ULA Atlas V 551 scale 1/92

[Raptor 2]

I was inspired by bwp0001 post of his model using the SRBs as fin tubes to try my hand at making this one. Using a BT60 as the main frame and AMX paper modelling for the wraps the scale works out to 1/92. I’ll be using the medium length PLF on this model and will use A BT70 tube with 4 extra wraps of heavy card stock on the exterior to bring the diameter to the correct scale diameter. Pictured below are the 5 SRBs with wraps and the nozzle inserts constructed of .04” plastic with 28# paper cones CA harden. The plastic and cones were glued with RC Modellers Canopy glue and will be painted white before being glued into the SRBs.

 

[Raptor 2]

SRB nozzles spray painted and installed. Completed constructing the nose cone coupler c/w eyehook for attachment to the main frame.

 

[KenECoyote]

Fantastic work so far!

 

[Raptor 2]

Installed 4 wraps of orange coloured cardstock to the BT-70 PLF using doubled sided tape to increase the diameter from 56 to 59 mm required for this scale. Installed 2 sets of 7 cardstock wraps 12mm wide on the lower reduction tube so that it fits inside the BT-60 main frame.

 

[Raptor 2]

Constructed 4 nose cone transitions from cardstock. Each transitions consists of two layers cardstock and a centering ring at the top and bottom. These are all glued using RC Modellers Canopy glue. This glue does not wrap the cardstock. The centering rings are obstructed of Premium Soda cracker cardboard. I print out circumference dimensions for each ring and use spray adhesive to secure the pattern to the cardboard and then cut out. Glued double layered centering rings to the main frame BT-60 tube for the upper BT-70 PLF tube. Made the parts for an ejection baffle.

 

[lakeroadster]

Great thread... a treasure trove of excellent techniques and ideas. Thanks for taking the time to document the build.

These are all glued using RC Modellers Canopy glue. This glue does not wrap the cardstock.

What do you mean by: "This glue does not wrap the cardstock"?

 

[Raptor 2]

When you apply to much carpenters wood glue as when securing a centering ring when it drys it creates an indent in the exterior of the tube. To much of thei glue will wrinkle paper, cardstock and tubes as it dries so I use Modellers glue on the cardstock.

 

[Raptor 2]

Glued the nose cone transition section to the nose cone coupler using a very thin layer of RC glue. After apeach section was placed CA glue was applied to the top centring ring and the central BT-5 tube. Will apply a couple of layers of filler primer, CWF and a light sanding prior to painting. Also glued in an ejection baffle 190mm up the bottom end of the BT-60 main frame.

 

[Hobie1dog]

You are quite the expert modeler.

 

[Raptor 2]

Applied a couple of coats of primer filler and filled gaps between the transitions with filler then sanded.Applied the main wrap to the upper PLF using double sided tape. Installed a 24mm engine mount in the lower 35mm extension tube with epoxy. Used a couple of plywood centering rings from rocketarium on the mount.

 

[Raptor 2]

Nose cone spray painted and main frame tube wraps installed using 3M double sided tape.

 

[Raptor 2]

I cut slots in the bottom wrap to expose the tube below once installed. The slots are 1/8” x 5/8” long and provide and opening to secure the balsa strip standoffs for the 5 SRBs directly to the main frame tube. Balsa strips were hardened with CA, sanded and glued to the main frame with Carpenters glue. Once dry they were filleted with Canopy glue all around. Cable raceways were installed, constructed of two layers of cereal box cardboard upper section and shaped balsa form lower section and AMX printed wrap all secured with double sided tape and Canopy glue. Fuel line wraps covers a 3/16” dowel.

 

[bwp0001]

Excellent work!

 

[Raptor 2]

Secured the 5 SRBs to the main frame balsa standoffs. Used Used carpenters wood glue for the initial glue down and once cured added a fillet of Canopy glue to the connection. Painted the exposed balsa a gold colour. Still have to install launch lugs and the parachute attachment and an insert tube for the upper BT-5 tube in the nose cone. This insert will provide a location a the top of the cone for added weights if required. Stability will be checked by swinging a string. Hopefully this will fly as this model depends on the open ended SRBs as fin tubes. As she stands right now without a chute or the insert tube it weighs 209.22g (7.38oz) and is 28.5” tall. 24mm MMT.

 

[cls]

Looks really nice! Coming along.

I wonder, why canopy glue?

 

[Raptor 2]

Looks really nice! Coming along.

I wonder, why canopy glue?

When Canopy glue is cured it remains some what flexible and drys completely clear. Carpenters wood glue used on the balsa standoff contact surface to the tube fin would not be flexible as a fillet on the side and appears yellow in colour when it drys. I’m hoping the flex in the fillet will help in keeping things together when it launches.

 

[Raptor 2]

String tested the model today fully loaded for flight with a E30-4T in the back end and she flew straight once I really started spinning. Fully loaded she weighed in at 294.1 grams (10.37 oz) and stands 720mm tall (28 3/8”).
CG is located at 378mm from the nose cone with10 grams of weight in the nose. Can add more weight if I fly with an Estes E12-4 Which weighs 15 g more than the E30-4T
Will launch this one and others once the fire ban is lifted and the wind dies down. It’s been windy for a long time now which doesn’t help with fire situation here in Alberta.

 

[Raptor 2]

Launched the Atlas on June 24th with an Aerotech E30-4T and a 24” chute and 16 grams nose weight.
Went straight up then angled off a bit and continued upwards, angled again and then continued in a straight flight. Good altitude and recovered by hand before impact. Only damage was one of the side boosters was a bit loose and will have to be re-secured to the main airframe.
Wonder if the wobbly side booster had something to do with the two angled flight maneuvers?

View attachment Atlas V 551.mov
View attachment Atlas V 551 Rec.mov

 

[ljwilley]

Awesome!