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  #1  
Old 04-26-2020, 12:17 PM
frognbuff frognbuff is offline
Aggressor Aerospace
 
Join Date: Oct 2012
Location: Colorado Springs, CO
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Default 'MPC B3-3s - a known 'CATO Threat?'

I recently got some old, original MPC motors in an auction and thought it would be fun to try them out. First, I tried to static-fire a B3-3 and WHAM! It blew out big time! No spit casing or anything (those cases are WAY think), just shot everything through the forward end in a heartbeat.

Undeterred, today I flew a couple of the old motors. A C6-4 (LOVE that delay time) worked like a champ. Another B3-3, however, had the same loud, fiery, destructive result.

Since I never got the chance to use the original MPC products when they were being made, I wonder if anybody has heard warnings about the B3-3s. They seem to be useless except for possibly making NAR safety training videos! ("Be prepared for bad things like THIS....").

Thoughts?
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  #2  
Old 04-26-2020, 01:22 PM
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Chas Russell Chas Russell is offline
Retired Missile Technician
 
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Location: Fort Worth, TX
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I have many MPC Minijets in my collection. For some reason all of the motors are date stamped 26 Jul 1971. At NARAM-15 in 1973 we flew a B motor event and most people used the B3-5m motors. After a series of cato's, we implored contestants not to use them, but most had built models for 13mm motors and did not have an 18mm model to fly.
So yes, the B Minijets were a known motor to fail.

Chas
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  #3  
Old 04-26-2020, 03:17 PM
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ghrocketman ghrocketman is offline
President, MAYHEM AGITATORS, Inc.
 
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Location: Nunya Bizznuss, Michigan
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Agreed. Lousy motors.
The Centuri B4-xM were known to be cato prone but were far more reliable than those MPC junkers.
Then again, I enjoy watching other's rockets go "KABLOOEY !"
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Yes, there is such a thing as NORMAL
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  #4  
Old 04-26-2020, 05:05 PM
frognbuff frognbuff is offline
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I should have been clearer. My apologies.

The B3-3 motors I'm talking about are standard size 18mm motors. I don't own any minijets.

Again - sorry for the confusion. Frankly I forgot all about the MPC minis!
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  #5  
Old 04-26-2020, 05:28 PM
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ghrocketman ghrocketman is offline
President, MAYHEM AGITATORS, Inc.
 
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Location: Nunya Bizznuss, Michigan
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Have no experience with their 18mm B3s, only their awful minis.
Those made a decent M80 replacement.
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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL
, if you have to ask what is "NORMAL" , you probably aren't !

Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !
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  #6  
Old 04-26-2020, 05:59 PM
A Fish Named Wallyum A Fish Named Wallyum is offline
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Location: Ft. Thomas, KY
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Quote:
Originally Posted by ghrocketman
Agreed. Lousy motors.
The Centuri B4-xM were known to be cato prone but were far more reliable than those MPC junkers.
Then again, I enjoy watching other's rockets go "KABLOOEY !"

How have you not flown with me yet? Every time I bring an E9 to the pads, people gather round, cameras going full blast.
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Build floor: Centuri Design Contest F-150 Hurricane Estes - Low Boom SST Semroc - Gee'Hod, Shrike, SST Shuttle

In paint: Canaroc Starfighter Scorpion Estes F-22 Air Superiority Fighter, Solar Sailer II Semroc Cyber III

Ready to fly: Estes - Multi-Roc, Solar Sailer II Semroc - Earmark, Snake Jumper
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  #7  
Old 04-26-2020, 07:50 PM
ghrocketman's Avatar
ghrocketman ghrocketman is offline
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I have never had an E9 cato... Consider them lousy low thrust motors and rarely used though.
The E12 is a much better motor.
__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL
, if you have to ask what is "NORMAL" , you probably aren't !

Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, and HAVOC !
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