MAC BlackFly build thread

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I haven't had to try adding a dowel yet. I've got removable weight setups in smaller cones, and for the bigger cones, I've gotten away reaching in and creating X-shaped scarring on the inside of the tip with a strong blade. My hope is that this creates channels and ridges for the epoxy to grab onto beyond what sanding produces.
 
I forgot about that technique. I recall a thread showing it and they used brass rod. I even purchased some small brass rod several years ago for another project that is still on the bench. I know exactly where it is and I think I will attempt to drill through the nosecone and lead weight, and insert it in. It should be soft enough to do this without any issue.



Based on what I have already done with the AV bay, it is likely going to be easier for me to try your "anchor" idea first.

I will give it a shot this evening, worst case I will really screw it up and need a new nosecone.

Thanks guys!

I'll be honest... My first thought is... You don't have these issues with a FWFG NC. LoL
 
I haven't had to try adding a dowel yet. I've got removable weight setups in smaller cones, and for the bigger cones, I've gotten away reaching in and creating X-shaped scarring on the inside of the tip with a strong blade. My hope is that this creates channels and ridges for the epoxy to grab onto beyond what sanding produces.

I was hoping for the same thing. However for the amount of effort it takes I would rather deal with this now before it becomes an issue and then I am looking at fixing the paint.

I'll be honest... My first thought is... You don't have these issues with a FWFG NC. LoL

I was just thinking the same thing. As a matter of fact I really wanted to use the FW/FG conical nosecone for this design but the thin-wall one does not come close to the O/D of the canvas phenolic body tube.

I got home early as I have to pack and do some last min running around this evening and tomorrow, so I just did this and it took 15-20 and the epoxy is now drying.

I found the two 1/8" brass rods I picked up from HD a few years back. Working with brass brings me back to high school machine shop, and also when I was a kid watching my father build a Mirror Dinghy in the basement only realize it wouldn't fit up the basement stairs and through the door once he finished it lol.



I had to cut a couple of wood blocks just to support the tip of the nosecone while drilling it at the correct angle so it would end up square. I also placed a cleanup rag in the vice just to protect it from any grease or unnecessary scratches that I would just have to fill or cleanup.

35457294630_7651ef2231_z.jpg


Drilling was very easy and the drill bit cut through the lead like butter. The only issue I had was when the bit popped through the other side and grabbed onto the rag, I am sure some of you saw that one coming.



A test fit of the rod and it was perfect, not too tight but firm. For a bit of extra security as I was not sure how well epoxy grips on smooth brass, I took my vice grips and clamped down to make some grooves in the brass rod.



I just have some careful filing to do on both sides to match the profile, possibly some filling with the putty and hopefully you will never know.

35457295380_c19c34ca7d_z.jpg


So far the net result is less than a gram and I am sure once the epoxy dries and the excess is filed and any imperfections filled I may net pretty close to zero.



At this stage I will leave it for about a week and deal with it when I get back.
 
I wonder if the brass nubs can be worked into the color scheme, thereby saving having to smooth them out flush... :cool:
 
Got mine today! I have to say, I loved unboxing it... Weird, but it was all put dry-fit in the bag (except for fins, obviously), so the first thing I did was slap the nosecone on it and get a feel for what will soon be my favorite sport flyer... Great little 5-fin kit! Built the OR file from scratch (as is my custom). The NC coupler was perfectly machined, but alas... I ditched it. I'm leaving the NC open entirely because with the APE NC sled, I wouldn't have room for recovery gear with a CTI 6XL case. (Using the Wildman NC option) I popped out the NC tip, added an eyebolt, and tied a 1/4" Kevlar harness to the eyebolt. Then dropped in about 2ozs of nosewight and squirt some 2-part foam to lock it all in place. Used some West 5-minute epoxy to attach the NC coupler. Boom Nosecone done in about 15 minutes.
So... the only altimeters I'll get in this one are JL. Actually, that means it'll be nothing but simple Shoot, Pop, and JLCR which is my favorite kind of flying... Plop a motor in, fire it off and enjoy. I'll tape a tracker to the shock cord and enjoy the hell out of the Black Fly. Early sims are saying about a mile up at just over mach on an I224 Classic.

I'm really looking forward to how you finish yours off, Mike. I wanna see the final paint scheme with decals... looking very cool so far!
 
