Blackfish - L1 Super DX3 Build

[Budro0]

After years of LPR and MPR, I've finally decided to get my L1. I bought most of the kit required during Black Friday sales and they are just now filtering in. I opted for the Madcow Super DX3 for no other reason than I liked the fins... also, it's 38mm whereas other kits I was looking at were 54mm and I just don't feel like I need to jump up to that size quite yet. I do think I will be setting this up for traditional DD, but otherwise it will be a fairly basic build for me.

Right now, the weight in OR seems a bit heavy (I've deleted Madcow's overridden weights until I can verify myself), but I imagine it is within a couple hundred grams of actual for me. Although a sub-300m cert flight sounds pretty nice. Planned tweaks and changes are:

Traditional DD
Nosecone tracker bay
Extra CR for MMT (just in case I bump up to L2 in the future)
Reinforce couplers/BT ends with wood hardener/thinned epoxy
Glass the body tubes?
Tip to tip glass
Spherachute or Recon chute - still trying to decide

I mostly scratch build, so the process of putting this kit together seems pretty easy. I do have some ideas/questions about the dual deploy. I've read the posts about reinforcing cardboard tube with brass shims and I like the idea. Could I put the shims in (or a shim band as I'm thinking right now) and then drill my shear pin holes? Any objections? I'm also considering setting up the cert flight as single deploy with an apogee main event and motor ejection redundancy. Again, any objections?

Finally, the design of the rocket also includes the paint job. I am kicking around two ideas: using black and grey primer to mimic the markings of an orca with a transparent pearl color over it, or replicating a Coastal Native art design to make it look like an orca totem. I think the first is well within my ability, but the second will definitely stress my masking abilities. More to follow as I sketch out the designs.

 

[mbeels]

Spherachutes are really nice, as a plus you get to pick the colors!

 

[Budro0]

Spherachutes are really nice, as a plus you get to pick the colors!

I've heard great things, but never flown them. I've got a standard Rocketman chute that I like for my heavier MPR flights, but otherwise I have not had much occasion for anything fancier than a flat sheet.

 

[Budro0]

Jumping right into this build as I've been tinkering with the kit since I got it last week. I did the Coker nosecone mod to add the tracker bay. Nothing really fancy, but I did scratch build the sled. I used a 4x54 CR and 4" coupler bulkplate for the mount. I had to do a fair amount of sanding to get it all to fit, but it turned out nicely.


I think I ended up using 6-32 screws and t-nuts because I had some extra lying around.


The mock up of my sled base. I misjudged the 54mm when grabbing holesaws, but a little extra glue and it sorted out fine. I also used a chunk of 54mm tube to add a little extra rigidity to the base mount.


After I got the poorly cut 54mm bulkplate glued up, I realized I forgot to cut a dado for the actual sled. Grabbed a coping saw and 10 minutes later it was fine.


I opted for an Eggfinder Mini for tracking, not because I trust it, but because I had one for a 29mm MD build which I'd like to keep in the arsenal. I've never flown it though, mainly because I've never been able to get it to acquire satellites. I probably need to call up Cris and see what I'm doing wrong.


My battery placement (sketched in pencil) worked out great until I mounted it in the 54mm tube. It sits pretty low in the tube. I will probably need to cut a bit of the tube to make it easier to fish zipties through.


It's okay to be jealous of my joinery skills. Mounting up a battery tray to give some more support during liftoff.


Lots of glue, some beer, and intermittently paying attention to my wife's TV show.


Fortunately, as ugly as it all is, it will be hidden from view in the nosecone. After the epoxy cured, I decided I needed to widen the CR a bit to make it easier to slide the tracker bay in.

 

[David Schwantz]

Looks like she will be a great ride. Cert flights are thought to be KISS. The Orca scheme sounds cool, but might want a neon orange chute to go with that. Tall grass and plowed fields suck at giving back rockets that land in them. I fly 54mm with card board all the time, no glass on tube. I also will use brass inside of card board for the shear pins. And these are not objections, just thoughts.

