G-Force for Lv 1?- Built (page 2)

Hi all,

I'm going to attempt a NAR Lv 1 certification flight at October Skies and had a few questions about using an aerotech G-force for the flight.

I've heard it can have problems deploying the chute and separating the nose cone, would removing the baffle and using a nomex cloth help?

Are there any reinforcements I should add before flying on an H (and eventually an I)? I'm already planning on swapping the motor hook/ front ring for and estes/aeropack retainer.

Finally, is it safe on a rocket as big as the G-force to deploy the chute after falling a few hundred feet? I know this would keep it closer to the launch site but if it risks damaging the rocket I'll use a long delay.

Thanks,
SC

SCrocketfan said:

Hi all,

I'm going to attempt a NAR Lv 1 certification flight at October Skies and had a few questions about using an aerotech G-force for the flight.

I've heard it can have problems deploying the chute and separating the nose cone, would removing the baffle and using a nomex cloth help?

Are there any reinforcements I should add before flying on an H (and eventually an I)? I'm already planning on swapping the motor hook/ front ring for and estes/aeropack retainer.

Finally, is it safe on a rocket as big as the G-force to deploy the chute after falling a few hundred feet? I know this would keep it closer to the launch site but if it risks damaging the rocket I'll use a long delay.

Thanks,
SC

Click to expand...

With mine I beefed up the aft end with a piece of heavy duty coupler, beefed up the recovery with Kevlar and tubular nylon Shock cord.
I removed the cooling mesh and use a Kevlar blanket (Works great)

As far as longer delay.......the faster it's going downward the more chance you have for trouble. I would not do that....I use a 4 second delay for "G" motors and it works out just fine.

I too plan on using it for a L1 attempt and will use an "H" motor. The motor choices I'm considering have anywhere from 7 to 10 sec delays.

Hope this helps and good luck.

Ed

I've never had any trouble expelling the nose with mine using G motors. If you want to fly it level 1, leave out the motor retainer clip and install an Aeropack or Estes 29 mm screw on retainer. Also, leave out the forward motor block.

Lots of threads exactly like this if you search.

Bat-mite said:

I've never had any trouble expelling the nose with mine using G motors.

Click to expand...

I did back in 2008 and discussed it back on the old TRF. Others at the time said they had similar experiences with the ejection that seemed to suggest the cooling mesh....either to much of it or shoved up to far and blocking air flow and/or the ejection charge was not strong enough in the G64's I was using at the time. A call to Aerotech seemed to confirm at the time that some batches of the motor may not have had enough BP for the ejection packed with the reload. Never actually confirmed either but Aerotech replaced the rocket for me. Since removing the cooling mesh, adding a bit more BP and adding a Kevlar blanket that never happened again.
Since the mods I know know that the G64 is not a good motor for it unless it's a fairly calm day due to not enough speed off the 6" rail,, I now have 7 1/2' of rail so maybe that will me to use the G64.

Bat-mite said:

If you want to fly it level 1, leave out the motor retainer clip and install an Aeropack or Estes 29 mm screw on retainer. Also, leave out the forward motor block.

Lots of threads exactly like this if you search.

Click to expand...

Yes Bat-Mite is correct.. I did the same thing regarding the retainer clip and forward motor block,, just forgot to mention it. Damn CRS

I also added PMR... I just used this one which uses 2 4-40 hex head screws and blind nuts.



Here is a shot of it removed which also shows the beefed up aft end.



Here is the ejection baffle and a coupler riveted, not glued in for future DD plans.



These pictures show the shockcords, 42" Sperachute and Kevlar blanket and how I set it up to fit in the coupler(it deploys nicely with no problems)





The last pictures show where I used the 2 existing launch rod guides by removing the top part and attached rail buttons to the base, I used a piece of the removed part to make a third rail button attachment point.
The rail buttons make a huge difference on windier days when it can really whip around even on the 1/4 rod (ask me how I know:wink and adding the 3rd one keeps it straight until it's about to leave the rail.




Pictures are worth a thousand words and everybody here likes lots of pictures.

Ed

Thanks for the info! I'm considering adding both launch lugs and rail buttons for versatility and will definitely use an estes retainer with no block. I saw a few older threads about having ejection problems especially with longer delays, so I think I'll swap the baffle for a kevlar/nomex cloth.
One last thing, I heard this has a 18' nonelastic shock cord. Would a shorter cord/harness be okay and helpful if it was elastic?

