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

Seagull Mosquito Laser build

All Topics | Latest Posts

Search for:  in Thread Title in  
Chris Walby08/09/2018 21:48:22
avatar
995 forum posts
236 photos

Blustery afternoon at the flying field with a few of the hardened pros enjoying the conditions. For me it was have another go at setting the engines up now I have them on separate channels.

I was scratching my head until Dave helped out (well took over!) and in no time we had full and tick over set up on both engines.

Following more tea we conducted the noise test with it passing nicely. Must be those 13 x 8 blades that make the difference!

Few minor mods and double check everything and I'll be ready to maiden...I know this is over thinking it but it only has 10% more wing area compared with 25% more weight for two aircraft both powered by Laser 70's

On the plus side the Mossie wing is about 25% thicker wing and the engines are not trimmed back to get through the noise test (It was darn windy doing the 4 point noise test!).

I'll post some photos once the decals are on.

Chris Walby13/09/2018 21:45:17
avatar
995 forum posts
236 photos

No more excuses maiden day.

Can’t say I really enjoy flying from this end of the field (trees look closer), but wind direction was directly along and I had a couple of aborted cross wind landing with the Dual Ace prior to flying the mossie!

And onto the Mosquito maiden

Into 10mph head wind with gradual increase to ¾ throttle aircraft accelerated on very short grass promptly, but not with the urgency of the Dual Ace (the mossie is 2.5kg heavier). I edged the throttle up a bit more and fed in a little elevator with the resulting gentle climb out, with no detectable swing.

Balance seem good with no elevator trim required and throttle returned to ¾ and expected increased in speed and height. Aileron response was okay, not too much, but might not be sufficient for a less that scale roll and very good distance sight.

Did a few circuits at various power settings with the observation that below ½ throttle its was noticeably more difficult to maintain height and speed. Turns at less than ¾ throttle seemed to wash speed off.

Landing, gear down, no noticeable change in pitch (was cross/down wind so not easy to see). Flaps ½ resulted in no appreciable pitch up however after my down wind runs with gear down and flaps ½ and a quite tight (still scale) turn in I ran out of aileron travel. One poorly lined up landing run resulting in power up and go around (not snapped open, but no appreciable yaw). Second attempt landing with no flap was more comfortable and head wind was closer to 15mph. Very smooth decent with throttle resulting in gentle flare that was surprisingly long. I was expecting the weight to have greater affect like the Dual Ace where you hold it off the ground and then plops down as the wing stalls. This seemed far more progressive.

Ran into longer grass, but did not nose over.

Conclusion, first ever time flying a 7.5kg model and it was very pleasant with little vices if the speed is kept up. Best flown at ¾ throttle although with flaps ½ or full (30 degrees) it will go quite slow I expect, but might have a nasty sting!)

Comments from club members

  • Seemed a little nose heavy flight

  • Take off from the club house looked prompt/quick

  • Sounded so good with the two lasers very slightly out of synchronisation!

Jon, thanks for your assistance throughout the build + all the other Mossie owners who chipped in with valuable advice. Lastly to club members for encouragement, words of wisdom and assistance, oh an a hole load of micky taking!

Photos and video to follow.

Chris Walby13/09/2018 21:53:15
avatar
995 forum posts
236 photos

img-20180913-wa0002.jpgimg-20180913-wa0001.jpg

Chris Walby13/09/2018 22:40:26
avatar
995 forum posts
236 photos

Try this?

https://www.youtube.com/watch?v=tscAU_xfLNg&feature=youtu.be

chris larkins13/09/2018 23:04:44
avatar
207 forum posts
144 photos

Next time I'll have my camera ready and get some better pics.

Ronos14/09/2018 07:37:01
avatar
170 forum posts
17 photos
Congratulations Chris, great video and nice first flight, bit windy up in Cumbria, so will have to wait. Hope mine goes as well as yours mate.
Ace14/09/2018 08:12:33
271 forum posts
15 photos

Thoroughly enjoyed following your excellent build blog with a successful maiden, what more can I say - Brilliant thumbs up

Danny Fenton14/09/2018 08:33:14
avatar
9204 forum posts
4052 photos

Well done Chris, I am so glad you had a good flight, I would be wary of your club mates comments about nose heavy, but you could slowy inch it back if you want I suppose?

I must get mine out again soon

Cheers

Danny

Chris Walby14/09/2018 08:50:12
avatar
995 forum posts
236 photos

Thanks guys for the kind comments although it was made a lot easier with everyone else's advice.

Danny,

I'll leave the C of G where it is and get a few more flights in first as there was a comment about ailerons and yaw that I might have a play with in flight modes.

The other thing was how benign the landing was (yes I came in fast), but as the speed bled off there seemed plenty of elevator authority all the way down.

PS as winter sets in just watch out for the poor light...I find matt camouflage and big circuits a particular challenge.