 

[Budro0]

Looks like she will be a great ride. Cert flights are thought to be KISS. The Orca scheme sounds cool, but might want a neon orange chute to go with that. Tall grass and plowed fields suck at giving back rockets that land in them. I fly 54mm with card board all the time, no glass on tube. I also will use brass inside of card board for the shear pins. And these are not objections, just thoughts.

Thanks for the pics - so that's what I was thinking. Thanks for the confirmation bias.

I agree with the simplicity concept, but I also like redundancy... It's a toss up. I'll take your thoughts into consideration. Especially about the orange chute...

 

[David Schwantz]

Lost a rocket in a carrot field for a month. Another club member found it while looking for his rocket. And I HAD a neon orange chute on it

 

[Nytrunner]

I was hoping this was an upscale of Neil's Blackfish scratch build, but you've got a good thing going anyway.

If you only have a 38mm mount, glassed tubes or fins should be unnecessary

What motor are you planning for?
Good luck!

 

[Budro0]

I was hoping this was an upscale of Neil's Blackfish scratch build, but you've got a good thing going anyway.

If you only have a 38mm mount, glassed tubes or fins should be unnecessary

What motor are you planning for?
Good luck!

Well now I'm going to need a new name...

I agree that it is probably unnecessary, but I'm the king of overbuilding. I actually like doing the glass, and it's good practice. I'm going to try the FG sleeves and Soller's heat shrink wraps on this one. Maybe. I need to do some tests to see how much weight I'm really adding.

I've got it simmed on an H130, but I don't have anything in hand. Once I get a better idea of final weight, I'll see if it's still a valid motor.

 

[thzero]

I used the Soller socks on a 3" LOC tube for a build of mine; done to learn new techniques and also actually add weight (hit certain alt goals due to field size, etc). I had used the sock then the heat shrink wrap, but TBH I found it a bit of a pain getting the shrink wraps over the epoxied sock. I saw someone else post basically using mylar wrap instead. Might try that next time instead. I also had lots of pin holes after it cured... so ended up going over it again with epoxy and fighting pin holes - maybe just poor execution or such on my part. Was using West Systems epoxy.

 

[neil_w]

I was hoping this was an upscale of Neil's Blackfish scratch build, but you've got a good thing going anyway.

I confess I was too.

Well now I'm going to need a new name...

Don't change it on my behalf, there's no exclusive ownership of rocket names here.

 

[Budro0]

I used the Soller socks on a 3" LOC tube for a build of mine; done to learn new techniques and also actually add weight (hit certain alt goals due to field size, etc). I had used the sock then the heat shrink wrap, but TBH I found it a bit of a pain getting the shrink wraps over the epoxied sock. I saw someone else post basically using mylar wrap instead. Might try that next time instead. I also had lots of pin holes after it cured... so ended up going over it again with epoxy and fighting pin holes - maybe just poor execution or such on my part. Was using West Systems epoxy.

What size shrink wrap did you use? I am planning to up size a bit to help get it over the tube. I've done mylar sheets for other projects and it works fine, I'm just hoping the shrink wrap will be easier. Sounds like it might just be a balance on the difficulties.

 

[Budro0]

I confess I was too.


Don't change it on my behalf, there's no exclusive ownership of rocket names here.

I know, I know...

 

[thzero]

What size shrink wrap did you use? I am planning to up size a bit to help get it over the tube. I've done mylar sheets for other projects and it works fine, I'm just hoping the shrink wrap will be easier. Sounds like it might just be a balance on the difficulties.

Since it was a 3" tube, I tried both the 3.1 and 3.8 shrinkwrap. The latter was a bit easier to get on without scraping off epoxy, however then it was harder to 'iron out' with the heat gun to make it smooth. 3.1 was bit tougher to get on, but was easier to heat shrink. Perhaps I had too much epoxy still on the tube; dunno, first time I did it.

 

[Budro0]

Trying to post from my phone, we'll see how it goes.

