Sentinel upscale 2019

[neil_w]

I only ask because I've used the Krylon UV-resistant clear a few times on top of Rusto 2x with no issues at all, and I didn't know what the heck I was doing. I do strongly recommend the UV-resistant clears if you have the choice, since they'll prevent yellowing.

 

[Event Horizon]

Here's the part number and description and a photo.

3403 Gloss Crystal Clear

 

[Gramparocket]

That's a nice build. Just me but I would put in a bigger MMT if i built one that size. I have an Optima clone with a 29mm MMT.
I built my upscale Sentinel HPR. 3" 38mm MMT 65" dual deployment.

 

[Gramparocket]

HPR Sentinal

 

[Event Horizon]

Gramparocket, Thanks for the kind words. Where were you when I asked the questions about motors way back at the beginning?? LOL. Just kidding.

Being a green horn in this size rocket I asked and really didn't get an answer that convinced me differently until it was too late and the MMT and tail fins were installed.

I've come to the conclusion that this rocket isn't going to fly because of the MMT. I have all the parts needed to build another 2.6" Sentinel with a 29mm MMT. I just gotta get going on it.
Got side tracked doing some stick and tissue aircraft and some RC stuff.

That's an awesome looking one your building.

 

[Event Horizon]

Almost forgot to ask, where did you find a 3" diameter nose cone with the correct ogive shape, IIRC it is 5.1

 

[Gramparocket]

I was out flying rockets lol. That's a PML nosecone i think it's a 4:1 i wasn't too concerned with an exact match its just a fun scale clone.
What kind of tubing did you get for your 2.6? Heavy wall our thin?

 

[Event Horizon]

I bought 2.6" body tubes from Erockets (thick wall),
and Rocketarium (thin wall)
The thicknesses are in a post on this thread on page one

 

[Event Horizon]

The first Sentinel upscale was built using the thinner tubes. I know thick wall tubes are heavier but I don't suggest building thin wall airframes, everything is just a bit more difficult.

The second Sentinel upscale will use the thick wall tubes from Erockets. I have all the parts, except I haven't figured out exactly the best way to make a parachute cord and I just need a bit of motivation.

 

[Gramparocket]

You can use KEVLAR cord and epoxy it right to the motor mount. 10- 15 ft is good for mid power. Cords are rated at different strenght from each supplier but any 1/4"cord should due. tie the other end off to the nose cone, put a loop in the cord about 1/3 of the way down and attatch the parachute to that. It should fly well on f-g motors

 

[Gramparocket]

oh and notch out the top c-ring to fit the cord trough

 

[Event Horizon]

Thanks for the advice Grampa. I'll look into that

 

[Gramparocket]

Just thought I'd update on my Sentinel. And ask if you had built the other one you had planned with the thick wall tube?

 

[Event Horizon]

That is awesome granparocket. Just a mere .4 inch increase in the diameter of the tube sure builds a tall rocket.
Sadly I haven't got a lot completed on the 2nd build. The nose cone is prepped for primer and the fins are ready for sealer /filler. I got bogged down building stick and tissue airplanes during the virus. so far I've completed three of them with two more to go. Here's one of them, a kitbashed Veron
Classic Glider. The vertical stab, wing and cockpit have been modified. It's a great flyer. I look at the upscale sentinel rocket and the parts for the 2nd one a lot though, and want to get going on it too.

.

 

[Gramparocket]

Free flight? Bungee launch?

 

[Event Horizon]

free flight hand launch, although it could be easily converted to either towline or bungee, just needs a hook.

 

[Gramparocket]

Sweet. I've only built one free flight.
I was a kid and didn't do a very good job.
I do fly rc though.

 

[Event Horizon]

I have flown a bit of RC, not much, I was heavily onto towline gliders, handlaunch gliders and sailplanes as a kid. At about 10 years of age I was drawing my own plans and scratch building hand launch and towline gliders. My older brother was into similar things so that helped encourage me, but when he left for college I was on my own. I could never get all that model building out of my system. Rockets, plastic display models (aircraft, cars and space), slot car racing, RC boats, RC sailplanes, free flight, towline, I had fun with all of them and still enjoy all of them today.

 

[Event Horizon]

Here's an update on the Upscale Sentinel #2 with the thicker body tube. Progress has been made after a two year hiatus.
I fear that it won't be ready until 2023, as I cannot paint indoors and all it needs now is the gloss white finish on the body. October is too cold to paint outside in Minnesota. The nose cone has been painted gloss white. After the body gets painted then all it will need is to apply the markings which I got from StickerShock.com.
It's got the larger engine mount and has lug style guides. The motor mount is 29mm. The rocket with parachute and cords, without motor and last coats of paint weighs in at 570 grams or 1 lb 4 ounces. I think it might be a pig. Is that too heavy for a 29 mm motor?

The background is another of my current projects. It's a 1/4 scale 12ft wingspan Focke Wulf Ta 152H RC plane I've been working on. The fuselage is 10ft 8 in from spinner to rudder.
It uses a four cylinder Roto engine. It's a short kit produced by FokkeRC in Bulgaria. Here's a link https://www.fokkerc.com/