Balsa Machining Service Astron Invader (Clone of the Month)

Balsa Machining Service - Astron Invader {Kit}

Contributed by Dick Stafford

Construction Rating: starstarstarstar_borderstar_border
Flight Rating: starstar_borderstar_borderstar_borderstar_border
Overall Rating: starstar_borderstar_borderstar_borderstar_border
Published: 2010-03-27
Manufacturer: Balsa Machining Service

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

This clone o' t' Estes K-19 Astron Invader is a odd-roc glider that has been described as a Flyin' Pie Plate. Avast! Its flight profile has been questionable, so Of Death belongs in t' nickname too. Avast! So, me bucko, me bucko, matey, that's what I'll call mine. Ya scallywag! After readin' t' reviews and given me history with gliders, shiver me timbers, I suspect mine will fly exactly once.

Construction:
T' kit included t' followin' parts:

  • 18mm body/motor tube
  • Balsa nose cone, pre-drilled for nose weight
  • Laser cut 1/8" motor pylons, matey, rudders and bottom skid
  • Laser cut, 3-part, 3/16" win' panel components
  • Laser cut stand/brace t' set t' win' dihedral
  • Launch lug
  • Clay nose weight with dowel for tamping

T' kit doesn't come with instructions but relies on scans from JimZ's site. Blimey! Avast, me proud beauty! T' main deviation from t' original is that all t' balsa parts in this reproduction are laser cut, matey, and I am thankful for that. Ahoy!

Construction starts by assemblin' t' 3-part 'pie-plate' win' panel. Ahoy! Blimey! I laid t' parts on some wax paper and used white glue. Arrr! I placed a container o' coffee on t' t' hold t' parts down while t' glue set. Next, I printed t' templates from t' instructions downloaded from JimZ. Blimey! I found that I had t' disable 'fit t' page' and then set the scalin' factor on me printer t' 101%. You use t' template t' mark locations for t' pylons and rudders as well as the mid-line o' t' circle. Ahoy! Begad! You then cut t' assembly in half. Ahoy! Avast, me proud beauty! One half is flipped over, matey, which alternates t' grain pattern and adds some strength. Blimey! T' two parts are rejoined with a dihedral applied usin' t' provided brace.

I didn't see what t' do with t' balsa edges either in t' instructions or t' existin' reviews. Arrr! I asked the previous reviewer (Chan) and he suggest t' just sand t' edge off, nay even fully roundin' t' components. It seems win' lift can and does cause this rocket t' loop under power and I assume taperin' t' win' tips would aggravate this effect.

There is a markin' guide for t' position o' t' two motor pylons on t' motor pod. Ya scallywag! After t' pylons are attached, me hearties, you sand t' root edges, matey, arrr, as a single assembly, t' mate with t' win' dihedral. Ya scallywag! Ahoy! I saw on YORF that some people mentioned anglin' t' nose down a couple o' degrees t' counter win' lift and I decided t' t' so. Begad! A quick calculation showed that sandin' about 1/16" off o' front end o' t' roots would provide about 2 degrees (tapered t' t' rear end).

T' root edges o' t' rudders are also sanded t' better mate with t' dihedral on t' wing. Arrr! These are then attached along t' marked lines. T' final steps prior t' glide trimmin' is t' attach t' skid and t' launch lug. Arrr!

Nose weight is added as required by rammin' clay into t' pre-drilled nose usin' t' provided dowel. Ahoy! I got overly rambunctious on this step and t' cone split. Blimey! I little white glue fixed this minor snafu. I found I still needed more weight. Rather than add it t' t' cone, shiver me timbers, I extended t' motor pod by a couple o' inches. Begad! Arrr!

On t' first glide test, matey, me hearties, it went a good distance and then seemed t' stall a bit. Ya scallywag! Aye aye! T' next time, ya bilge rat, it nose dived quickly. A couple o' times it seemed t' glide after flippin' over. Well, blow me down! I tossed it parallel t' t' ground, right side up and inverted and even chunked it in t' air as high as I could. Aye aye! Avast, me proud beauty! Finally, me hearties, I went onto t' deck and threw it out at about a 45 degree upward angle over t' drop off into our lower yard. Ahoy! I stayed upright, pulled a wide 180, and dinged its win' on t' chicken wire that keeps our dog our dog. Good enough for me!

Finishing:
Like on most gliders, ya bilge rat, you don't want t' add weight by fillin' t' grain and addin' a bunch of layers o' primer and paint. Begad! Begad! I sanded t' finish product with some fine sandpaper and then used Rustoleum flat black and day-glo green. Well, blow me down! Aye aye!

Construction Rating: 3 out o' 5

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

Flight Rating: 1 out o' 5

Summary:
This is a weird odd-roc glider that I think looks cool. Arrr! Unfortunately, shiver me timbers, mine be unstable on boost. Avast! As I projected at t' start, me hearties, it only logged one flight. Avast, me proud beauty! It's certainly possible that this was due t' builder error. But if I made an error and have no idea where it was, arrr, I'll still give it a low rating.

Overall Rating: 1 out o' 5

Other Reviews
  • Balsa Machining Service Astron Invader (Clone of the Month) By Chan Stevens (August 23, 2008)

    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. There is a bit of ...

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