Estes Sandpiper, Kit #1389, Part 4, Cutting Out The Fins

These kids have it too easy! 

In 1970, we had to hand cut 36 pieces of balsa to assemble an Orbital Transport!

If you ever have to cut balsa from a cardstock template, be sure your (sharp) blade is at a 90 degree angle to the balsa sheet. The illustration is from the yellow pages in the 1971 Estes catalog.

 

Here's the four smaller fins being gang sanded using 220 grit on a block.

After gang sanding - 

Check the corners being sure everything is even and square.

The root edges of the wings were glued together on a sheet of glass.

Weights were set on the top while the glue dried.

Estes Sandpiper, Kit #1389, Part 3, Tail Cone

Payloadbay.com is down right now, that's usually my source for cardstock reducers and tail cones.

I did my best to size the kit pattern sheet (CLICK HERE) but there was no 1" reference in the image.

Crossing my fingers, I test fitted the shroud dry and marked the overlap line. In the picture, I'm burnishing down the glue tab. 

I'm using a heavy wall BT-50 and a standard BT-20 engine mount tube.

This will require some fitting, the heavy wall BT-50 has a slightly larger diameter over a standard BT-50.

The engine mount was glued in place with the lower centering ring extended out the back, about 1/16". This picture shows the assembly upside down.

To fit the imperfect shroud, I had to use some paper wraps. Two 20 lb. copy paper strips gave a good friction fit.

Light glue was applied and the shroud slipped in place.

Before the glue sets up, you can do some "molding" of the still wet shroud edges. I'm using the smooth barrel of a Sharpie pen to press the shroud edge against the body tubes.

Estes Sandpiper, Kit #1389, Part 2, Engine Mount

The instructions have you set a line of glue 2" up inside the 3 1/2" long BT-20 tube. Then push the engine block up from the bottom.

The engine mount tube is only 3 1/2" long, I can add a glue fillet from the top.

Tape and engine casing with 1/4" extending out the bottom. Slide the engine block in from the top dry, no glue yet. 

Slide the block down until it stops against the top of the engine casing.

Add glue using a Q-tip making a fillet around the joint.

After it is dry, remove the engine casing.

The upper 2050 centering ring gets a notch for the Kevlar shock cord.

There is very little room between the tubes for a knot, I did a wrap.

Tighten the Kevlar, set it into the glue fillet.

Estes Sandpiper, Kit # 1389, Part 1, Parts

The Estes Sandpiper kit was produced from 1983 - 1984.

Vashon (Freon, "cold power") previously produced a Sandpiper about the same size. The Vashon version was hardly scale, there was no tapering tail cone.

With the release of the new, large Estes Jayhawk, I thought it would be interesting to build this variant.

This is almost a spare parts build, the 3D printed nose cone was explained in the previous post.

I redrew the decals, fin patterns and shroud. The shroud (as it is right now) may not fit the BT-20 and BT-50 tubes. I'll make adjustments before the PDF is available to Patreon subscribers. 

The original instructions and parts list: CLICK HERE 

The BT-50 tube is 7 3/4" long, the engine mount tube is 3 1/2" long.

The tail cone length is approximately 1 11/16" tall. The nose cone is 4 3/8" tall, exposed.

The launch lug is an LL-2E at 9 1/2" long. 12" long launch lugs can be ordered from jonrocket.com and cut to size.

Clay weight square (not shown) is 1/2 oz.

The payloadbay.com website is down right now, 

I had to find another shroud generator, this one is from:

https://www.delorie.com/rockets/transitions.html

Before I had the 3D nosecone, I had ordered a SEM-BNC-50YP balsa nose cone from Erockets.biz. 

If I couldn't get a plastic PNC-50S, I was going to add the upper vanes like in the old Vashon kit. The vane template is directly below the balsa cone.

Estes Sandpiper, Kit # 1389, Nose Cone Backstory

Blog readers might remember a post about a badly produced 3D nose cone:

CLICK HERE

That smaller nose cone is pictured on the left. It wasn't sized to a BT-50 and had a rough ridged surface.

On the right is the correct size 3D nose cone sent to me by James G. (Augendoc on the forums)

This is a well produced nose cone! Smooth (fine ridges, easily smoothed) with a perfect fit in a BT-50.

The rocketry community can be very helpful. Thanks James!

The nose tip did need minor shaping, easily cleaned up with a sanding block.

Here's the two different shoulder bases.

One has a hole for a screw eye, the other a horizontal bar to tie off a shock cord.

I'll be using the base with the screw eye, it seems stronger.

Meanwhile - at Odd'l Rockets . . .

Here's the floor of my living room after completing three of my largest orders to date! That black box in the back holds an Accordion. This might be why I'm single.

The brown bags contain the smaller items like Raise Springs, Birdies and Adeptors.

40 Raise springs, 20 Adeptors and 162 kits  - Whew!

New Way Lunar Jumper Build, Finished

Another great design from New Way.

This model captures the spirit of the sci-fi films from the 1950s.

I should get a lighter red paint for the nose cone to match the tape trim.

The addition of the red trim tape reminds me of some Centuri kits. Centuri included red trim tape in their Skylab. Other kits included chrome trim.

Lots of detail in the multi piece fins. I like the curved trailing edges.