Dragon Rocketry 4" upscale Estes Photon Probe Build.

[MarsLander]

I like the photon probe.

Others [3 I can find] have preceded me with 4" Photon Probe [that I can find], with scratch builds. Two ended in disaster/rebuild, one...well they disappeared and we never got a launch report.
https://www.rocketryforum.com/threads/4-estes-photon-probe-upscale.93/
https://www.rocketryforum.com/threads/4-inch-upscale-estes-photon-probe-project.47480/
https://www.rocketryforum.com/threads/big-photon-probe.28192/

This will be a build of the Dragon Rocketry 4" Photon Probe. [https://dragonrocketry.com/products/4-photon-probe], looks like I got the last one (for now).

I'm really comfortable with epoxy/fiberglass rocket builds (airplane building and boat building experience)...see my Viper build in my signature. No so much with high power cardboard/plywood.

Pics of the kit:
Fins, MMT and airframe/NC (Yes, fins are upside down in this pic).

Avbay...nice components! Likely will replace the eyes with welded/forged, but nice thought on the connectors (charge connectors, switches, and battery).

I assume stickershock vinyl...nice!


So, to the direction...given the inexperience with cardboard/ply...

1. Seal the outside of the avbay tube, and interior of airframe with CA or epoxy? Leave it NAKED?
2. Do you build the fins on the motor tube and cut the airframe on the aft end, or glue the motor mount with the forward two CRs, and do internal fillets?

Yours,
MarsLander.

 

[MarsLander]

Gettin to work! Filling main fins, epoxy the canards and forward strips.

 

[MarsLander]

@Onebadhawk harness showed up…as always, the best!

 

[Hobie1dog]

Thanks for the pictures. Keep them coming.

 

[cwbullet]

Gettin to work! Filling main fins, epoxy the canards and forward strips.

View attachment 638580View attachment 638582

What filler did you use?

 

[MarsLander]

What filler did you use?

Trying out Bondo Spot filler. I used it on FG, just testing it out on Ply...

 

[RokitFlyr]

I like the photon probe.

Others [3 I can find] have preceded me with 4" Photon Probe [that I can find], with scratch builds. Two ended in disaster/rebuild, one...well they disappeared and we never got a launch report.
https://www.rocketryforum.com/threads/4-estes-photon-probe-upscale.93/
https://www.rocketryforum.com/threads/4-inch-upscale-estes-photon-probe-project.47480/
https://www.rocketryforum.com/threads/big-photon-probe.28192/

This will be a build of the Dragon Rocketry 4" Photon Probe. [https://dragonrocketry.com/products/4-photon-probe], looks like I got the last one (for now).

I'm really comfortable with epoxy/fiberglass rocket builds (airplane building and boat building experience)...see my Viper build in my signature. No so much with high power cardboard/plywood.

Pics of the kit:
Fins, MMT and airframe/NC (Yes, fins are upside down in this pic).
View attachment 637038
Avbay...nice components! Likely will replace the eyes with welded/forged, but nice thought on the connectors (charge connectors, switches, and battery).
View attachment 637039
I assume stickershock vinyl...nice!
View attachment 637040

So, to the direction...given the inexperience with cardboard/ply...

1. Seal the outside of the avbay tube, and interior of airframe with CA or epoxy? Leave it NAKED?
2. Do you build the fins on the motor tube and cut the airframe on the aft end, or glue the motor mount with the forward two CRs, and do internal fillets?

Yours,
MarsLander.

I seal all my Avbay couplers with thinned epoxy.

 

[RokitFlyr]

Oops. And inside 2-3" of the tubes.

 

[MarsLander]

Pretty standard fare. Drilled 4-40s for a bay retention with brass tube. Nice clean holes. Little CA to harden. T it’s epoxied. MMT started with @Onebadhawk harness.

 

[MarsLander]

Little bit of filler…

 

[MarsLander]

MMT and two on, 6 to go.

 

[MarsLander]

Avbay together! Beep, Beep, Beepity Beep...

 

[MarsLander]

4 of 8 on…

 

[MarsLander]

Avbay mounts nice…switch holes next!

 

[MarsLander]

An upscale video I found....

An upscale (?x) on a CTI K160 long burn...


I still can't find anyone that has successfully launched a 4" (3x) upscale photon probe...will MarsLander be the first?

 

[MarsLander]

2 strakes/canards on and fillets!

 

[MarsLander]

All fins on with TBII, external fillets done with TBII, will get TB quick and thick for final fillets. Internal fillets down!



Avbay vents/switch holes done!

 

[MarsLander]

Time for rail buttons! OneBadHawk rail buttons!




After tightening:


After folding and smoothing:

 

[MarsLander]

Does anyone look at these build threads? Are they even worth posting/valuable?

 

[Back_at_it]

Does anyone look at these build threads? Are they even worth posting/valuable?

Yes. In my opinion, the best part of this forum are the builds. I've picked up a number of tips from other builders and have gotten countless messages from other members with specific questions on something I've posted in a build thread.

I do wish people would interact a bit more on the threads instead of messaging but it is what it is and this thread has 500 views

 

[jmasterj]

What's the purpose of the milliput? It seems like an unusual adhesive choice.

How do you like the Roy's Rockets fin guides?

 

[MarsLander]

What's the purpose of the milliput? It seems like an unusual adhesive choice.

It's just an 2 part epoxy putty (hardens and is workable (drill/sand). It holds the tnut in place so it doesn't turn. Nice part is that it fills in under the tnut so you don't have to bend it to conform to the body tube. Makes it easier to install inside the bodytube without using epoxy on a stick and hope you get it in the right place. You could use jbweld putty or Apogee Fix-it epoxy putty, all the same type of stuff...

How do you like the Roy's Rockets fin guides?

It's ok. It is a bit wonky and fiddly.

To get it to work with fins, you need to have a spare piece to put in the other end, or have a clamp on both fore and aft sides of the fin. Since the angle aluminum faces the tube, it has to be a small clamp to fit under the aluminum and on top of the tube.

The rubber band technique takes some practice...it can impart a rotational force on the tube when you stretch it in place. For just fins, I like the two board with 45 method you can see here: https://www.rocketryforum.com/threads/l2-design-and-build-4x-upscale-eac-viper.183182/post-2519751

 

[MarsLander]

Final Quick and Thick fillets down. Last CR in. Shear pins/brass shear plates next then primer. Waiting on charge wells, the avbay will be done! Then final filler, sand, paint! (Oh and motor retainer).

 

[bad_idea]

Avbay together! Beep, Beep, Beepity Beep...

View attachment 639731View attachment 639732

Having to date only built avbays 3" and smaller (and only one 3"), I'm deeply envious of all of that space.

 

[MarsLander]

Lots of progress! All the shear pins in. CA on all coupler joints. First round of primer down.

Tried Tamiya putty on Loc NC. Ha Ha, chipped off like chipped beef. Ordered some adhesion promoter.

First round of bondo glaze on fillets and sanded. More sanding tomorrow and second round of filler/primer.

 

[RokitFlyr]

NICE! I use the Glazing Putty on nose cones all the time. Works great.

 

[MarsLander]

It is a grey day…

 

[MarsLander]

Drilled and epoxied Rocket Junkies wire retainers. Drilled for charge wells. Wood hardener tomorrow on bulkheads and avbay sleeve. Then install wells. Also got FW mag switch for the egg finder tracker and will install tomorrow.

 

[MarsLander]

White takes the day!

 

[MarsLander]

Charge wells and wire holders on!