Onyx construction suggestions

[tnrocketman]

I just acquired a LOC Onyx. Haven't started yet, but wondered what suggestions I could get. I am considering a lightweight fiberglass layer, but I don't want to make it too heavy-- would like to be able to fly it on E-G motors.

Should I replace the surface mount fins with TTW? Or is it overkill?

 

[Darian Rachal]

I built one years ago, just using epoxy & surface mounting the fins. You might try drilling a series of small holes along the line where the fins go. Use 30 minute epoxy & this will form small rivets which make a very strong joint.

Also, if it still comes with a 12" chute, you might want to replace it with an 18" or slightly larger.

I used to like flying it on an AT F16(I believe) Black Jack; nice slow flight & long thrust.

 

[astrowolf67]

I've had one for a couple of years now. I built it stock with the exception of drilling holes for epoxy rivets. After about the 4th or 5th flight, it completely tore two fins off on landing, along with lots of paper from the tube. I rebuilt it, same as before, only I cut a few layers of tube down at the fin roots (kind of like slotting the tube only not all the way through). Two flights later, and even after upsizing to a 22" AT chute, ripped a fin off. So, I tore the other two fins off, cut slots in the tube, and cut out new fins with tabs. I drilled 1/4" holes in the tabs, and installed the fins. Applied outer fillets, then drilled 3 holes in the aft CR, off set from the fins, and poured in some foam. I flew it again a couple of weeks ago, with the stock chute, and she recovered fine. If you haven't started yet, I'd extend the fins to the mmt. Light glass should be fine, but I would recommend upsizing the chute.

 

[TheRadiator]

I built one last year, and it's a blast! It flies pretty low on the E but still fun to watch! But I definitely agree with upgrading to at least an 18" parachute. I use that little 10" or 12" circle chute for small Estes rockets. I've launched it twice on an F20 (yet to do a 'G') and the fins seem do fine being surface mounted. However I did use 1 hour epoxy for the fillets.

 

[Rocketmaniac]

I did not build my Onyx....... I got it off Ebay last year, so I don't have any building tips.......... I use a Aerotech 22" chute and about 12' of shock cord..........

I fly mine on F25's and F50's all the time....... I have even tried a G35 once......... Great flight..........

 

[DPatell]

Love the Onyx! I think mine is in retirement, about 15 flights on it, and I can't fit an H in it I built mine stock, and it worked great. I use a Nomex Heat Shield and a 22" AT chute, good recovery with maybe one or two broken fins. Biggest motor was a G80FWL and smallest was an E18W, both great flights!!

To anyone that read the Sport Rocketry article about NARAM43 two years ago, it mentions are rocket that landed in a trunk. That was my Onyx! Landed right in the trunk of someones car, landed on an SA-14 Archer, but did no damage. I walked up to the car and said "I'm so sorry!!!" All I got back was a look of amazement and confusment as I pulled it out of the trunk, lol!! No damage done!