MicroMaxx two stage

[billspad]

The sun was out today and it was warm so I had to try out staging with the new NE motors. I cobbled together something in about a half an hour out of the Quest RTF's that I have too many of. It worked! As you can see from the pictures the motors were butted together with no space. The only thing holding the two together was the piece of body tube. The delay before the second stage fired was interesting. Even though I new it was there I didn't think it was going to stage. Of course I lost both stages. There wasn't much hope for finding the booster on the black asphalt although I'm sure I heard it hit near me. The top stage was headed for a muddy field behind the pile of snow that was still at the edge of the parking lot. It's either on top of the pile of snow or in the muddy field. I'll build another.

 

[n3tjm]

Whats the "new NE motors?"

 

[billspad]

Whats the "new NE motors?"

Delay but no ejection charge.

 

[jj94]

Whats the "new NE motors?"

No Ejection.

 

[Huge Blues]

I cobbled together something in about a half an hour out of the Quest RTF's that I have too many of....

Excellent idea!
I'm working-up a booster for a Bic pen conversion. I expect to spend twice as long in fabrication.

 

[Micromeister]

Good Going Bill:

I also had good weather both Saturday and Sunday.
On Saturday morning the better 2/3rds and I got out early to try a T4 body size 2 Stage and a couple 1/8A HD prototypes. Only had the one MMX-II-NE with me and it failed to light the upper stage but boosted the 8.8g model about 40'.
On Sunday we had much better luck with 3 more flights with the same model. I think I had the vent holes to large on the first flight. by covering one with tape these three flights staged fine. I never did see sustainer deployment at altitude, but got the model back each time on a 12" yellow telon streamer coming back into view...Soooo lucky the winds were very light. The sky was kind of semi grey yuck making it awful for tracking both days. When I post the flight pics you'll see what I mean.

The good news is, Yes these factory prepared motors fly exactly like all the other "test booster" MMX-II motors we've been flying. The First flight didn't even seperate the booster/sustainer at delay burnthur or kick the motor casing.
On the three that staged the delay seem to be a bit longer then 1/2sec but didn't seem to be slowing this larger diameter T4 (.448") model much at staging. Was a busy weekend, I'll post the few pics I caught in the next couple days when I get them out of the camera.

 

[billspad]

Good Going Bill:

I also had good weather both Saturday and Sunday.
On Saturday morning the better 2/3rds and I got out early to try a T4 body size 2 Stage and a couple 1/8A HD prototypes. Only had the one MMX-II-NE with me and it failed to light the upper stage but boosted the 8.8g model about 40'.
On Sunday we had much better luck with 3 more flights with the same model. I think I had the vent holes to large on the first flight. by covering one with tape these three flights staged fine. I never did see sustainer deployment at altitude, but got the model back each time on a 12" yellow telon streamer coming back into view...Soooo lucky the winds were very light. The sky was kind of semi grey yuck making it awful for tracking both days. When I post the flight pics you'll see what I mean.

The good news is, Yes these factory prepared motors fly exactly like all the other "test booster" MMX-II motors we've been flying. The First flight didn't even seperate the booster/sustainer at delay burnthur or kick the motor casing.
On the three that staged the delay seem to be a bit longer then 1/2sec but didn't seem to be slowing this larger diameter T4 (.448") model much at staging. Was a busy weekend, I'll post the few pics I caught in the next couple days when I get them out of the camera.

How big a gap have you tried with no vent holes?

 

[Micromeister]

Bill I've never tried gap stagging without at least one vent hole. I'm still experimenting with vented models About the largest gap that i've had stage has been 1 inch. Just don't have enough flights to give any kind of decent answer as to reliability with it. The model I've flying at the moment can vary the gap 1/8 to 1/4" depending on how far in a set the booster motor.
Over the weekend I was using a 1/4" gap.
Hope this helps.

 

[billspad]

Bill I've never tried gap stagging without at least one vent hole. I'm still experimenting with vented models About the largest gap that i've had stage has been 1 inch. Just don't have enough flights to give any kind of decent answer as to reliability with it. The model I've flying at the moment can vary the gap 1/8 to 1/4" depending on how far in a set the booster motor.
Over the weekend I was using a 1/4" gap.
Hope this helps.

It sounds like it needs to be tried. Maybe the next time the snow melts.

 

[Micromeister]

Had a few minutes to get some of the older photos out of the camera this weekend.
Here's one of the micro test models i'm currently flying. They are acturally some of my old 10.5mm competition SD models that i've added Micro motor mounts to and fashioned boosters for. By using the larger body but keeping the weight down I'm hoping I can get some of these sustainers back, rather then loosing them as has been the case up to now with Minimum dia. T2+ sustainers.

Apparently the clouds were just to dark as all buy one liftoff shot from last weekend were so dark I couldn't find the models in the pics Still haven't caught a staging event as I'm still working with a digital camera. The 3 flights that did stage are still putting the sustainers higher then the better 2/3rds or I can see. We hear the faint pop then have to wait a few seconds to see the streamer/model come back into view. May just be these old eyes aren't as sharp as they used to be, but it's a strain even with these larger models. I think I may add some payload ballast just to lower the overall alt to see if we can get a photo in flight. Maybe next weekend?

 

[abw]

Has anyone tried CHAD staging a MicroMaxx? Would it still be stable?

 

[jj94]

Has anyone tried CHAD staging a MicroMaxx? Would it still be stable?

