Black Brant XII Build Thread (Tips Appreciated!)

[jackiboi_11]

Hello, this is going to be my build thread for my black brant xii. I’ve already got most of it done but would like to share this with you all because this is a beautiful kit and would like some help for future builds (Der Big Red Max/ Mega Der Red Max clone) anyways i’m still working on it but will also post what i’ve already done!

 

[jackiboi_11]

I started by dry fitting all the tubes and blow molded parts to make sure i don’t need to sand anything down a good amount. I also cut out the fin slots (not to good at that stuff) and it turned out OK. ( My Room is a mess ) The rocket is a lot taller than i was expecting so that’s cool.

 

[jackiboi_11]

Next I cut out and and glued the balsa skins on to the core. For me the skins didn’t line up perfectly so some sanding was needed for me.

 

[jackiboi_11]

After that I put together and epoxied the motor mount into the tube (i don’t have photos of that) and got the bottom portion of body tubes put together. As well as the kevlar shock cord mount.

 

[jackiboi_11]

After I put together the 2nd stage fins they did not fit well at all for me . So i made the decision to put some fillets on the 2nd stage fins which didn’t turn out bad but some of the tape came unstuck and let some epoxy leak into that portion.

 

[jackiboi_11]

I did not take to many photos so I know i’m skipping a lot but after that i started to bevel the 1st stage fins but during that I made the decision to not bevel them exactly like the instructions said and instead keep them a little thicker because it’s just balsa with no plywood upgrades. I know it’s now not scale but I still like it! The fin in the second photo was beveled even more that as you see and rounded at the edges so it looks a lot better but that’s the only photo I have

 

[jackiboi_11]

In between that I glued the third stage fins on as well as the small details but it was late at night and didn’t have my phone. But that leads to were I am now. Not to bad in my opinion but i am definitely not a skilled builder compared to some of you guys on here. So any constructive criticism is welcome! I still have to finish the fins, glue the last centering ring on, motor retainer and paint. And I have to balance it out then eventually glue the nose cone on!

 

[Brent]

Was thinking about designing a 3D printed sanding jig for the fins. My kit is not in yet. Has anyone else thought about doing this? I remember a kit that Aerospace Specialties had a sanding jig with it for the fins.

 

[jackiboi_11]

yea sanding it is definitely not easy for me even with a decent sanding block. I think you should design one as i think it will be easier for you!

Was thinking about designing a 3D printed sanding jig for the fins. My kit is not in yet. Has anyone else thought about doing this? I remember a kit that Aerospace Specialties had a sanding jig with it for the fins.

 

[ecargmij]

Was thinking about designing a 3D printed sanding jig for the fins. My kit is not in yet. Has anyone else thought about doing this? I remember a kit that Aerospace Specialties had a sanding jig with it for the fins.

If you find a design that works I'd love to buy one from you.. I was envisioning a block with two tapers that you fit the glued up fin in and sand along along both tapers until you reach the block taper, problem is you'd need a flat bottom and then one that's tapered so that when you flip the fin it would center out. Or different inserts for flat and then tapered.. may not make full sense without a drawing.. maybe one day I'll get my own 3d printer..

 

[rkoenn]

yea sanding it is definitely not easy for me even with a decent sanding block. I think you should design one as i think it will be easier for you!

I plan on picking one of these up when they are out at hobby suppliers which they aren't as of 12/13. I bought a flat plane sanding device off Amazon from Du-Bro in the medium size. I bought it specifically for when I build this but it will be good on any larger sanding project. I know sanding a wedge that significant into balsa is going to take some heavy sanding elbow grease but also care not to go too far. Nothing I can recommend except if you do it again to take a look at the sanding block tools from Du-Bro. Also I've seen that an aftermarket place is selling basswood fin sets for it. They would obviously require much more sanding but would be far stronger and resilient to dents. Bad Boy Rocketry.

 

[jackiboi_11]

I plan on picking one of these up when they are out at hobby suppliers which they aren't as of 12/13. I bought a flat plane sanding device off Amazon from Du-Bro in the medium size. I bought it specifically for when I build this but it will be good on any larger sanding project. I know sanding a wedge that significant into balsa is going to take some heavy sanding elbow grease but also care not to go too far. Nothing I can recommend except if you do it again to take a look at the sanding block tools from Du-Bro. Also I've seen that an aftermarket place is selling basswood fin sets for it. They would obviously require much more sanding but would be far stronger and resilient to dents. Bad Boy Rocketry.

Yeah, I ended up just using a big rubber sanding block but it did take some elbow grease. It ended up turning out OK but I was happy with it.

 

[ecargmij]

I put my belt sander in the bench vise (upside down) with a fine grit belt.. I used light pressure and used the edge of the belt to follow the lines and all of the fins came out good.. my shoulders cant hack heavy sanding these days. I purchased the same upgrade kit from bad boy rocketry . I might pick up another XII to keep in the box.. should have bought it on the scale model day of estes 12 days of Christmas as with adding the launch23 code it was only $45

 

[Huxter]

Thanks for posting jackiboi_11, I WILL have one of these kits some day!

Your build techniques will come naturally - the more you build the better the rockets will turn out! It's good to fly those rockets to verify your build techniques too.

I myself do not fill tube spirals or fill in balsa very much - so all my rockets are "6 foot rockets" - meaning they look great from 6 feet away!

Good luck!

 

[Ronz Rocketz]

I hope you have better luck than I had. All damage fixed. I think it needs a F67 or F25.