Spiderbot

[craig_colliass]

Re: Spiderbot

Hi Alan

I like the walking action of this type of robot too it dose look like a spider.

It's not as efficient as the pilgrim design, as the robot tends to bounce up and down as it walks (this uses a lot of the available energy and why I'm trying to loose weight). with the pilgrim design this problem is reduced to a minimum.

Also with the sets of legs so close together they tend to get tangled when you turn. one reason Pilgrim has the legs equidistant.

Hi Archie

With regard to the Sidewinder this came with the robot so I am putting it in to start with. the motors are only 240w 24v, so a Sidewinder is a little over kill.

In Pilgrim I used the Dimension Sabertooth 2X25 with the same setup and the controller never even gets warm. I may go with a small Wotty 100 I have and see how that dose in the robot.

I did get the robot moving yestarday but only on 12v.

[archie2000]

Re: Spiderbot

OK hope you put it to good use

[craig_colliass]

Re: Spiderbot

I was trying to leave as much of the robot as I could untouched.
But the spacer arrangement with its carnival colours was just too much for me.
I have decided to re-do them as they made the legs a little too loose for my liking anyway.




For some reason the 12mm nuts on the robot had been cut across the flats. I could not see any advantage to this so they were changed.




A picture of the side with all the legs removed the crank and the con-rods are a welded unit so there is nothing to be done with these.
They were replaced very recently and are in very good condition.




The start of the new spacer bushes




You can see they have a recess cut in one side to accommodate a hose clip,
these are being used as a retaining clip so I can adjust clearances.
The old method was a plastic collar with a retaining screw.

[craig_colliass]

Re: Spiderbot

Got feed up of making lots of bushes so for a change I turned my eye to the chassis on Spiderbot.
It is made from two lengths of thick walled steel box section and some heavy gauge aluminium angle about 50mm I think!
Anyway the Old chassis weighed in at a massive 4.77Kg and seemed to be made for a fighting robot rather than a walker.



The new chassis is all aluminium with the heavy gauge aluminium angle replaced with something more suited for the task. the box sections on the old chassis have been replaced by aluminium channel fabricated for the task with the ends folded up to produce leg plate mountings to support the sides of the robot better. also Fitting an aluminium plate for the batteries.

All this weighed in at a respectable 1.87Kg



Also an electronics tray has been made to fit over the drive motors.







I haven't sorted out how to fix it yet but I am sure something will come to me.

Also a picture of the Chassis dummied in place with some batteries showing how the mountings should work.



Hope you found this interesting or informative.

Craig

[archie2000]

Re: Spiderbot

do fw walkers have extra weight allowance?
those are quite big drive motors

[psycho_fling]

Re: Spiderbot

this isnt a fighting robot project purely and engineering and fun exploit ....or so i believe

[archie2000]

Re: Spiderbot

if it has a party piece it can be like skelletron and entertain the crowd.

[craig_colliass]

Re: Spiderbot

That is right this is just an entertainment machine, not for the arena. I have Pilgrim as well, the idea is we can have a race, tug of war or some other competition between them.

I am looking at building a feather walker (this can be 26Kg double the normal limit.)

No walker combat machine has ever won any competition. I can only think of one fight a walker has won that was on Robot Wars a few years ago.

The reason is even with the weight advantage, they are by definition too complex and unreliable.

If you can fix this problem, they are too slow to make an effective combat platform.

you fix those two problems and you find the manoeuvrability is to unresponsive.

You fix that and you have a competitive walker that cost ten times as much as an equivalent wheeled machine.

That's what makes it interesting.

[archie2000]

Re: Spiderbot

26kg!
that's loads
maybe I should do that've
but when you see bots like drumroll 2 they just wouldn't be the same.
but a bot like ls4 dosent need ti be fast

[Leonardomayo]

Re: Spiderbot

That is right this is just an entertainment machine, not for the arena. I have Pilgrim as well, the idea is we can have a race, tug of war or some other competition between them.

I am looking at building a feather walker (this can be 26Kg double the normal limit.)

No walker combat machine has ever won any competition. I can only think of one fight a walker has won that was on Robot Wars a few years ago.

The reason is even with the weight advantage, they are by definition too complex and unreliable.

If you can fix this problem, they are too slow to make an effective combat platform.

you fix those two problems and you find the manoeuvrability is to unresponsive.

You fix that and you have a competitive walker that cost ten times as much as an equivalent wheeled machine.

That's what makes it interesting.

On the robot wars point, Jim Struts won the reserve rumble in series 2, Miss Struts won it's only battle in a fight with another walker in series 3, the other walker didn't move much bar spinning around. Clawed hopper won against Twister in series 5, the first robot to do so in the main competition. Drillzilla got to the final of the second world championship, and the German and Dutch robots Angsar and Scarab had limited success in other events, but i'm not sure if you count those because they are shufflebots. Then there was Anarchy in series 6 that got to the heat final, losing to Tornado. So there has been limited success. :P

Anyway, would Spiderbot satisfy the rules for walkers?

[craig_colliass]

Re: Spiderbot

Thanks for the potted history of walking robots round the world

Anarchy was the only one I knew about, but I hoped someone would fill in the gaps if I pushed the right buttons.

With regard to the question would it qualify as a walker, here is an extract from the rules.

2.2 Legged Robots
Legged Robots [Walkers] can weigh up to twice the specified weight in all classes. A walker must employ
moveable legs to support its weight. Each leg must have at least 2 axis€Ÿ of motion. Robots with rolling or
sliding mechanisms will not be classified as walkers.

Lets take a vote! :shock:

[mattsdragons]

Re: Spiderbot

In theory then a FW walker could be 27.2kg?

[craig_colliass]

Re: Spiderbot

This is true 27.2Kg is the limit for a walker feather.
But I always aim for 13Kg for a feather, as I find I always go over anyway. Or I find I need to modify something after the first few battles this then gives me weight to do that.
So I would say the best method for making a robot is to work out how small you can make it with all the stuff you need then work from there.

But yes 27.2Kg is the maximum weight

[craig_colliass]

Re: Spiderbot

Just weighed Spiderbot. with no batteries and most of the covers etc. it comes in at 35Kg, so I would expect the total weight finished to be between 50-60Kg.
So not bad

[craig_colliass]

Re: Spiderbot

Doing a little more on the leg rebuild, this means lots of bushes had
to be made to space everything out also modified the links these
are the ones that connect to the crank con rods and the lower swivel.




You can see the link now has a spacer fitted between the two link
plates this had stiffened the sideways play on the legs quite a lot.
One of the targets I set myself with the leg rebuild.



Now putting the legs back together again the problem is they all
are slightly different so the spacers have to be matched to an
individual leg dimensions.