GMAC Forum

General Category => General Discussion => Topic started by: Jim (Chairman) on 03/04/2015, 01:41:04 PM

Title: RadJet 800 Launch Catapult!
Post by: Jim (Chairman) on 03/04/2015, 01:41:04 PM

Behold the madness!

Inspried by Morgan and a need to have a way of launching a RadJet solo, without chopping all your fingers off.

I give you RadJet 800 Launch Catapult Mark I...

(https://www.greenacresmac.co.uk/Forum/proxy.php?request=http%3A%2F%2Fwww.eight33n.com%2Fgallery2%2Fd%2F2142-2%2FIMG_2664.JPG&hash=3d2d1bb9237a3bd142a0d42858bb97710993262e)

(https://www.greenacresmac.co.uk/Forum/proxy.php?request=http%3A%2F%2Fwww.eight33n.com%2Fgallery2%2Fd%2F2146-2%2FIMG_2667.JPG&hash=1f1191f193b16d5fae81c64734f285083e52a57d)

(https://www.greenacresmac.co.uk/Forum/proxy.php?request=http%3A%2F%2Fwww.eight33n.com%2Fgallery2%2Fd%2F2149-2%2FIMG_2668.JPG&hash=47f2ab69ebb2d9a899e82efc6d0f79a9bf885321)

(https://www.greenacresmac.co.uk/Forum/proxy.php?request=http%3A%2F%2Fwww.eight33n.com%2Fgallery2%2Fd%2F2152-2%2FIMG_2669.JPG&hash=ef14ab4e54aa5f2d1069e9dd63e2a7138b7b9898)

LiPo powered. Arduino ATtiny45 control. Mechanical power from woven nylon shock cord.

Obviously the RadJet would have some throttle set, probably about 50%, as I think 100% will make it launch vertically out of the carrier...

I have a YouTube video of testing also: http://youtu.be/jU2-lAZj8RE (http://youtu.be/jU2-lAZj8RE)

Embrace the madness...

Title: Re: RadJet 800 Launch Catapult!
Post by: Chairman on 09/04/2015, 08:40:20 PM

Wow! is all I can say Jim. Can you make sure someone get's a video when you first try it?

Title: Re: RadJet 800 Launch Catapult!
Post by: Jim (Chairman) on 10/04/2015, 11:32:54 AM

Chris,

Will get field video when I have a new Radjet to test with.

Got 2 controlled flights in over the weekend including reversals.

Control still very twitchy so dial in more expo. Problem was on third flight I basically had no (very little) up elevator so climb out resulted in messy wing-over followed by ground vertically under power.

No problem, Hobbyking have a listing for a Radjet at only £27 in the UK: https://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=31128 (https://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=31128)

I have all the other parts, so it won't take long to have a new one flying again...

Title: Re: RadJet 800 Launch Catapult!
Post by: ANDY MUCKLEY (Safety Officer) on 28/04/2015, 11:22:21 PM

Brilliant Jim just brilliant,