MAC BlackFly build thread

[mpitfield]

I have wanted to do a build thread for some time, however, because of other commitments in my life I tend to drag my builds out with inconsistent building 1 hour here, 15 min there and 30 min there. Hopefully, I can keep this interesting and progress at a pace that keeps your attention.

This rocket was born out my desire to have something simple to take to mid-power and high power launches, and fly as a simple quick-prep pop and drop, or have the flexibility to fly on an H out of site. Initially, I was looking for a 24mm MMT. However, as the discussion progressed in this thread, I decided to use a 29mm MMT. From a design perspective, I knew that I wanted something stout and rugged enough to build and fly on a wide range of motors. I also wanted something a bit more unique than 3FNC, so I settled on 5FNC :wink:.

To meet my desire to use materials that were rugged and of high quality/high precision, but at a reasonable cost, I reached out to Mike @ MAC Performance Rocketry. After sending Mike the RockSim file followed by a brief discussion, it was pretty obvious that Mike liked the design and wanted to help. He had a tailcone printing on his 3D printer within minutes. After further discussion, I realized that Mike also had all of the components for this project, which made it a convenient one-stop shop.

BTW if you have not had the chance see one of MAC's kits, you really should drop by Mike's tent, if you are lucky enough to attend a launch he is at. I can't overstate this, but his components are not just quality in the materials used, but the precision is second to none. His kits and components are manufactured to a very high standard.

I will begin building sometime this weekend and will post results as I go.

Below is the package I received from Mike.



My initial colour scheme but still lacking some details.



Not just a bunch of parts but Mike turned this into a kit for me, talk about service.



Mike also took care of providing a high-quality precision CNCd top CR with an integrated Kevlar attachment point for my harness, top left. Also bottom right is a MAC nosecone AV bay. As I mentioned, I wanted the option to fly this on a range of motors, including some that will pop it out of sight. So I plan on building a removable AV bay to host an Eggfinder Mini and Eggtimer Quark (for apogee only). The BT is 54mm, so there is a lot of room to use the JLCR without the need to get creative in packing or under-size the chute and recovery gear due to space restrictions.

A quick dry fit...Mike produces a premium product! Here it is beside a Rocketry Warehouse, now Madcow, Formula 38. Very similar in height and although my Jolly Logic Chute release fits in the Formula, it fits a heck of a lot better in the MAC BlackFly. The rocket is 28" from tailcone to tip. Remarkably even though the BlackFly is a substantially beefier airframe with much tougher/thicker fins, only 25 grams separates the two rockets at this stage. This is one robust little rocket!



A shot from above to show the five fin design.

And a close-up of the custom tailcone. See how well an Aeropack fits. The tailcone in the pic is not the one I am using, more on that down a pic or two.



One thing I was concerned with in using five fins with a 54mm BT, was rail clearance, however, it easily clears if you use a 1010 rail. I plan on using the 20mmx20mm x 48" rail with the mini rail buttons.

Why the name BlackFly? If you have ever been to Canada's North in the Summer, or anywhere in the world for that matter where these little buggers are, then you know that they are tenacious, relentless and very adaptable. Beyond those characteristics, they are also known as a good flier with a stout, robust little body.

So the obvious thing to do next, send Mark at stickershock a picture, along with the background story. If you have ever worked with Mark, you know how great he is at this stuff. Just shoot some ideas at him and "wallah" he shoots back some quick, creative visuals. After a few revisions, below is a rendering of the final scheme and the decal set that will adorn my MAC BlackFly...as Mark says, never fly naked!




This is why the yellow tailcone is not being used. Although one might wonder there are 4 in the picture...

As mentioned, I will post more pics and updates as the build progresses...thanks for watching and I look forward to your comments!

 

[Woody's Workshop]

op:

 

[DavidMcCann]

some day, I'm flying a mac kit without glue.


Some day, after my luck changes that is....

 

[dhbarr]

MAC Fly!

 

[mpitfield]

MAC Fly!

Thanks for the throwback! I got a good chuckle out of that one.

[video=youtube;95_DB6GgLQs]

 

[Q-Aero]

Also bottom right is a MAC nosecone AV bay. .....So I plan on building a removable AV bay

Nice looking removable nose bay, would like to see more detail.

I have 2 rules with noses

1. Never put a fixed weight in it. (I want it variable, not only you can adjust with the motor weight, but you can use the cone on another rocket )
2. Removable bay , I use a lot cable cutter, so I need a place to put an altimeter on non DD rocket.

I prefer now the chute releaser, but sometime you need something more reliable than motor ejection charge. Also on heavy rockets , you can’t use only the motor charge at CAR launch

CAR HPR rules :
“All vehicles over 5 kg in loaded mass shall have a redundant deployment system activated independently and in addition to the rocket motors ejection charge(s). This system will provide safe recovery in the event of primary deployment system failure.”

