Brief:
Best described as a flying pie plate, this is another in the BMS clone of the month program offerings. This particular kit is a clone of the K-19 Astron Invader, introduced in the 1966 Estes catalog, making the original only a year younger than this modeler.

Designed to be a spit-motor glider, it's a very finicky design but worth the effort for a decent glide.

Construction:
There is a bit of controversy over whether or not the parts are true reproductions or slightly modified (see construction notes), but my kit included:

• 18mm motor tube
• Balsa nose cone
• Laser cut 1/8" balsa fins, braces, etc.
• 3 3/16" balsa sheets
• Launch Lug, nose weight

BMS's clone kits do not include directions. Instead, the modeler is pointed to online scanned instructions at places such as JimZ's archive site. This is a nice approach, as it saves everyone a small amount of money for printing, especially since most of the readers of this review can probably build this near a computer.

Construction starts by gluing together the balsa sheets. With the original, this appears to have required 4 sheets bonded together side by side, from which a large circle was cut. In my case, there were only 3 sheets, and it looked like the cutting was already done, as my three parts already formed a circle once bonded.

Next, I had to mark several lines on the circle using a pattern sheet, including the center line. Then, I cut the circle in half, flipped one side over, and rebonded at a dihedral using the supplied dihedral angle tool/stand. Very handy little piece... The reason behind flipping the one side is so that the grains of each piece wind up being bonded at an angle to each other, offering much better boost strength.

After allowing the wing to completely cure (think overnight), it was time to bond the various laser-cut balsa trim pieces. First came a pair of rudders, each of which were to be sanded for a very slight angle to better align with the dihedral wings. After that came the pair of motor tube braces, which are carefully aligned to lines drawn on the wings earlier. Finally there is a two-piece keel to go on the bottom. I have no idea why it was two-piece other than possibly offering a little extra strength against hard landings.

The nose cone is supposed to be glued into the BT-20, but you might want to wait until trimming first--including a test flight (with it taped on)--as it takes very subtle adjustment of nose weight and CG to get right. The original kit used a lead washer, although the BMS clone opts for clay to be crammed into a pre-drilled hole in the nose cone. Give some serious thought to ditching the clay for a few BBs or lead shot and epoxy, as even a slight pressure in packing the clay will cause the nose cone to split open.

CG is supposed to be 2-15/16" aft of the leading edge of the plate, however, mine tended to fly like a tank when hand tossing in that configuration.

Finishing:
Normally for a glider, you do not wan to add weight for stufflike filling grains and painting. The original kit recommended painting the underside black for easy tracking, and the top side orange to better spotting in the grass. I decided to go with much lighter dope, 50% thinned, just on the underside until I could get a few decent flights in.

Construction Rating: 4 out of 5

Flight:
This clearly wants short delays, so I figured 1/2A6-2, A8-3, or maybe even a B4-2 would do. After the fits I had trying to hand toss and trim it, I decided to go a very conservative first flight with the 1/2A6-2. In general, I think this is too wimpy a motor for it, and it should go with at least an A8.

The flight pitched up almost immediately off the rod, arcing over and heading right back to Earth. Continuing the pitch though, it completed the somersault and headed back up very briefly before finishing the thrust, spitting the motor, and trying to find a glide orientation in the meager 10 feet of accumulated altitude.

The flight was certainly not enough to tell me anything about the glide or trim, but was cause for investigation on the unstable path. Looking at it more closely, I noticed the motor tube was slightly angled, resulting in a nose-up slant, which amplifies the natural pitch up of a decent glider. This should be purely horizontal or even 1-2 degrees angled nose-down to counteract the pitch. I'll have to rework it a bit before flying again.

Recovery:
The first flight, while sloppy, was fairly harmless and everything survived fine.

Flight Rating: 2 out of 5

Summary:
This is certainly an unusual design, and I have to take the blame for the flight performance against my construction, not the kit or the parts. It's a finicky beast, but I think will be worth the extra effort to work out the kinks.

Overall Rating: 3 out of 5

Brief:
I won this kit in EMRR's end-of-2009 Quarterly Rocket Give-Away, so I'll first give a hat tip to Nick. {TIP}

This clone of the Estes K-19 Astron Invader is a odd-roc glider that has been described as a Flying Pie Plate. Its flight profile has been questionable, so Of Death belongs in the nickname too. So, that's what I'll call mine. After reading the reviews and given my history with gliders, I suspect mine will fly exactly once.

Construction:
The kit included the following parts:

• 18mm body/motor tube
• Balsa nose cone, pre-drilled for nose weight
• Laser cut 1/8" motor pylons, rudders and bottom skid
• Laser cut, 3-part, 3/16" wing panel components
• Laser cut stand/brace to set the wing dihedral
• Launch lug
• Clay nose weight with dowel for tamping

Construction starts by assembling the 3-part 'pie-plate' wing panel. I laid the parts on some wax paper and used white glue. I placed a container of coffee on to to hold the parts down while the glue set. Next, I printed the templates from the instructions downloaded from JimZ. I found that I had to disable 'fit to page' and then set the scaling factor on my printer to 101%. You use the template to mark locations for the pylons and rudders as well as the mid-line of the circle. You then cut the assembly in half. One half is flipped over, which alternates the grain pattern and adds some strength. The two parts are rejoined with a dihedral applied using the provided brace.

I didn't see what to do with the balsa edges either in the instructions or the existing reviews. I asked the previous reviewer (Chan) and he suggest to just sand the edge off, not even fully rounding the components. It seems wing lift can and does cause this rocket to loop under power and I assume tapering the wing tips would aggravate this effect.

There is a marking guide for the position of the two motor pylons on the motor pod. After the pylons are attached, you sand the root edges, as a single assembly, to mate with the wing dihedral. I saw on YORF that some people mentioned angling the nose down a couple of degrees to counter wing lift and I decided to to so. A quick calculation showed that sanding about 1/16" off of front end of the roots would provide about 2 degrees (tapered to the rear end).

The root edges of the rudders are also sanded to better mate with the dihedral on the wing. These are then attached along the marked lines. The final steps prior to glide trimming is to attach the skid and the launch lug.

Nose weight is added as required by ramming clay into the pre-drilled nose using the provided dowel. I got overly rambunctious on this step and the cone split. I little white glue fixed this minor snafu. I found I still needed more weight. Rather than add it to the cone, I extended the motor pod by a couple of inches.

On the first glide test, it went a good distance and then seemed to stall a bit. The next time, it nose dived quickly. A couple of times it seemed to glide after flipping over. I tossed it parallel to the ground, right side up and inverted and even chunked it in the air as high as I could. Finally, I went onto the deck and threw it out at about a 45 degree upward angle over the drop off into our lower yard. I stayed upright, pulled a wide 180, and dinged its wing on the chicken wire that keeps our dog our dog. Good enough for me!

Finishing:
Like on most gliders, you don't want to add weight by filling the grain and adding a bunch of layers of primer and paint. I sanded the finish product with some fine sandpaper and then used Rustoleum flat black and day-glo green.

Construction Rating: 3 ½ out of 5

Flight:
This glider is meant to spit the motor so you don't really even need to friction fit it. I decided to try an A8-3 since that is the only recommended motor that I had on hand. Well, it arced right over and lawn darted. It's dead but I saved the motor pod.

Flight Rating: 1 out of 5

Summary:
This is a weird odd-roc glider that I think looks cool. Unfortunately, mine was unstable on boost. As I projected at the start, it only logged one flight. It's certainly possible that this was due to builder error. But if I made an error and have no idea where it was, I'll still give it a low rating.

Overall Rating: 1 out of 5