MAC BlackFly build thread

[BobSemp]

First foray into hi perf rocketry (my friend gave me a 54mm Mac Performance Black Fly Kit), and this thread (albeit old) has been a real godsend. I would be interested to find out what engines you used for your first couple of flights, and what the delay was set to. I'm building my kit using the Cesaroni Engines, and will be installing the 3 grain motor tube. Figured I'd stay in the "F" category for the first flight or two. Any advice / real life examples? Thanks!!!

 

[dr wogz]

Welcome to the forums!
Where you from / Fly?
A lot of us have a Blackfly! My club has pretty much every diameter! including a 6"!

Learn to use a flight sim such as Rocksim ($$) or Open Rocket (free). This will tell you all you need to know! (And more!)

Thrustcurve.org will also help you choose your motor choice

 

[caffeinated]

You may want to simm that out in Open Rocket or RockSim. F class may not get it off the pad. Check into thrust / weight ratios. I love my 4" Mac Performance Black Fly ! Got Level 2 certified with this great kit on a J380-SS to 4861 ft.

 

[dr wogz]

54mm Blackfly is a 29mm mount.

and the website says "F thru H" motors. 14oz suggested weight. Make sure you pick the right 'F' motor.. An F15 likely won't do it..

CTI or AT (Aerotech) will work either way at this point!

https://macperformancerocketry.com/...s-1/products/copy-of-scorpion-54mm-diameter-1

 

[Crazyrocket]

For my 3" black fly, I have launched it twice on a G70 CT (Loki) drilled to 9 seconds. Worked well. Only issue I had was I put too much powder in for the ejection charge and zippered the body tube. It is fixed now and I ended up making a head end dual deployment option for this rocket. Using a WM nose cone from another rocket which I can switch out if I want to fly on larger motors.

 

[dr wogz]

For my 3" black fly, I have launched it twice on a G70 CT (Loki) drilled to 9 seconds. Worked well. Only issue I had was I put too much powder in for the ejection charge and zippered the body tube. It is fixed now and I ended up making a head end dual deployment option for this rocket. Using a WM nose cone from another rocket which I can switch out if I want to fly on larger motors.

how do you zipper a cloth phenolic tube?! very curious to know more behind this!

In a good "how can we learn from this" way, not a condescending "what an idiot" way.. I am genuinely curious, and am chuckling to myself as to how teh story might go!

 

[tim cubbedge]

how do you zipper a cloth phenolic tube?! very curious to know more behind this!

I was going to ask that question too. I’m guessing either his shock cord is either too short or the delay was off. I’ve seen Kevlar slice through fiberglassed blue tube like it was butter when the delay was way off.

 

[bobbyg23]

how do you zipper a cloth phenolic tube?! very curious to know more behind this!

In a good "how can we learn from this" way, not a condescending "what an idiot" way.. I am genuinely curious, and am chuckling to myself as to how teh story might go!

I was going to ask that question too. I’m guessing either his shock cord is either too short or the delay was off. I’ve seen Kevlar slice through fiberglassed blue tube like it was butter when the delay was way off.

Also curious? And how does too much bp cause a zipper?

 

[Donnager]

I'd be interested to hear as well. I have a 4" Mac Radial flyer that split the tube between a shear pin hole and the nose (~1" long split). The split had black powder smut in it, so it likely occurred during main deployment. Not really a big deal. The rocket is 1.5" shorter now.

According to the logs and observation, it deployed the drogue at apogee, and the main went as scheduled. Both charges were a little larger than you'd have for a motor deploy, but were nothing to write home about.

I kind of chalked it up to a possible tube defect, over pressure, or drogue descent velocity was higher than it would have liked---Edit when the main came out.

 

[BobSemp]

Welcome to the forums!
Where you from / Fly?
A lot of us have a Blackfly! My club has pretty much every diameter! including a 6"!

Learn to use a flight sim such as Rocksim ($$) or Open Rocket (free). This will tell you all you need to know! (And more!)

Thrustcurve.org will also help you choose your motor choice

I live in upstate NY, about 15 minutes from Mike @ Mac Performance in Altamont. I'm not flying (yet), but have attended a couple of events in St. Albans, VT with a friend who flies. I'll take a look at the flight simulators and thrustcurve.org as well. Thanks for the info.

 

[dr wogz]

I live in upstate NY, about 15 minutes from Mike @ Mac Performance in Altamont. I'm not flying (yet), but have attended a couple of events in St. Albans, VT with a friend who flies. I'll take a look at the flight simulators and thrustcurve.org as well. Thanks for the info.

CRMRC! My club!! Who's your friend?

I'm in Montreal, so I haven't been able to fly since.. what.. 1782.. (it feels like that long!)

 

[BobSemp]

CRMRC! My club!! Who's your friend?

I'm in Montreal, so I haven't been able to fly since.. what.. 1782.. (it feels like that long!)

My friend and brother in the Lord John Andersen. I feel your pain - we have friends in PEI that are getting long in years, and haven't been able to see them since like 1782, too!!!

 

[dr wogz]

My friend and brother in the Lord John Andersen. I feel your pain - we have friends in PEI that are getting long in years, and haven't been able to see them since like 1782, too!!!

Yes, I know John! he always has something cool to fly!

I do hope the borders will open soon! I likely won't be around till October at this point!

Mike (MAC Performance) should be up this launch too, July was cancelled / postponed..

 

[Crazyrocket]

how do you zipper a cloth phenolic tube?! very curious to know more behind this!

In a good "how can we learn from this" way, not a condescending "what an idiot" way.. I am genuinely curious, and am chuckling to myself as to how teh story might go!

I had about 12 - 15' of 1/8" tubular kevlar installed. I normally adjust the amount of BP based on the size of the rocket, but forgot in this particular instance. Very energetic ejection and I am guessing that the shock cord was not long enough (shock cord was fully extended). The delay may have been a little too long as well. I honestly cannot remember. Everything looked fine and I recovered the rocket. I did not notice the zipper until I got back to my car. About 8 inched long. I now have a longer 3/8" kevlar installed which should help. As I mentioned, I also modified it so that I can use electronics for apogee deploy or as dual deploy depending on the motor (or I can still use motor ejection). Since I ground test with electronics, the size of the charge is better controlled.

This is my first time with the Mac Performance material. Never had a problem with fiberglass. Hopefully this was just a one-off mishap. I need to be a little more diligent the next time I fly it with motor ejection.