SE5a CONSTRUCTION BEGINNING TO . . .

[Greyhead]

Because the basics were worked out well in advance the radio gear has all fitted in with no unexpected problems. The throttle servo, bomb release servo and onboard / remote glow driver are located in the engine compartment, their leads have to pass through the firewall so the resultant hole needs to be sealed to prevent the ingress of fuel / oil into the main fuselage.


A standard grommet won’t work very well because the leads have their plugs permanently fitted, so I made a 2 part seal from a rubber wine bottle “cork”; another of those useful Christmas necessities!





An appropriately sized hole is drilled through the firewall, one half of the seal fitted in place, the leads / plugs threaded through, then the second half fitted, the rubber compresses around the leads forming a good seal.





The onboard / remote glow is located in the engine compartment in order to keep the glow plug power leads as short as possible, the control unit and battery are wrapped in foam and held in place by a cable tie. I’ve complicated the wiring somewhat by including a stereo, switched socket, which enables me to use a remote connection for starting and also, using a different jack plug, to charge the battery.





Previously I've used a homemade onboard glow driver, which simply switched on the glow at a preset throttle setting. But this one is an “intelligent” glow driver; it continuously monitors the glow temperature (actually the resistance of the element) and connects the battery only when required, whatever the throttle setting happens to be. In theory it should be a lot better, but I’ll let you know how it actually works in practice at a later date!

 

[Greyhead]

I ran the Laser up yesterday to test the plumbing and adjust the onboard glow. As I mentioned earlier I now have an “intelligent” glow driver, that is, it only switches on if the plug goes cold and needs energising not at a set throttle opening. The driver has an LED, which shows when current is being supplied to the glow plug; this is very useful as you can see exactly what is happening.

Having adjusted the driver following the instructions, one thing became quite obvious; with a Laser you really don’t need an onboard glow driver. I’ll still use it if only as extra security just in case a plug goes faulty when I’m sure it would help.

 

[Greyhead]

I’ve altered the exhaust slightly by incorporating a 10mm copper 90º bend, I found that as the silicone pipe heated up with the engine running, it tended to collapse slightly at the apex of the bend so restricting the gas flow. I have to admit that I didn’t notice any change in the engines performance but decided that it’s better to be safe than sorry.


Connecting the remote glow lead to the plug can be a problem with Lasers, along with most other four strokes, because the plug is recessed quite a way into the head; there are many methods used to make this connection, this time I’ve used the threaded section from a 3mm “quick link”. A very short bolt holds the solder tag and the rest of the 3mm tapped section pushes tightly over the plug post, being made of “springy” metal the threaded section can be adjusted slightly if necessary to ensure a tight fit by squeezing with a pair of pliers.





The power lead is sheathed in silicone fuel tubing for heat proofing.

 

[Greyhead]

I was chatting in the model shop recently and as is often the case when I’m involved the subject turned to biplanes. The consensus was that they’re more trouble than they’re worth, just too fiddly to set up and awkward to takeoff and land in anything but ideal conditions. I pointed out that my Elf, with its folding wings, is easier to rig than most sports models; but I had to admit that it is the exception rather than the rule! I also had to admit that the flying characteristics of biplanes can be “challenging” but in my opinion the inconvenience of rigging is far outweighed by the appearance of the assembled model and that it doesn’t have to be all that time consuming with a bit of forethought.


My decision to use the scale closed loop control system for the ailerons on the SE5a has made the assembly somewhat more difficult and as I explained the procedure it did sound horrendous, which in reality it isn’t. It’s one of those things that sound complicated in words but when you see what is involved it isn’t, so I’ll take some photos as I assemble the model, which won’t be today as my workroom is too small and it’s raining quite heavily; don’t want to get all those rigging wires rusty!


I’ll start with a photo of the “tools” that I’ve made to make the rigging easier and a brief explanation; it will be much clearer what they do when I post the assembly photos.





From left to right:


One of a set of 4, which keep the cables tight during storage and whilst connecting the first quicklink.


The third version of a tool to hold the quicklinks open


A spring-loaded quicklink


Tensioning tool for the rear flying wires.


I'll assemble the model and take photos ASAP, but just checked our 5 day forecast and it's not looking promising for next week!

 

[smcouch77]

OK. Now you've got our curiosity up and tell us we have to wait for it to stop raining in the springtime? ARRRRRRG!!

Steve

 

[Greyhead]

This is England we're talking about! No such thing as predicable seasons.

 

[Gaz]

Seasons??? Do we still have them?

 

[rjwood_uk]

nice and sunny at the moment.....get those photos!!! lol

Richard

 

[Greyhead]

You don't live in the North East!!!!!

20 minutes later and the sun’s out!!

But we’re still surrounded by ominous black clouds; I don’t think I’ll risk it

 

[Gaz]

North Scotland, seasons are defined by the warmth of the rain!!

 

[Greyhead]

OK Steve so here it is, the method of assembling the SE5a with closed loop aileron control!


