Ye Olde Rocket Forum

Ye Olde Rocket Forum (http://www.oldrocketforum.com/index.php)
-   SVDT - Semroc Virtual Design Team (http://www.oldrocketforum.com/forumdisplay.php?f=20)
-   -   Motor manufacturing equipment (http://www.oldrocketforum.com/showthread.php?t=1341)

CQBArms 01-02-2007 08:05 PM

Now this is a huge step up for contemporary BP engines!

CPMcGraw 01-02-2007 08:49 PM

Quote:
Originally Posted by Carl@Semroc
...Here is a preliminary lineup...


What body tubes are available for the 15mm and 10mm motors? These look like they could generate some interesting models.

Something I thought about as a possible sideline item -- Pre-packaged deployment charges (not delay chains) for use with electronic triggers, each with specific amounts of pyro, and with two firing ports (one at each end) for redundancy triggering. Not exactly what we'd be using with our smaller models, but possibly for some of those upper-end 29mm birds...

I see the DECAPs used for the 13mm and 10mm motors, but can this be adapted for the 18mm as well? Or does the pressure generated in the 18mm package exceed the limits for whatever adhesive/mechanical fixatives will be used?

Carl@Semroc 01-02-2007 09:03 PM

Quote:
Originally Posted by CPMcGraw
What body tubes are available for the 15mm and 10mm motors? These look like they could generate some interesting models.
None yet. The 10mm is the minimum allowed in FAI competition. The 15mm is a mid-size for B motors. Just a suggestion of possibility.
Quote:
Something I thought about as a possible sideline item -- Pre-packaged deployment charges (not delay chains) for use with electronic triggers, each with specific amounts of pyro, and with two firing ports (one at each end) for redundancy triggering. Not exactly what we'd be using with our smaller models, but possibly for some of those upper-end 29mm birds...
The Ejection-only DECAP is a pre-packaged deployment charge.

Quote:
I see the DECAPs used for the 13mm and 10mm motors, but can this be adapted for the 18mm as well? Or does the pressure generated in the 18mm package exceed the limits for whatever adhesive/mechanical fixatives will be used?
The 13mm DECAP glues inside an 18mm engine. The 10mm DECAP glues inside a 13mm engine. Probably a potential source of confusion.

The 13mm DECAP (for 18mm standard engines) will probably be the one we do. If it is popular, we might add the 10mm. One of the primary advantages of the DECAP is precision times. The accuracy of a standard engine is only as accurate as how much of the propellant "runs" up around the ram. The DECAP eliminates this variable. Another advantage is the ability to pick in-between times for models that don't fit the 2 second spread.

CPMcGraw 01-02-2007 09:08 PM

Quote:
Originally Posted by Carl@Semroc
...The Ejection-only DECAP is a pre-packaged deployment charge...

...The 13mm DECAP glues inside an 18mm engine. The 10mm DECAP glues inside a 13mm engine. Probably a potential source of confusion...


Now I understand. Thanks.

One presumes the "ejection-only DECAP" can be fired with an igniter, not just as part of a motor assembly?

A Fish Named Wallyum 01-02-2007 09:12 PM

Quote:
Originally Posted by CPMcGraw
What body tubes are available for the 15mm and 10mm motors? These look like they could generate some interesting models.

Something I thought about as a possible sideline item -- Pre-packaged deployment charges (not delay chains) for use with electronic triggers, each with specific amounts of pyro, and with two firing ports (one at each end) for redundancy triggering. Not exactly what we'd be using with our smaller models, but possibly for some of those upper-end 29mm birds...

I see the DECAPs used for the 13mm and 10mm motors, but can this be adapted for the 18mm as well? Or does the pressure generated in the 18mm package exceed the limits for whatever adhesive/mechanical fixatives will be used?


One of the first things I did when stumbling back into the hobby in 2001 was buy a bunch of Apogee cones, rings and tubes. Somewhere in my shop I've got a mess of 10mm tubing that was part of the deal. I was all excited when I got the tubes, but he almost immediately ditched the 10mm motor line, so my excitement was short-lived. Guess I have to dig again. :rolleyes:

Carl@Semroc 01-02-2007 09:12 PM

Quote:
Originally Posted by CPMcGraw
One presumes the "ejection-only DECAP" can be fired with an igniter, not just as part of a motor assembly?
That is correct. Since BP can not be used loosely in model rockets without a LEUP, there is a demand for a pre-packaged ejection charge in several "sizes" of BP loads.

CPMcGraw 01-02-2007 09:23 PM

Quote:
Originally Posted by A Fish Named Wallyum
One of the first things I did when stumbling back into the hobby in 2001 was buy a bunch of Apogee cones, rings and tubes. Somewhere in my shop I've got a mess of 10mm tubing that was part of the deal. I was all excited when I got the tubes, but he almost immediately ditched the 10mm motor line, so my excitement was short-lived. Guess I have to dig again. :rolleyes:


Is that what those tubes were? I've got a bunch myself, from the same source. I think I bought at least two bags of tubes a few years ago, before I knew about SEMROC or even BMS. I may have to look at these tubes again for future BARCLONE projects. They might be useful in some smaller "Schoolyard Sounders"...

For Carl: Those Apogee bags were likely filled with Euclid's tubes, so they may still have the mandrels for making them. The last time I checked the Apogee site, like Bill said, I think those tubes had been dropped from the packs (TVM has dropped them; I just looked), but they've been replaced with 29mm tubes.

CPMcGraw 01-02-2007 09:39 PM

Quote:
Originally Posted by Carl@Semroc
...Another advantage is the ability to pick in-between times for models that don't fit the 2 second spread...


What will be the minimum delay tick? 1 Second or 1/2 Second intervals?

Carl@Semroc 01-02-2007 09:41 PM

Planned is 1 second to keep inventory down.

Carl@Semroc 01-02-2007 09:42 PM

We will probably get a slightly smaller BT-4 (.410"ID/.436"OD).

Tim's micros were 10.5mm. We wanted ours to be as small as possible within FAI limits.


All times are GMT -5. The time now is 12:42 PM.

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