AH-6Z Littlebird Night-Ops build project

[wgt40w]

Looking at the side profile of your 'crew' in the heli, may I suggest the base of the seats need cutting down a bit - i.e. lowering - as per this image:

http://img149.imageshack.us/img149/8973/steveah6jsmallcq4.jpg

[Zeeflyboy]

Hah, sorry... She's not going anywhere ;)

The seats are about as low as I can go (already cut them down slightly) due to various constraints in the fuselage... However the head height is actually about right I reckon - check out my pic from the side and look carefully at the panel line around the side window cut out. This is where I will be cutting the doors out up to.

Once you remove that "door" as per your photo, it actually seems they are sitting at around the right height I think?

So, in other news I just made my first model in solidworks - I redid my pan tilt design with a bit more detail and more nicely modelled. I'm sure I went about it completely the wrong way but I'm chuffed I managed to make anything at all lol... solidworks seems much more logical to me than some of the other advanced software I've tried.

This is the result (again, just go to next picture in order to see 3D view) http://www.shapeways.com/model/715017/0e7ddd4d8431d0c51266a8f2e1b38c47

The upper mount is designed specifically for this camera now and should hold it quite nicely. Total price in "black, strong and flexible" is 14 euros which is pretty reasonable.

[wgt40w]

Zeeflyboy - Yes, you are RIGHT and I am WRONG.

I agree that with the doors cut out the 'crew' will be correct.

Lovely pan & tilt system.

Are you an design engineer by profession ? 
If not I think you have missed your true vocation in life.

Keep up the great work - it's truly fascinating following your progress.

[Zeeflyboy]

Goodness no, I'm far too stupid for that....

Always enjoyed engineering at school though!

Cheers for the input by the way, right or wrong I appreciate thoughts on the build. The eurofighter was improved in several areas by chaps on forums just like this one asking questions and suggesting things.

[wgt40w]

Another crazy thought - maybe for your next project !!

Head cam Pam - yes
BUT instead of 'head' also tilting - how about making the torso tilt ?  You would only need it to move a few degrees.

[Zeeflyboy]

Wg, not sure I get what you mean? I have seen people with 3 axis head tracking that also does "roll" - is that what you mean?

I've spent today playing with solidworks again and I finally managed to make the skid lights I was trying to! The MD500 has a funny nav light location in the front of the skids, and some people just literally seem to bung an led on the end of the tube and call it a day. Not me however, I spend hours making this:



link is here http://www.shapeways.com/model/716242/md500_skid_lights_for_5mm_high_flux_led.html?key=0be663c41110f9d781a2fb49c1f95c88 and once again click next pic for a 3D view.

I designed them around these 5mm high flux LEDs, you can probably use your imagination to see how it goes together... If not the led sits in its square hole and then the cover goes over the top, wires run down into the skids through the centre channel.

[g.collins]

Your certainly getting your head around solidworks, its a great tool to have, I have seen this program in action, the demo wouldn't allow me to save or export the parts, but it looked pretty good, way to expensive for me to buy the licence to use it, Rhino was all I could afford, and that was dear enough. Lol.
Keep up the good work, its going to be a beauty.
:) G

[Zeeflyboy]

Cheers!

So, There's one thing I really hate on scale helis, and that's when you can see the mechanics inside... completely ruins the illusion for me.

I've been doing some google image searching and popped up with the AH-6X... it has some nice looking doors covering the rear area which I think I'll replicate. The rub is that the opening there is really quite handy for getting screw drivers in and accessing equipment so I think the answer is to make working doors at the back there. Looks good in flight but can be opened for maintenance access.

This pic shows the doors quite nicely and also note the skid lights - this is the style I was going for when I modelled mine.




I'm also having a re-think about the secondary camera position... I think I may make an FLIR pod as in that pic. It leaves potential in future to make a moveable pod and of course fits the theme of having a "FLIR" a bit better. I think I'll modify that design slightly though.

[Zeeflyboy]

So, had a bit of spare time this arvo and decided to get my hands dirty (and the floor). First I removed the moulded hinges and then covered the window from behind.... then painstakingly made  a spacer to fill the window space before masking the whole lot off... in hindsight this was stoopid and I should have just gone with a sheet of thin plastic on the outside... live and learn and all that! There's always the other side to do!

Anyway here it is all masked off and ready to go:





And here after 5 layers of fibreglass.






This stuff is slooooooow curing so it will need 24 hours to finish. Bit of a pain but I find it much easier to work with as there's no rush before it sets up (about 45 mins) and goes on nice and smoothly. The quicker drying stuff tends to end up a bit more lumpy in my (limited) experience.


Once it's cured I'll give it a good sand/fill/sand/fill until smooth then lastly cut to shape.

[Pooch]

Kudos to you man, you fairly rattle through these projects! I spent about 6 months building my wing FFS :laugh:

Looks like it's going to be even more impressive than the Typhoon.

[Zeeflyboy]

My aim is to be mostly done by January - so that's about 3-4 months. We'll see how that goes lol.

Cheers though - I hope this is going to be a better build than the Typhoon. I'm really going for as best I can on this one!