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Got mine today! I have to say, I loved unboxing it... Weird, but it was all put dry-fit in the bag (except for fins, obviously), so the first thing I did was slap the nosecone on it and get a feel for what will soon be my favorite sport flyer... Great little 5-fin kit! Built the OR file from scratch (as is my custom). The NC coupler was perfectly machined, but alas... I ditched it. I'm leaving the NC open entirely because with the APE NC sled, I wouldn't have room for recovery gear with a CTI 6XL case. (Using the Wildman NC option) I popped out the NC tip, added an eyebolt, and tied a 1/4" Kevlar harness to the eyebolt. Then dropped in about 2ozs of nosewight and squirt some 2-part foam to lock it all in place. Used some West 5-minute epoxy to attach the NC coupler. Boom Nosecone done in about 15 minutes.
So... the only altimeters I'll get in this one are JL. Actually, that means it'll be nothing but simple Shoot, Pop, and JLCR which is my favorite kind of flying... Plop a motor in, fire it off and enjoy. I'll tape a tracker to the shock cord and enjoy the hell out of the Black Fly. Early sims are saying about a mile up at just over mach on an I224 Classic.

I'm really looking forward to how you finish yours off, Mike. I wanna see the final paint scheme with decals... looking very cool so far!

Man you don't mess around, I think you need to post some pics. I am pretty sure yours will be lifting off the pad before mine.

I won't be posting for a week or so as I will be out of town but when I get back I should be able to get through the last bit of paint. BTW I like the gloss/matte theme you mentioned, it should be pretty cool. I tried this with mixed results on my 3" Darkstar, matte black body and half matte black and half gloss red fins, it was challenging. I ended up repainting it over last winter and it is now black/yellow but all matte.
 
Man you don't mess around, I think you need to post some pics. I am pretty sure yours will be lifting off the pad before mine.

I won't be posting for a week or so as I will be out of town but when I get back I should be able to get through the last bit of paint. BTW I like the gloss/matte theme you mentioned, it should be pretty cool. I tried this with mixed results on my 3" Darkstar, matte black body and half matte black and half gloss red fins, it was challenging. I ended up repainting it over last winter and it is now black/yellow but all matte.

I just finished my MMT today, fins tomorrow. I'm using 5-minute West this far, and will foam the back-end. Quick question... Do I need to do anything to epoxy the tailcone? It's a nice, tight fit to begin with, but I've never bonded printed plastic, so I'm looking for any tips. Also, painting the tailcone... I still haven't decided if paint is the way to go, but if I do, I'm assuming primer will do just fine? My only beef is the 3D printed texture. I prefer my tail be smooth. ... ...
Also... I'll be drilling for my rail buttons and vent-hole. Does the canvas drill fine, or do I need to strengthen the inside (tape, wood block, etc)?
As far as paint, I'm definitely going with the matte/gloss black, maybe horizontal stripes? And I've ordered decals from Mark...

1500006454481.jpg
 
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The texture is tied to the print resolution that MAC uses - the finer resolution takes a lot longer to print, but still has a discernible texture to it. So, if you want it to have a smooth finish, you'll need to do a bit of filling and sanding. For some parts, the texture might be a nice surface detail, but I agree that on a boat tail, smooth is better. I did the same using that tailcone on my Radial Flyer, and it took a little more work than anticipated. Even though I had it printed on a 50 micron resolution, it had enough texture that it didn't simply sand off. After filling (actually using Elmers wood filler putty) and sanding, I used the same Rustoleum filler primer I used on everything else. I don't expect that you need to over think it.

As far as bonding it goes, it really comes down to surface prep like anything else. Here, the printed texture works for you, giving something for the epoxy to bite into. This cone was designed to attach to the motor tube (I don't recall if MAC is using the version with the body tube shoulder), so just scuff sand the tube like you would for epoxying anything else. Its kind of a no brainer either way; once the motor retainer is adhered to the motor tube, the tailcone can't come off. See below:
32421548315_797485ecf0_z.jpg


The retainer essentially traps the tailcone in place. You could probably get away without even gluing it, assuming the retainer gets bonded suitably. I guess that also assumes that you build your motor mount so that the retainer base can be pushed up against the inside of the tailcone's counterbore without any gap (keeping the retainer about half recessed). There isn't really any load on the cone, so it shouldn't be a big deal.
 
OK Guru’s,
Are there mathematic computations involved in the placement of launch lugs /rail buttons?

I opted for 1/4" 54mm conformal launch lugs instead of rail buttons here in East Texas so I won’t have to drive several hours for every launch. These are quite a bit bigger/longer than the ones that come with the Estes PSII kits for example.

My question is how do you determine where they go and how many are required? I would like to center one in the “fin can” area for aesthetic purposes but I’m not sure if I need to put a second one up close to the nose cone or not?

