Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > The Golden Age of Model Rocketry > Model Rocket History
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #21  
Old 03-02-2014, 07:03 AM
5x7's Avatar
5x7 5x7 is offline
Sometimes collector
 
Join Date: May 2008
Posts: 1,786
Default

Quote:
Originally Posted by Earl
You win.


John Cato has posted a few times on TRF, maybe he will post here. The RMR mess was awful but impossible to ignore. It's ironic but TMT still does not publish thrust curves, they just make announcements as far as I can tell.
Reply With Quote
  #22  
Old 03-02-2014, 07:18 AM
Jerry Irvine's Avatar
Jerry Irvine Jerry Irvine is offline
Freeform rocketry advocate.
 
Join Date: Jan 2008
Location: Claremont, CA "The intellectual capitol of the world."-WSJ
Posts: 3,780
Default

Half of my TMT motor approvals were made without even any data. When Kelly and Rogers unilaterally decertified them, they could not find a reliable date to report.
Reply With Quote
  #23  
Old 03-02-2014, 07:34 AM
billspad's Avatar
billspad billspad is offline
MMXCVII
 
Join Date: Jan 2007
Location: Saugus, MA
Posts: 371
Default

Quote:
Originally Posted by 5x7
John Cato has posted a few times on TRF, maybe he will post here. The RMR mess was awful but impossible to ignore. It's ironic but TMT still does not publish thrust curves, they just make announcements as far as I can tell.


They don't but I've talked to Paul at TMT and I have no doubt he actually fires the motors and collects data. TMT is pretty much a one man show so if no one asks for the curves I can see where creating them wouldn't be a priority. NAR S & T has plenty of members so the work load gets spread out.
Reply With Quote
  #24  
Old 03-02-2014, 08:25 AM
kurtschachner's Avatar
kurtschachner kurtschachner is offline
Master Modeler
 
Join Date: Mar 2005
Location: Southeastern Wisconsin
Posts: 1,243
Default

Lol here we go again, where's Kaplow?

So without publishing the data or curves, then you just have to go on trust, right?

Why wouldn't creating them be a priority? Wouldn't they want to compare them to the manufacturer's published curves? Don't you?

Quote:
Originally Posted by billspad
They don't but I've talked to Paul at TMT and I have no doubt he actually fires the motors and collects data. TMT is pretty much a one man show so if no one asks for the curves I can see where creating them wouldn't be a priority. NAR S & T has plenty of members so the work load gets spread out.
Reply With Quote
  #25  
Old 03-02-2014, 08:32 AM
Jerry Irvine's Avatar
Jerry Irvine Jerry Irvine is offline
Freeform rocketry advocate.
 
Join Date: Jan 2008
Location: Claremont, CA "The intellectual capitol of the world."-WSJ
Posts: 3,780
Default

Quote:
Originally Posted by billspad
They don't but I've talked to Paul at TMT and I have no doubt he actually fires the motors and collects data. TMT is pretty much a one man show so if no one asks for the curves I can see where creating them wouldn't be a priority. NAR S & T has plenty of members so the work load gets spread out.
Since the curves are needed for thrustcurve.org to have something, and they really only need 5-7 data points to make a JEND thrust curve. Why not?

cite:
http://www.thrustcurve.org/motorsearch.jsp?id=145
Reply With Quote
  #26  
Old 03-02-2014, 08:58 AM
Ltvscout Ltvscout is offline
Ye Olde Rocket Shoppe
 
Join Date: Jun 2004
Location: Milwaukee, WI
Posts: 6,472
Default

Quote:
Originally Posted by tbzep
Only 1/3 correct. It's John H. Cato, Jr. , Registered Architect.



Did the a$inine (censored if spelled correctly) use of punctuation do it for you or did you need to read the hint?




.

He registered here about a year ago, FYI. Don't know offhand the last time he logged in though.
__________________
Scott D. Hansen
Ye Olde Rocket Shoppe - Your One Stop BAR Shoppe!
Ye Olde Rocket Plans - OOP Rocket Plans From 38 Companies!
Ye Olde Rocket Forum
WOOSH NAR Section #558
Reply With Quote
  #27  
Old 03-02-2014, 09:14 AM
Earl's Avatar
Earl Earl is offline
Apollo Nut
 
Join Date: Dec 2006
Posts: 4,893
Default

Quote:
Originally Posted by Jerry Irvine
Since the curves are needed for thrustcurve.org to have something, and they really only need 5-7 data points to make a JEND thrust curve. Why not?

cite:
http://www.thrustcurve.org/motorsearch.jsp?id=145


Good point.
__________________
Earl L. Cagle, Jr.
NAR# 29523
TRA# 962
SAM# 73
Owner/Producer
Point 39 Productions

Rocket-Brained Since 1970
Reply With Quote
  #28  
Old 03-02-2014, 09:28 AM
billspad's Avatar
billspad billspad is offline
MMXCVII
 
Join Date: Jan 2007
Location: Saugus, MA
Posts: 371
Default

Quote:
Originally Posted by kurtschachner
Lol here we go again, where's Kaplow?

So without publishing the data or curves, then you just have to go on trust, right?

Why wouldn't creating them be a priority? Wouldn't they want to compare them to the manufacturer's published curves? Don't you?



It's always a matter of trust.

I can't answer for TMT but, unless the members ask for the curves, I can see where it wouldn't be high on the list.

You really don't need to compare the curve to the manufacturers published curve. You just need to check what NFPA 1125 calls for. That said, it's easier to do the job with the curve in front of you. I've seen an energetic ejection charge create a false peak thrust. Since the burn time and delay time are computed starting and ending at 5% of peak, that has to be cleaned up to get accurate numbers. The data acquisition that S & T uses (and I assume TMT) displays the curve but it takes time to make it look good enough to be useful.

And to answer Jerry's question, I'm almost positive TMT is providing data to thrustcurve.org so the job is getting done.
Reply With Quote
  #29  
Old 03-02-2014, 09:32 AM
astronwolf's Avatar
astronwolf astronwolf is offline
Lost his Drifter
 
Join Date: Mar 2013
Location: Northeast Ohio
Posts: 1,277
Default

Quote:
Originally Posted by 5x7
The RMR mess was awful but impossible to ignore. It's ironic but TMT still does not publish thrust curves, they just make announcements as far as I can tell.

I only remember the awfulness of it, and not much of its substance. I remember forming an opinion that I would probably never join TRA. I started the ContestRoc YahooGroup in 2002 and moved on.
__________________
-Wolfram v. Kiparski
NAR 28643 - TRA 15520
MTMA Section #606 President
Reply With Quote
  #30  
Old 03-02-2014, 09:41 AM
kurtschachner's Avatar
kurtschachner kurtschachner is offline
Master Modeler
 
Join Date: Mar 2005
Location: Southeastern Wisconsin
Posts: 1,243
Default

Thanks for the reply. After I posted those questions I started to suspect that the curve isn't part of the requirement.

OK thanks.

Quote:
Originally Posted by billspad
It's always a matter of trust.

I can't answer for TMT but, unless the members ask for the curves, I can see where it wouldn't be high on the list.

You really don't need to compare the curve to the manufacturers published curve. You just need to check what NFPA 1125 calls for. That said, it's easier to do the job with the curve in front of you. I've seen an energetic ejection charge create a false peak thrust. Since the burn time and delay time are computed starting and ending at 5% of peak, that has to be cleaned up to get accurate numbers. The data acquisition that S & T uses (and I assume TMT) displays the curve but it takes time to make it look good enough to be useful.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 03:35 AM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024