Ye Olde Rocket Forum

Ye Olde Rocket Forum (http://www.oldrocketforum.com/index.php)
-   Model Rocket History (http://www.oldrocketforum.com/forumdisplay.php?f=2)
-   -   Centuri Mini-Motor Revision (http://www.oldrocketforum.com/showthread.php?t=16923)

Royatl 11-05-2017 07:00 PM

Quote:
Originally Posted by georgegassaway
4. B motor version MIGHT have had a much higher cato rate?

Not saying they did, but that is another possible reason.
.


That too.

tbzep 11-05-2017 07:12 PM

Quote:
Originally Posted by georgegassaway
4. B motor version MIGHT have had a much higher cato rate?

Not saying they did, but that is another possible reason.

IIRC the MPC B size 13mm Mini-Jets had a significantly higher cato rate than the smaller ones. Though it may have been one nororious bad batch and they didn't make that many batches of B's (or the others) before MPC bailed.

Yes, which falls under #3...stopped making B's. Once you stop making B's, there's no reason to keep the long casing. Cato issues was what I was thinking about when I listed it, but it could have been simply due poor sales numbers, or any number of other reasons involving materials and/or profitability.

Royatl 11-05-2017 07:31 PM

Quote:
Originally Posted by tbzep
Yes, which falls under #3...stopped making B's. Once you stop making B's, there's no reason to keep the long casing. Cato issues was what I was thinking about when I listed it, but it could have been simply due poor sales numbers, or any number of other reasons involving materials and/or profitability.


Back in the early 80's, a hobby shop in Roswell was moving and was selling their rocket stuff (getting back to their RC plane basics in a smaller space) and I bought a big bag of Centuri mini-Bs for a song. I still have most of them. The few I've flown didn't cato, but had another failure mode -- weak or no ejection charges.

tbzep 11-05-2017 07:37 PM

Quote:
Originally Posted by Royatl
Back in the early 80's, a hobby shop in Roswell was moving and was selling their rocket stuff (getting back to their RC plane basics in a smaller space) and I bought a big bag of Centuri mini-Bs for a song. I still have most of them. The few I've flown didn't cato, but had another failure mode -- weak or no ejection charges.

Bad news for the rockets of the first few flights, but at least the motors could be salvaged with a little extra powder, albeit not safety nazi approved. :rolleyes:

Jerry Irvine 11-05-2017 07:51 PM

Quote:
Originally Posted by Royatl
Back in the early 80's, a hobby shop in Roswell was moving and was selling their rocket stuff (getting back to their RC plane basics in a smaller space) and I bought a big bag of Centuri mini-Bs for a song. I still have most of them. The few I've flown didn't cato, but had another failure mode -- weak or no ejection charges.

I'll buy them

Royatl 11-05-2017 09:20 PM

Quote:
Originally Posted by Jerry Irvine
I'll buy them


I'm slowly flying them, not at NAR launches (though select ones I'll eventually fly under the expired motors program).

I'm also starting to fly my older (still certified) motors. The rare motors, like the D13-0, B3 (lbs)-5, the 1968 B.8-4 (with the trumpet bell nozzle), etc. I'll still keep, though even the Estes-made Rock-a-Chute motors (photo in another current thread) will get flown eventually (at least one or two).

aeppel_cpm 11-06-2017 07:27 AM

Quote:
Originally Posted by Royatl
I'm slowly flying them, not at NAR launches (though select ones I'll eventually fly under the expired motors program).

I'm also starting to fly my older (still certified) motors. The rare motors, like the D13-0, B3 (lbs)-5, the 1968 B.8-4 (with the trumpet bell nozzle), etc. I'll still keep, though even the Estes-made Rock-a-Chute motors (photo in another current thread) will get flown eventually (at least one or two).



I bought an unopened box (8 4 packs??) of B4-3s from a fellow rocketeer a couple years ago. They are -awesome- in the original scale Estes Blender, or my mini Photon Disruptor.

I have a 13mm based downscale of the Little Beth X2 that I've tried a longer delay in - but I've had poor luck staging recently - it keeps blowing out the booster motor mount. I only had 1 B4-7. Would really like a couple more -5s or -7s.

I fly them at Bong. Once the WOOSH sked is posted for the year, I apply for the Expired Motor Program permission for all the launch dates. (Yes, I note it on the flight card, too.) The staged one was flown by a friend at a TWA launch as a research flight. A 3xA+B research flight :-)

I've had no delay troubles. I've been counting them out, and they seem run about a half second long. I also notice that the smoke is thicker, yellower and distinctly more sulfury than current motors.

Joe Wooten 11-06-2017 07:52 PM

Quote:
Originally Posted by georgegassaway
4. B motor version MIGHT have had a much higher cato rate?

Not saying they did, but that is another possible reason.

IIRC the MPC B size 13mm Mini-Jets had a significantly higher cato rate than the smaller ones. Though it may have been one nororious bad batch and they didn't make that many batches of B's (or the others) before MPC bailed.


I have launched at least 20 of the mini B's and never had a CATO

Joe Wooten 11-06-2017 07:55 PM

Quote:
Originally Posted by Royatl
Back in the early 80's, a hobby shop in Roswell was moving and was selling their rocket stuff (getting back to their RC plane basics in a smaller space) and I bought a big bag of Centuri mini-Bs for a song. I still have most of them. The few I've flown didn't cato, but had another failure mode -- weak or no ejection charges.


That has happened to me with the mini B's, about one out of 15 or so.

ghrocketman 11-08-2017 07:22 AM

I never had any issue with the 13mm Centuri B4 mini-motors...have always flown great without a single cato.
The 13mm MPC B3-xM minis are a totally different story....those things have been absolute trash for me with a cato rate about the same as the awful FSI E60.

The last dozen or so MPC B motors I had were taped to small dowels and 'flown' as bottle rockets. Less than half actually "flew"; most had a casing rupture with no definable upward flight. This was sometime back in the 90's. I still have a couple of them in my collection somewhere.


All times are GMT -5. The time now is 04:03 AM.

Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.