1/8A Micro PD vehicle tests

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Micro Craftman/ClusterNut
TRF Supporter
Jan 18, 2009
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Washington DC
Had a great flying day saturday Sept. 11th at Middletwon Park, Maryand. I don't think we could have had a much nicer day. Temps in the mid 70's, 47% humidity, High broken clouds and bright blue skys all day. the only minor draw back was the constant 5-7mph wind for the southeast blowing the models across the tree lined creek up the hills toward other fields and baseball diamonds.

Testing for Steel city Smoke trail contest has been very interesting for the new 1/8A parachute duration NAR motor class. After posted a dismal 12 sec National record for 1/8A pd at Naram-46 in the HIGH Humidity and using a nasty old taped up 12" chute that refused to open.. it was back to the drawing boards to come up with a few alternate methods.

Since I loath laying up fibreglass super light model bodies I've been using different mylars and tracing vellums for many years. Originally designed back in the mid 80's to compete with the fibreglass 2 to 6 grams models flown by the FAI guys. these models hold up well (for 3 or 4 flights) and are competitive.

Unfortunately the micor-maxx motors both MM-1 and MM-II's just don't quite have enough ejection charge to deploy the larger chutes in these larger diameter models. My TaperPaper designs have evolved from the simple 7inch long, 10.5-7mm single taper to a little over 12" OA length .711-.544-.281" double taper models to hold up to 30" chutes.....Well; you can get the chutes in but getting them out is another matter:)
Test conducted Saturday tell me the double taper is a Cool looking model that flys extreamly well on both Micro-Maxx motors, though the old MM-I with it's slightlty longer 1.07 sec avg. delay is still to short of the Hi-performance models. neither motor has the umph to deploy even a 16" 1/4mil mylar chute completely out of the body. Wadding or 1/2" Thick styrofoam plug...neither would allow the chutes to come out more than about halfway. I'll go to a straight .518" x 8" vellum tube with the single 1" x .544 to .281" boattail to see if a foam plug will work on a 16" chute, I think this will make for a good comprimise to against the double taper.
The very good news is I thermaled away another 7" staight 10.5-7mm TaperPaper on a 12" 1/4mil mylar chute. last sighted at 362.35 seconds again going up toward south mountain. slightly over 6 minutes!!! the good news here is the tiny model and 12" silver mylar chute were VERY visible at this long distance. so it should be possible to use these smaller models and get one back:D I'll post a Group photo of the TaperPapers and Double TaperPapers below. the small dark and light green 7" model is the one that logged this impressive time. that model with motor and 12" 1/4mil mylar chute tipped the scales at 6.3grams. The largest and heaviest double taper with a 24inch mylar chute weighed in at 10.4grams. with a 16" chute the LO weight was 8.6grams.
I think these large double taper papers will be fun to fly as demo models with crape streamers if nothing else.
cool....looks like the MMx motors pose a whole set of challenges when it comes to competitive design reliability..great!
Sure does shockie!
One of the Novaar/FAI guys tried a layed up model with a 30" chute. the model was so light that the chute wouldn't blossom. I'm convinced that will be the major challange, to get whatever chute to blossom. That's why I'm concentrating on getting something that will release a 16 or 18 inch chute. with any lift at all they will go bye-bye:D So far on sunny days I've thermaled away 5 or 6 of the smaller models I discribed earlier... I'm pertty sure this will be a retrieval battle as much as a flight time battle, any lift at all and these things float away:D
Instead of blowing the nose, how about popping open a split body (like the old CMR kit whose name escapes me).

You are absolutely correct about the blossoming problem. I would think that 'crinkly' material like metallized mylar would not be the best material. How about dry cleaner bags?
Originally posted by shreadvector
Instead of blowing the nose, how about popping open a split body (like the old CMR kit whose name escapes me).

You are absolutely correct about the blossoming problem. I would think that 'crinkly' material like metallized mylar would not be the best material. How about dry cleaner bags?

The body split might work on standard body tubes, I'm not so sure on vellum or even layed up glass tubes.. have to do a little experimenting on that, maybe some sort of burn-string wrap or something similar.

Visibility of drycleaner bags that tend to make me lean away from them for chutes smaller then 36". Maybe some of those really cheap very very thin black trashcan liners might be an option?

Your right about the crumpled mylar. I try not to crinkle the mylar, folding instead of spiking the chutes. leaving as much unfolded surface as possilble. This is one of the reasons the main tube is 8.25 long to allow a 16" chute to be installed with only a peak fold allowing it to spring open on release...IF it gets out of the tube;)
The NEW 12" mylar 8 shroud chute opened well. again in the 7" body only only the end crammed into the aft end is crinkeled sightly.
Heres a little better look a the TaperPaper SD ready to fly in an earlier test before I started using colored vellum. This one used a 2" x 20" crape streamer... the model was out of sight for awhile i only picked it up a 120 feet or so above the trees into which it landed:( Precolored vellum or colored on the inside before assemble of the tube seems to work best, making the model much easier to see at higher 150 to 250' altitudes. these little buggers Honk!