Team Bitza

[PJ-27]

It weighs a fair amount, my guess would be around 4kgs, but I'll stick on the scales in a bit.

That's an off cut too of what he had!

My plan is to bore out the middle to 20mm, make it a lot shorter and effectively use it as a stand to hold a 20mm Silver Steel shaft that will support the wheel.
The flat top will make a nice surface for a thrust bearing and it's size will means lots of mounting options.
Although looking at the build pics of Tetanus it may be a little overkill, very conscience of weight.

[PJ-27]

Too heavy for the kitchen scales, comes up as 4kgs on the bathroom scales. 100mm dia and 180mm tall. The internal height of the car wheel is 135mm (but that could be due to change if I can't find a better way to get the weight down).

Take away wheel clearance, thickness of the base, room for a thrust bearing and I'll likely need a 100mm tall block. That'll weigh 2kgs with the centre bored out. hhhhmmmm

[PJ-27]

What I need is one of these:

http://www.ebay.co.uk/itm/3707867405...84.m1438.l2649

Although one ideally not intended for an Aston.... Anyone any idea what I would search for to find one of these 'generally'?

[plargen]

does it have to be exactly the same

or would something like this do
http://www.ebay.co.uk/itm/Ford-Atlas...item1e79570089

[Dan-27]

You've not blown another prop shaft on your Aston have you?

[PJ-27]

I wish! I want me one of these:


@Plargen No, but that could be useful otherwise though!

[PJ-27]

So the single block of Ali plan was a no go, far too heavy.

So I had a plan to create 2 x 20mm thick braces separated by 4 x M10 bolts holding a 20mm Silver Steel shaft.

We're concerned that there will be too much flex and potential twist. Thoughts?

Screen Shot 2013-07-04 at 22.56.02.png

[Max]

As long as you have good bearings there should be little twisting force between the two 'layers'. I imagine it should work as the main force acting on it is a sideways force from an impact. As I see it if you tried to push the shaft to one side it would put one of te bolts under tension, another under compression- the one under tension should be strong enough so should stop it be bending.
But obviously all this is just thinking out loud- there is no maths behind what I'm saying!

[PJ-27]

Alternative link positions on a FBS?

Other than out of the central stationary column? Ideally want it somewhere else to save weakening the shaft.

Ideas?

[Mega Masher]

Put a hole in the shell, and when the bot stops spinning then you could reach the link through that????

[PJ-27]

Too dangerous I would fear.

[Eventorizon]

Put a hole in the shell, and when the bot stops spinning then you could reach the link through that????

That is totally against the concept of a safety link. You have to be able to get at the link even if the machine is out of control. If the weapon is spinning at all, that would make it impossible.

As for a solution, the only truly safe solution is the stationary central column if you are going for a design similar to LS4. I have seen links with long cable ties attached to them that stick out on the side but they can get cut or could be pulled out mid-fight.

[Mega Masher]

Ok, I didn't know. Sorry peoples

[Max]

Bit of a crazy solution but maybe you could take your steel shaft, cut it in half along the length (leaving two semicircular sections) then stick/bolt the two halfs back together with a thin layer of insulating plastic between them. The top of the axle is open at the top, you then have a circular magnet which you drop on the top of the shaft and acts as a conductor so connects the 2 halfs of the shaft. Inside the robot you have two "brushes" like on a brushed motor pressing against either side if the shaft, this acts as your link. To activate you put the magnet in place to deactivate you just pull it off.

[PJ-27]

That is crazy!

Anyone else have issues getting 3/8UNF studding connectors to wind onto their drill shafts? I get about 2 turns and then it locks.

Seems a waste to buy a 3/8UNF tap just to sort out 2 studding connectors!