Q-Jet Follies

[jsdemar]

@ATGM We had a Q-Jet E26 burn through the side of the case today. Standard supplied igniter. 021422-1 date code. One more left in that pack. Also several packs of C's where the nozzle won't fit an igniter. Those were purchased by the flyer from Belleville Hobbies with 111319-01 date code. A C12-4 burned through the side, a C12-6 bulged the case. The rest of the packs he's afraid to use.

 

[BEC]

Wow....that's a higher failure rate than I've ever seen flying a bunch of 18mm Q-Jets and a few 24s.

As Gary will certainly say, contact Karl at Aerotech. The info is in all of Gary's posts in the big Aerotech thread. The user ATGM is no longer on, I think.

I flew three 18mms today. One each C12-6, D16-6, C18-6. The C18 took two igniters to go (sadly not unusual with these) but otherwise all worked well.

The new beefed-up igniters and the nozzles on C18/D20s is a thing. I've just gently persuaded them to go in with no ill effects. But with these, YMMV....

 

[sr205347d]

I flew my last two E26s in my bellyflopper yesterday. One of them needed two ignitors, and then when it did launch, it gave me the raspberries. I have never heard anything like this from a motor. Have you?

 

[kjhambrick]

I flew my last two E26s in my bellyflopper yesterday. One of them needed two ignitors, and then when it did launch, it gave me the raspberries. I have never heard anything like this from a motor. Have you?

<<snip>>

@sr205347d --

That's a new one for me but ...

Besides the raspberries, I noticed that the rocket coned.

Have you flown the same rocket with a different motor and did it cone ?

And what did the nozzle look like when you recovered the rocket ?

Thanks.

-- kjh

 

[sr205347d]

Besides the raspberries, I noticed that the rocket coned.

Have you flown the same rocket with a different motor and did it cone ?

That is normal for my bellyflopper.

 

[loopy]

That was definitely an interesting one...

 

[4regt4]

Flew a 18mm D20-4 and a 24mm E26-4 this last Saturday. Each had rapid multi-chuffs. Like "pow-pow-pow" then lit OK. But the smaller rocket with the D20 climbed a ways up the rod before igniting, so not great rod clearance speed. The E26 arced severely leaving the rod. Both also were sub-optimal in altitude.

Hans.

 

[rcktnut]

I flew my last two E26s in my bellyflopper yesterday. One of them needed two ignitors, and then when it did launch, it gave me the raspberries. I have never heard anything like this from a motor. Have you?

Looks and sure sounds like you got one of those P-jets (pulse) there instead of a Q-jet!!

 

[smstachwick]

Looks and sure sounds like you got one of those P-jets (pulse) there instead of a Q-jet!!

That’s an F motor (for “flatulence!”)