Madcow Super Batray build thread

madcow rocketry
eggtimer rocketry
the rocketry show
Shop deals on ebay
The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
rockets

rockets

Well-Known Member
Joined
Nov 18, 2014
Messages
1,274
Reaction score
56
Location
Denver, CO
Well, the time has come for one of the most exciting moments of my rocket building.

My Jr. L1!!

I will be building a Madcow Super Batray, and fly it on a CTI H163WT for my NAR Jr. L1 certification.



IMG_3691.jpg
Thanks,
 
To start this build off, I peel the top layer of the MMT, so that the fins will tack on better & stronger.
IMG_3693.jpgIMG_3692.jpg

Now I will drill holes in a centering ring for the retainer.
IMG_3696.jpgIMG_3695.jpgIMG_3694.jpg

Now I draw the lines on the MMT and glue the upper centering ring on. BTW, I used 30 minute epoxy for this.
IMG_3701.jpgIMG_3700.jpgIMG_3699.jpg

Gluing the other centering ring on.
IMG_3704.jpg




Thanks,
 
Glued the inserts into the lower centering ring for the retainer.
IMG_3703.jpgIMG_3702.jpg

Tied the shock cord to the eye bolt on the upper centering ring.
IMG_3705.jpg

Inserted the MMT into the main body tube.
IMG_3706.jpgIMG_3707.jpg

Thanks,
 
Gluing on fin 1 with 30 minute epoxy.
IMG_3710.jpg
Gluing on fin 2 with 30 minute epoxy.
IMG_3708.jpg
Gluing on fin 3 with 30 minute epoxy.
IMG_3713.jpg

Fin fillets:
I did the fillets with wood glue, but I never did take pictures; sorry.



Thanks,
 
With lots of work with the finishing ahead of me, I started to fill the spirals early on in the build:
IMG_3711.jpg

All sanded down:
IMG_3714.jpg

I filled the spirals on the other tube as well, but never did take pictures of that either.

Painting:
Here is the finished nose cone:
IMG_3722.jpg

The fins & lower BT:
IMG_3721.jpg

Upper BT painted, BATRAY decal on:
IMG_3716.jpg

Aero-Tech decal on:
IMG_3717.jpgIMG_3718.jpg

Both decals:
IMG_3720.jpg


And, the finishing is done!

IMG_3719.jpg


Now, all I need to do is attach the rail buttons, do some more fillets on the MMT, and glue the coupler into the BT.



Thanks,
 
Love the SB! My son will be building his too for Jr L1! Will be watching. I have anSB booster finished but decided to stretch it a little


Sent from my iPhone using Rocketry Forum
 
Nick@JET said:
Love the SB! My son will be building his too for Jr L1! Will be watching. I have anSB booster finished but decided to stretch it a little


Sent from my iPhone using Rocketry Forum
Click to expand...

Yeah, I thought about stretching mine, but I figured I'd just leave it be for now.
What does your son plan to fly his Super Batray on?
Tell him I said good luck! :)

Thanks,
 
Looks good so far,

a few questions though..
1) did you glue both CRs to the MMT? Leaving off the rearward CR, allows you to easily get inside and add internal glue fillet.
2) did you add a fillet to the top & bottom of the CR(S)?
3) have you ensure the nut on the back of the eye-bolt is 'locked' (either with loc-tite, glue, pinched threads, etc..) and, I personally prefer to use a nut & washer both top & bottom of the eye bold. much better / more solid locking / securing to the CR.
4) what kind of knot did you use to secure your shock cord?


I don't think you needed to peel the other layer off the MMT. I good hard sanding should suffice. At Least, that's what I do, and so far no issues..
I prefer 'T' nuts (or 'blind nuts') for threaded features in wood. easier to use, less glue & such, and more area for pull-put strength..

Buttons? add a bit of wood to the CRs, so you have more 'meat' to aim for when you get to that point..
 
dr wogz said:
Looks good so far,

a few questions though..
1) did you glue both CRs to the MMT? Leaving off the rearward CR, allows you to easily get inside and add internal glue fillet.
2) did you add a fillet to the top & bottom of the CR(S)?
3) have you ensure the nut on the back of the eye-bolt is 'locked' (either with loc-tite, glue, pinched threads, etc..) and, I personally prefer to use a nut & washer both top & bottom of the eye bold. much better / more solid locking / securing to the CR.
4) what kind of knot did you use to secure your shock cord?


I don't think you needed to peel the other layer off the MMT. I good hard sanding should suffice. At Least, that's what I do, and so far no issues..
I prefer 'T' nuts (or 'blind nuts') for threaded features in wood. easier to use, less glue & such, and more area for pull-put strength..

Buttons? add a bit of wood to the CRs, so you have more 'meat' to aim for when you get to that point..
Click to expand...

1-3 Yes.
4. I used a simple knot, not sure what the name of it is.
The peeling off the "skin" is something my brother taught me to do.
Yes, I'm using rail buttons.


Thanks,
 
Andrew,

Good luck on your build and Jr. L1 certification flight! I will be following your build with interest as I also have built a SB in the past. Will you be finishing it in black and silver, or something else?
 
kuririn said:
Andrew,

Good luck on your build and Jr. L1 certification flight! I will be following your build with interest as I also have built a SB in the past. Will you be finishing it in black and silver, or something else?
Click to expand...

Thanks!!
Well, I know that these colors won't really go with the name "Batray" but, I'm thinking it might be:
Green fins, white body tube, black sparkly nose cone.



Thanks,
 
This is what Dr. Wogz was talking about - blocks on the centering rings to screw the rail buttons into. Don't know if it's too late though.

038.jpg

039.JPG
 
No worries on the buttons, you can always use well nuts or something and still good a good strong hold that is spread out over the cardboard. Especially since it wont be that heavy of a rocket.