SCrocketfan said:

Thanks for the info! I'm considering adding both launch lugs and rail buttons for versatility and will definitely use an estes retainer with no block. I saw a few older threads about having ejection problems especially with longer delays, so I think I'll swap the baffle for a kevlar/nomex cloth.
One last thing, I heard this has a 18' nonelastic shock cord. Would a shorter cord/harness be okay and helpful if it was elastic?

Click to expand...

On your first point, I did not replace the baffle just removed the cooling mesh.
I also swapped out the composite forward bulkhead and screw eye for a 3/32 ply and u-bolt.(Surprisingly it was lighter than the composite bulkhead and screw eye the kit came with.) I went with 12' of 1/4" Tublar kevlar,5' of 9/16 Tubular nylon and a small piece about 2' of the original 5/8" elastic attached with a swivel to a 48" Sperachute with a kevlar chute protector. All of this was connected with quick links.

2Ft of Elastic attached to chute and swivel 1st three pics. Last one is the shockcord and blanket. The parachute swivel attaches to the delta quicklink.
I got all of it from Giant Leap except the chute which is a "Sperachute"

Thanks! I haven't seen a bulkhead setup like this before (my only 29mm builds have been estes so far). So you basically added a third centering ring to mount the bolt?

SCrocketfan said:

Thanks! I haven't seen a bulkhead setup like this before (my only 29mm builds have been estes so far). So you basically added a third centering ring to mount the bolt?

Click to expand...

If you're referring to the eyehook where the shockcord hooks up the answer is no... that is the stock one that screws into the baffle with no additional centering ring.

The ejection issues I've seen with the G-Force has been with G motors. Some of them don't seem to have enough force to eject everything. I've watch them fall flat with the nose cone loose and the chute still in the BT. After hitting the ground, the rocket is picked up by the fins and the chute falls out. There just wasn't enough ejection force to cause the nose cone to pull the chute out.

With a G motor, I would recommend about 0.2 to 0.3 g of FFFFg powder be added to the ejection charge. With H and larger motors, you should have enough charge with the motors that you shouldn't have to add any powder. Your mileage may vary, but that's the way I would fly it.

race 58 said:

...

...Pictures are worth a thousand words and everybody here likes lots of pictures.

Ed

Click to expand...

Cool White Sands #3 in the background !

I just finished mine, not too long ago . . .

You can also see my G-Force Incredibles I-Force) in the back right

Kenny

Handeman said:

The ejection issues I've seen with the G-Force has been with G motors. Some of them don't seem to have enough force to eject everything. I've watch them fall flat with the nose cone loose and the chute still in the BT. After hitting the ground, the rocket is picked up by the fins and the chute falls out. There just wasn't enough ejection force to cause the nose cone to pull the chute out.

With a G motor, I would recommend about 0.2 to 0.3 g of FFFFg powder be added to the ejection charge. With H and larger motors, you should have enough charge with the motors that you shouldn't have to add any powder. Your mileage may vary, but that's the way I would fly it.

Click to expand...

What Handeman said!!! I already documented how I found that out.:y:

KenRico said:

Cool White Sands #3 in the background !

I just finished mine, not too long ago . . .

You can also see my G-Force Incredibles I-Force) in the back right

Kenny
View attachment 178256

Click to expand...

Thanks yours looks great as well. Mine is not the scale length but a Canadian Arrow painted that way so it's longer. I also have another in the "Operation Sandy" markings.


Ed

race 58 said:

Thanks yours looks great as well. Mine is not the scale length but a Canadian Arrow painted that way so it's longer. I also have another in the "Operation Sandy" markings.


Ed

Click to expand...

I like Sports Scale , not Super Scale.. so no points off in my book. Oh, and no 'Scale' recovery on these . . .

think LOC sold an R6 version of the Canadian Arrow too in the longer configuration.

Right after I posted this checked out Skippy's LDRS 33 photos .. and saw another WS#3 V2 flying ..and lots of other V2s also !

