Lawn Dart MkIII (oz15233)

  1. Home
  2. Lawn Dart MkIII
 

Lawn Dart MkIII (oz15233) by Bruce Matthews 2014 - plan thumbnail

About this Plan

Lawn Dart MkIII. Simple catapult glider model. Wingspan 17.5 in

Quote: "I've done six of the following gliders with the idea that they were a lower cost "disposable" sort of model. As such I made them in pairs using a sheet of 1/8x4 for the two wings each time.

And they didn't disappoint since all 6 have gone away in thermals flown in various contests. The materials being chosen for low'ish cost.... Mind you with balsa being what it is these days I think my next go at a good catapult glider is going to have a DT setup.

Notice the mention on the drawing about not strongly airfoiling the stabilizer. With the thin wing section I found that the tail could over power the wing. This resulted in a trim where the model glided very nicely in a minimally pitch stable manner at low speed. But if it sped up it would live up to its name. "dulling" the stabilizer edges so the edges are 1/32 thick fixes this but still aids with a nice near vertical launch.

Sorry there is no balance point marked on the plan. I always find it by test gliding. What I look for is a nice slow glide but if I push it out and slightly up into a slight stall that it shows signs of recovering where it pulls out and just barely misses the ground after a low angle stall at head height. And I do mean JUST pulls out. To climb and glide well we want minimal pitch stability with just enough to recover from stalls. I'd check one of my previous builds but as mentioned above they all thermalled away from me. But it's somewhere around 1.7 to 2.0 inches back at the root .

What you're after for the climb is to launch upward at around a 60 to 70° angle. It should climb well with a slight left hand spiral. And if done just right it stops at the top and sort of side slips into a glide with very little altitude loss and no stalling. Tweak and try different amounts of fin and launch angles until you get it to do that."

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction

Lawn Dart MkIII (oz15233) by Bruce Matthews 2014 - model pic

Datafile:

Do you have a photo you'd like to submit for this page? Then email admin@outerzone.co.uk

User comments

It should print to proper size on a piece of legal paper.
Bruce Matthews - 25/04/2024
Add a comment

 

 
 

Download File(s):
 

Notes

* Credit field

The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.

Scaling

This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.

 

Terms of Use

© Outerzone, 2011-2024.

All content is free to download for personal use.

For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.

Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.