4 inch upscale Estes Photon Probe project

[skyway2k]

Hello Mike,

For the long burn motors, I was looking at using a 38mm CTI I125 (4.41 seconds, 2,125 feet) or a 54mm I100 (6.23 seconds, 2,300 feet) for level 1 flights. Eventually, after getting level 2 certified, I was looking at a J140 (8.47 seconds, 4,400 feet) or K160 (9.66 seconds, 5,500 feet).

Looking at the initial one second of thrust of each motor, I'm over the 5:1 thrust to weight ratio. So as long as it's not real windy, each motor should be successful if I'm looking at this correctly. I'm assuming an 8 foot launch rail.

I'm going to certify on my G-Force using 29mm hardware. I'm sure there will be a CTI vendor there with motors I can purchase for the Probe, correct?

 

[thobin]

Looks great, nice build.



TA

 

[MikeL]

I'm sure there will be a CTI vendor there with motors I can purchase for the Probe, correct?

At Thunderstruck, I believe at least Wildman will be there. They are a huge CTI dealer. Other vendors will be there as well - just not sure if they carry CTI or not.

 

[skyway2k]

Looks great, nice build.

TA

Thank you!!

 

[skyway2k]

Got some work done on the avbay. I still have some more wiring to do. I need to wire the main and drogue circuits to the bulkhead terminal blocks. I went with a rotary switch and mounted it at an angle so that when the sled is in the avbay, the switch is aligned just right with the hole in the 1" body tube band on the avbay coupler. The layout was copied from the example on Apogee's website.



If you guys see me doing anything wrong or foolish, please speak up!

 

[skyway2k]

At Thunderstruck, I believe at least Wildman will be there. They are a huge CTI dealer. Other vendors will be there as well - just not sure if they carry CTI or not.

Awesome. It probably wouldn't be a bad idea to stock up at Thunderstruck to avoid the hazmat fees, right? I got my CTI hardware the other day. I got a 29mm set so I can certify L1 on the G-Force. I want to use an H54. Then my 38mm starter set came so I'll be ready for Thunderstruck with the Probe.

 

[bill2654]

I like how you mounted your switch at an angle. Lookin good.

 

[skyway2k]

I almost have the electronics bay finished up. I just need to weld the eye bolts closed, attach them, and use a few wire ties to secure the loose wiring. I ended up using 3/4" PVC plugs for the BP charge wells. Any concerns with the head of a screw being in the middle of the floor of the wells? I also ended up having to change the angle that I mounted the terminal blocks so that it would be easier to insert the ends of the igniters.

 

[skyway2k]

I'm going to use 3 #2-56 nylon screws for shear pins. I was going to get some brass shim stock for the nose cone to use to cut the pins, but in lieu of spending money, I cut up an empty Mountain Dew can. I cut 2" strips and folded them in half to double the thickness. I used JB Weld to attach the strips to the nose cone between the two ringed bands in the shoulder. I'm hoping that the aluminum will work the same as a brass sheet.



I then drilled holes in the body tube, threaded in the shear pins, then removed them and reinforced the holes with super thin CA. One more clean up with a drill bit and sand paper, and the pins thread in and out really well. I also drilled the nose cone one size larger so that I won't have to drill out the broken pins after flight. The pins just barely fit the nose cone without having to thread them.

 

[skyway2k]

I'm also using plastic push rivets to attach the upper body tube to the electronics bay.



And here it is all stacked up and pinned / riveted... it's almost ready for primer!

 

[skyway2k]

Well, I had some nice weather today, so I got it primed.



I foresee lots of sanding in my future... :cry:

 

[skyway2k]

So, I'm still plugging away at this project. I've finished priming and sanding and shot a couple of gloss white coats on the upper section. I plan to get more work done this week and hopefully by the weekend, I'll have the vinyl on.

The plan is still to fly at Thunderstruck in a few weeks.

 

[skyway2k]

I have pink color added to the upper section, waiting on the last coat of gloss white on the lower section to fully cure before shooting the pink on the bottom. Then it's time to adorn it with those awesome Stickershock decals!

 

[skyway2k]

This thing is getting Stickershocked tomorrow!

 

[RodRocket]

Very nice! Aren't upscaled fun!

See ya,
Rod

 

[rocketgeek101]

Wow! Don't know how I missed this thread Very nice build.

 

[skyway2k]

Very nice! Aren't upscaled fun!

See ya,
Rod

Thanks! Very fun!! This is the most fun I've had in rocketry yet. I just loved developing this from a clean sheet of paper with only the dimensions of the original model. It was fun! I can only imagine an original design scratch build of your own would be even more fun!

 

[skyway2k]

Wow! Don't know how I missed this thread Very nice build.

Thank you very much! I can't wait to see it lift off.

 

[skyway2k]

Here's the almost finished product! All that's left is a wipe down and clear coat, then install the rail buttons.

 

[Boosterdude]

Looks great!

 

[kelltym88]

Beautiful job!!

 

[skyway2k]

Thanks for all the kind words, guys! They mean a lot. Having the build thread played a role in motivating me to do as well as I could on it since I was showing it off to you all. I can't wait to see it fly here in a few weeks at Thunderstruck!

 

[soopirV]

Thanks for all the kind words, guys! They mean a lot. Having the build thread played a role in motivating me to do as well as I could on it since I was showing it off to you all. I can't wait to see it fly here in a few weeks at Thunderstruck!

If I didn't know any better I'd say you had the worlds smallest TV in that last build picture- it looks EXACTLY like my Estes version in the garage! To me, that's the mark of an excellent scale build! Bravo!!