Seagull Boomerang Assembly.......

[Delta Whiskey]

Just putting together a Boomerang, my 2nd one, but the first was 2nd hand and already to go, so this is the first assembly of one (I was going to say build but did not want to offend anyone as I'm certainly no model maker! )

Anyhow, first thing, I pushed in the tank a bit too hard, and broke the former (not sure this it the correct word for it?) that has the hole cut to the size of the tank neck and sits just behind the firewall, anyhow, it still fitted snug up behind the firewall fine, I padded it out with some foam and it feels nice and solid, it was really a thin bit of ply / balsa, will this make any difference?

 

2nd issue is that the engine mount, which comes already fitted to the firewall and when fitting a irvine 40 engine the blue plastic mount seems to push out futher at the ends than it does further back nearer the back plate, so much so that the mounting screws are very near the edge of the mount, so  as it was a bit flexible I drilled the holes slightly inwards from my markings and manage to secure the engine ok by pushing the ends of the mounts inwards while pushing the screws home, is this normal for this type of mount? .......

 

......and this leads to my last question (for now), is that the manual and kit supplied and descibes that normal wood type 25mm screws should be used, as it's in the plastic mount they seemed to fit nice and tight, anyone found problems with these or should I change to bolts and nuts?

Cheers!

Edited By Delta Whiskey on 28/04/2010 22:26:48

Edited By Delta Whiskey on 28/04/2010 22:27:56

Edited By Delta Whiskey on 28/04/2010 22:30:14

Edited By Delta Whiskey on 28/04/2010 22:32:29

[Stephen Grigg]

High DW,I would use nuts and bolts.The way you descibe the engine mount sounds similar to my experience and I held mine tight to the engine when I drilled the holes.I seem to remember them being very close to the edge also.The tank sounds as if itll be fine.mine was held in fine and when I had to remove it for repairs the mount was also damaged but the tank stayed where it was meant to.I used thicker push rod wire on the steerable nose wheel also as that supplied seemed to bend a bit.I did finish up fixing the nose wheel solid as I tended to oversteer with it

[Hugh Coleman]

Hi DW.

 

Two things.  The engine mount is very flexible and any nose shunts will bend it.

ALWAYS USE MACHINE SCREWS AND LOCK NUTS FOR ENGINE MOUNTING.

 

Seagull tanks are notorious for leaking at the neck seal.  Pressure test before fitting.

 

Good luck with your build!

 

Cheers,

 

Hugh

[David Davis]

Hi DW

 

I'm a Radical from the Modelling Tendency so cannot advise directly on the Boomerang but having built over 40 models I feel experienced enough to comment on your queries. Please bear in mind however, that if you ask ten modellers the same question, you're likely to get ten different answers!

 

1. Concerning the former. If this former is the F2 former, i.e the one beneath the leading edge of the wing at the tallest point of the fuselage, it MUST  be repaired or replaced otherwise the structural integrity of the fuselage will be impaired.

 

2. Are the legs of the engine mount being forced apart because the engine is too tight a fit in the mount? If so, I've always removed some of the material on the inside of the mount using a rasp so that the engine fits in neatly.

 

3. I've never had a problem using screws in nylon engine mounts.

 

Finally I've always advised beginners to replace the steerable nose-wheel with a fixed one which you can buy at your Local Hobby Store (LHS) because the original equipment tends to break on the first rough landing but if you've flown before you should be alright with the steerable nose wheel. 

[Tim Mackey]

DD said....

3. I've never had a problem using screws in nylon engine mounts. held engines as large as 120 fs with 'em with no problem

 

Me neither.

[Delta Whiskey]

Thanks all for your tips / comments.

I can report that I had a successful maiden today, and a few more flights after that!

The engine still seems well secure using screws in the nylon mount, so I will keep and eye on it but leave as is. I filled the tank up with the hand crank Stephen kindly sent me, and held the boomer at all angles without the wing on and no sign of any leaks !

Although I had the control surfaces all visually lined up, I needed a fair amount of right aileron to keep level, +88 on my futab 6EX 2.4.  After a tadge of up elevator all was well, I thought it was a bit nose heavy on the ground, but thought better nose than tail, so went for it!

Having flown other fast models it was a joy to fly and land easily and having the steerable nose wheel was a bonus on the ground so much so that I taxied around for a bit too just for the sake of it ! (my previous one had a fixed front wheel)

Edited By Delta Whiskey on 29/04/2010 17:57:41

[Stephen Grigg]

Well done DW,some guys at the club still fly there Boomerangs and enjoy them even though they have moved on to low wingers and scale.They go further than just being a trainer.I was a bit to eager with my control input at first so tended to zig zag a bit when taking off.Then a fellow Boomerangist showed me how he had put aileron/rudder mix and steered with the right thumb.Ive done it ever since and it gave me the confidence on take offs.I was warned that I could roll the model on take off when the aileron speed was reached,never had a problem.If your turnong right on take off you know which way the model is going and can correct it accordingly.

[Delta Whiskey]

Thanks Stephen , coming from heli's first, I am well versed in using the rudder always anyhow.