Build #3 - My take on an LPR Saturn

[neil_w]

For what it's worth, I've had the same problem where masking tape crosses and overlaps. Not sure of the solution.

 

[snrkl]

I'm wondering if the solution is to mask the inside of the section to be painted, then using masking film hand painted on the section to be masked, remove the masking tape, then spraying, then removing the masking film.

 

[TangoJuliet]

The best way to do it is to shoot your base color after masking, then shoot the color you want. If the base color bleeds, no big deal, but it seals the tape edge so the next, top color can't bleed under. It takes longer to get a finished paint job, and I'm guilty of not following my own advice, but it works.

 

[snrkl]

Woot! My Estes 18mm-24mm motor adapters from Canada arrived today, 10 whole days ahead of the shipping eta given by eBay.

Looks like I also might get to fly this at the QRS launch day on Sunday.

 

[snrkl]

The best way to do it is to shoot your base color after masking, then shoot the color you want. If the base color bleeds, no big deal, but it seals the tape edge so the next, top color can't bleed under. It takes longer to get a finished paint job, and I'm guilty of not following my own advice, but it works.

I hear you. I shot the base colour first but I must not have done it right. Not enough? To quick to lay the top after?

Maybe I need to shoot the base and wait 48hrs before the top colour.

It just means I need to build more and practice.

I have an Estes v2 kit next, which definitely needs roll patterns so... 😜

 

[TangoJuliet]

I have an Estes v2 kit next, which definitely needs roll patterns so... 

Or not... There's the WWII Camo version. :wink:

 

[neil_w]

Maybe I need to shoot the base and wait 48hrs before the top colour.

As far as I understand the process, this is not necessary.

It just means I need to build more and practice.

Can never argue with that.

 

[snrkl]

Or not... There's the WWII Camo version. :wink:

I have an aversion to painting rocket in colours that mean I can't see them.

I'm with Robin Williams on this one:

"If you're going to the jungle, Clash!"

https://youtu.be/RIXD3eNocV4

 

[snrkl]

As far as I understand the process, this is not necessary.

It would be with the rustoleum I'm using. Re-coat within the hour or after 48... I'm pretty sure the 2 hours between base and top colour on the roll pattern is what caused it to wrinkle.

 

[neil_w]

It would be with the rustoleum I'm using. Re-coat within the hour or after 48... I'm pretty sure the 2 hours between base and top colour on the roll pattern is what caused it to wrinkle.

Oh yeah, 2 hours is a no-no. But you can easily get all your coats done within the initial 1 hour window.

 

[Mugs914]

Hey Snrkl, great looking rocket!

I'm a big fan of roll patterns too, and no, I haven't found a good way around all the masking either. But I do use a different method for preventing the top coat from running under the tape; use a gloss clear coat that is compatible with your chosen paints to seal the edges of the tape.

Spray a little of the clear coat into a paper cup and use a very small brush to apply it just to the edges of the tape, particularly at the corners where the tape crosses. It takes very little to ensure a good seal. Spray the next color as usual. This method avoids the need to spray a second base color coat over your masking and results in a lighter finish and thinner edges between colors.


Painting can be the most frustrating part of building these things, but perseverance will pay off and you will soon learn what works with what and the best methods of use. Keep up the good work!

Following your Kraken build as well!

Mike

 

[snrkl]

Thanks Mike. I'll definitely try that hand brush technique for the next build.

I have an Estes V2 next that will get more roll pattern treatment.

 

[snrkl]

Ok. Build is done. All is left to do now is the recovery installation.

And with my 18mm-24mm motor adapters, hopefully I'll be able to test it with B,C and D motors this weekend.

😜

 

[snrkl]

Oops. Forgot the pic...

 

[snrkl]

Maiden flight on an SCR b6-4 flew well to about 63.7m and landed softly.




Second flight on an SCR c6-5 went very squirrelly almost immediately and was a lawn dart with ground eject.





After it was exhumed, I noticed the motor adapter was DOA




Nose cone was a write off.



At least I might be able to recover the transitions and NC pieces.

Failure reason not yet established but we will take a look into in some more.

It wasn't underpowered as it flew beautifully on a b6-4, I'll have to look a little more into the CG/CP more closely - this flight was supposed to have >1.5 calibers of stability from memory so...

 

[TangoJuliet]

Initially, I'd say that C6-5 motor is suspect somehow. Obviously not a true CATO, but I wonder if there was some problem with the nozzle that caused asymmetric thrust.

 

[Mugs914]

So sorry to hear that. The rocket does look repairable though...

I'm with TJ on this one; I suspect a motor problem. Normally it would never have gotten hot enough around the middle to melt the adapter. Could you post a pic or two of the nozzle end of the motor?

 

[Rex R]

I suspect that the culprit is the 'SCR' motor thrust curve. an Estes C6-5 has a much shorter thrust duration (by about a second) and has a higher thrust. the scr motor sounds much like the Quest C6-5 (which worked great in light rockets) complete with the high case temps. I would imagine that your rocket simply wasn't going fast enough off the rod.
Rex

 

[snrkl]

Mike: here you go.

 

[snrkl]

Compared to many other SCR motors I've flown successfully.



(One is shorter as I've taxed it for an engine block... &#128540

 

[snrkl]

As an update - I was able to soak the tube off enough in warm water and was able to flake most of the epoxy off the NC and transitions, so this will likely be a cheap repair.

One of the transitions that had more stuck on it, I soaked in water just boiled from the kettle and the aft end has warped a little.

I'll try to reheat and reform it, but I have a spare of that transition anyway.

Whether or not I put as much work into the roll pattern this time is yet to be seen.

I might replace a section with a clear payload tube and use that for the altimeter three. Much to contemplate.

 

[TangoJuliet]

Remaking the roll pattern could be viewed as an opportunity to improve your skills. :wink: (A lesson I still need to learn myself in regards to some skills)

 

[snrkl]

After an evening of thought (and pondering how hard it was to get the chute and altimeter into the BT on launch day, if come up with a cunning plan.

Using a clear payload tube for the altimeter.

As I need to be able to get in/out of the payload tube, here's the cunning plan:



The clear tube will be epoxied at the top but not before a long Kevlar loop is run between the top transition and the base transition.

Altimeter can be slung on the internal Kevlar loop and the payload tube is held with a tape wrap onto the base transition.

Worst case, if it all comes unstuck, the Kevlar keeps the whole chain together.

Thoughts?

I can't think of any other way to make the payload bay accessible unless we start adding threading or some kind of pin through the base...

 

[TangoJuliet]

That should work fine. To give you more room in the payload section, the portions of each transition that insert into the payload bay can be trimmed to a shorter length and still be just fine.