I haven't worked much on the rocketduring the winter break, but I did get a new router table built. So I've got that going for me, which is nice...


So after getting in the right headspace to play with dremels and epoxy, I got to work on some kevlar on the motor mount.



Couple quick marks on center and another of those delicious IPAs and I forgot to take pictures of the cutouts and my amazing dremel work. Way too much 5min epoxy to tack everything together and we're off to the races.




I've never used Proline before (plenty of other epoxy), but this stuff is a beast compared to West or System Three. For those that have used it, do you get black marks on your hands after its cured? Or did I screw something up? It's been inside for 48 hours and I'm not getting much, but I can get black marks still on a paper towel.



It's okay to be envious of my epoxy skills too.

I've also got the av-bay pretty well pieced together, but I got this wonderful whiskey for my bday and I forgot to take pictures. I'll pull it apart to take a couple shots once I get the switchband on. Which may be a bit because I am going to glass the tubes (for fun? for practice?), but I don't have the right wrap for the tubes. Once that comes in, I'll have more to do. Maybe I'll get another ring on the motor mount and get fins prepped this week....

Maybe

 

[SeanW78]

Trying to post from my phone, we'll see how it goes.

I haven't worked much on the rocketduring the winter break, but I did get a new router table built. So I've got that going for me, which is nice...
View attachment 445420

So after getting in the right headspace to play with dremels and epoxy, I got to work on some kevlar on the motor mount.

View attachment 445421

Couple quick marks on center and another of those delicious IPAs and I forgot to take pictures of the cutouts and my amazing dremel work. Way too much 5min epoxy to tack everything together and we're off to the races.

View attachment 445424
View attachment 445422

I've never used Proline before (plenty of other epoxy), but this stuff is a beast compared to West or System Three. For those that have used it, do you get black marks on your hands after its cured? Or did I screw something up? It's been inside for 48 hours and I'm not getting much, but I can get black marks still on a paper towel.

View attachment 445423

It's okay to be envious of my epoxy skills too.

I've also got the av-bay pretty well pieced together, but I got this wonderful whiskey for my bday and I forgot to take pictures. I'll pull it apart to take a couple shots once I get the switchband on. Which may be a bit because I am going to glass the tubes (for fun? for practice?), but I don't have the right wrap for the tubes. Once that comes in, I'll have more to do. Maybe I'll get another ring on the motor mount and get fins prepped this week....

Maybe

I recognize that router table design. That's a Norm inspired piece. Nice work all around.

 

[jqavins]

Well now I'm going to need a new name...

Namu? Willy? Tilikum? (Actually, "blackfish" can refer to a number of different whale species. In the Stan Rogers song "Free in the Harbor" it refers to pilot whales.)

 

[Budro0]

I recognize that router table design. That's a Norm inspired piece. Nice work all around.

I don't know this Norm character, but he obviously has great taste in router tables.

Namu? Willy? Tilikum? (Actually, "blackfish" can refer to a number of different whale species. In the Stan Rogers song "Free in the Harbor" it refers to pilot whales.)

Love the ideas - for now, I'm sticking with Blackfish (until something better comes along). I sketched out the design last night, and just for S&Gs I tried to replicate one of the fin designs in tape. It's going to be a bear masking this thing up. I'm starting to think a white base and a single black fish sticker will suffice....

 

[Nytrunner]

Lookup masking film. I've used the stuff from Frisket, wide roll of peel off masking sheet. Easy to draw on and cut out without applying tons of strips of tape and cutting through multiple pieces

 

[Budro0]

Lookup masking film. I've used the stuff from Frisket, wide roll of peel off masking sheet. Easy to draw on and cut out without applying tons of strips of tape and cutting through multiple pieces

Great note - I've been using pinstriping vinyl tape for any curved/complex designs. Just having trouble freehanding this one.

 

[dr wogz]

I don't know this Norm character, but he obviously has great taste in router tables.

Norm Abrams - New Yankee Workshop..

