Dragon Rocketry 4" upscale Estes Photon Probe Build.

[KenECoyote]

Fantastic work so far! Thanks for sharing!

 

[MarsLander]

Paint color and compatibility test…

 

[roytyson]

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...

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

It takes a bit of practice, no doubt. I have tried to come up with ways to space out the front of the angles, but there is just no good way (scrap/popsicle sticks). But once it is all setup and clamped on, it self-aligns and makes a square fin.

 

[MarsLander]

Decided to try shearing pins without .005 brass. Going to try just CA given some experiences here....

I figure even if they elongate/deform the tubes, I can always install later. #greatdebateandexperiment.

 

[darrenf]

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?

Ha, no tracker. Does anyone know if this rocket was ever found and if the cert attempt succeeded?

 

[MarsLander]

Bondo glazing and spot putty worked great on the fins and fillets!

 

[MarsLander]

Got my featherweight mag switch installed and working! Just need some strain relief!

 

[MarsLander]

Got some color down!

 

[MarsLander]

Payload and NC painted. Stickers next then clear coat…

 

[MarsLander]

Payload and NC painted. Stickers next then clear coat…

 

[MarsLander]

More progress!!!

 

[MarsLander]

Decals and clear coat on…RTF!

 

[Hobie1dog]

One of the better build threads, great work. Thanks for all the pictures

 

[MarsLander]

Charge testing…1.2g (a little heavy) for booster. 2g (a little light) for payload.

View attachment IMG_0537.mov
View attachment IMG_0538.mov

 

[ClarkusAurelius]

I love the build threads. I’m newer to the hobby and I like to see how others do things. I learned with this thread that lots of people put CA or epoxy on their AV bay couple section. I do that on tube ends but never thought to do it on the couple itself. Great build thread, thank you!

 

[gldknght]

I love the build threads. I’m newer to the hobby and I like to see how others do things. I learned with this thread that lots of people put CA or epoxy on their AV bay couple section. I do that on tube ends but never thought to do it on the couple itself. Great build thread, thank you!

Personally, I would never use CA on tube couplers. Ca makes things brittle. That's the last thing you want for your coupler. If you think you need to re-enforce the coupler, epoxy and a layer of lightweight fiberglass applied to the INSIDE of the tube will do the trick without adding a lot of weight.

 

[ClarkusAurelius]

Personally, I would never use CA on tube couplers. Ca makes things brittle. That's the last thing you want for your coupler. If you think you need to re-enforce the coupler, epoxy and a layer of lightweight fiberglass applied to the INSIDE of the tube will do the trick without adding a lot of weight.

I see what you’re saying here. My first two AV bays have the LOC stiffy coupler epoxied in so I think they’re good and I’ve never had an issue with a coupler so far. Could this be one of those things that exists as a problem online but not in the real world? I can’t imagine I’ll be putting a large enough motor in any of my cardboard rockets to be concerned about it.

 

[MarsLander]

Could this be one of those things that exists as a problem online but not in the real world?

Not necessary. I just wanted some ding/scrape protection…

 

[jhill9693]

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

Nice idea using the putty on the tee nuts.

 

[gldknght]

I see what you’re saying here. My first two AV bays have the LOC stiffy coupler epoxied in so I think they’re good and I’ve never had an issue with a coupler so far. Could this be one of those things that exists as a problem online but not in the real world? I can’t imagine I’ll be putting a large enough motor in any of my cardboard rockets to be concerned about it.

The only situation I can see needing to reinforce a coupler would be for use in a very small diameter extra long rocket, like a Mean Machine designed for high power, or if you are building one that goes supersonic.

I gave the coupler / av-bay on my L3 build the fiberglass treatment, due to the possibility of a supersonic flight.