One question - how is the eye-bolt attached to the nose cone? If it is just screwed into the nose cone as it appears you might want to consider drilling some holes and feeding the harness through to give it more area or cutting a slot and adding a washer / nut to it to spread the load some. Don't want to see it pop out and cost you your cert flight.

Looks good Andrew - good luck with it.
 
rockets said:
Yeah, it's too late to do that..


Thanks,
Click to expand...

Looks like you room on the aft end to add a block for your rail button to grab. It'll look cockeyed but there is room. Or put another CR back there to flush it up and give something for the button to grab. You should be able to get down the forward end as well, if you can't reach, get creative and use tape on a stick or something to get it down in there. Or use weld nuts, t nuts or well nuts.

I've gotten to where I peel all of my MMT as well. It's easy and none of that "Is it scuffed enough".
 
dr wogz said:
Don't you guys worry that you get too loose a fit? and rely on a thick (relative!) layer of epoxy between the two?
Click to expand...

Yeah that could be a problem, I had one that was a hair loose, I used filler in the epoxy and in the fillets. When I did just scuff the mmt, I usually had to open the rings up anyway. But I haven't had any not hold either way I've done it.
 
What did you do about that knot? Kevlar probably would have been better. I find those cords from Madcow last about 5-6 flights.
 
timbucktoo said:
What did you do about that knot? Kevlar probably would have been better. I find those cords from Madcow last about 5-6 flights.
Click to expand...
I just used a simple knot. I reinforced it with some glue. The eyebolt holding it is very secure with a washer and a nut, and it has also been glued for extra security.
The shock cord is nylon cord with kevlar thread in it.



Thanks,
 
timbucktoo said:
Judging by your photos it’s finished? When’s the maiden flight?
Click to expand...

It's pretty much finished. I need to insert the rail buttons, and take care of a few small touch ups here and there.
The maiden flight should be in February. I'll be launching it in Dayton OH at WSR, wsr703.org.
The flight could be on a CTI H163 (which will bring it up to 1100') or a KBA I301 (Which will bring it up to 4400') or a AT H170 (Which will bring it to 2000')
Maybe some people can give their thoughts on what motor I should burn it on??


Thanks,
 
Since it's single deploy I would do the CTI. Definitely not the I, that's going to be really hard to keep an eye on.
 
viciouspeanut said:
Since it's single deploy I would do the CTI. Definitely not the I, that's going to be really hard to keep an eye on.
Click to expand...
How about I throw a Jolly Logic Chute Release in there for the I motor?
It would pretty much be dual deploy, just without black powder. :)


Thanks,
 
mine flies & whistles nicely on an H148 or H242, the short burn higher thrust gets it moving then quiets down at a low enough altitude to let folks hear the whistle. both motors top out at around 1500'.
Rex
 
Looking good Andrew!
My son is Andrew too - he is building his for 4-H so likely maiden flight in fall.
Your Batray has a different Nose cone, but otherwise identical to my L1 even down to the epoxy and I flew mine numerous times until a zipper - that is when I stretched it and turned into dual deploy.

We may decide to fly in OH once complete depending on schedule. Probably H244 or the like to start with - stretched mine was not good anything less than an H195 - flew really nice I-180.

For reference.
Stock form - H128 DM was about 1100’
Stretched DD - H195 - 1050’

You seam to be the guy that likes to push things so I’ll be interested to see what you put in yours! Hope you post when you are going to fly - if our schedule permits - we will try to come to OH and join in the fun


Sent from my iPhone using Rocketry Forum
 
Nick@JET said:
Looking good Andrew!
My son is Andrew too - he is building his for 4-H so likely maiden flight in fall.
Your Batray has a different Nose cone, but otherwise identical to my L1 even down to the epoxy and I flew mine numerous times until a zipper - that is when I stretched it and turned into dual deploy.

We may decide to fly in OH once complete depending on schedule. Probably H244 or the like to start with - stretched mine was not good anything less than an H195 - flew really nice I-180.

For reference.
Stock form - H128 DM was about 1100’
Stretched DD - H195 - 1050’

You seam to be the guy that likes to push things so I’ll be interested to see what you put in yours! Hope you post when you are going to fly - if our schedule permits - we will try to come to OH and join in the fun


Sent from my iPhone using Rocketry Forum
Click to expand...

Yeah, this Batray is decently old. One of my brothers bought it like 10 years ago, and never had done anything with it, except for painting the nose cone.
Then, about a week or two ago, I was searching around in my basement for a decal for a kit, and I found the Batray kit just laying there, it had everything but the parachute.
I called my brother, and he told me I could have it for free! :)
I'll be flying this bird at a WSR launch, which is pretty close to the TMO field. wsr703.org. I plan on flying this at either the February 10th launch, or the February 24th launch.
It should fly on a H163, or a H115, or some other sort of an H or a small I motor.


Thanks,
 
rockets said:
Yeah, it's too late to do that..


Thanks,
Click to expand...

Not to worry. Add a dab of CA or epoxy to the holes and then install the buttons. This has worked just fine for me on dozens of rockets in the L1 range...long before people decided nuts or backing was a necessity.
 

Similar threads

DJRNY
Yet another Zephyr build thread? / Zephyr L1 cert motor?
Replies
16
Views
540
DJRNY
DJRNY
N
Rocket Separate - Internal Pressure?
Replies
12
Views
840
Chad
Chad
burritoman1
L1/L2 Super DX3 Build
Replies
27
Views
1K
Approx
Approx
D
54mm motor retainer question Madcow Frenzy
Replies
5
Views
529
DirkTheDaring
D
SteelyEyed
Project Aether Breather
2
Replies
34
Views
2K
Aeva
Aeva

Latest posts

Back
Top