HyperLoc 835 Single Deployment

[Sailfish1957]

Does anyone have any thoughts on going with a single deployment on a HyperLoc 835? I’m going to the National Launch at SLVROC in Alamosa in 2024. I have a HyperLoc 835 set up for DD, but I thought I go for a high altitude single deployment with the Main in the lower airframe. Just for kicks. I wouldn’t launch in a windy condition, so I’d hope it wouldn’t drift to far. I may use a Jolly Logic chute release to counter that.

Thoughts?

 

[NTP2]

Does anyone have any thoughts on going with a single deployment on a HyperLoc 835? I’m going to the National Launch at SLVROC in Alamosa in 2024. I have a HyperLoc 835 set up for DD, but I thought I go for a high altitude single deployment with the Main in the lower airframe. Just for kicks. I wouldn’t launch in a windy condition, so I’d hope it wouldn’t drift to far. I may use a Jolly Logic chute release to counter that.

Thoughts?

Ok if you want but it seems like a bad idea.

 

[Sailfish1957]

Ok if you want but it seems like a bad idea.

Why would it be bad idea? I'm considering using a Jolly Logic chute release with the main; maybe deploy a streamer as well on ejection charge.

 

[neil_w]

If you use a chute release with the main then it basically is a form of DD and you should be fine.

What kind of altitude are we talking about here?

 

[Sailfish1957]

If you use a chute release with the main then it basically is a form of DD and you should be fine.

What kind of altitude are we talking about here?

8000 + AGL

 

[Sailfish1957]

8000 + AGL

 

[David_Stack]

If your 835 is already set up for DD, then why not simply fly it that way?

I don't see what you are gaining with your proposed mission profile. Should the Jolly Logic fail to restrain the chute during your descent from 8k, you are looking at potentially a very long walk to recover...

Does this have to do with your earlier post where you were considering moving the main down into the booster because your payload volume was a concern? If so, it may be worth your time/money to simply purchase a longer section of airframe from LOC so that your payload section is long enough to comfortably house your main chute.

 

[wsume99]

I'm confused by this too. You are clearly in DD altitude territory. The primary reason for using a JLCR is when you are flying a non DD rocket at higher altitudes. In this case the rocket is already DD. If you have issues fitting everything into your payload bay you could also buy more a compact recovery harness (i.e. tubular kevlar) or a more compact parachute. If I were in your position I'd just fly it DD.

The only situation I can think of where I would do this is if I were attempting to set a record with the flight and using the JLCR allowed me to get more altitude. But if I was going after altitude records I probably would not be flying a 4in rocket with a 54mm motor.

 

[Sailfish1957]

If your 835 is already set up for DD, then why not simply fly it that way?

I don't see what you are gaining with your proposed mission profile. Should the Jolly Logic fail to restrain the chute during your descent from 8k, you are looking at potentially a very long walk to recover...

Does this have to do with your earlier post where you were considering moving the main down into the booster because your payload volume was a concern? If so, it may be worth your time/money to simply purchase a longer section of airframe from LOC so that your payload section is long enough to comfortably house your main chute.

I agree with your assessment. Thanks. I can enlarge the upper air frame easily. I just don’t necessarily trust the RRC3 because I had one fail in flight recently, (did a complete destruction of the LOC IRIS 3) and I am told that was because it sat on the pad in the heat too long. In Alamosa, I hope I don’t have to wait on the pad too long.

 

[Sailfish1957]

Agreed. I guess I’m going DD on this. As suggested above, I can get a longer upper airframe tube from LOC. Easy fix.

 

[Handeman]

I agree with your assessment. Thanks. I can enlarge the upper air frame easily. I just don’t necessarily trust the RRC3 because I had one fail in flight recently, (did a complete destruction of the LOC IRIS 3) and I am told that was because it sat on the pad in the heat too long. In Alamosa, I hope I don’t have to wait on the pad too long.

I would wonder about sitting in the heat too long being the cause of a failure. If that is true, it's because the fit of the tubes were not right for those conditions, not because of the altimeter.

My suggestion would be to get the fit of the tubes correct for the worst conditions and then adjust with tape, etc. when the conditions aren't that bad.

Just like motor eject with a nose cone, most DD rockets don't really need much friction fit at the av-bay/booster joint. I know most use shear pins there, but it isn't really needed. If you can pick up the rocket without it falling apart, that is enough friction to keep it together at motor burnout since the air drag force is largest against the nose cone, way more then the drag of the fins. In most cases, no friction in the joint between the upper section and the lower section will still work just fine. Certainly enough friction and/or shear pins to cause an apogee charge to fail is way too much resistance for that joint.

 

[Sailfish1957]

I would wonder about sitting in the heat too long being the cause of a failure. If that is true, it's because the fit of the tubes were not right for those conditions, not because of the altimeter.

My suggestion would be to get the fit of the tubes correct for the worst conditions and then adjust with tape, etc. when the conditions aren't that bad.

Just like motor eject with a nose cone, most DD rockets don't really need much friction fit at the av-bay/booster joint. I know most use shear pins there, but it isn't really needed. If you can pick up the rocket without it falling apart, that is enough friction to keep it together at motor burnout since the air drag force is largest against the nose cone, way more then the drag of the fins. In most cases, no friction in the joint between the upper section and the lower section will still work just fine. Certainly enough friction and/or shear pins to cause an apogee charge to fail is way too much resistance for that joint.

Thanks for the input….but the rocket friction separation was fine; but the drogue was followed immediately by the main , even though they were set at apogee and 300 ft. respectively. Caused a chute tangle that led to disaster. Many folks opined that the RRC3 got hot. No disrespect for that product, I was just not happy with the RSO delaying launches.

 

[Handeman]

Thanks for the input….but the rocket friction separation was fine; but the drogue was followed immediately by the main , even though they were set at apogee and 300 ft. respectively. Caused a chute tangle that led to disaster. Many folks opined that the RRC3 got hot. No disrespect for that product, I was just not happy with the RSO delaying launches.

I totally agree about the LCO delaying. It can get very frustrating.

So you're saying the main set for 300 ft. deployed at apogee along with the drogue? That is usually an issue with the drogue charge being too big and causing the nose cone and laundry to exit the end of the payload tube when it hits the end of the shock cord.

Are you sure that didn't happen? It's very, very, rare for an altimeter to mess up and fire a main and apogee charge at the same time. Unless it's wired wrong. Has it worked correctly before?

 

[frognbuff2.0]

I did my L2 cert flight on a HyperLOC 835 with an Aerotech J270 motor and a motor-ejection deployment of my main parachute in the main tube, attached to all 40 ft of shock cord it came with in that main bay. Had zero issues whatsoever. However, that motor only sent the thing up to about 3,300 ft.