By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Seagull Hurricane Laser

All Topics | Latest Posts

Search for:  in Thread Title in  
Chris Freeman 314/02/2020 09:21:10
353 forum posts
525 photos

Do you have any expo on the elevator? Years ago whilst teaching my son to fly a Spitfire I set up some expo to soften the elevator and that it made the Spitfire a pig to land as it would not settle on the approach and porpoise. We found that flaps and undercart down would lower the nose so you counter with some up and when you want to land the expo is now working against you as it is now a super sensitve elevator. Taking the EXPO out changed the situation and the Spitfire was back to the pleasent landing one that I was used to.

Jon - Laser Engines14/02/2020 09:38:27
5422 forum posts
263 photos
Posted by Piers Bowlan on 14/02/2020 08:47:09:

I appreciate that the model flies well in normal flight Jon, so from that perspective the c of g is in the 'right place' for that regime of flight. However if the model is uncontrollable at landing speeds then you have a problem which I feel no amount of elevator /flap mix tweaking will sort out.

Edited By Piers Bowlan on 14/02/2020 08:53:33

With gear and flaps down its almost impossible to hold the nose up without the ele/flap mix so adding more weight to the front wont help us and the rollercoaster nature of the approach seems to stem from the fact that the wing just provides so much lift that a small deviation in pitch, in either direction, has a significant impact. As the model is very slow when landing the tail looses effectiveness, which is not uncommon on a warbird, so higher rates are needed. This would all be fine if the wing was not so sensitive to pitch at low speed and that where we will focus our attention. 

Chris, no expo. Expo is a powerful tool but it is over used and very often used at the wrong times. I had a similar experience to you with a H9 Spitfire where a club mate could not get the thing on the ground as it was all over the place on approach. I looked at his tx settings and was horrified to find 60% rates and 65% expo. I dropped the rates to 25% and ditched all the expo. It was on rails after that.

The trap was he set the radio up according to the deflections called for in the manual. As it was too sensitive he added expo, as thats what popular misconception told him to do. This didnt help so he added more, and more... When i and another warbird proficient friend looked at it we immediately saw that the travel was too high and that was the root cause of the problem. Out of 12 models only one of mine has 10% expo in it and even then only on 1 channel. Its just not needed on the rest of them.

Always get rates set first, then add expo as the cherry on top. On warbirds starting with 30% is just insanity in my view as you are on the back foot before you even begin.


Edited By Jon - Laser Engines on 14/02/2020 09:39:58

All Topics | Latest Posts

Please login to post a reply.

Latest Forum Posts
Support Our Partners
electricwingman 2017
Sussex Model Centre
Advertise With Us
Latest "For Sale" Ads
Has home isolation prompted you to start trad' building?
Q: The effects of Coronavirus

 Yes - for the first time
 Yes - but Ive bashed balsa before
 No - Ive existing projects on the bench
 No - Im strictly an ARTF person

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E!