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Aerotech G-Force motor mount question

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Luv2launch

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Hi all,
I picked up a G-Force yesterday and after reading the instructions it says to put in a thrust ring inside the motormount.From what I can tell this ring not only holds the motor in place but is also part of the baffle system too.I am wondering if I can put this ring in from the other side of the tube for the baffle and give it enough room to put in the baffle so I can use longer motors in it then just G's.
Any other ideas would be helpful also for those that have built this kit.

And as a side note I will probably use the motor hook but will straighten the end that should go through the motor tube more like the sumo motor mount.
 
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barstoolmike

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I went the hard route & knocked the thrust ring out later. A real pain. Your better off leaving it out completly now, so you can fly any 29mm. Iv'e flown on I200s without a problem. I also put in another center ring at the bottom of the motor mount tube with T nuts in it so I can use three brass clips instead of the stock motor hook.
 

Luv2launch

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But what about the wire mesh for the baffle system doesn't the thrust ring also act as a retainer for that or will it stay up in the tube either way?
 

barstoolmike

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It will stay up there, but one of the guys in our club had a lot of flights on his G force & that mesh got clogged up with soot & blocked enough ejection gas from pushing the nose out. och!! So I no longer use it, I now use a piece of Nomex to protect the chute.
Mike
 

Luv2launch

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Well at least if there no thrust ring in there you could find something long enough to pull it out and clean it once in awhile.I think I will leave out the thrust ring still might put in the hook although i might not the one on my sumo ended up breaking off when i was loading a motor into it.
Thanks for the tips.
 

Initiator001

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Be aware that the thrust ring, also, is used to keep the motor hook from pulling out from the motor mount tube from the force of the motor ejection charge.

If you modify the hook, ala SUMO kit, then this is not a concern.

My G-Force only flew on 'G' motors prior to it's demise (My error http://www.rocketryforum.com/showthread.php?t=1424&highlight=G-Force). :( I used the baffle system and it worked fine. I have always used the AeroTech baffle system in AeroTech kits and it has never given me any problems. I have worn out and retired AeroTech kits after 40-50 flights and the baffle system worked fine every time. :)
 
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terryg

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Use the sumo style clip but replace the motor tube with one that is long enough for the higher power motors plus what is needed for the baffle assembly. I would also add positive motor retention, as I have recovered rockets with the engine popped half way out of the clip.
 

dpower

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Be aware that the thrust ring, also, is used to keep the motor hook from pulling out from the motor mount tube from the force of the motor ejection charge.

If you modify the hook, ala SUMO kit, then this is not a concern. ...
Would you mind detailing this a bit? I'd like to modify an Astrobee-D the same way; what holds the hook in for a Sumo?
 

terryg

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The sumo clip bends away from the motor tube. Thus it does not block the use of longer cases. It is secured by have it against a ring on the outside of the motor tube. I bought mine from aerotech, but you can probably just bend the existing clip 180 degrees (assuming that it does break in the process)
 

Luv2launch

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Use the sumo style clip but replace the motor tube with one that is long enough for the higher power motors plus what is needed for the baffle assembly. I would also add positive motor retention, as I have recovered rockets with the engine popped half way out of the clip.
I left out the motor hook and I think the motor tube is plenty long enough for and 29mm motor case out there it is almost the length of the lower section of body tube well over 12 inches long maybe close to 24 inches.
 

dpower

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I left out the motor hook and I think the motor tube is plenty long enough for and 29mm motor case out there it is almost the length of the lower section of body tube well over 12 inches long maybe close to 24 inches.
AT makes 12" and 17 3/4" motor tubes - anyone know which comes with the Astrobee-D kit? I'd like to have room for small H motors, with room to spare for the mesh baffle. It would also be cool to use rail guides similar to the scale one provided as functioning guides. I wouldn't want to add much weight, to keep it flyable on G motors.
 

terryg

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I did my L1 with an Aerotech Astrobee-D that I modified with a sumo clip and a longer motor mount tube. The tube that comes with it is the 12 inch tube and I replaced it with the longer tube. It can take up to the 29/240 case (the 360 is too long). I fly it mainly with the hobby line and the 29/120 case. My cert flight was with an H128 in the 29/180 case and it had an amazing coast and even longer walk for recovery. I added an extra centering ring for positive motor retention with blind T nuts. I also highly recommend tieing the two sections together, as chasing two sections is a major pain since on higher flights they will land a considerable distance apart.

View attachment aerotech_astrobeed.rkt
 

dpower

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Thanks Terry, good stuff. Did you use the cooling mesh? How much room was left for the chute after you put in the longer motor tube?

Sorry Andy if I've steered the thread too far off-topic :eek:
 
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terryg

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Yes, I used the cooling mesh and I suppose I probably ought to check on its condition. I have lost track of the number of times this rocket has flown. It is always a great flier, perfect boost and coast to apogee with a perfectly timed separation. This is a long rocket and there is plenty of room for both chutes (the upper chute is packed below the lower chute to help it deploy). Aerotech chutes are very thin and pack in very little space. No muss, no fuss recovery. A friend of mine has always been impressed with the great flight characteristics of this design and is building a 4 inch upscaled high power version (boy is it tall).
 

knarfster

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Terry,

What do you use for a thrust ring if you don't use the original? I want to be able to launch an Arreaux on some H motors, but still want to use the Single use f adn g for my son.

Thanks in advance

I did my L1 with an Aerotech Astrobee-D that I modified with a sumo clip and a longer motor mount tube. The tube that comes with it is the 12 inch tube and I replaced it with the longer tube. It can take up to the 29/240 case (the 360 is too long). I fly it mainly with the hobby line and the 29/120 case. My cert flight was with an H128 in the 29/180 case and it had an amazing coast and even longer walk for recovery. I added an extra centering ring for positive motor retention with blind T nuts. I also highly recommend tieing the two sections together, as chasing two sections is a major pain since on higher flights they will land a considerable distance apart.
 

TheAviator

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Terry,

What do you use for a thrust ring if you don't use the original? I want to be able to launch an Arreaux on some H motors, but still want to use the Single use f adn g for my son.

Thanks in advance
Personally, I'd recommend getting a Hobby Line (29/40-120) case for F's and G's, but if you want to use the single uses, I use a 1/4" piece of 29mm MMT epoxied to the end for a thrust ring. Of course, if you use a new G80, the thrust ring is built in.
 

n3tjm

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masking tape works better than epoxy. I seen many times where the epoxy did not hold and the motor shot up into the rocket. I to built my G-Force to use H motor, and flown it on motors up to H180.
 

Handeman

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I agree, a 1/4 to 3/8 wide wrap of masking tape, about 5 wraps works great!
 

terryg

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As the others have stated the lack of a thrust ring is not much of an issue. Reload cases have built in thrust rings and masking tape works well on single use ones. The force of the engine wedges the it further into the tube, so as long as it is a tight fit (Can you push on it hard and not have it shift?) it will be fine. I have also made thrust rings by running a bead of gorilla glue around the single use engine.
 
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