Liftoff (FW) build diary

[Liftoff]

Ah recognised the Sabertooth :wink: I got the 2x60 in there, I know its not highly recommended but we've used it with no issues last November... fingers crossed!!
Yes that L shaped piece is there because I got a piece of titanium in a roughly similar shape and thought I'd use it but triangular shape would be a better bet - will re design!

Drive is still a question mark, I had tracks on it and maneuverability was top notch, the down side was the added weight and less grip. I might go the 4WD way like you said or tracks again - both are possible in the available space.
Yes the wedge shape really looks like a stealth something - keeping it as low as possible - the highest point is just 160mm!

Thanks for the encouragement hope to make it to an event in the Uk next year

[maddox10]

Hammerhead II used that decoupled setup with reasonable succes, and I based the Gravity 2-3 setup on it.

[Liftoff]

Good to hear that Mario - I'll try to look up Hammerhead II to see how it's set up.
I tend to get a bit discouraged when I start complicating things...got to find some local waterjet cutting shop to do these little bits and pieces as most will be done from titanium and that's a nightmare to cut without proper tooling - I'll post a few close ups of the lever system - if there's anything wrong please point it out, thanks

[Liftoff]

Couldn't find any close up views of Hammerhead II internals... anyway here's my setup:

My concern here is that the links come almost in a straight position, and not sure if it will be too much of a mechanical disadvantage to overcome.



Flipper up

[maddox10]

Why not using bigger wheels or a Hard drivetrain and not needing a selfrighter?

[Eventorizon]

In theory I can see that it works but in reality... I wonder about the strength of the parts and the leverage you get.

Do you have accsess to something like MD Solids. You can used that to optimise the geometry of the mechanism my messing with the lengths of all the shaft and that kind of thing.

I am not sure what an alternative method might be but I don't think this will work reliably. Sorry...

[daliad100]

You could run a cable or two to pull it up and possibly down

[Ellis]

It looks like you have plenty of space to put in some friction driven wheels on top of the drive wheels, much like Crushtacean, seen at around 1:15 - - (I believe they worked like that, if not it serves to explain this)

Just trying to think sideways. This is a really nice robot!

[craig_anto]

fantastic work, loving the cad drawings too,

[Liftoff]

Thanks for the replies guys... For drawings I'm using Sketch up, got used to it now but some times its a real pita don't have MS solids Alex, will see if its downloadable and have a try there.
Material for the levers will be 4mm thick Gr5 Titanium - I think that will be suitable for the job, the problem is geting it into shape. There's no way I can form the levers in titanium using normal hand tools, the only solution is having them waterjet cut - I'm currently looking for some local shop which could do it for me without costing an eye :|
For sure I'll make a mock-up of the system using wood or acrylic just to see if the system works at all...hate surprises!!
Wheels on top might work to retain mobility upside down but I'd need to get the thing back in upright position to be able to fight!



Been thinking about cables Jordan, its possible to do it that way - got to refresh my memory on cables and pulleys (its been a while since I last worked on a 737!) Off to the drawing board!!
Thanks for the ideas!