Team Bitza

Using the torque limiter is a good idea! I think Mike who built a lifter on here bought a dedicated one for his system.
Using 2 drills should help me share the load hopefully.

Having a bit of trouble deciding lengths for the 4 bar arms. Simulating the movement is proving tricky so thought I'd look at other 4 bar bots to see what they used.
At which point it occurred to me that I had never considered looking at Storm 2, d'oh!

So has anyone got any decent side on pictures of some 4bars with the arms up so I can deduct ratios, or better yet the actual measurements!

Cheers!

I know its a little tricky to simulate in 3d but if you have any measurments I can quickly do a few mockup animation tests in maya. Sorry I havnt read the past 12 pages but is it electric of pneumatic?

There's this, if it helps:

http://i1088.photobucket.com/albums/...2032012327.jpg

You can see the lower pivot point for the rear "leg" of the lifter glinting towards the back of the machine, at top panel height. That's the very top of an m10 bolt. You should be able to fairly accurately deduce the dimensions from that.

We designed the weapon as we did because it gave us the greatest lift height achievable in the space we had inside the machine.

Attachment 3783

Found this online years back (I think it was the Aussie forum). The sizes are specific to that robot but I seem to remember the user saying that this was the optimum ratio he'd deduced and it would be easy enough to transplant your sizes in keeping the same ratios. Although obviously you can vary it if you want more power or travel.

http://www.totalinsanity.net/tut/mec...arfrontbar.php - Finds the torque to hold a load at each point in the travel of your lifter, find the maximum and spec a bigger motor so it will actually lift things.

isnt there somthing on storm 2 in the real robots books with pics of the arm

An alternative use for our 50x100mm cylinder is a 4 bar lifter. I have been examining Ziggy, the US Superheavy weight. That makes things fly! Though the whole thing is built from Titanium and has 2 massive buffer tanks to insure a constant thrust which you cant really do in a feather but its worth a look!

Thanks for the responses everyone, a great help!

@Marco, that would be a great help thanks!
I found Biohazard to have:
Top Bar is twice the length of Front Bar
Front Bar is twice that of Rear Bar
Where they attach is a differebt matter.

It's electric. The tricky parts are designing so that the thing will lay flat (at at least ear flat) when retracted, and have decent reach when fully extended. I figured to be decent at this scale the tip of the arm should be at least 30cm from the floor and from the robot.

@Ellis, cheers! Deciding height over reach is a tricky one.

@Jamie, that's a great help. Ignoring the right angle in the front bar it's length is 210mm, so;

Top Bar 360mm
Front Bar 210mm
Rear Bar 135mm
Lower Pivot Distance 235mm
Upper Pivot Distance 160mm

@Marco, could you possible animate this?

@Daliad, that's a great tool I used a bit to calculate how much torque I would need, but it's quite buggy and difficult to set up.

@Plargen, I believe Jamie has them all online, I'll have to trawl through.

@Alex, Ziggy is something else! Have you seen it self right?