Pro 75 ignitor

[jimzcatz]

Hey yall!! Is the included ingnitor in the Pro 75 loads "low current". Like an E match? I know the ones in the smaller motors are. I did a cluster of a L820 and 2 J520's at Thunderstruck 2012 not realising there were different ignitors for the bigger loads. Heck, they all come in a pink plastic bag. I prepped the L820 with a standard Ematch and a Pyrodex pellet. Flight was great, but the L came up a bit late. I know this is sorta normal for clusters. I am doing the same shot this weekend, and was wondering if I use the CORRECT included ignitors, do you think I will get a more even ignition?

[Mad Bomber F/X]

I witnessed the flight your referring too. It was awesome!! (Hot Tub is now calling it the Scarpine Trio)! I would think you'll get the same results with any igniter combo. The L is going to take a little longer to come up to pressure. If you have the ability to stage the ignition, maybe lighting the L .5 sec before the J's would get a even ignition off the pad. If you look at Reese's pic on the TS forum you can see the L was just coming up to pressure.

[bobkrech]

The Pro75 motors do not have an integral BP starter pellet, however the included igniter appears to have a booster pellet attached to it.

The instructions with a photograph of the igniter is located here. http://pro38.com/pdfs/Pro75_Instructions.pdf

Startup time is proportional to bore volume so larger motors take longer to come to full presssure.

Bob

[jimzcatz]

Bob, the ignitor pictured in the link you sent is NOT what was included in my L820. That PDF is dated 2005

[Sailorbill]

I will state that I have only flown one Pro75, an M1300 dual thrust plus I have one more, an M3100. Both of the ignitors look like they are a doubled over ematch dipped in a silvery pyrogen.
My M1300 was slow to ignite, you could hear the igniter pop then after a short delay it started to smoke then Bang Zoom it was gone!
Hope that helps.

You might try Rocketry Planet Vendors forum Dr. Jerone frome CTI hangs out there. Probably the best person to ask.

[jimzcatz]

Yea, thats what I have too. Thanks

[xenon]

I flew an L1395 (4 grain blue) last weekend with a pad cam that took a full 3 seconds from the first sign of smoke to rocket movement. This was with the stock igniter. In my experience, they're usually about that slow.

[Whodunit13579]

That was indeed a pretty flight!

[Adrian A]

One technique you can do in a situation with a big central motors and smaller clustered motors is to only ignite the smaller ones after the big central rocket motor gets the rocket moving. The Raven altimeter can be set up to fire at liftoff, which it detects as soon as it sees 3 Gs that add up to 3 feet/second of velocity. That generally happens just a few feet up the rail.

[Rocketman248]

I've had mixed results with CTI's igniters for big motors. Some light the motor almost instantly, but others just fizzled and didn't do anything. After flying my Redstone a few times, I'm sold on using thermite for big clusters.

[SteelyEyed]

The attached video (my L3 cert flight using a CTI M1400 with the supplied igniter) clearly shows the time between pushing the button and leaving the rail...
I was almost convinced we had a mis-fire before it finally came up to pressure.