Kenny

Has anyone flown a G-force on an estes (aerotech) F50-4T? Rocksim says velocity at the end of the (6 foot) launch guide is 40 ft/s and that it will deploy right after apogee. I'm a bit worried it would not be stable at only 40 ft/s.

SCrocketfan said:

Has anyone flown a G-force on an estes (aerotech) F50-4T? Rocksim says velocity at the end of the (6 foot) launch guide is 40 ft/s and that it will deploy right after apogee. I'm a bit worried it would not be stable at only 40 ft/s.

Click to expand...

Definately not the right motor for the GForce. I just recently found that mine was too slow on a G64-4 and in order to use it I needed a longer rail. I did that and now have a 7.5' rail and can use the G64 but an F50 still shows as a motor that will fail even with the 7.5' rail.
Another good motor I have used is the G76 Mohave Green and it will give you the speed off the rail you need.
Here is a list of motors that work and ones that fail from my Gforce on Thrustcurve.org. If you can't see it thru the link let me know and I will put it up another way. Notice only 1 F motor that works, with a 6' launch rod/rail. Another factor of course is the weight of your GForce.

https://www.thrustcurve.org/motorguide.jsp?rocket=371#download

Ed

Thanks, when I build it I'll probably fly it on a G74-6 economax or a G78-4 Mojave Green. The thrustcurve results aren't working ("The rocket you have requested has not been made public by its owner.") but after running a few motors in rocksim it seems like it needs a G to launch safely.

At URRF II, I launched mine on an F120 VM. It didn't go high, but it had plenty of thrust off the pad. I think 70N would be your lowest possible acceptable thrust.

I don't know why they call it G-Force, it's really a H motors rocket

If you build it stock, you can't fit an H motor tube in it. It is designed for 29 mm SU and up to 29/140 casings. But it makes a great Level 1 rocket if you build it for longer motors.

I'm planning to build it without the engine block and hook and use an estes retainer, would that let it take longer motors? I will probably use a 29/180 casing for Lv 1.

SCrocketfan said:

Thanks, when I build it I'll probably fly it on a G74-6 economax or a G78-4 Mojave Green. The thrustcurve results aren't working ("The rocket you have requested has not been made public by its owner.") but after running a few motors in rocksim it seems like it needs a G to launch safely.

Click to expand...

I'm trying to find out how to make my files at Thrustcurve public so in the meantime see if the pic of it works.

Bat-mite said:

If you build it stock, you can't fit an H motor tube in it. It is designed for 29 mm SU and up to 29/140 casings. But it makes a great Level 1 rocket if you build it for longer motors.

Click to expand...

Exactly why I built it to handle the bigger motors, It will be going up in the fall (maybe Sep) on an "H" for my L1. Just haven't decided which "H" yet.

That said it looks great flying on the white lightning propellant. :grin:

The resolution is a bit to low to read, but it looks like all the data is there.

SCrocketfan said:

I'm planning to build it without the engine block and hook and use an estes retainer, would that let it take longer motors? I will probably use a 29/180 casing for Lv 1.

Click to expand...

The 29/180 casing is 7.253", plus the forward closure and ejection well. Call it 7.5". The G-Force motor tube is over 17" long, minus a little for the baffle. So you should presumably be able to put a 15" long motor in it.

SCrocketfan said:

The resolution is a bit to low to read, but it looks like all the data is there.

Click to expand...

I'm trying to fix that and find out how to make my Thrustcurve files public. Stay tuned got "Honey Do's" :eyeroll:

Meanwhile here are some shots of the G64 liftoffs.

Nice launches! Is that a G64W?

SCrocketfan said:

Nice launches! Is that a G64W?

Click to expand...

Look at the sentence above the pictures.:wink:

Sorry, I meant is it a reloadable engine or single use? I haven't heard of a single use aerotech G with white flames before.

Needless to say I'd say go with the PAINKILLER 3!!!

https://www.rocketryforum.com/showthread.php?65807-NEW-Kit-The-PAINKILLER-3!-by-Gary-T-Designs

OH,, Ok it is a reload but so far no SU White Lightning I've found except the new G74 but not sure if it will work yet.

Blastcap Rocketry said:

Needless to say I'd say go with the PAINKILLER 3!!!

Click to expand...

Yes and pair it with a K185 , you gone have a lot of White Smoke and for a lonnnnnnnnnnnng time