L2 Project: WM Drago 4 "EX-1127"

[Tim51]

“Aluminium”

Both spellings/pronunciations are correct, you know

 

[Theory]

LOLz

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

 

[GalantVR41062]

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]

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.

 

[rfjustin]

Looks great!

 

[pondman]

View attachment 417738

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.

Very clean layout! I like the mounting.

 

[Theory]

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]

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]

Good advice. ...and I have me plenty of zip ties.

 

[Theory]

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




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]

Looks like you did a great job.

 

[Theory]

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]

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]

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]

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.


then this happened



insert expletive here -> ( )

time to sand it out and re spray :-/

 

[crossfire]

What caused that to happen??

 

[Theory]

Not sure.

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

 

[mbeels]

oh man, that's disappointing. Are you just re-doing that one little spot, or more?

 

[Joe Rocket 97]

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]

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]

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]

Heck get rid of the wrinkle and but a USA flag over the top of it.

 

[RocketTree]

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]

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]

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:

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


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!


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

 

[rfjustin]

That yellow and grey is going to pop.

 

[Theory]

cleared the fins with 2K gloss yesterday

VERY happy with this product. got one small sag in one fin that i might try and wet sand / buff out. but then i might leave it... dont want to screw it up chasing perfection

next step is a final coat of silver then a coat of 2K satin clear coat then the decals.

i can see the light at the end... and it looks like a 6' blue flame from a K1127!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Adam3836]

It is officially that time, time to kick off my L2 project. Before I get into that, I want to talk about how I came up with this and why I am doing what I am doing.

When approaching a new build I generally build to the motors that I want to fly. That said I have always enjoyed the sledge hammer quick burn motors, especially those with a high length to diameter ratio. There is just something aggressive about them, 100% unapologetic... to that end I knew that my next big project would be built for the Loki 38/1200 case and more specifically the K1127, but also wanted a 54mm mount for the J1799.

Enter the Wildman Drago 4! Its 48"airframe set up for HED and 54mm motor mount can easily accommodate most any motor I will fly. Its final weight of around 8.5 pounds (purely a guess based on what I have seen others come in at) will allow respectable flights on moderate 'I' motors at NOVAAR's obstacle filled field, and will return some serious performance when I let it rip at Battle Park.

To the build plan. Keeping this fairly straight forward, but with a few twists from stock as, well, that's what I do. The most dramatic change will be swapping the stock nose cone for more aggressive 6-1 version also from WM. I will also be using a 19" long motor mount. This affords me two benefits, one real and one perceived. First I am a fan of anchoring my rail buttons into the forward and aft centering ring. The longer motor mount and addition of birch ply rings will allow this. Also, and this is 100% on me, I like having my motors "contained" especially if using motor ejection as a back up. The longer motor mount allows for that. No not for the aforementioned 38/1200 case, but then I do not see me using motor backup there... after that that the major components are as follows:

-Birch ply forward and aft rings with the stock fiberglass ring acing as the center centering ring. (I strongly prefer 3 rings on my builds.

-A 10" long AV bay to hold an RRC3, RRC2+ and eventually the Missile Works RTx tracker. This will be spaced accordingly by the use of a 2" long switch band. Don't want to have a ton of coupler in the airframe and secured via 2-56 pins.

-Motor retention will be via a flange mounted Aeropack using a 38mm adapter when needed

-Recovery will be a combination of 1/2" Kevlar adhered directly to the motor mount and 20' OBH 9/16 3 loop nylon harness. To save space the nose cone HED will use a 3/8" nylon harness. Thinking now that the "drogue" will be a 70" X 7" streamer with the main being either a 48" crossfire chute or a 7' RM. I also have a 70" Top Flight X form in my rocket box from a previous project that will likely work for the time being so long as it will fit. All components will be protected with Nomex blankets.

-All structural bonding will be with T88 by System Three and external fillets will be made with RocketPoxy.

-Rail buttons will be a standard 10/10 affair with an 1/8" aluminum spacer to move the rail off the airframe a touch.

-And as always, graphics will by from StickerShock23. ...really goes without saying!

really going to take my time with this one. more than the whole measure twice deal... currently I am looking to have the first flight be at the NOVAAR July or August launch. Already have an I300 in the range box.

That's about it for now. Placed an order with McMaster-Carr for the electronics bay components earlier, and aim to have the WM order completed later today.

Stay tuned as this should be fun.
[/QUOTE


Awesome !!!!!

 

[Theory]

Finally...

 

[crossfire]

cleared the fins with 2K gloss yesterday

VERY happy with this product. got one small sag in one fin that i might try and wet sand / buff out. but then i might leave it... dont want to screw it up chasing perfection

next step is a final coat of silver then a coat of 2K satin clear coat then the decals.

i can see the light at the end... and it looks like a 6' blue flame from a K1127!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I looked up when to apply clear coat. Rustoleum says apply clear coat 10-15 minutes after final color coat. I have never done it that way. But I know people that do it and they dont get any sagging.