BLUE MOUNTAIN ROCKETEERS DISCUSSION FORUM

Here's something new we've added to BMR's GSE... a Gold Medalist launch tower. Approximately 4 feet tall, full adjustable for various diameter 3-fin rockets.



Will be available for use at Rolling Thunder.

I should note that as per manufacturer's recommendations, this should be used for black powder A through E flights only. No AP motors (apparently too warm or something).

Interesting about using BP motors only.
I'm quite confident that the Jopons won (actually they bribed the real winner to part with it) one of these. It is well used (compared to the nice shiney unit pictured here). Jopson have already flown from it a couple times with composite motors. No immediate sign of any damage.
I'll pass this information along to them with plans to continue 'testing' their version with some larger composite motors.

The tower itself sure is a nifty little device.
Fast and easy to adjust with fin span a more probable limiting factor than body tube diameter.

I think the reason the book said no AP motors was because of the really thin piece of (stainless/aluminum?) sheet they have on the bottom, I think to act as a blast deflector. Would AP burn through it before B/P? Dunno. I don't think it would matter much if we put a piece of wood or something under it for use with AP motors. You have to raise the rocket up off any blast deflector in a tower anyway, don't you Bob?

(As you can tell, I've never used one of these things before!)

I didn't look at Jopsons unit close enough to confirm/deny a blast plate.
I do know theirs is missing the legs (they were just setting the thing on the ground).
While fairly stable, they do plan to incorporate guy lines to allow downrange tilting and improved stability.

Current plan is for Jopsons to be a part of the SPARC contingent heading south for Rolling Thunder so we can compare both units side by side then.

As for stand-offs, they become more and more important as impulse increases due to shock wave issues when a motor comes up to pressure.

SPARC has confirmed (twice now) that even BP motors will burn through a blast plate if/when they burn on the pad (one bad nozzle, one stuck launch lug).

bobdawg wrote:SPARC has confirmed (twice now) that even BP motors will burn through a blast plate if/when they burn on the pad (one bad nozzle, one stuck launch lug).

Indeed! So have we! I changed out all of the blast deflectors on the model pads with new, thick steel ones as even the Estes motors were melting through them at times. Have had no problems since we went to plate steel blast deflectors.

bobdawg wrote:I didn't look at Jopsons unit close enough to confirm/deny a blast plate.
I do know theirs is missing the legs (they were just setting the thing on the ground).
While fairly stable, they do plan to incorporate guy lines to allow downrange tilting and improved stability.

Current plan is for Jopsons to be a part of the SPARC contingent heading south for Rolling Thunder so we can compare both units side by side then.

As for stand-offs, they become more and more important as impulse increases due to shock wave issues when a motor comes up to pressure.

SPARC has confirmed (twice now) that even BP motors will burn through a blast plate if/when they burn on the pad (one bad nozzle, one stuck launch lug).

Yeah, this thing has a REALLY thin blast deflector plate/sheet at the bottom, I think more than anything, to comply with the spirit of the NAR Model Rocket Safety Code. I'm wondering if I could get someone at Coyote Engineering here in Dayton to take the original and fab us up a steel one in its place...