That Mongoose 29

[TomSmith58]

Hi Gents
Long time no post. After my terrible horrible no-good day at LDRS 36 I am finally back at it. I will have my Mongoose 29 finished and will fly it at this coming Rocstock on everything from a G80 to an I205...unless... I have an Eggfinder in the nose and an Eggtimer Quantum in the coupler. I found Cris Erving at LDRS an he just so happened to have the exact same bird with the same electronics to fly. I took pictures of all of his attachments and I am building my own bird accordingly, with a couple of exceptions. I chose to overengineer the mount for the Eggtimer.
Here is the CAD

and here is the actual purple fitting 3D printed from Shapeways.com


Funny how reality looks just like CAD.

The other exception is this. I don't know how Cris attached the nose to the payload to the coupler to the sustainer.

Here is what I propose. I want to have the nose be just a slip fit into the payload with adequate venting to prevent drag separation (on an I205). I also want to use one 2-56 nylon screw per joint to attach the payload to the coupler to the sustainer like this.


What do you think of the slip fit nose and what do you think of the nylon screw attachments?

I have a bit of time before I commit. I am going to paint the green stuff you see in the image and take my time. Then I will drill vent holes and nylon screw attachments.

Thanks
Tom

 

[CoyoteNumber2]

That's fantastic. Estimated altitude on the I205?

 

[TomSmith58]

7800 feet and Mach 1.15. Of course I am always more interested the the Mach number. After I get comfortable with my electronics (I've not been successful yet) with this rocket I will build a 38mm min diameter. I still have lots of 38mm motors I bought in anticipation of flying my Go Devil 38 lots of times at LDRS. I even have a CTI 6XL case still loaded with the max impulse it can carry. All I have left of my Go Devil is the last 12 inches. I have essentially a well made fin can 10 inches long.

 

[captbk]

Sounds like you need another GD Tom. They can take anything you stuff em. I think you would be OK with one nylon pin per joint. I've fly my
GD 38 with one pin all the time. Good luck with the mongoose. (wish I didn't sell mine)

 

[TomSmith58]

Here are some gratuitous images from my CAD model.

 

[GrouchoDuke]

Have fun with your Mongoose - they go like mad!

 

[Crash-n-Burn]

Keep this up and you'll force me to build mine. Liking your work so far!

 

[Nytrunner]

Where do you get the altimeter models?

 

[TomSmith58]

I soldered my Eggtimer and Eggfinder myself like everyone else. Then I took my micrometer and measured every feature in them and built the CAD model myself.

 

[TomSmith58]

I finished painting. I also added a clear coat. That makes the carbon tube really pop. Prior to that the tubing has a satin finish. When you clear coat it you get that sense of depth we are used to with carbon parts.
This next photo is prior to the clear coat. You can see the satin look of the tubing. It also shows off my paint job which was inspired by the image shown on the Madcow website.


Incidentally, I wanted to do the cool swoopy stripe but I found using a printed template difficult. I had to freehand the edges and then adjust the lumpy borders by scraping paint off with an exacting knife afterwards. Does anybody know how to do this well?

Tom

 

[crossfire]

I finished painting. I also added a clear coat. That makes the carbon tube really pop. Prior to that the tubing has a satin finish. When you clear coat it you get that sense of depth we are used to with carbon parts. View attachment 328658
This next photo is prior to the clear coat. You can see the satin look of the tubing. It also shows off my paint job which was inspired by the image shown on the Madcow website.
View attachment 328659

Incidentally, I wanted to do the cool swoopy stripe but I found using a printed template difficult. I had to freehand the edges and then adjust the lumpy borders by scraping paint off with an exacting knife afterwards. Does anybody know how to do this well?

Tom

Now you need the mongoose name on it. Very nice build you did there.

 

[TomSmith58]

Oops. That would have been better before I clear coated. Thanks for reminding me. I just ordered it. Sticker Shock has stickers for a Mongoose at any size and in a variety of colors (plug plug). They even have it in Flourescent green. They made it so easy for me to spend my money!😉