New Way Blade Runner, Part 2, Engine Mount

The 20/50 centering rings are laser cut from plywood.

I like to sand off the charring from the faces using 400 grit on a block. 

It's not necessary to do this, I want cleaner parts - especially when the surfaces can be seen on the finished model.

The motor mount tube is marked 1/2" from both ends for centering ring positions.

Slot the tube for the engine hook at 1/4" from the top and insert the upper bend of the hook.

The retainer ring ends up centered between the centering rings. Slide on, apply a ring of glue and into position. 

The fit of the rings was almost perfect! A hair tight.

For a smooth slide over the ends of the tube, a piece of 400 grit was wrapped around a finger and used to lightly "ream" the center hole.

New Way Letter - Go Build, Part 3, Engine Mount

The bottom edge of the engine mount tube got an interior wipe of CA Glue.

Then the edge got a quick coat.

Then sand the edge square, flat and smooth with 400 grit.

This shows the engine hook retaining ring, not glued on yet.

Always be sure your engine hook runs straight down the tube after gluing the ring over it. The hook can slip around so check it before the glue sets up.

The upper centering ring is plywood.

The fit was a bit loose so I added a thin line of wood glue to the inside edge to get a friction fit.

Let the glue dry before doing a second dry fit.

Estes Star Seeker BT-50 Upscale (Tri-Pack) Kit #0866, Part 3, Engine Mount

The tube was slit for the upper bend of the engine hook. A  installed motor will extend 1/4" out the bottom end of the tube.

One of the laminated rings got rotary punched for movement of the engine hook. 

For a bit more strength, the upper ring was set right over the upper bend of the engine hook. 

The lower notched ring was placed 1/2" from the bottom of the motor mount tube.

Notice the ruler. The low (and top) end starts at the zero point. Usually rulers have a 1/8"extension before the 1" point  starts.  

A wrap of electrical tape holds the engine hook and allows flexibility.

TIP: Electrical tape won't deteriorate over time like paper masking tape will.

Estes Star Stryker Build, #3206, Part 5, Filler Primer Spraying

I slid the nose cone and adapter into the clear payload tube to spray on the filler/primer. 

The clear tube was masked off.

The body tube already had a seam fill of CWF and sanding.

A shot of filler/primer followed. Slide the engine mount into a painting dowel.

The fins were held down on scrap cardboard on tape with the sticky side up.

On the left is a fin after CWF and sanding. 

On the right is a fin side after spraying with filler/primer. 

Note the fin root edges are butted up against each other to keep the primer off the gluing surface.

Estes Star Stryker Build, #3206, Part 4, Joining Tubes & Fin Marking - Gotcha!

I sand the ends of the clear retainer ring with 400 grit to clean up the edges.

Here's the yellow coupler / engine block.

A line of glue is set inside the tube and the block is slid in until it rests against the top ben of the hook. 

Before gluing the long upper tube over the coupler - 

Slide the tube over the coupler (dry). Turn the tube until you get the best match of the two tube ends. Mark the position with pencil. 

Set a line of glue in the upper tube - slide over the coupler and turn so the pencil marks line up.

GOTCHA: The tube marking guide is printed a little wide to fit over the engine hook and retainer ring.

I marked the tube then rotated the guide to check the fin spacing against the next set of marks. It was off no matter how many times I turned the paper guide.

I went to payloadbay.com and printed off a new five fin marking guide. On the right you can see the difference between the two guides. The payloadbay.com guide is on the left.

The payloadbay.com marking guide was printed to fit a BT-20 tube.

I wrapped it above the engine hook and marked for the fins. Extend the marks down the tube.

Estes Star Stryker Build, #3206, Part 3, Engine Hook & Engine Mount

I don't like finger tabs on engine hooks. 

Score it with a wire cutter, then bend back and forth until it breaks off. File off any rough edges.

Flip over with the cut end up.

I made a bent a slight curve into the engine hook.

The extra tension makes for a better hold of the engine. 

Some history:

The top picture is from the Estes instructions.

Notice the engine tube is 3" long, the hook extends 1/4" over the low end.

A couple joins the engine tube to the longer upper tube. The coupler also serves as the engine block.

This design was first used in some minimum diameter Centuri kits. This instruction illustration is from the Scram Jet.

Gluing an engine block in the correct position (by sliding it into some glue in the tube) has always been iffy, especially for first time builders. Gluing a coupler in a shorter tube from the top does two things. It easily places the engine block in the correct position. The longer engine block works as a coupler joining the two tube lengths.