 

[RocketFeller]

Very nice! I am going to have to get a Mac rocket one of these days...

 

[mpitfield]

Okay, time to start this bug.

First thing I always do, in my OCD manner, is measure, weigh, and catalog all individual components then refine my sim file. In this case, I used RockSim. I do this at this stage to confirm my desired stability range, based on a range of motors, as well as try to predict the optimal nose weight.

As I mentioned I initially wanted this as a simple "pop n' drop," however, based on the quality of the components it can also easily handle some of the H motors, so I opted to add a removable nosecone AV Bay. MAC sells these as options for all of their nosecones, so it fits perfectly. Because of this optional add on nosecone AV Bay, I adjusted the sim file specific to my setup.

As you will see with the sim file, everything is individually weighed; however, once fully assembled, I will do a mass and CG override based on the actuals. Based on the range of motors I simulated, with 75g of nose weight, it can fly on anything from a 24mm F to a 29mm H, and the stability margin is between just under 2 to just over 1 Cal.

Here is the RockSim View attachment MAC BlackFly.rkt

Below are some pics of the nosecone and MAC Nosecone AV Bay, it kills me on how tight the tolerances are on his stuff. I thought this was glued together when I first looked at it, but it's not. Dave all kidding aside I bet Mike could make something that you could fly without glue. At this stage, I decided to cut the end off the nosecone to get its weight for the sim. Keep in mind when looking at the sim, if the rocket were built as a standard pop n' drop, with no AV Bay, then this component would have to be adjusted in the sim file.

A dry fit of the AV bay...looks like it will just require some minor sanding with a small drum sander. This is better than I expected considering the variance of thickness on plastic nosecones, then again Mike uses Pinnacle, which is nice.



Side profile of the nosecone AV bay part. This will eventually slip inside the nosecone flush to the bottom.

Dry assembled AV bay, with the Eggtimer Quark and Eggfinder Mini I just assembled for it. I plan on using one 2S 430 mAh LiPo for both, connected to the other side of the sled along with a magnetic switch. I was going to use a screw switch but lining up the access hole would be more than I would like to deal with on this build. For scale, the AV bay is a 38mm tube...plenty of room for what I plan to use it for. I moved the centering ring down to roughly be where the inside of the nosecone shoulder steps out. I could push it up further, so it is resting on the inside wall of the nosecone, but this thing is not going anywhere.

Lots of thread to hold it all together, this is not coming apart in flight

A pic of the forward bulkhead of the AV Bay. I was thinking of leaving this off for access to the nose weight, but I need to think that one over a bit.

A close-up shot of the top CR. There is no bottom CR because the tailcone centers the MMT. As you can see MAC's top CR has an integrated Kevlar harness...just look at the thought and precision on this component. That is a metal bar, and this CR is .25 thick.



The last pic of the night shows the internal structural detail MAC put into the design of the tailcone. It is substantial in thickness, but it only weighs just under 18g. The pic is hard to read the scale, but I think it says 17.78 grams.

 

[Q-Aero]

I'm Sold to this nose cone kit

 

[qquake2k]

Very cool design!

 

[Banzai88]

Have you simmed it yet? What altitudes do you expect on that thing?

 

[Q-Aero]

Have you simmed it yet? What altitudes do you expect on that thing?

You means before it fall a parts ( they are joking about building a MAC without glue )

 

[mpitfield]

Have you simmed it yet? What altitudes do you expect on that thing?

The latest RockSim file is here View attachment MAC BlackFly.rkt I will continually update this file as it changes on my end.

However, if you do not own RS then here is a print out for quick reference. What was simmed was a variety of both AT and CTI 24mm and 29mm reloads. Some other motors were simulated, but I removed them because I did not like what the sim was indicating.

You means before it fall a parts ( they are joking about building a MAC without glue )

No issues, it's a fair question

 

[Q-Aero]

No issues, it's a fair question

I was trying to make a joke....

 

[mpitfield]

I was trying to make a joke....

No joking is permitted...this is a very serious rocket science thread :wink:

 

[EXPjawa]

Cool design, Mike. I'm a big fan of 5 (and 6)-fin designs. So, are the red boat tails the same as the yellow, save for color, or are they a different design? And why is it there are 4 of them?

Are you sure about the mini buttons? I'm starting to wear out the first ones I installed, and that's on smaller/lighter rockets on E20 motors. Basically, the washers are wearing down. I'd think that you might be able to overpower the buttons on an H-motor... I'll also point out that, at least in Potter, the mini rails are typically closer-in than the B-racks, so flying a G or H off of that might require some rearranging.

