Twinstar

[Steve W-O]

My Twinstar arrived today, now the 4th Multiplex foam model I have.

 

Main reason I bought it was to put a camera on. I have go some fairly good shots with the Mentor, but I like to have the camera facing forward, ubfortunately the prop gets in the way, and it doesn't take off very well without the prop.

 

Won't be in too much of a hurry with the build, I want to include a couple of extras, and want to get it right.

 

I want flaps and undercarriage to start with, and will include the wiring at build time to convert to brushless later. Also want to make sure there is room for a couple of gyros as a possibility, may make the photos orv video better. Still experimentign with that on the Funcub.

 

I have seen several articles on the web about flaps and undercart , wondering if anyone has had any personal experience of the mods, or any suggestions before I start?

[Steve W-O]

Did a few bits this morning, the servo wires are too short to be able to plug them into the receiver without straining connectors.

 

so cut up a couple of extensions and fitted longer wires to the servos

 

Also marked the outside of the fuselage so that I can cut openings into it if I want to use the space just behind the wings, or if I need to get to the satellite receiver. Also cut notches in the inner parts of the fuselage for the satellite receiver wire

 

[Steve W-O]

Wanted to mount the motors in the wings this morning, but not getting far, only because I can't decide what to do.

 

I wanted to use these motors, and can be mounted either for a spinner prop mount, or a protector mount

 

My biggest worry with either of these two is getting access to the motpr mounting screws, though the second one with the protector isn't as bad.

 

 

 

 

Or I could use anther pair of motors like this

Either way it will be easy to change motors if needed.

 

 

 

 

 

But, these are the two types of motor I could use

 

Both will do, but I don't have the full specs for either motor, in particular the no load current and the internal resistance, and it doesn't seem to be listed anywhere.

 

 

Or I could make a ply mounting, and not use the original ones.

 

Or, or, or.........................

 

 

Maybe I should do something else for a while

[Steve W-O]

Made up my mind, and decided to make my own mounts. There have been complaints about the stock mounts, and one of the screws on one of mine was a very loose fit/

 

 

They come out lighter than the plastic ones, and I have more confidence in them.

[TonyS]

Hi Steve, 

Watching with real interest - my kind of stuff - really like the motor mount solution.

Two of those little aerodrivers should be more than enough. Just put a 3530-1100 in my MX2 and it has bags of spare and very smooth.

Waiting eagerly to see what you do about undercarriage.. Have you thought about E-Flight electric retracts...?

T 

[Stephen Grigg]

Yes this is an interesting thread and I also like the wooden engine mounts.Its interesting also your thinking of under carriage.I bought  fresh u/c for my Mentor,but never used it.It comes complete with plastic mounts bolts,the lot.May be that might do.If you think it might,I could photograph it for you

[Steve W-O]

Undercarriage is nearly decided on. The mounting will be a ply plate inside the fuselage, and another on the outside, sitting on two pieces of tapered depron to fit the shape of the fuselage. The undercarriage itself will either be a straight across wire with 90degree bends down at the wheels, or crossed wires with springs and dampers. My main use for the twinstar will be for a camera, and I can see some fairly steep approaches into small spaces sometimes, so I'm quite keen on springs and dampers.

 

It will be taildragger, you can see here I added another snake for the tail wheel

 

Also changed the position of the satellite receiver, buried it in the side if the battery bay and put a tube in the nose for the antenna

 

Not in any hurry, would like to get it as near to good as possible first time

[Steve W-O]

Little more progress, in-between cooking, making baby formula, and the other kids homework.

Decided to replace the Multiplex motor wire with silicon wire (or at least silicon rubber insulation), and also needed to run the servo extensions for the ESC along the wing. Just cut slots in the wing, and pushed the servo wire into the slots.

 

 

 

 

Was going to be quite difficult to hold the wires in place while gluing the spar cover in place, so I tacked the wires to the spar cover with cyano first

 

 

 

 

Then I decided that Multiplex's positioning of the aileron servo cable join wasn't wise (you can see the place allowed for the plugs by the thick red wire) as once the spar cover was glued in place, there would be no way to get to the connection.

 

 

I shortened the servo wires, and will now cut away the wing for the connectors, which means if I have to replace a servo,the connectors will be accessible.

[Frank Skilbeck]

  I have mine (Mk1) as a tail dragger and have the throttles mixed with rudder, I use a V tail mixer on mine so I can have differential throttle, not needed in flight but without it on the ground its impossible to keep straight on take off. I don't have a steerable tail wheel though but the differential throttle works quite well and you wouldn't need the steerable tail wheel.

 

I have a separate servo cut into the canopy to mount my Flycam Eco on so I can rotate the camera while in flight.

 

 For Motors I'm using are two of these

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=5423 running on a 4,000 mah 3s Lipo or 2300 4s LiFe with 18A ESC and separate BEC with 7 x 4.5 props.

[Steve W-O]

Getting there at last, all done now apart from finishing the trim, then check all the linkages etc are tight and locked, and it will be ready to fly

 

The receiver harness, only two plugs for each wing, the green mps plugs here and the power cables.

 

 

 

 

The battery harness.

 

 

 

The wing wires, fairly easy to connect.

 

Next three show the trim part finished

 

 

Had it outside to test all was OK and run the motors up.