Yeah, I did. I did it once on my tube fin rocket, and the sustainer ignited as it was pointed down. The delay killed the launch. Same with the MMX saucer I had.

 

[abw]

Yeah, I did. I did it once on my tube fin rocket, and the sustainer ignited as it was pointed down. The delay killed the launch. Same with the MMX saucer I had.

Have you tried it with the NE motors yet? I guess it would work with those since you have settled the stability issue.

 

[jj94]

Have you tried it with the NE motors yet? I guess it would work with those since you have settled the stability issue.

I haven't bought any motors since maybe fall of last year.

 

[Micromeister]

I strongly discourage Chad staging micros, the percentage of added mass added to aft end of these already very light models makes it very likely the coupled model will be unstable from the start.

If your gonna try staging micros do it the right way. building lower stages takes very little time, just keep it as light weight as you can.

Josh:
Please explain "the delay Killed the Launch".... What does that mean? Details like the diameter, size and weight of the models you launched are also very important when trying to determine what really occured during a specific flight. I'm sure 3" dia. saucers would have a problem with the delay as they are so draggy. Need the other details to really get an idea about what went on with your ring-fin model.

 

[abw]

Good idea John... What would you make the fins out of, though?

Josh, come to think of it, I remember when you staged three saucers together. 24mm-18mm-13mm. Do you think you could add a 4th to that and put a MicroMaxx on top? (Assuming literally NO wind...)

 

[jflis]

Good idea John... What would you make the fins out of, though?

Josh, come to think of it, I remember when you staged three saucers together. 24mm-18mm-13mm. Do you think you could add a 4th to that and put a MicroMaxx on top? (Assuming literally NO wind...)

Doug Gardei did that with a Pheord X-150 (18mm) to an Athena (13mm) to his Quest MMX saucer with great success. It's only 3 stages, but it worked!

 

[jj94]

Good idea John... What would you make the fins out of, though?

Josh, come to think of it, I remember when you staged three saucers together. 24mm-18mm-13mm. Do you think you could add a 4th to that and put a MicroMaxx on top? (Assuming literally NO wind...)

The only reason I did it like that was because each motor fit inside one another. The 18mm motor's overhang would slide nicely into the top of the 24mm's and the 13mm would slide into the top of the 18mm. Wouldn't work so nicely with a MMX. If you make me an adapter, then I'll try it out.

 

[Micromeister]

Good idea John... What would you make the fins out of, though?

Josh, come to think of it, I remember when you staged three saucers together. 24mm-18mm-13mm. Do you think you could add a 4th to that and put a MicroMaxx on top? (Assuming literally NO wind...)

Micro fins can be made from all sorts of stuff, I regularly use 1/64th and 3/64 3ply lit-ply, .020" styrene, .010" to .030" clear polycarbonate, .005" to .020" Waferglass (G10). 1/32" Basswood, 1/32" balsa, or in a pinch CA soaked file folder.


Josh:
Shouldn't take much adapting, a few wraps of tape should be all thats needed to fit a MMX-II to your 13mm saucer booster. I've tought about doing it also

 

[jj94]

Micro fins can be made from all sorts of stuff, I regularly use 1/64th and 3/64 3ply lit-ply, .020" styrene, .010" to .030" clear polycarbonate, .005" to .020" Waferglass (G10). 1/32" Basswood, 1/32" balsa, or in a pinch CA soaked file folder.


Josh:
Shouldn't take much adapting, a few wraps of tape should be all thats needed to fit a MMX-II to your 13mm saucer booster. I've tought about doing it also

I'm just afraid that the 13mm will blow off the MMX off its top before it gets a chance to ignite. The nozzle is really small and I don't know whether or not it is large enough for burning particles to reach through in that small amount of time.

 

[abw]

I'm just afraid that the 13mm will blow off the MMX off its top before it gets a chance to ignite. The nozzle is really small and I don't know whether or not it is large enough for burning particles to reach through in that small amount of time.

You could always try that blue thunder trick ; put a little bit in the nozzle of the MMX motor... The tape idea is a good one, though.

 

[Micromeister]

I'm just afraid that the 13mm will blow off the MMX off its top before it gets a chance to ignite. The nozzle is really small and I don't know whether or not it is large enough for burning particles to reach through in that small amount of time.

What makes you think you need "burning particles" to start the MMX? We don't know what actually begins the ignition process of an upper stage motor, Heat, radiation, particles. My educated guess is it's more radiated heat then anything else. But even if it doesn't go so what, its a saucer itll just float back down with the 13mm saucer.
Try it, just don't make the tape fit to tight, just enough friction to keep the Micro saucer in place

 

[jj94]

What makes you think you need "burning particles" to start the MMX? We don't know what actually begins the ignition process of an upper stage motor, Heat, radiation, particles. My educated guess is it's more radiated heat then anything else. But even if it doesn't go so what, its a saucer itll just float back down with the 13mm saucer.
Try it, just don't make the tape fit to tight, just enough friction to keep the Micro saucer in place

Well. I would need to get the motors first. Maybe a helpful friend can make a generous donation...(cough*abw*cough)

 

[Micromeister]

I'd be happy to help ya out, We Narhams folks have several member from PA who come down to our sport launches in Mt.Airy (just east of Frederick) Md.
Just be sure to let me know when, I always carry several spare 6 packs of MMX motors