Jump to content

The Norwegian Gnat Squad


Recommended Posts

Good luck with the turtledeck bending, I soaked with water which didn't come anywhere near so I finished up planking it. Looks OK though. I've covering at the moment and have left the fin off while turning the model over and round etc. I'll fit it before covering the rear top area.

Your model is looking very nice

Link to comment
Share on other sites

The turtledeck turned out to be a doddle. After prebending the sheet around a kit cartridge I did another round where one end was wrapped around a 15mm tube. Note that I soak with ammonia with water, that works a lot better then just water:

img_6874.jpg

Next to none spring back.

Gluing it in place is easy when you do not have to force it.

img_6878.jpg

This was the last bit to be glued, now an evening with filler and sanding paper and some cockpit detailing and we are ready to cover.

Cheers, Lucas

Link to comment
Share on other sites

Finishing the cockpit now. Grey with matt black panels, seats etc. I am not going to put much effort in this area, first see if she flies.

img_6884.jpg

Total weigh 352 gr. now, with all electronics on board except the aileron servo's. She should end up on or under the weight published I think.

Cheers, Lucas

Link to comment
Share on other sites

Beatifull cockpit Steve! And also covered the insides of air intakes! May I ask what the weight of your Gnat is?

I glued the cockpit in place tonight:

img_6914.jpg

Covering is next. This is a complicated model to cover, with all flying surfaces already attachted and many "bulbs" on the fuselage. We will see how it goes.

Regards, Lucas

Link to comment
Share on other sites

  • 2 weeks later...

The maiden was eventful, to say the least. I had chosen a site where the launcher could stand about 4 m. over the terrain. At launch she sank a bit and then was away like a scalded cat. Very quickly very small.

I had to trim the elevator up a lot before she would fly straight and level. Elevator authority was lacking with the specified 6 mm up and down and 30% expo. Aileron was ok.

What I had not though well through about this site was the lack of a straight line in and out for landing and abort. When coming I saw the gnat going too far and when aborting I pulled a turn with too low speed. The inner wing dropped and touched the grass, with a cartwheel leaving the fuselage cracked before the wing.

Damage after removal of the covering is a separated fuselage:

img_6955.jpg

Link to comment
Share on other sites

Awww Lucas, what a shame. I think we all share your pain!

After a crash my first thoughts are to chuck the remains in the bin but I know to resist that urge because a couple of days later I always find myself figuring out how best to execute a repair.

With your building skills it will soon be back in the air.

By the sounds of it the main learning point from all this is that the Gnat needs more elevator movement than the recommended 6mm? My build is close to completion and, with a relaxation in Scotlands lockdown rules now imminent, my maiden flight isn't far off (hopefully!).

All the best with your repair.

Link to comment
Share on other sites

Lucas,

Sorry to hear about the mishap, hopefully you can repair it . I also needed a significant amount of up trim but still had sufficient control authority. I decided I had probably been too conservative with the cg and marked it up to move the battery slightly rearwards for subsequent outings. Not got chance to see if there is any difference because the field has been in lockdown ever since and my ‘ home ‘ flying field is too small for such a missile !

Good luck for the next trip.

Tim

Link to comment
Share on other sites

To John: I think it is too early to conclude that more elevator movement is needed. I have increased it by 15% but maybe more important reduced exponential from 30 to 10%. What do other fly with?

Main learning point for me is that a site with a straight in-out flying path is needed so that an aborted landing can be done by just opening the throttle keeping wings level and pull up after sufficient speed has been reached.

Also trim in 1-2 mm up elevator straight away. At launch you may need a bit of up elevator to prevent a dive before flying speed has been reached.

Link to comment
Share on other sites

Hi Lucas... opps on the flight BUT ...take 3 positives the model flys well, the cause of the crash is being unlucky with the site ...and the model looks straightforward to fix

i have had many models like this and it’s the great thing about wood builds with splinters like that🤣. Some wood glue on those splits and a great wetter area . The repair will be stronger that the original . You will soon be back in the air.
Keep it in close, keep the speed in the turns , smooth and wide and enjoy. My favourite by far. Until the baby Hawk is finished

steve

Link to comment
Share on other sites

The repair is well underway. I double the damaged former(with holds the battery sidewise). And put a 2mm balsa plate under the area with the small fragments.

img_6957.jpg

Some extra wood to align and top deck:

img_6958.jpg

and glueing everything back together:

img_6960 (1).jpg

All holes were sparkled with light weight car body filler and sanded afterwards. I noticed front and back fuselage have little contact after one cuts the battery hatch. I reinforced the gluejoint in the lower triagle stringers with 1mm ply plates in the air intakes and a piece of 25gr grass over the bottom of the fuse to the air intakes.

img_6963.jpg

Litt paintwork in the cockpit, glue the canopy back on and ready for covering again.

Edited By Lucas Hofman on 25/05/2020 07:45:14

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...