Scrath 54mm UFO

[n3tjm]

I wanted to build a new 38mm UFO to fly my G sparkies in. So I looked around the shop to see what I had on hand. I didn't have any more 38mm tubing so I decided to use a 54mm tube instead. I bought some foam board, and poster board, and started building. Here I am cutting out the horizontal disk from the foam board (disk from now on).

 

[n3tjm]

Test fitting the 5.5" long 54mm motor tube in the disk.

 

[n3tjm]

Printed out the patterns for the top and bottom skirts. Then I taped them together and cut them out.

 

[n3tjm]

Launch lug is glue onto the motor tube. I used an Aerotech Igniter Tube from a RMS 29/180 reload, and just by chance, its the exact same length of the motor tube.

 

[n3tjm]

The top skirt is glued into place. For alignment purposes, the ring is placed into position but not glued on.

 

[n3tjm]

The Ring is removed and the forward skirt and motor tube joint is reinforced with epoxy.

 

[n3tjm]

The Ring is finally epoxied into place, followed by the bottom skirt. I am using a Kosdon 2 grain case loaded with sparky propellant

 

[n3tjm]

Assembled body of the UFO. The Launch Lug is trimmed to match the skirts.

 

[n3tjm]

Top coat of fiberglass.

 

[Handeman]

Test fitting the 5.5" long 54mm motor tube in the disk.

Hope that is red paint on the front edge of the bench and not an exacto knife issue.

Like the thread. I might have to build one myself.

 

[n3tjm]

Hope that is red paint on the front edge of the bench and not an exacto knife issue.

Like the thread. I might have to build one myself.

Actually its bondo

 

[Luv2launch]

What/how did you make the upper and lower skirts a program to make patterns from?If so what did you use?

 

[n3tjm]

I used VCP. You can download it from a link from this thread.

https://www.rocketryforum.com/showthread.php?t=4987&highlight=transistions

I probably should of made the saucer a little wider, and maybe thinner, but I'll fly what I made.

 

[sailmike]

Nice looking saucer you have there. It's good that you made the motor tube short, because you want the CG to be as far forward as possible. I made the motor tube a bit too long on my 54 mm saucer and that limits the number of motors I can use. I'm wondering what kind of foam did you use?

I made mine from 1/2" insulation foam from the local hardware store. It is a very soft foam. The thin plastic sheet on it was peeled off and then 2 oz fiberglass was used to strengthen it. It flies awesome on motors like the J135 and K185. I've got a build thread going on a 38 mm version in the scratch section of this forum. It is being constructed almost exactly the same way as the 54 mm. I look forward to flying it on an I49 or I59. Here's a couple photos of the 54 mm, which weighs 1.25 pounds.

 

[n3tjm]

Nice looking saucer you have there.... I'm wondering what kind of foam did you use?

Thanks

I am using regular science fair grade foam board I bought at work (Target). The stuff I got is Elmers brand.

 

[n3tjm]

Flew my UFO on thirsday.

Here it is on one of my G70 blue motors:
[YOUTUBE]<object width="425" height="344"><param name="movie" value="https://www.youtube.com/v/t2P1HQNiyUI&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="https://www.youtube.com/v/t2P1HQNiyUI&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/YOUTUBE]

Again on one of my G53 Sparky motors. Had some rod whiplash but still was a cool flight.
[YOUTUBE]<object width="425" height="344"><param name="movie" value="https://www.youtube.com/v/ov6oXioMIl8&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="https://www.youtube.com/v/ov6oXioMIl8&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/YOUTUBE]

And a third time with a 54mm Sparky I motor
[YOUTUBE]<object width="425" height="344"><param name="movie" value="https://www.youtube.com/v/jfkbNPHQGxk&hl=en&fs=1&"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="https://www.youtube.com/v/jfkbNPHQGxk&hl=en&fs=1&" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="425" height="344"></embed></object>[/YOUTUBE]