Hogster
Key Veteran
Location: Surrey, UK
| Hi all 
Having seen the number of people use front-mounts on their helis, I knew it was something I would eventually want to do with my Logo ...
Just as a refresher, this is how it was originally:
(click to enlarge)
I spent quite a while thinking up different ideas (remember, 99% think, 1% do!), and without having any CAD software to hand, sketched down my ideas on paper. To help me visualise how the final idea would look, I took a photo of the side of the heli against a white background, and printed it very faintly on paper. This gave me a basis to draw on as you can see here:
That first idea would have put too much stress on the shocks .... so, on to plan B:
This looked much more promising, so with dimensions in hand, I went to my Dad's garage and started sourcing the materials - it's such a help having everything to hand Several hours of cutting and filing produced these:
(I hadn't build the part in the last drawing at this stage)
The two pieces at the top are the main supporting arms, the next two long parts are for the battery tray, the two with rounded ends provide the pivot point for the main supporting arms, and the last two are to support one end of the shocks. All cut by hand! No CNC here  The two small round things are thrust bearings which theoretically would give me near-zero friction on the pivot point for the mount ... sadly I neglected to allow for the friction caused between the screw head against the side of the supporting arm ... ah well!  Still works ok ... just not as super-free as I hoped! The last drawing shows the joining piece which holds the two supporting arms together.
I didn't take any construction shots, so the next photos show the finished result. Basically just drilling the mounting holes, lightening holes, spraying the parts with satin black paint and screwing them all together
The camera cradle is separated from the supporting plate with a thick foam rubber pad which helps absorb vibration and also stops the camera mount from rotating horizontally.
The battery tray is surprisingly rigid! It's supported on four aluminium tubes which have lengths of M3 studding running through them. I have hot-glued the ends of two lengths of velcro to one side of the tray - to clamp the battery in place you simply insert it, pull the velcro over it and push it onto itself
Overall I'm exceptionally pleased with the mount! The shocks have variable spring-tension and hence allow the mount to support different weight cameras. In the photos above the cradle is holding my Powershot A620, but I've also test-flown the heli with my family's Panasonic NV-GS500 camcorder:
And it can support the weight just fine!
http://www.vimeo.com/784240
The beauty of the battery tray is that you can just slide the battery forward/backward depending on the weight you've got in the camera mount. With the GS500, the flight pack needs to be as far back as possible, and with the A620, as far forward as possible. The velcro allows the battery position to be changed very easily.
Improvements to be made? Well there's a bit of slop in the gears on the camera cradle at the moment which allows the cradle to rock as the helicopter flies .... I think the only way to get around this would be to use a pulley and belt system .... That or go direct-drive with the servo output directly moving the cradle. There's also a very small vibration still present, although it's considerably better than it was! I doubt it will affect photos at all, but it might manifest itself in videos ...
Also, only time will tell whether I'll miss the bright orange canopy to help with orientation at high altitude ..... still, without a canopy the motor stays a lot cooler
Oh, and I feel the foam skids and supporting legs look rather disproportionate now so I'm considering shortening them ...
Other than that, it's worked out exactly as I'd planned, and I look forward to doing more test flights with it!
Cheers for now,
David |