Mike Rowe01/10/2018 16:21:39
avatar
22 forum posts
3 photos

Hi Chris, I collected my 2 Laser 70s on Thursday from Jon, and I am now starting to mockup the installation, I think it will fit without moving the bulkhead although it will be tight. Any thoughts after having done all the work?

laser mockup.jpg

Chris Walby01/10/2018 16:54:14
avatar
995 forum posts
236 photos

Hi,

Well done I am sure you won't regret it although Jon would have seriously considered keeping them for himself as I think he can't scratch that twin itch!

The issue for me was with the existing mounts is everything ends up very tight like throttle linkage etc. I just prized the bulkhead out, measured back the same amount on each side plate to maintain the offset and glued a new one in (without all the holes in it!). The tank sits below the bulkhead in line with the carb just in front of the retract.

I retained the throttle servo position and re-angled the linkage + put a reinforcement braces in.

PS IMHO I would really suggest running them in for a bit (I ran mine in the Dual Ace first as I have not flow IC twins) + I really wanted them ultra reliable + the 70's have to work for their money to get 7.5kg of model up to speed (and it really starts to shift when it get going). Jon suggested not trying to take off on full power for a couple of reasons, most likely time to find out you haven't quite got the set up and one dies + there is not a lot of rudder authority at low air speed so you end up with a bit of tail wagging if you don't take your time.

Nice build, flies well with the Lasers and just sounds superb!

The guys before me with electric and IC have been invaluable with their help, so if you have any questions fire away.

Chris Walby01/10/2018 16:59:59
avatar
995 forum posts
236 photos

Ronos and anyone else who is interested, last Saturday I flew her a couple of times and the wind was not straight down the runway.

I needed a fair bit of rudder in to keep her straight, made a right mess once and aborted a take off, so that might explain others issues with a swing to one side.

Bottom line, keep your cool add a bit in and bear in mind once the motors are at 3/4 throttle she will be more responsive to rudder input (I over corrected)...failing that just take off into wind!

Ronos01/10/2018 17:03:18
avatar
170 forum posts
17 photos
Thanks Chris, I got my maiden in last Friday, I have written a post in the thread I put on about the weight.
Mike Rowe14/10/2018 08:32:26
avatar
22 forum posts
3 photos

It is a tight fit but I think it will work.20181014_082224.jpg20181014_082203.jpg

Chris Walby14/10/2018 09:39:12
avatar
995 forum posts
236 photos
Hi, looking good
I found that I hand to tip the carb and exhaust together to get the cowl on.Then move them apart or the cowl will fill up with exhaust oil! Neat job...but how will you get to adjust the slow run needle...it may have to be adjusted one day

Edited By Chris Walby on 14/10/2018 09:41:51

Edited By Chris Walby on 14/10/2018 09:42:54

Mike Rowe21/10/2018 06:35:52
avatar
22 forum posts
3 photos

Hi, I ran the Lasers for the first time yesterday all seems good, no big trouble to balance them. I am off to Spain for the winter so I will maiden it there https://www.club-cr.es/. anyway took a short video of the engine run.

https://youtu.be/rQXNQVVK0Lc

Mike Rowe10/11/2018 17:22:12
avatar
22 forum posts
3 photos

Hi all,

It was maiden day today, unfortunately it didn't go that well, firstly it pulled heavily to the left taxying so I had to increase the rudder movement, once the tail wheel lifted off it straightened up ok. Flew well could probably do with a bit of downthrust on the engines. Landing was a different story it dropped a wing when it was about 3 meters of the ground, broke the left hand wing into quite a lot of pieces, repairable. A little damage to the right hand wing, broke the engine mount and pulled the undercarriage leg out. I am going to ask Seagull if they could supply me with a LH wing. Everything else is fine . I guess I came in too slow!!!

Chris Walby10/11/2018 19:23:06
avatar
995 forum posts
236 photos

Sorry to hear all did not go well. Did you come in with flaps deployed?

I bottled out as when I went to flaps it seemed to lose aileron authority in the final down wind turn and had the advantage of long runway/into wind.

What was you C of G position and AUW in the end?

 

PS no consolation, but the TN electric Mosquitos have had their fare share of tip stall incidents.

 

Edited By Chris Walby on 10/11/2018 19:33:51

cymaz10/11/2018 20:38:03
avatar
8743 forum posts
1190 photos
Posted by Chris Walby on 13/09/2018 22:40:26:

Try this?

https://www.youtube.com/watch?v=tscAU_xfLNg&feature=youtu.be

As I posted on YouTube.......THAT’S A GREAT NOISE yes

cymaz10/11/2018 20:47:35
avatar
8743 forum posts
1190 photos

 

 

Two for the price of one

Edited By cymaz on 10/11/2018 20:48:27

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

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

Find RCM&E! 

Latest Forum Posts
Support Our Partners
Pepe Aircraft
Slec
Wings & Wheels 2019
electricwingman 2017
Cambridge Gliding Club
Gliders Distribution
CML
Advertise With Us
Sarik
Latest "For Sale" Ads
Do you use a throttle kill switch?
Q: This refers to electric-powered models but do you use a throttle kill switch?

 Yes
 No
 Sometimes
 Rarely

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us