L2 Project: WM Drago 4 "EX-1127"

The Rocketry Forum

Help Support The Rocketry Forum:

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
LOLz

i did not. never have been good at spelling...
 

GalantVR41062

Celebrate Recovery
TRF Supporter
Joined
Oct 25, 2017
Messages
235
Reaction score
142
Location
Plymouth MN
4BACFD03-8C2E-4F89-B065-E6E14A4CA9AC.jpeg


I see you have 2 zip ties around the 9 volt batteries, what's going to hold the batteries from moving up or down on the vertical axis?

Amazing build and good luck on your level 2 attempt.
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
they are simply there now (actually they arent there now at all ;-) ) for the test fit.

for flight they will be held together with double sided tape then held to the sled with double sided foam tape. The zip ties hold quite tight, and with the foam tape being "crushed" along with the "stickiness" of the adhesive, they betteries wont go anywhere.
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
Thank you all for the kind comments.


Had a little time so I put all the pieces together to get an initial weight. Looks like she will be right at 10 pounds w/o the motor.

Time to order a new chute' as the old 70" top flight X-form isnt going to work.
 

eggplant

L3 | NAR 93664, TRA 17791
Joined
Jan 5, 2011
Messages
1,667
Reaction score
136
Great work, looks beautiful!

Based on the outcome of one of my earliest DD flights, I recommend adding a zip tie that runs around the batteries and their connectors. I had a setup very similar to what you've described here and the altimeter lost power when the drogue charge fired, resulting in the main not firing. I suspect the connector was able to come free because it was better attached to the sled than the (relatively) heavy 9v battery was. Adding a zip tie around them constrains the connector to the battery, which is how you want it to be. Since then I've used redundant altimeters and lipos for every flight.
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
Good advice. ...and I have me plenty of zip ties.
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
Wet sanded last night. Went over the imperfections with 800 grit. Then hit the entire thing with 2000. Spent a good 45min on it.

First thing this morning I got the spray can in some warm water. Changed it twice to get the internal pressure up the prepped the garage and went for it

51227753-8451-4431-BAB3-B3D0D0741DC0.jpeg


D8B1B85D-8E95-48B4-A7D0-376B13D6C803.jpeg

its still a little wet, but I think I have done all I can with a spray can and my current skill set.

I am going to let it harden all week then mask it off and shoot the fins this coming Sunday
 

crossfire

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 16, 2011
Messages
3,928
Reaction score
309
Looks like you did a great job.
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
update on the recovery system:

pulled the trigger on the parachute, an 8' Rocket Man and also purchased a 15' three loop kevlar harness for the HED system. i was originally going to use 15' of 3/8" nylon with an kevlar piece at the electronics bay end to provide protection from the charges, but opted for full kevlar. there isnt any give, but the full fire protection provided swayed me in that direction. i still have the nylon should i want to change back.

the booster uses a piece of 1/2 tubular nylon that is epoxied to the motor mount (see pictures earlier in the thread). there is then a 20' three loop 9/16" nylon harness from OBH. created a short (18 inch) kevlar tether to connect the OBH harness to the electronics bay. all connections are made with 1/4" quick links (other than the nose cone which has a 3/16 as there isnt a lot of stress there) and where needed the material is knotted and then secured with fabric glue.

the drogue for this project is a 7" wide ultra streamer from Top Flight. ejection charge protection for the booster is an 18" blanket from Wild Man and the HED uses a 12".

i do see times where i will use simple apogee deploy, and with this set up i can easily move the main from the nose cone to the booster.

excited to be close to the end. we are actually moving in the end of June so the timing cant be better.

fingers crossed she gets to fly by the end of the summer!
 

Joe Rocket 97

Well-Known Member
Joined
Jun 30, 2018
Messages
154
Reaction score
24
That's a big chute. I just got my BAMA 5 foot VPD, that will have a decent rate of 17 FPS for my Drago I'm building
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
Mine will have a recovery weight of 10.3 pounds or more

I like the RM chutes as they come with a slide that makes them easy to reef. Also those have a CoD of .97 which is lower than most.
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
So close yet so far...

spent the morning wet sanding the fins. First 800 grit then 1000. Then I masked it off with “yellow” frog tape and shot the fins with bright yellow. The paint laid out great

let it sit for 20min and started removing the tape. Issue #1 is the tape left marks all over the silver it was covering. This is inductive of the paint being soft, but it’s had 5 days to cure, two spent in the sun... not sure why this happened. I do have some vertical black stripes, so I am thinking I can work with this.
DF753FE3-EA13-4CE2-8EC3-F443020A7AF4.jpeg


then this happened
3ABDA609-71F6-492B-AB12-58F87E5851FC.jpeg



insert expletive here -> ( )

time to sand it out and re spray :-/
 

crossfire

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 16, 2011
Messages
3,928
Reaction score
309
What caused that to happen??
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
Not sure.

the paint clearly didn’t adhere, but I have no idea what caused that
 

mbeels

Yes balsa
TRF Supporter
Joined
Feb 9, 2019
Messages
2,019
Reaction score
920
oh man, that's disappointing. Are you just re-doing that one little spot, or more?
 

Joe Rocket 97

Well-Known Member
Joined
Jun 30, 2018
Messages
154
Reaction score
24
The Silver wasn't fully cured that's why you got tape marks. 1000 is too fine of a grit for mechanical adhesion. Don't go finer than 600
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
Yea, thinking it wasn’t fully cured either. Surprised at that

...and did I think spray paint functioned on a mechanical bond. More chemical from layer to layer
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
Going to wait a few days and work on the fin.

right now I’m not really sure what to do with the silver. Not sure I have enough for another full cost. And I really don’t like using the last part of the spray can...
 

crossfire

Lifetime Supporter
TRF Lifetime Supporter
Joined
Jan 16, 2011
Messages
3,928
Reaction score
309
Heck get rid of the wrinkle and but a USA flag over the top of it.
 

RocketTree

Active Member
Joined
Apr 10, 2020
Messages
40
Reaction score
25
Location
Canada
400 grit is high as you should go before paint. 320 is typically used as final sanding stage before automotive paint jobs. Anything beyond that will have poor adhesion, if not other issues. 1000+ grit is polishing sandpaper for clear coats, and pre-buffing.

All the best!
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
Kinda in a holding pattern with this one

Wanted to correct the issue with the fin but didn’t let the paint cure long enough so it “orange pealed”on me. Pisser there cuz I knew better.

Letting it all cure real good now which will be easy as we are in the process of moving. All is good, for as I’ve said before, with all the COVID lockdowns in place in Northern VA, she isn’t going to be flying any time soon.
 

Theory

Well-Known Member
Joined
Nov 30, 2018
Messages
658
Reaction score
363
Getting back on track here. Had to hit pause on the build, well painting, as we just moved. Now with 79% of unpacking complete and the new work areas finished (both the garage and “unfinished” area of the basement) I can get back too it!
Garage:
AE708BF0-5AB7-48DB-B765-89F56AD0C1C3.jpeg


basement: my wife requested this workbench. I typically like to build my own, however, as she fully supports this hobby(and others) I thought it best not to argue
FA25F661-FE28-40AD-A3A1-4390D587A84B.jpeg
265B77DD-B82A-4456-88A8-007A042EFCA2.jpeg


so yea, getting all of that together definitely took some time, but I did shoot the last coat of yellow on the fins. Will clear it tomorrow!
5B31DDC7-C116-465D-BE3B-731FE578152D.jpeg


as for the move, I am happy to say that it went well and I am still close enough to fly with my friends at NOVAAR and Tripoli Central Va
 
Top