violently. Rumored cause was worn pintle resulting in sharp edge in center ore where a crack formed as they cured (dried out over time).
 
neil_w said:
Even bean counters have reasons. Would the C5 have been more expensive to produce?
Click to expand...

One possibility might have been subjective, based on "image" . . .

When you hear "C6", you think of Estes but "C5" sounds "foreign" to the ear and, unless one remembers the Centuri "Super-C's", and might be perceived as a "step down" in power ( C6 to C5 ).

Just a theory . . .

Dave F.
 
mbeels said:
At first I was wondering if the C5 is to the C6 what the B4 is the B6
Click to expand...

If I'm not mistaken, I believe the B8 was the same motor as the C5, just with less propellant and a shorter burn. Search for a thrust curve for the B8 and compare it. The B8 has been discontinued for a while as well.

My guess is they were discontinued because it simply didn't make sense to have too many different motors. If you think about it, with all the different ejection delays and with boosters, it makes for a lot of different motors to have to produce and keep in stock. And if those motors wind up not being sold, that represents a loss. In the catalog they only list the C5-3. So apparently they must not have plans to make any others. In a way, I understand this for the reasons previously stated. However, If it were up to me, I'd think the best solution would be to make the C5-0 and C5-3 and drop the C6-0 and C6-3. This way you'd have C5-0. C5-3, C6-5. and C6-7. This would make sense because the higher initial thrust of the C5 makes it better as a booster and in heavier models where a short delay is also needed.
 
Stefan2k4 said:
If I'm not mistaken, I believe the B8 was the same motor as the C5, just with less propellant and a shorter burn. Search for a thrust curve for the B8 and compare it. The B8 has been discontinued for a while as well.

My guess is they were discontinued because it simply didn't make sense to have too many different motors. If you think about it, with all the different ejection delays and with boosters, it makes for a lot of different motors to have to produce and keep in stock. And if those motors wind up not being sold, that represents a loss. In the catalog they only list the C5-3. So apparently they must not have plans to make any others. In a way, I understand this for the reasons previously stated. However, If it were up to me, I'd think the best solution would be to make the C5-0 and C5-3 and drop the C6-0 and C6-3. This way you'd have C5-0. C5-3, C6-5. and C6-7. This would make sense because the higher initial thrust of the C5 makes it better as a booster and in heavier models where a short delay is also needed.
Click to expand...

The problem with C5-0 is the long low thrust sustainer. not good for anything other than light weight 2 stagers. However the C5's having a short core are easier to light , so are great for clusters. The C5 is also less efficient than C6, which is why there was never a C5-5 or C5-7, no room for that much delay. (C5-7's would have been great for large clusters. (19 will fit in a 4" tube) The B8 was the replacement for the B14 which was harder to produce. The B4 motor has more propellant than a B6. But the nozzle is larger, thus lower pressure and longer burn, with same total impulse. (B4's are extremely reliable because of that little fact...)
 
C5's were my favorite c motor! Great for the heavy Mercury Redstone model....Sidewinder too! It was the original motor in my Deuce/Space Shuttle boost glider!
 
I also used them in the Alien Exo-skell and that other alien rocket that looked like a black egg with folding landing legs and alien...can't think of the name.
 
Does anyone know for certain if Estes only uses one formula of BP for their engines? I’m not referring to delay or ejection but to the thrust propellant only.
Coming from a pyrotechnics background, I know that not all black powders are the same. There are many factors involved that can vary the way it performs, including but not limited to, purity of oxidizer, charcoal type, ratio of constituent components, mill time, and additional additives such as binders. I have no idea if any of that changes the specific impulse of the propellant, but I know it can affect the burn rate. So does anyone know for sure? I’d be curious to know.
 
DeepOvertone said:
Does anyone know for certain if Estes only uses one formula of BP for their engines? I’m not referring to delay or ejection but to the thrust propellant only.
Coming from a pyrotechnics background, I know that not all black powders are the same. There are many factors involved that can vary the way it performs, including but not limited to, purity of oxidizer, charcoal type, ratio of constituent components, mill time, and additional additives such as binders. I have no idea if any of that changes the specific impulse of the propellant, but I know it can affect the burn rate. So does anyone know for sure? I’d be curious to know.
Click to expand...

I think that Estes uses the same BP in all of their motors. HOWEVER, the QUALITY ( ISP ) of the BP used has diminished from what it was ( in the 1970's, for example ), with the result being a decline in performance of the motors. I believe that the characteristics of the Oxidizer are the biggest issue.