The fuselage is held inverted in the assembly support and the underpan and wheels removed.





The aileron control is not strictly a “closed loop” because there is in fact a gap between the two servo arms, although in operation this gap stays the same effectively making it a closed loop. Moving both arms outward in essence makes the loop longer enabling the quicklinks to be accessed with the wings not fully butted up to the fuselage and centre section. Notice the spring inside the fuselage pulls the servo links inwards.





During storage, with the ailerons at neutral, the quicklinks just protrude from the root ribs and they are kept under tension by button thread attached to springs.





The top quicklink is pulled out from its wing tube and is held open and in a protruding position by my third generation “special tool”, at the same time the spring tension on the lower quicklink is eased to allow it to retract into its wing tube but still maintain tension in the cables. As you can see the ailerons are now deflected up.





The spring-loaded quicklink is attached to the link on the opposite side of the centre section.





The wings are then located loosely in position and their supporting frame removed; the bottom wing grub screws are tightened slightly to hold the wings in place whilst allowing the top wing to slide somewhat.





Pressing on the spring-loaded quicklink pushes out the centre section link, which is attached to the wing quicklink and the special tool removed, tension in the cables being maintained by the spring-loaded quicklink.


At the same time as pushing on the spring loaded quicklink the bottom wing quicklink is pulled from its wing tube and held in position by the “special tool”. The servo link is pushed out from the fuselage against the internal spring tension, engaged with the wing quicklink and the “special tool” removed. Tension being maintained by the spring loaded quicklink and the internal spring.





Both wings can now be pushed fully home and the bottom wing grub screws tightened. The tails of the rear flying wires are threaded through their anchor block and hooked to another of my special tools. Pulling on the ring applies equal tension to both wires and the bolt is then tightened; this is the most awkward part of assembling the model and is a procedure that would be simplified if I had three hands!





The spring-loaded quicklink is removed and the centre section link held in position with a pair of forceps, tension now being maintained purely by the internal spring.





The whole procedure is repeated for the other wings except this time the internal spring replaces the spring-loaded quicklink.


Finally the wheels and underpan are fitted, the model turned the right way up and the top wing grub screws tightened.


I was hoping that the weather would allow me to take some good outdoor photos but although the rain stopped long enough for me to get the model assembled it’s now looking decidedly dodgy so they’ll just have to wait for another day.

 

[rjwood_uk]

...and then it chucked it down lol!

sounds complicated to me...i wonder how many times you said "quick link" in that post lol.

looking forward to the pics!

Richard

 

[smcouch77]

Thanks Grahme. That's a neat setup. I'm sure I'ts a lot harder to explain than it is to do!

Steve

 

[Greyhead]

I agree that it does still sound a wee bit complicated, but I hope the photos at least clarify the procedure somewhat! When I next assembly the model I’ll time just how long it does take, it all seems fairly straightforward when I’m doing it but as they say “time flies when you’re having fun”!!

 

[Greyhead]

Well summer has arrived, at least for today! That gave me something of a dilemma, should I go flying to get some thumb practice, or assemble the SE5a and take some “good” outdoor shots. I decided on the latter, which was the right decision as it turned out because the wind ended up quite strong; the streamers on the interplane struts were blown horizontal.


To assemble the model actually took 20 minutes, not too bad, but longer than I thought it would be. I have only done it a few times and I’m sure I will get quicker with practice; I did make a couple of mistakes which meant I had to reverse a bit.


The photos have turned out well; the only problem was the “giant” dandelions, which I’ve removed with the PhotoShop clone tool. I’m no expert when it comes to photo manipulation but so long as you don’t zoom in too close the overall effect is OK.








I think the hangers in the background really add to the photos, hope you agree.

 

[smcouch77]

What a beauty!:clap2:

Steve

 

[Greyhead]

I’m getting to quite like this photo manipulation! On this one I’ve also removed the grass overlapping the wheels, which gave the game away somewhat.

 

[Bluewavestudios]

Looks like all your hard work has paid off nicely Grahame,

She looks great from the pics and the choice of Background setting is spot on, shame you can't get them to cut the grass a bit for you and it would be even better.

But I am not complaining, nice to see the outdoor pics, truly stunning !!

Regards

Mark

 

[Bunkerbarge]

Looking absolutely superb Grahame. As you say the setting suits the plane perfectly and I'm sure if you also had a play around with sepia tints you would get a very convincing period picture.

I had a quick play with some sepia toning, added a bit of noise and some softening and it doesn't look too bad. Those hangers give the game away a bit though, you need a period airfield!!

View attachment 16390

 

[Greyhead]

Thanks for the positive comments.

I have to say that your “aged” photo looks excellent Richard; unfortunately I don’t know of any old restored airfields around here but at least the hangers add a bit of atmosphere.

Although I’m getting to enjoy using PhotoShop in an “artistic” way, previously I’ve only used it to produce instrument dials etc. from photos, replacing all the grass is way beyond my capabilities. But I’ll keep practicing!