BF2.jpgBF1.jpg

Most low power kits only use one lug but my Mega Der Red Max, Scion & Leviathan all use two (albeit smaller) lugs but they are much bigger (longer) rockets.
I could probably even cut these in half and use two smaller ones? I’m not really concerned with excess drag, I just want to be sure it is stable off the launch rod and I get the dang thing back!
 
If you are going to use those, you probably could / should cut them in half and use them shortened. That'll aid in getting the rod through them if their alignment is off a little, bind on the rod less. Since they're surface mounted, they can be anywhere - I'd put one as far back as practical, and the other at or slightly above the flying CG. But its a short enough rocket that it won't matter much.
 
I tend to place one lug as far aft as I can, and one roughly at the CG. I have also flown high power with one lug, but it was probably 4-6" long, and closer to the CG.
 
Thanks all...sooooooooooo many questions
This one directed to CzTeacherMan...
1) what brand/model of tracker are you planning to tape to the shock cord?
2) would you be willing to share your OR file?

I have the standard nose cone that comes with the kit and I don’t see any wayto add weight here without substantial cutting/modification...

nc.jpg




and I am sure that it will need nose weight since I "fat finger'd"the internal fillets in the fin can with epoxy and probably added a few ozthere.

I would like to add an altimeter at some point
and possibly an Eggfinder so I shouldprobably go ahead and order the removable nosecone AV Bay right? That would notonly add weight to the nosecone area but also allow for additional electronics?

Are you guys using 19.16" from the tip of nose cone as the center of pressure per the instructions provided by MAC?


 
Thanks all...sooooooooooo many questions
This one directed to CzTeacherMan...
1) what brand/model of tracker are you planning to tape to the shock cord?
2) would you be willing to share your OR file?

I have the standard nose cone that comes with the kit and I don’t see any wayto add weight here without substantial cutting/modification...

and I am sure that it will need nose weight since I "fat finger'd"the internal fillets in the fin can with epoxy and probably added a few ozthere.

I would like to add an altimeter at some point
and possibly an Eggfinder so I shouldprobably go ahead and order the removable nosecone AV Bay right? That would notonly add weight to the nosecone area but also allow for additional electronics?

Are you guys using 19.16" from the tip of nose cone as the center of pressure per the instructions provided by MAC?



Thanks for the answers on the tailcone! The texture isn't too bad, but I'm picky. LoL!

1) tracker: ComSpec, sold by Wildman. I always just tape it to the shock cord or use Tim's new Nomex tracker pouch
2) sure I can share! When I'm close to my computer again, I'll get it posted. I always build my files from scratch and get them accurate to the mm and g. I'll update it after construction and a first flight to make sure I have the Cd, weight, and CG correct.
3) I bought the Wildman nosecone, mostly because I hate painting plastic. But I like the looks of the Mac NC av-bay.
4) My sim said the CP was back a bit from 19", so that's what I'm relying on.
 
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Nice. The extreme point of that cone gives it a little different of a look...

Indeed. I'm anxious to see it painted. Now it looks like almost all nosecone, but once painted, it should be a more cohesive unit.
 
As far as I can tell, it doesn't look like anyone actually posted their sim files for this. Here's mine:

35908178306_06a2b5df16_c.jpg

A couple of things to note - this file has the 3D printed tailcone modeled fairly correctly, which is different from what was in the original sim that MAC used (which was based on having a boattail retainer instead, though there isn't one for 29mm). The tail cone that actually comes with the kit is shorter and more truncated; its designed to partially hide a normal Aeropack retainer instead of taper down to the motor diameter. That's also the reason that the sim image above shows the overall length as slightly shorter. What all that means is that the impact it has on CP at least appears favorable. The 19" dimension comes from Mike @ MAC's OR file, but what Rocksim tells me is that its more like 20.1" from the nose tip if using simplified Barrowman equations (to compare to OR), or better yet, about 21.5" if using the full equation set (the "Rocksim stability equations" option). So, based on that version, in Rocksim, the stability factor is better still. Though ballast is needed either way...

View attachment MAC Black Fly 54 - SD.rkt

Edit: also added .ork file conversion, but I'd consider that a starting point, since I didn't do anything but import the .rkt and resave...
View attachment MAC Black Fly 54 - SD.ork
 
I tried to upload my OpenRocket file, but couldn't figure out how to get it below the size limit. For some reason I couldn't "save as" in a smaller format. Over I get that figured out, I've got it modeled pretty well, including the tailcone.
 