FWIW, I've started using these conformal surface-mount 1010 airfoil buttons on a couple of MAC 54 mm kits:

They're 3D printed, curved specifically for the 54mm canvas tube. You just epoxy them on. I've got an extra set - if you're coming down for NYPower next weekend and want to take a look, let me know. I'd be happy to have someone else give them a try.

 

[seth_cooper]

I saw this thread yesterday evening. I got about half way through the first post and said to myself "um, I need one of those." Then I thought "could Mike (from MAC Performance) could put another one together for me?" So I sent a message to Mike last night and he replied within the hour. Mine will ship out on Monday morning!!

MAC Performance has great customer service! (And the kits are amazing too. This makes my 5th MAC kit.)

Michael Pitfield: This design is great! 2 thumbs up from me.

 

[mpitfield]

Cool design, Mike. I'm a big fan of 5 (and 6)-fin designs. So, are the red boat tails the same as the yellow, save for color, or are they a different design? And why is it there are 4 of them?

Are you sure about the mini buttons? I'm starting to wear out the first ones I installed, and that's on smaller/lighter rockets on E20 motors. Basically, the washers are wearing down. I'd think that you might be able to overpower the buttons on an H-motor... I'll also point out that, at least in Potter, the mini rails are typically closer-in than the B-racks, so flying a G or H off of that might require some rearranging.

FWIW, I've started using these conformal surface-mount 1010 airfoil buttons on a couple of MAC 54 mm kits:
View attachment 320468
They're 3D printed, curved specifically for the 54mm canvas tube. You just epoxy them on. I've got an extra set - if you're coming down for NYPower next weekend and want to take a look, let me know. I'd be happy to have someone else give them a try.

Thanks Rick,

I have also always liked five and six fin rockets whenever I see them at a launch, then I think of all the fillets.

The red boat tail is physically and structurally identical to the yellow, just red to match the theme of the rocket. The idea of the rocket was to be an easy build, so I wanted the option of not having to paint the tailcone. Also, my paint choice was selected along the same theme, so my choice is to use the Krylon camo paints for the main body. I find the Krylon camo paints the most forgiving and easiest to use. I ended up ordering a case of the Krylon matte clear, which I believe is a bit more satin than the very dry camo colours. The upside should be a more uniform look and wear once I add the decals then lay down the clear.

Why there are 4 of them is a question you need to ask Mike.

Funny you should question the mini rail button choice. Ever since I wrote it down, I have been questioning it, and I would be very interested in seeing the conformal surface mount 1010 buttons at NYPOWER. I have also been re-thinking my perception of the "hassle" of lining up a screw switch, and I have thought of a simple solution so that I may use one after all.

It's an evolving project, so your input is very much appreciated.

 

[mpitfield]

I saw this thread yesterday evening. I got about half way through the first post and said to myself "um, I need one of those." Then I thought "could Mike (from MAC Performance) could put another one together for me?" So I sent a message to Mike last night and he replied within the hour. Mine will ship out on Monday morning!!

MAC Performance has great customer service! (And the kits are amazing too. This makes my 5th MAC kit.)

Michael Pitfield: This design is great! 2 thumbs up from me.

Hi Seth,

Thanks for the thumbs up. I am thrilled that you liked it so much that you had to have one.

To be honest I have been putting designs together in RS and OR for a while, but always in an attempt just to to come up with something unique, and never out of necessity or for a purpose. When this design evolved it was on the heels of destroying one of my favourite little pop and drop flyers (BadAzz Nike) that I like to bring with me to a HP launch. I like to bring at least one in an effort to get away from the focus that is required for all of the prep associated with my HP rockets. I think the BlackFly will serve that purpose well.

 

[mike2wander]

So, are the red boat tails the same as the yellow, save for color, or are they a different design? And why is it there are 4 of them?

Ok, so When Mike (Pit) asked me to put the Black Fly together for him I had yellow filament in the printer. The color scheme for the Fly was still being worked out. When the final graphics were decided it included a red tail cone. This was about the same time that Mike and I agreed that it would be a great design to kit. I took a picture of the first batch of red cones to come off the printer and sent it to Mike for approval. Mike posted it on his thread to show what the finished product would look like and drop a hint that there was going to be more than one Fly available. The question we had was, would someone ask why there was more than one..........You asked:smile:

 

[Tim51]

FWIW, I've started using these conformal surface-mount 1010 airfoil buttons on a couple of MAC 54 mm kits:
View attachment 320468

If you don't mind me asking - which MAC kit is that? It doesn't resemble any I can see on the website.

 

[EXPjawa]

If you don't mind me asking - which MAC kit is that? It doesn't resemble any I can see on the website.

