Estes C5-3 motors available

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Bill S

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How would these compare to say an Q-Jet C12 series motor? I bought some C12-4 and 6s to try out, but... more options are always good.
 

BABAR

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According to something I read a while ago, it is a "partial cored" motor.
Okay, I get it will burn faster if it has more surface area to start with. But doesn't it also have to have more propellant to have higher total thrust? I figgered that was why the delay was limited to 3 seconds, cuz with propellant, 3 second delay, ejection charge, and clay cap the 18 mm casing was full, no room for larger delay. But a beautiful option for a ZERO delay booster (fingers crossed!)
 

Rocketjunkie

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It has a slightly deeper core and slightly larger nozzle. The B8 was the same dimensions. Also a slightly lower sustain thrust due to the larger nozzle.
 

neil_w

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Okay, I get it will burn faster if it has more surface area to start with. But doesn't it also have to have more propellant to have higher total thrust?
Same total impulse as the C6 (10 N-s). Just burns more at the beginning, and then more slowly after that.
 

BABAR

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Also interesting is the propellant weight is almost identical. ???More efficient??
 

Nytrunner

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Also interesting is the propellant weight is almost identical. ???More efficient??
Theorizing, I'd say the volume (and associated mass) of the propellant is the same. The core at the beginning wastes some case volume, thus not leaving room for -5 or -7 delays that the C6 have
 

BABAR

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Theorizing, I'd say the volume (and associated mass) of the propellant is the same. The core at the beginning wastes some case volume, thus not leaving room for -5 or -7 delays that the C6 have
Makes sense, particularly volume-wise

. Per RocketReview data above, the C5 total thrust is 13% higher, while propellant mass is only 2% higher.

I have insufficient knowledge of the accuracy of the data (not knocking RocketReviews or their source.). Both mass in grams and thrust in Newton’s are carried out to 2 decimal places. As a graduate of an engineering school (okay, my DEGREE was biology, but I got it at an ENGINEERING school) I find it a bit suspect that a random batch of C5 motors came out with an average peak thrust of EXACTLY 10.00N. Then again, the only thermodynamics law I routinely use is the second law of entropy, particularly on the floor under my rocket building table and all to often on top of said table.
 

jadebox

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It is old data. Unfortunately I'm having no luck bringing up the new data right now (link on NAR page is broken).
The info was updated to match the new C6-5 specs as reported by Estes. The older C6-5 was slightly less than a full C motor.
 

neil_w

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The info was updated to match the new C6-5 specs as reported by Estes. The older C6-5 was slightly less than a full C motor.
Thanks. We'll see how those numbers compare to the NAR cert data when the link comes up.
 

Stefan2k4

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It has a slightly deeper core and slightly larger nozzle. The B8 was the same dimensions. Also a slightly lower sustain thrust due to the larger nozzle.
My understanding was that the B8 was essentially just a C5 with a shorter burn due to a shorter propellant grain. There used to be a small insert in the package and on that insert, along with instructions would usually be a graph showing the thrust curves of various Estes motors. Anyway, according to that graph, the thrust curves for the B8 and C5 were identical until of course the B8 burn out and the C5 continued.
 

BEC

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Note that afadeev's comparison of time-thrust curves uses the 1995 C5 data, not whatever the current one looks like. I pinged a couple of contacts at NAR, they are aware of the broken link. Hopefully the right file will get uploaded soon.

The C12 is certified at 9.8 N-s. The Estes C6 is 8.82 N-s (per NAR cert data). It remains to be seen what the new Estes C5s actually tested at.

I know from flying lots of C12s in models with altimeters aboard that they punch above their 1 N-s delta total impulse as they will send a heavy model (MAV, 1/200 Saturn V RTF) almost twice as high as an Estes C6. In a lighter model the difference in performance is still significant. I am looking forward to trying the re-released C5s. I have a few of the old ones, but the last one I used blew up my original Fat Boy, so I'm a little leery of using any of the ones I have left.
 

Johnly

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The latest version of the C5-3 tested had a total impulse was 7.79 N-s
 

Alan15578

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The latest version of the C5-3 tested had a total impulse was 7.79 N-s
I was concerned something like that might happen. Reportedly today's Estes PB just is not as as good as was in the good old days. Still, the NEW C5 is welcome, and I amwaiting to see the official assay report from NAR S&T.
 

neil_w

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Once I get an up-to-date motor file for the C5 I really want to compare performance to both the C6 and the QJ C12 with regard to speed off the rod for rockets in the 3-4 oz range. For the heavier 18mm rockets, some additional speed off the rod would be really welcome. I think the C5 should give it.

On the other hand, I never realized that it would only be available in -3 delay. That is a wee bummer, though I won't know how much of one until I can sim it.
 

rklapp

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This is cool, but begs a question: if the "new" C5 has an average thrust of 5.3N, should't the "old" C6, with its average thrust of 4.7N, had been called C4 or C5?
View attachment 418583

I don't mind doing a little mental back flip with Estes C5 being all around more powerful than C6.
But what's the history behind C6's "stretch" naming designation?
I suspect it occurred when Estes started producing rockets like Saturn and Redstone that needed a More modest engine but didn’t want to call it the C4 for marketing reasons.
 

shreadvector

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I was concerned something like that might happen. Reportedly today's Estes PB just is not as as good as was in the good old days. Still, the NEW C5 is welcome, and I amwaiting to see the official assay report from NAR S&T.
Is it Skippy or Jif?
 

Initiator001

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I received my order of C5-3 motors from Estes today.

I have attached some pictures.

They (Estes) are sure playing up the 'Super C' marketing of these motors.

Estes C5-3 Motors 001 Packaging Front.jpgEstes C5-3 Motors 003 Instructions.jpgEstes C5-3 Motors 004 Starters and plugs.jpgEstes C5-3 Motors 005 Side view.jpg
 

afadeev

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Note that afadeev's comparison of time-thrust curves uses the 1995 C5 data, not whatever the current one looks like. I pinged a couple of contacts at NAR, they are aware of the broken link. Hopefully the right file will get uploaded soon.
Sorry about that.
I was going to manually download the thrust curves for both motors off thrustcurve.org and re-graph it myself, but then life got in the way ;-)

BTW, C5-3's are now available from ACSupply:
 

BABAR

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And here is the new cert data: https://www.nar.org/SandT/pdf/Estes/C5.pdf The link is still broken from the NAR certified motors page, but the file is in the Estes directory and it is current.
I went to the link above. Says updated 3/14. And says MARCH 2014. So did they retest the new one or just saying it is the same as the old one?
 
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BABAR

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Suspiciously identical values -- I would expect the old numbers got re-used for that file.
Crossing posts, I edit my prior after you replied but before I read yours
 

BEC

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I went to the link above. Says updated 3/14. And says MARCH 2014. So did they retest the new one or just saying it is the same as the old one?
Look again. The form is dated 2014. The testing date is December 15, 2019. These are not the same data as the older C5. I'm kicking myself for not saving the 1995 data while it was accessible on the NAR web site. I thought I had, but apparently not....

Added: saved by the Wayback Machine! Attached is the older C5 cert data for comparison. I'll leave the comparison graph-building to someone else for now.
 

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UhClem

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Look again. The form is dated 2014. The testing date is December 15, 2019.
For a good laugh check the document properties which claim it was created in 1938.
 

neil_w

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Jon Coker has the new files up at Thrustcurve.org.
 
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