Base coat of matte black primer is done... Have to shoot gloss black tomorrow and red (tailcone) a few days after that.
Smoothing out the tailcone was simple. Used Elmer's Wood Filler. Basically: sit my first coat of filler primer, applied word filler, sanded it all down smooth, then shot the black primer. Everything's smooth as I'll make it already with just the black primer. Gloss black is going on the nosecone and fins only, then satin red on the tailcone. A virtual bevvy of textures on this one. Decals will go on the matte black.
Fun build, zero problems. Very well designed kit. I almost (almost but not quite because I have enough damn rockets already!) want to ask if Mike can upsize it to a 3" or 4". Might be hard to get the tailcone right in those sizes.
I'll post pics when it's all done. Definitely a fun Sport rocket. This will likely be my go-to shoot-pop rocket from now on.

1500348285466.jpg
 
I almost (almost but not quite because I have enough damn rockets already!) want to ask if Mike can upsize it to a 3" or 4". Might be hard to get the tailcone right in those sizes.

I like that idea. The tailcone could just be an Aeropack.

He used to have a short 4" kit designed for an Aeropack tailcone with a kind of unique dual deploy setup, that I had on my short list to get, but it seems he stopped making it. I like the fins on the black fly better anyway...
 
I like that idea. The tailcone could just be an Aeropack.

He used to have a short 4" kit designed for an Aeropack tailcone with a kind of unique dual deploy setup, that I had on my short list to get, but it seems he stopped making it. I like the fins on the black fly better anyway...

I think that's where this design started, but wound up with a 3D printed tail cone because there isn't a 29/54mm Aeropack retainer cone available. But go up to 3 or 4" and that problem goes away.

AdAstraPerAspera - if there was a design that MAC used to offer that you liked, contact them. I think there's a good chance that Mike will work with you, he's is pretty good about making what customers want (assuming there isn't something preventing it from being made)...
 
I like that idea. The tailcone could just be an Aeropack.

He used to have a short 4" kit designed for an Aeropack tailcone with a kind of unique dual deploy setup, that I had on my short list to get, but it seems he stopped making it. I like the fins on the black fly better anyway...

interesting... Aeropack does make a 3" to 38mm tailcone....

Also, I'll bet you're thinking about the Ethos: https://www.rocketryforum.com/showthread.php?129771-MAC-Performance-Rocketry-New-Release-ETHOS
Glen (djs) and I were just talking about it the other day since his wife bought one back in 2015 and STILL hasn't finished it! (Come on, Roberta... Build that sucker!)
 
First off Eric your BlackFly looks great. I like the combination of matte and gloss.

As for an upscale to 3" or 4" not a problem.I can print a tailcone for any size. I'm thinking a 38 motor mount in a 3" and a 54 mount in a 4".

ETHOS has been removed from the website but is still available. Roberta bought the third one built. (OK Roberta times up:wink:)....The compact Avbay used in ETHOS would definitely work in a 4" BlackFly to make it D/D or keep it simple with a Jolly Logic.

EXPjawa (Rick) is right. We've been doing more and more custom work. If there is something you would like made into a kit send me an Ork. or drawing.

Thanks everyone for all the support!
 
EXPjawa (Rick) is right. We've been doing more and more custom work. If there is something you would like made into a kit send me an Ork. or drawing.

orly? ;) I don't have any ideas...but I saw this the other day and I'm sharing for no related reason ;)

oop_strikefighter02.jpg
 
First off Eric your BlackFly looks great. I like the combination of matte and gloss.

As for an upscale to 3" or 4" not a problem.I can print a tailcone for any size. I'm thinking a 38 motor mount in a 3" and a 54 mount in a 4".

ETHOS has been removed from the website but is still available. Roberta bought the third one built. (OK Roberta times up:wink:)....The compact Avbay used in ETHOS would definitely work in a 4" BlackFly to make it D/D or keep it simple with a Jolly Logic.

EXPjawa (Rick) is right. We've been doing more and more custom work. If there is something you would like made into a kit send me an Ork. or drawing.

Thanks everyone for all the support!

There it is... Hard to get a good picture today, very poor lighting outside. I'll have to figure out how to photograph the matte v gloss black because no photo yet does it justice. It looks sleek and mean, like a stealth fighter. StickerShock decals make the rocket; a perfect compliment to the angles of the fins and tailcone.
Final dry weight is exactly 750g with a Wildman nosecone, Recon Chute, and a OneBadHawk 1/4" Kevlar harness. Just barely heavier than my Wildman Sport.
First flight will probably be on an H165 on the 29th.
...
I may be asking my wife to grab a 3" Black Fly for my birthday in November. LoL!

