1/6.78 Scale Hawker Typhoon

[wollins]

My switch works! Whoo hoo! lol! So I hooked everything up tonight and ran a test and it works perfectly.  I really like the simplicity of the solution. It's just basically two connectors that close the circuit.

In addition to the simplicity of it (mechanical so less prone to failure) it also saves me a channel and provides some more of the needed weight up front. (9V battery stored under my battery hatch)


Pic #1: Part A of my "switch".  This is glued to the strut of my retracts.

Pic #2: Part B of my "switch".  This is glued in a corresponding position so that when the gear deploys it connects or "mates" with Part A to complete the circuit.

Pic #3: This shows the positioning of the two parts.

Pic #4: The 9V battery which powers this circuit and is housed neatly in the main battery hatch.  This provides a cool extra benefit of providing an additional ounce and a half of weight forward of the CG. (I need every ounce I can get forward) This means I can reduce my "dead weight" to balance even further to about 7 ounces!

Videos being uploaded to YouTube as we speak ... stay tuned!

Colin

[wollins]

Here's the video.  BTW, you'll see after the lights come on ... almost immediately they then go back off.  That's obviously not supposed to happen. As long as the gear is deployed the lights should stay on.  Turns out that I had a bad connector which has since been replaced so all is well!

Colin

http://youtu.be/qnnMl2D6qbg

[Ededge2002]

But what if on the landing checklist in the full scale your supposed to put the landing lights on before the gear is down?  Hahahaha !  Just joking!

If the switch gives you troubles you could always use a brushed esc with the positive pulled in the connector.

[sihinch]

I have no idea what Ed just explained, but awesome job, Colin.

[piker]

Hey Colin!  I like your videos and commentary     Nice simple idea too.

Oh, and I had to think about what Ed was saying too, then realized he was suggesting using a brushed ESC as an electrical switch.

[wollins]

Thanks guys!  Trying to keep it simple Ed, and you don't get much simpler than this.
Colin

[wollins]

So I've decided to make things simpler by using a couple of Multiplex connectors for the wing connections. With these you can connect up to four leads per connector and since the wing is where all the connecting and disconnecting takes place, not only will it make it less work, but it'll leave no room for error.

Guys, are there any multi pin connectors out there that have more than the four servo capacity of the MPX (Multiplex clones) connectors?  Since I need six connections via my wing, I'll need to use two of my MPX ones (capability of four connections each) so I'd love to find connectors that have more so that I can just do ONE connector for my wing.  Basically I just need a six servo capable multi pin connector. This 8 pin example can be seen here. Any suggestions where I might find something like this locally?

Thanks!
Colin

[Papa]

Why not solder them all together in "Y"'s to reduce the number of plugs?

1 for Ailerons, 1 for flaps and 1 for landing gear.

Jack.

[wollins]

Why not solder them all together in "Y"'s to reduce the number of plugs?

1 for Ailerons, 1 for flaps and 1 for landing gear.

Jack.

Cause that negates that whole individual surface trimming thing that I like to do!     The 8 pin would be perfect. See pic. 

Colin 

[wollins]

Pic #2: Part B of my "switch".  This is glued in a corresponding position so that when the gear deploys it connects or "mates" with Part A to complete the circuit.
Colin

Turns out that I had a bad connector which has since been replaced so all is well!

Quick update to that whole "bad connector" situation ... it was not a "bad" connector. In reality the fabrication of the base on which Part B sat was ill conceived.    You'll notice that the connector sat on a piece of foam. 

Well the whole concept was that I needed a base which had some "give" so that when the strut with Part A mated with Part B, it would collapse so as to not only get a better connection, but so it wouldn't trigger the over current protection feature of the retracts ... which would have caused it to not deploy to its end point ... which would then cause the gear to collapse on landing ... yada yada yada...

The concept was sound but the flaw in the design was the material used.  That foam did have "give" but no resilience or "bounce back".  So what happened was upon cycling a few times, it collapsed (as it should) but didn't bounce back upon retraction, thereby making an incomplete connection the next time (and thereafter) that I deployed.

So how did I fix it?  I crept upstairs and snipped a piece of memory foam from my wife's side of the mattress and replaced the defective foam in Part B. Problem solved! YES! 
























KIDDING!    The woman would kill me!!! 

What I actually did was redesign Part B to now have a compression spring to ensure "bounce back".  Another thing that I did was I increased the surface area of part B by wrapping it with copper wire and then soldering and filing it. This will ensure an even better connection because as anyone who has worked with these connectors before would know ... they are not designed for the application that I'm using them for. (see the hole in the middle?) They're a screw down type connector.

BTW, the base beneath the connector now is a piece of the Hitec rubber/foam protector mat that used to come with their receivers that I had lying around.  This was added to ensure that upon compression the connector and spring didn't bend/twist as it was being compressed.  In other words it keeps it straight.

Ok enough talk ... pics and video will wrap this part of the build up ... FINALLY. hee hee!

Pic #1 ... Part B ... the original
Pic #2 ... Part B ... revised parts
Pic #3 ... Part B ... compression spring insert
Pic #4 ... Part B ... revised parts assembled

Colin.



P.S Can ya see why this has taken so long now?     




http://youtu.be/WV0gyjV4E7o

[wollins]

Ok, all the is soldering is killing me!     Soon be done though.    Incidentally Ed had brought up a valid concern to me the other day. He was concerned that I'd be relying on one connector for all of these connections.  Specifically he was concerned about a scenario where the LG might hang up thereby over amping my connections and/or browning out my receiver.
However I assured him that I thought I was pretty safe because  of the following:
1. The BEC I'm using is rated for 10A/15A
2. The retracts have over current protection so as soon as they hang up they shut down ... provided no further draw on the system.
3. Supposedly ... the 8 pin connectors that I'm trying to source are rated for 15 amps per pin or a max of 60A per connector.
HOWEVER  ... despite all that I have decided that I'll go with two connectors to "spread the load" just to be safe.  So thanks ED!  This is the reason that these forums are so valuable ... its always a good feeling to know that fellow modelers are always looking out for you and are willing to help out. I'm always trying to learn something every day.  Sometimes you're so close to a build or project that you miss stuff that others may see as plain as day.
Colin

[wollins]

Wiring done! 
Colin

[sihinch]

Very nice Colin.

[Ededge2002]

The before and after photos tell it all.

Come on over tomorrow I've got more soldering to do.

[wollins]

Come on over tomorrow I've got more soldering to do.

Good luck with that my friend, I don't want to see another soldering iron for awhile.     Just did a "test wiring" vid and everything's checked out so I'm now gonna put this Typhoon aside for a week or so cause it's now ....

NOONER TIME! 


Finally I'll be opening my "bag o' bits". (see pic)  Goal is to finish by month end. (Based on my track record I'm being ambitious but hey gotta aim for something right?

Colin.


http://youtu.be/VvMujZ35ZsY