So I got called from standby this morning only to then find out they had changed their mind and I had a few hours before they actually needed me so I came home and did some work on the door.... leaving it out in the sun yesterday appears to have worked since it's solid as a rock now.

Here's the piece removed from the heli after a bit of preliminary sanding (window marked out for alignment purposes).




I then drew in pen around the panel lines on the heli so I could see them through the fibreglass, traced them out on the fibreglass part and cut the part out leaving a couple mm spare around the edges. I then sanded the edges back using some sand paper on a wood block to make sure the edges were nice and straight... and ended up with this:





and here it is on the heli:




It'll need a slot cutting in the bottom (it'll look just like the AH-6X door when it's done) to allow the weapons arm out plus just some general finishing polish to get it perfect, and then I'll need to do some cutting on the fuselage of course.

[Zeeflyboy]

So, a quick whizz on the 3D software again and now I've whipped up the first part of my design for the FLIR - the pod. It's designed to fit my low light camera very closely, but even so it's pretty big because the camera is on the porky side. The pod measures 6cm tall. Of course I had to chuck out the idea of the autoiris lens and just go with a standard f1.2 which is much smaller.

The wires for the camera will run out the hole on one side, into the supporting cradle then up into the fuselage. On the other side there will be a small servo at the top of the cradle (internal) with a thin piece of piano wire running down and attaching to the disc on the side of the pod. This will actuate the tilt mechanism... or at least that's the idea.

I had tried to design the servo into the pod itself but there's just not the room without making th epod bigger and that's something I wanted to avoid. I think this solution should work pretty well and give sufficient movement.

On the front there is the cut out for the lens, and I also made a small shelf around the lip so that I can cover the opening with a thin sheet of clear plastic from inside.

The mounting hard point should be fairly easy but the cradle is going to be a bit more complicated to build... we'll get there! The idea here is that it'll be fairly easy to switch camera should I wish to - just design/pop in a new cradle and pod. I may yet do a few tweaks to the design.

3D view available here (click next pic as usual) http://www.shapeways.com/model/718746/e866629c855d94e85b0c9eb1337aa6dc

[Zeeflyboy]

this is now my final (probably) FLIR cradle design. Beefed up the main mount to 12mm with thicker walls, so it should be much tougher, and also turned it into a single piece above the frame. Also added some "spacers" at the bottom where the FLIR pod mounts that I had forgotten.








I just need to do some tweaking to the FLIR pod itself and then finish off my main mount, then I can see how much it all costs together. Probably a fair bit unfortunately! I'm going to wait until my skid lights and pan/tilt get here too though so I can see how the flexible and strong polished plastic is before I decide what material to get it done in.

edit - shapeways link for 3D view (click next pic, then you can move it with your mouse) http://www.shapeways.com/model/719420/flir_cradle_v3.html?key=8eef998c887e76d4dac34f456a2b0da9

[Zeeflyboy]

Sorry for all the incremental updates... I probably should have just waited until I had finished. I'll try to behave better in future :)

Anyway, I've now finished the FLIR pod unit.

First we have the mount.... The cut out you see inside is for a 2x21x5mm bearing which should also give you a sense of scale.... the block is 30mm wide and the disc is 40mm diameter. This unit will be mounted into the front of the helicopter and fitted permanently with a bit of glass/epoxy.






Then we have the cradle... This as previously mentioned has a shelf that can accept a small servo which can then be attached to an arm on the FLIR pod axle and operate tilt. Another option is to mount a motor and a pulley system but I need to look into that a bit more... I've left enough space inside to be able to play a bit.

On the top we have the improved mounting axle which obviously gets inserted through the bearing in the above mount. Again an arm or wheel can be attached for a servo/motor operation. I've added a step which will press against the inner race of the bearing and so when tightened up it should be snug with very little play and hopefully no rubbing.








And last but not least the pod... just cleaned up a few bits and changed the axle to a straight design. I'll make end stops out of g10 as it gives me more control over tolerances and lets me play with arm length for the pod tilt.








The design is intended to allow the camera cable to run out of the pod through one of the axles and into the cradle, then the tilt servo and camera wire to run out from the cradle into the mount... from there it can get directly into the cockpit and be routed wherever needed. We'll see how all this fancy thinking actually works out when I get it printed.... fingers crossed! I'll be waiting to get my other pieces before deciding on material, and might do a few small tweaks to the design in the mean time.

[Zeeflyboy]

I decided that since my modelling skills are improving rather than make an adaptor plate, I would design an entirely new bottom bracket for the heli which fits the fuselage.

This means I can replace the plastic bottom bracket for a stronger aluminium one, with holes in the right place for the fuselage and also shelves to take the ESC (at the back) and the SPS switch (at the front, underneath).





I'm now just exploring how best to get it made lol. I fear it won't be cheap, but it seems very little I do is cheap these days :(


I also ordered a KDE adjustable motor mount to help with fitting my oversized motor, and a KDE gyro plate for the back where I will mount the FBL controller. Because I'm nuts, I also got the KDE thrusted bearing blocks while I'm at it - on my 600 Pro they help keep everything running smooth so I thought why not!

I've really been eying up the Naza-H as well... that could make me change from my skookum plans. I'll be waiting for more info on that.