SD's RamJet Build

[ScrapDaddy]

here Ben this one is for you

As I promised a while back, i would show a successful build thread, and so i picked up a Estes ricochet, and if any of you know me well enough i never build estes kits, i simply scrounge around for parts...... A few days ago i was fooling around with the parts and realized i could create something that could look a jet, but my original intention was to use the transition as the nose cone which made it look like a ram, I Combined both ideas and got the Ramjet ( i know this is a future technology.....)

EDIT: Jump to page 3 for flight video and pics!

 

[ScrapDaddy]

It is hard to visualize what i ment by a Ramjet Nose cone shape so here is a few quick pictures

Note: i didnt glue it in for ease of painting, i will do this later

 

[ScrapDaddy]

Here i connected the body tube with my homemade baffle

 

[ScrapDaddy]

Here i got Fin #1 on......

 

[ScrapDaddy]

the rest of the fins.......

 

[ScrapDaddy]

Oh And this was my fin prep:

I sharpened the Edges

I Put i coat of Filler on (i did it so well it almost looks like a paper skin )


i applied CyA along the edges

 

[ScrapDaddy]

And this is how she looks after A few coats of primer again i slid the NC in so you could see what it would look like, not glued in yet because of painting

 

[ScrapDaddy]

Heres a close up of the NC One again NOT GLUED IN YET i painted the NC metallic Silver, i painted the inside of the BT red

 

[ScrapDaddy]

Here is the road bump, i have NO IDEA what to paint the Fins/rest of the Bt Anyone have any ideas?

 

[cjl]

Very nice. Good to see a build thread from you

 

[ScrapDaddy]

Do you Wanna help out with the I have no clue what to paint it problem?

 

[TheAviator]

Go for a nice yellow, kinda like the stock FlisKits Deuce's Wild! scheme. Simple yet effective.

 

[Scotty Dog]

YO SD
Looks good. What kind of primer are you useing? It looks like blue paint to me.You could call it "MY-WAY.Seeing you built it your way. As far as the color-well remember "Beauty is in the eye of the beholder" Scotty Dog

 

[ScrapDaddy]

Sorry forgive the poor lighting, it is krylon Gray sandable primer

 

[Scotty Dog]

Sorry forgive the poor lighting, it is krylon Gray sandable primer

You wont believe this but its true. I had to hunt down "DRY" sandable primer. I finaly found some by Dupli-Color at V.I.P. Auto.
I live up in NH and there is not many places to shop localy. I went to 2 states (NH & VT) to get a fuel filter for my tractor.Ya, even up here in farm country. Scotty Dog

 

[ScrapDaddy]

I'm not sure, I only use wet sanding with this stuff

 

[InFlight]

So............ your worried about the paint job BEFORE you flight test this thing?

Interesting, I never paint prototypes. lol

op:

.

 

[InFlight]

There are tricks to painting that ramjet with it glued in. Roll up some paper, make it an inch longer than the nose cone and slide it over the nose cone. Let the roll go and it should snug up to the inside of the tube. Light coats of paint around the end of the tube and your good.

.

 

[GrossApproximator]

I'm not sure, I only use wet sanding with this stuff

You're talking about the Krylon Gray? Why do you only dry sand it. I ask because I like to dry sand the Krylon with 400 or 600 grit wet/dry paper first (helps people like me see those tiny imperfections, especially in balsa noses, which are otherwise hard to see). Then I switch to wet sanding.

 

[ScrapDaddy]

Hehe, I haven't thought about stability yet, I am fairly worried about about the nested nose cone, as it might move the CP forward, I am jut completely unsure how much, the CG is a full 2 inches in front of the fins(when I fly on a A8 )so I am not completely worried. I'll go for a swing test soon (if she fails I will be awfuly disspointed )

 

[ScrapDaddy]

You're talking about the Krylon Gray? Why do you only dry sand it. I ask because I like to dry sand the Krylon with 400 or 600 grit wet/dry paper first (helps people like me see those tiny imperfections, especially in balsa noses, which are otherwise hard to see). Then I switch to wet sanding.

Well I dry sand with the 320 and wet sand with the 1500.

 

[ScrapDaddy]

There are tricks to painting that ramjet with it glued in. Roll up some paper, make it an inch longer than the nose cone and slide it over the nose cone. Let the roll go and it should snug up to the inside of the tube. Light coats of paint around the end of the tube and your good.

.

Another reason I haven't glued it in yet is because I am wondering I'd I want a payload section.

 

[GrossApproximator]

Well I dry sand with the 320 and wet sand with the 1500.

oh. wow that's fine paper.

 

[ScrapDaddy]

Just a quick question, am I sanding to early because the stuff still feels like latex.

 

[ScrapDaddy]

oh. wow that's fine paper.

You can get the stuff at Ace, normally they use the stuff to sand granite countertops, because the rougher stuff will sratch the granite. The description of the 1500 is mirror fine

 

[TheAviator]

Just a quick question, am I sanding to early because the stuff still feels like latex.

Yep, you are; the primer should feel solid. I haven't used the new stuff, but from what I understand, you need to let the Krylon primer dry for a minimum of one full day (I would go two or three) before doing sanding work.

 

[exprditer789]

How long did you let it dry before you started to sand it???

 

[InFlight]

Hehe, I haven't thought about stability yet, I am fairly worried about about the nested nose cone, as it might move the CP forward, I am jut completely unsure how much, the CG is a full 2 inches in front of the fins(when I fly on a A8 )so I am not completely worried. I'll go for a swing test soon (if she fails I will be awfuly disspointed )

Your making me feel like I am getting a tooth pulled. :cyclops:

You could add some weight to the shoulder of the nose cone to correct the CG.
While doing a swing test of course.

.

 

[ScrapDaddy]

Yep, you are; the primer should feel solid. I haven't used the new stuff, but from what I understand, you need to let the Krylon primer dry for a minimum of one full day (I would go two or three) before doing sanding work.

I waited overnight..... Woops a little short

 

[ScrapDaddy]

Your making me feel like I am getting a tooth pulled. :cyclops:

You could add some weight to the shoulder of the nose cone to correct the CG.
While doing a swing test of course.

.

the test flight should be on a 1/2 A6 so to minimize any potentual damage