Watched him every Sunday morning. Then "This old house". (A double treat when Norm would come & help finish off a house they were featuring!!)

He does exquisite wood work & cabinetry (and your router table is close to his.. not exactly, but close!!)

https://www.newyankee.com/product/deluxe-router-station/

 

[dr wogz]

Add some blocks to the CRs to where you intend to put your rail buttons. Gives you more 'meat' to drive a screw into

and a shameless plug!! (although I should update it with "finished & flown" pics & reports!)

Mine's been up on a J (My L2) and has had a slight zipper repair.

https://www.rocketryforum.com/threads/madcow-super-dx3-patriot-a-build-thread.140215/

 

[jqavins]

Norm Abrams - New Yankee Workshop.

He has so many expensive specialty tools that someone who goes into the hobby and buys everything is called "a Norm" by others who, in there own eyes, rely more on skill than money.

 

[Budro0]

Norm Abrams - New Yankee Workshop..

Watched him every Sunday morning. Then "This old house". (A double treat when Norm would come & help finish off a house they were featuring!!)

He does exquisite wood work & cabinetry (and your router table is close to his.. not exactly, but close!!)

https://www.newyankee.com/product/deluxe-router-station/

That is awfully similar - I admit that I stole the concept from somewhere, but I don't think it was from Norm. Only so many ways to skin a cat...

I like the idea of doubling up on the CRs. I'll definitely be incorporating that.

 

[Budro0]

It's been kind a slow go the past few weeks. I have been not great about documenting this build, but I have snapped a couple pics of the glassing.

The Soller sleeve worked great as usual. I'm sure I could get a better tube with more traditional means, but the sleeves are super easy to work with. I did use Soller's heat shrink tubing on these, which was a first. I am not sure that these worked any better than a mylar wrap. I had a ton of filling to do just to smooth out the weave. I'm glad I tried it, but I think mylar is cheaper and better and to an extent, easier. Getting the heat shrink over a wet tube was a bear and then getting it to shrink down tight and uniformly was a lesson in futility. Finally, I had a ton of air bubbles caught under the shrink wrap which I ultimately lanced to get it to lay down right. There may be some special technique to it all, but I was not impressed. You'll see below where I had to fill extensively with bondo putty to get a smooth finish.

Which is actually what I need to be doing right now. I think I am done glassing this rocket, so I'm on to the finishes. Fortunately, we've got a snow day here, so I can take a little extra time today to work on her. Bondo for an hour and then sanding for the rest of the day. Wish me luck.

 

[Hobie1dog]

thanks for all the pictures.

 

[thzero]

I agree about the heat wrap with soller socks... did that recently, and would just do mylar wrap if I ever went that direction again. I did not have air bubbles, but did chase pockets in the epoxy.

I did a fair amount of sanding and filling, but still ended up with weave showing through paint. If I were to do it again, I'd use the mylar wrap, and then do a lightweight tight weave fiberglass layer on top.

 

[Budro0]

I agree about the heat wrap with soller socks... did that recently, and would just do mylar wrap if I ever went that direction again. I did not have air bubbles, but did chase pockets in the epoxy.

I did a fair amount of sanding and filling, but still ended up with weave showing through paint. If I were to do it again, I'd use the mylar wrap, and then do a lightweight tight weave fiberglass layer on top.

That's a great idea. I think I have some 3/4oz FG that would be perfect. And here I thought I was done with glassing....

 

[Hobie1dog]

deleted

 

[Handeman]

I agree about the heat wrap with soller socks... did that recently, and would just do mylar wrap if I ever went that direction again. I did not have air bubbles, but did chase pockets in the epoxy.

I did a fair amount of sanding and filling, but still ended up with weave showing through paint. If I were to do it again, I'd use the mylar wrap, and then do a lightweight tight weave fiberglass layer on top.

It's been a while since I glassed tubes, but after the first ones, I use 3 oz glass as a top layer on everything after and that made the whole finishing process much, much easier.