Dave F.
 
billeblurzz said:
Venus Probe!....yeah I'm an old guy!
Click to expand...
I modded both the ExoSkell and the Venus Probe to fly on 24mm Ds with great results on both. Wouldn’t have trusted them on the C6s which were available when I built them (got them both on eBay a while back, maybe the C5s were still in production when the rockets were released. If I built them now, I would probably go stock 18mm with the QuestJet D, or now mmmiiiiigggghhht try a C5-3.

I haven’t built my Outlander kit yet, I was going to mod it for the Estes 24mm D, but now I am thinking I can go stock with either a QuestJet D, maybe the Estes C5
 
mbeels said:
At first I was wondering if the C5 is to the C6 what the B4 is the B6. It is close, but not quite. In an end burning configuration, if the nozzle and BP opening were the same, the only difference would be thrust duration, but there are some other differences. The B4 and C5 start increasing thrust at similar rates, but the C5 continues to a higher peak thrust, so somehow the geometry allows for more BP exposed surface area. In each case, the higher peak thrust motor (B4 and C5) continues the tail of their burn at a lower thrust than the B6 and C6. Another situation where the lower average thrust motor has a higher peak thrust at lift off.

But yeah, the C5 looks like a good motor:

View attachment 404116
Click to expand...
My ignorance is probably showing, but eyeballing the curves, looks like the area under the curve is greater for the C5 than the C6, so wouldn’t the AVERAGE thrust be GREATER (especially as the duration of thrust is SHORTER)? So how is this a C- FIVE which should have less average thrust than a C-SIX?

Here’s the comparison data on rocketreviews.com

https://www.rocketreviews.com/compare-estes-c5-to-estes-c6.html

Here is C5 vs QuestJet D
https://www.rocketreviews.com/compare-motors---estes-c5-to-quest-d16-q-jet.html
 
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Because the average thrust given in the designation of the motor does not have to equal the average thrust measured by certification testing. There was a conversation about this some months ago. I can’t find the thread. The average thrust in the designation of the motor can be off by some percentage (that I don’t recall) of what was measured at certification. I believe there’s also a minimum amount it’s allowed to be off by, as well.

In this case, you’re right. The C6’s average thrust was measured at 4.7N and the old C5 had 5.3N.

https://www.nar.org/SandT/pdf/Estes/C6.pdf
https://www.nar.org/SandT/pdf/Estes/C5.pdf
 
I like the new kits from Estes but I honest to god wish they would stop teasing with that picture of all their best kits from over the years that they don't plan on bringing back even though it would be a smart decision. Wasn't there a discussion at NARAM or something where they claimed the Space Race kits would be permanent?
 
SecondRow said:
There was a conversation about this some months ago. I can’t find the thread. The average thrust in the designation of the motor can be off by some percentage (that I don’t recall) of what was measured at certification. I believe there’s also a minimum amount it’s allowed to be off by, as well.
Click to expand...
Found it! See post #19. 20% or 10 N, whichever is greater.
https://www.rocketryforum.com/threads/new-motor-certified-may-2019.152890/#post-1888056

So I suppose you could call a C6 anything from a C1 to a C14 (the extremes seem seems a little ridiculous).
 
SecondRow said:
Because the average thrust given in the designation of the motor does not have to equal the average thrust measured by certification testing. There was a conversation about this some months ago. I can’t find the thread. The average thrust in the designation of the motor can be off by some percentage (that I don’t recall) of what was measured at certification. I believe there’s also a minimum amount it’s allowed to be off by, as well.

In this case, you’re right. The C6’s average thrust was measured at 4.7N and the old C5 had 5.3N.

https://www.nar.org/SandT/pdf/Estes/C6.pdf
https://www.nar.org/SandT/pdf/Estes/C5.pdf
Click to expand...
I am guessing C4 might be a bad choice due to that also being a common designation for another ignitable material!
 
The only cato that I have ever experienced was with a C5-3 about 25+ years ago. It completely destroyed the bottom half of my Estes "Eggspress". I recall hearing that many other people were experiencing catos with their C5-3s back then. Perhaps the frequent catos of the C5-3s contributed to it being dropped.
 
David M Schigoda said:
The only cato that I have ever experienced was with a C5-3 about 25+ years ago. It completely destroyed the bottom half of my Estes "Eggspress". I recall hearing that many other people were experiencing catos with their C5-3s back then. Perhaps the frequent catos of the C5-3s contributed to it being dropped.
Click to expand...
Yes, year code X blew apart VIOLENTLY. Many schools and youth groups had ordered them in bulk. Results were not good.....
 
I love how a discussion about he new catalog turned into a detailed investigation of engines (complete with graphs). We are SUCH nerds. :)
 

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