1500483766415.jpg
 
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That's awesome. I think you skip right past the 3" (which isn't a huge departure from 2.275") and make the next one 4", with a 54mm mount as Mike suggested above. Call it "SuperFly"...
 
OK Guru’s,
Are there mathematic computations involved in the placement of launch lugs /rail buttons?

I opted for 1/4" 54mm conformal launch lugs instead of rail buttons here in East Texas so I won’t have to drive several hours for every launch. These are quite a bit bigger/longer than the ones that come with the Estes PSII kits for example.

My question is how do you determine where they go and how many are required? I would like to center one in the “fin can” area for aesthetic purposes but I’m not sure if I need to put a second one up close to the nose cone or not?

View attachment 323905View attachment 323906

Most low power kits only use one lug but my Mega Der Red Max, Scion & Leviathan all use two (albeit smaller) lugs but they are much bigger (longer) rockets.
I could probably even cut these in half and use two smaller ones? I’m not really concerned with excess drag, I just want to be sure it is stable off the launch rod and I get the dang thing back!

Hi Deke,

Welcome to the thread, great looking build so far. Looking forward to seeing some paint on that naked fly.

Build done. Time for finishing and paint.


Wow Eric you did a nice job putting that fly together and the aluminium tip is killer!

As far as I can tell, it doesn't look like anyone actually posted their sim files for this. Here's mine:

35908178306_06a2b5df16_c.jpg

A couple of things to note - this file has the 3D printed tailcone modeled fairly correctly, which is different from what was in the original sim that MAC used (which was based on having a boattail retainer instead, though there isn't one for 29mm). The tail cone that actually comes with the kit is shorter and more truncated; its designed to partially hide a normal Aeropack retainer instead of taper down to the motor diameter. That's also the reason that the sim image above shows the overall length as slightly shorter. What all that means is that the impact it has on CP at least appears favorable. The 19" dimension comes from Mike @ MAC's OR file, but what Rocksim tells me is that its more like 20.1" from the nose tip if using simplified Barrowman equations (to compare to OR), or better yet, about 21.5" if using the full equation set (the "Rocksim stability equations" option). So, based on that version, in Rocksim, the stability factor is better still. Though ballast is needed either way...

View attachment 323992

Edit: also added .ork file conversion, but I'd consider that a starting point, since I didn't do anything but import the .rkt and resave...
View attachment 323994

Thanks Rick, I thought I updated the .ork file on one of my posts.

There it is... Hard to get a good picture today, very poor lighting outside. I'll have to figure out how to photograph the matte v gloss black because no photo yet does it justice. It looks sleek and mean, like a stealth fighter. StickerShock decals make the rocket; a perfect compliment to the angles of the fins and tailcone.
Final dry weight is exactly 750g with a Wildman nosecone, Recon Chute, and a OneBadHawk 1/4" Kevlar harness. Just barely heavier than my Wildman Sport.
First flight will probably be on an H165 on the 29th.
...
I may be asking my wife to grab a 3" Black Fly for my birthday in November. LoL!


Eric she turned out great, looking forward to hearing some details on any flights.

Well after being in Florida for just over a week I am back now, so hopefully I will get this fly painted and finished in the next couple of weeks. One cool thing to mention, I hit KSC on the 16th (Apollo 11th launch anniversary) and took a special tour which included a visit to the famous 39A. Not the best pic as it was taken from my phone.



Adding the brass rod to the nosecone turned out very well. I ended up masking all around the rod then initially using a medium file I filed it to where is was roughly flush.

36017273206_34fc47a7bd.jpg


I then switched to fine file followed by a broader block sanding with 320 grit. This was followed up by a full wet sand for the entire nosecone with 400 and a couple of light coats of primer. At this stage it is pretty much invisible, so I will be painting it black tomorrow night.



This evening I also had a chance to knock down the masking line where I painted the tailcone red, and lay down 3 light coats of the base grey for the body, which looks a lot like primer grey. It is the Krylon camo paint and is dry to touch in 15 min with a re-coat window of up to 24 hours but anything over that and you have to wait 7 days. My plan is to have a look at it tomorrow night, and if it does not need any touch-ups, then I will mask and lay down the black. At that stage I will set it aside for a week and work on the nosecone AV bay.

 
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Thanks Michael!

I just got my nose cone AV bay from MAC in the mail yesterday so looking forward to your build.

This is going to take me forever since I'm ordering one piece at a time LOL!
 
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