It isn't a MAC kit per se. This is a case where its something I designed and MAC made, sort of like with mpitfield's Black Fly in this thread. In this case, its a semi-scale PAC-3 missile using MAC's 54mm tubing. I'd consider it experimental at this point; Rocksim says its fine, but the fins at least look questionable... I should be able to make the first flight next month some time.

 

[EXPjawa]

Funny you should question the mini rail button choice. Ever since I wrote it down I have been questioning it and I would be very interested in seeing the conformal surface mount 1010 buttons at NYPOWER. I have also been re-thinking my perception of the "hassle" of lining up a screw switch, and I have thought of a simple solution, so I may use one after all.

It's an evolving project so your input is very much appreciated.

Alright, if I don't find you first, feel free to stop by my tent whenever. Look for a dark blue Grand Cherokee with rally lights on the front and blue Harbor Freight pop-up. I'm not sure what days/times I'll be there, but Saturday is a good bet either way based on the current weather forecast. I can show you the buttons I've mounted and the pair that's still loose.

 

[Tim51]

It isn't a MAC kit per se. This is a case where its something I designed and MAC made, sort of like with mpitfield's Black Fly in this thread. In this case, its a semi-scale PAC-3 missile using MAC's 54mm tubing. I'd consider it experimental at this point; Rocksim says its fine, but the fins at least look questionable... I should be able to make the first flight next month some time.

I see - thanks! Hope the maiden flight goes well.

 

[Wingarcher]

First part from the new shop. Might be useful for this build?




Nat Kinsey
UpscaleCNC

 

[mpitfield]

First part from the new shop

Sure beats cutting it out of foam board! I sense movement on this build, post NYPOWER.

 

[mike2wander]

Want a BlackFly? There now available from MAC Performance Rocketry
https://macperformancerocketry.com/...s-1/products/copy-of-scorpion-54mm-diameter-1
A special thanks to Mike Pitfield for an awesome design and now an awesome kit. This is the first offering in our low/mid power rockets. Kit number two is just around the corner:wink:

 

[mpitfield]

Well, I did say my builds move at a slow pace and as you will see not much happens at once.

I did the following last week but have not had a chance to post. I also did a bit more last night so it may take me a day or so to post an update.

First thing I tackled was the MMT forward CR. The plan is to install the CR, and MMT assy in the rocket then tack the fins on but leaving the aft tailcone removable, which is also the aft CR. This way, I will have access to the fins for some small fillets. I will be using Aeropoxy ES6209 structural adhesive for this build. Not because it needs it but because it is what I have, and what I have is at the end of its storage life, so I need to use it.

To figure out the depth of the CR I simply dry fit the MMT, CR, tailcone and retainer, then used the tips of the fins to push the CR flush with the forward edge of the fin slots.



Once I had the CR in the right spot, I removed the assy, and masked the tube where it meets the backside of the CR. Then I reinserted everything to double check the depth.



Once I was happy I marked the backside of where the CR meets the tube with a pencil then took some 150 grit sand paper and sanded groves on the horizontal plain of the MMT. I always prep my surfaces for epoxy, keeping in mind the direction of the forces that will be applied, in this case, perpendicular.



I removed the temp masking tap and used it to protect the integrated recovery harness attachment cord and slide the CR back in preparation for applying a bead of epoxy.



Time for epoxy. Using a Popsicle stick, I applied a small bead where the CR will be, ensuring I had full coverage.

I then slide the CR up to the point where it made contact with the epoxy and then rotated the CR continuously as I pushed it slowly up to the previous pencil mark. This works the epoxy under the CR and makes a nice even bead above the CR that eventually settles as a fillet.



Two days later this is what the fillet looked like.

 

[mpitfield]

Forgot to post this, look what showed up in my mail.



Yay Stickershock delivery! Decals on top.



Mask on the bottom. I am not sure if I am going to use the decals or simply mask and paint, which is my preference. What is interesting is how much more film masking takes vs. a decal set.

 

[mpitfield]

MMT installation time.

Using 80 grit sand paper wrapped around a 1" dowel, I measured it for depth and marked it off with some tape. In this case the MMT forward CR will be level with the top of the fin slot.

With 80 grit it doesn't take much to prep the surface for epoxy. This is my first time working with the canvas phenolic. While it is rigid, it is still flexible and the surface is relatively hard, much harder than a traditional phenolic tube, but still sand able. It should make a very durable rocket.

Again using my highly scientific and accurate method of measuring, I marked the depth on my popsicle stick for applying the epoxy and laid down a nice internal bead.



Using the same method to install the CR on the MMT, I took the MMT assy and twisted it continuously until the epoxy was even and worked under the CR. Then I dry fit the tailcone and retainer to ensure the correct depth and set it aside to dry for 24 hours. Once dry I removed a bit of masking tape that I temporarily put on the integrated harness and it is now ready for fins.