Goony Cloud Hopper

[Thor]

Well, the first three build projects are completed. A 2X Goblin that is too heavy to fly except with F motors! Still a Hanger queen. And a nice 1.24X Goblin that flys great on a D12-5 up to about 1100', very happy with that one and my youngest daughters Red Max, wow looks super with all those decals. I put Phred's decals on ALL three and I cant compliment him enough on the decals and the instrucitons on applications. Worked out superb! Next project is my 11 year old daughter's latest rocket yearnings-a Goony Cloud Hopper. Looks pretty straight forward. Two questions for you folks, first can it be completed with buying the parts instead of a kit bash? Nose cone is main question there. Also I want to change the motor mount to fly standard size estes engines. I plan to fire it only with the A8-3 but wonder about this as it is originally set up for the 13mm engines and the A8-3 is a 18mm engine. With the rocket being so short will this make the balance point too far to the rear and cause stability problems? Looks like a fun project and I plan to let her do all the work herself unless she asks for help. My next project is an E powered BT-70 sized Cherokee D. :)

[CPMcGraw]

Next project is my 11 year old daughter's latest rocket yearnings-a Goony Cloud Hopper... I want to change the motor mount to fly standard size estes engines. I plan to fire it only with the A8-3 but wonder about this as it is originally set up for the 13mm engines and the A8-3 is a 18mm engine. With the rocket being so short will this make the balance point too far to the rear and cause stability problems?

Thor, you only need to add 3/8 oz of ballast into the nose cone. The 18mm conversion of the Cloud Hopper is a very good upgrade. Here's some quickie RKT file specs:

A8-3.....166'.....10.5 fps Dv
B4-4.....410'.....3 fps Dv

You'll have to pack the parachute carefully, as there isn't much room. Line the compartment with a good layer of dog barf and pack more barf around the 'chute. You'll have to fold the 'chute into a tight, flat little wad...

RS says it's stable in this configuration...

Note -- the rudders will add stability above and beyond the simplified version shown in the RKT file. The amount of weight added is negligible.

[Thor]

Thanks Craig. The A8-3 doesnt look too exciting. The B4-4 is okay but I would probably try the it with a C6-5 after a pack of A8s. I appreciate you simming it for me as I dont know how to do it myself. Thor

[CPMcGraw]

...a C6-5 after a pack of A8s.

You need to increase the ballast to 0.75 oz with the C6-5. The flight numbers come out as follows:

C6-5.....842'.....7.1 fps Dv.....~6" pre-apogee

The C6 is a much heavier motor than either the A8 or the B4...

[Thor]

Thanks Craig, I ordered the parts today. She wants to paint it a metallic gold. What would be a good nose cone weight be to be able to fly with the A8-3 and C6-5? I really appreciate the help. Thor

[CPMcGraw]

Thanks Craig, I ordered the parts today. She wants to paint it a metallic gold. What would be a good nose cone weight be to be able to fly with the A8-3 and C6-5? I really appreciate the help. Thor

First, epoxy three 1/8 oz sinkers into the tip of the nose cone. You know you'll need that much ballast no matter which motor you use...

Second, attach a 3" or 4" piece of Kevlar thread to a #12 or #10 snap link. Attach three 1/8 oz sinkers to the opposite end of the thread and coat them with a very thin layer of epoxy (just enough to secure them to the thread...).

Now, when you only want to fly with A or B power, you just stick in the motor and go. When you want to fly with C power, attach the snap link with the sinkers to the nose cone and stuff the weights through the hole in the base of the cone. You might need to open the hole a little to let the weights go through. Jam a piece of wadding into the hole to prevent the weights from falling back out.

[Thor]

Thanks Craig, she is doing the build right now. I appreciate your help. :)