Weapons

I need a weapon for my bot. I want something quite simple to build that wont bankrupt me and that can dish the damage :P
Maybe a spinning bar?
If so,how would I go about making one and where do I get the supplies needed?
Ive also been told that lifters are quite easy and can be acomplished with a drill motor.I really had my heart set on a lifter but If its really hard or expensive then il forget it for the mean time.Any suggestions?
Bear in mind I dont have a welder :sad:
Thanks

If you have your heart set on a lifter then youre pretty much in luck - they arent too difficult to build - infact a spinning bar is harder (many factors to get right, such as weapon strength, secure attachment to drive mechanism, plus the fact its kinda dangerous to test it in your kitchen) whereas a lifter can be built from existing parts and can be tested anywhere safely. Two options - one would be getting hold of a car scissor jack (£5 from a breakers yard) and attaching the threaded rod to a drill. Gives plenty of strength to lift a feather and it moves at a reasonable speed as well. Other parts of the scissor jack can be used in your lifting mech as well.

The other option is an electric window mechanism (the type which has a range of teeth on them - http://www.innerauto.com/includes/images/Inner_Auto/Honda_Parts/Honda_Parts_New/Honda_Window_Reg.jpghttp://www.innerauto.com/includes/im...nda_Parts_New/ Honda_Window_Reg.jpg). These have been used successfully in several feathers (although its been a while since) and can again easily lift a 12kg bot. Theyre available again at breakers yards or even on eBay - thats where I got mine to form the srimech mechanism on one of my new feathers. You dont need the whole mech as shown in the picture either, just really the motor, the 1/4 gear part and - if you want to utilise it as part of your lifter - the long arm attached to the 1/4 gear too. The fact that these usually have the drive mechanism contained as well means theyre less likely to fall apart.

Hope that is of some help :)

Lifters are extremely easy to build, ive built one using a drill motor and the zeobot lifter mech off technobots

Jamie you have mail :)

The siccor jack method seems easiest :)
How does it lift a bot tho? Wouldent they have to drive ontop?

(Message edited by HellsPlumber on January 15, 2007)

Also,could you suggest a simple and cheap damaging weapon? Incase they can selfright or are invertable ;)

http://www.robowars.org/wikka/ElectricAxeWeaponshttp://www.robowars.org/wikka/ElectricAxeWeapons
Maybe a little heavy for a pommy robot, but its cheap and easy to build.

Thanks. :)
do those axes do alot of damage or just a dint or to?

It depends on the armour of the robots its against. Its starting to get very, very difficult to damage the new Hardox robots with any form of weapon!
It will depend alot on the shape and weight of the axe head aswell. You could even use a more powerfull motor to make the axe hit harder.

http://www.youtube.com/watch?v=BsC5gON85Uwhttp://www.youtube.com/watch?v=BsC5gON85Uw

I dont know about doing too much damage, but it deffently gets everyone on your side. And its a lot of fun.
I wouldnt want to use a bigger motor. Youll either end up with the current draw being too high or putting in too much torque and not being able to keep your robot on the ground. Lighter weapons would fix that but then you wont be doing as much damage or be as entertaining.
And Ive found that hammers do more damage then axes or picks.

Thanks guys,I diddent think that a hammer would work better than a axe :o
Can some one give an answer to my scissor jack question?I need to know how It would lift to see how it should be mounted.
Thanks everyone!

Ok, scissor jack lifting methods: :)

Obviously the shape of your robot affect how you integrate the mechanism into your bot but Ive done a couple of setups based on standard lifting shapes (excuse the crudeness of the drawings - but Im only half awake :P)

The basic setup that I would probably use is similar to this: http://i31.photobucket.com/albums/c367/ayrshirerobotics/lift_1.jpg?t=1169006215http://i31.photobucket.com/albums/c3...g?t=1169006215

The threaded rod is attached to your motor. The rod threads into the nut (which comes as part of the lifting jack mech - usually at one of the pivot ends) and the nut, which if I remember rightly has a bolt on either side of it, is bolted to the lifting arm. As the motor rotates the rod, it causes the nut to move up and since the arm is pivoting at the back, this causes the front end to rise - and you have your lifter.

Its also possible to have your lifting arm as a straight arm rather than having the angle in it:
http://i31.photobucket.com/albums/c367/ayrshirerobotics/lift_2.jpg?t=1169007350http://i31.photobucket.com/albums/c3...g?t=1169007350

This would restrict the travel a bit, but would allow you to have a more shallow robot (if your design suits it). As to the optional part in the drawing - I reckon it would work with both a pivoted point there or a fixed point, although the nature of the lifting arm would change I think (could someone clarify this?)

The third option I sketched up is the same as above except that the lifting arm pivot point has moved to the front so the lifter operates Cassius style:
http://i31.photobucket.com/albums/c367/ayrshirerobotics/lift_3.jpg?t=1169007875http://i31.photobucket.com/albums/c3...g?t=1169007875

Again travel is limited and it means you have to get the whole bot on top to stand any chance of lifting them. Although, the mechanism the zeobot uses gets far more travel from a similar setup, but I cant remember exactly what the arrangement is.

Hope that is of some help,
Jamie

That was LOADS of help,really apreciate the pics too ;)
One more question,does it require welding?

I dont know what resources you have to work with, but i will put a picture on my profile of how I have made Ploughbots lifting mechanism. Its more than powerfull enoughto lift two feathers, and its very quick (the lifter in picture uses a 12v gold motor, over volted to 24v, but i now use a high power drill style motor with gearbox)

Im on my PSP at the moment coz my PC cant access the internet.The pic wont load on my PSP so il get on a PC tomorrow and look ;)

By the way,I have saws and drills and sanders.
No welder tho :sad:
I need a cheap one but my ebay account has broke.Me and a freind want to get an electric welder with both of our money.

It is possible without a welder - I dont have one and I reckon I could get away without one for making a lifting arm.

I was looking on eBay also for welders, but I found the weight of them bumps up the price considerably; so Im looking at Machine Mart at the moment for them - they appear to have a good range for reasonable prices:

http://www.machinemart.co.uk/product_105_welders_accessories/index.asphttp://www.machinemart.co.uk/product...ries/index.asp

Guys I wouldnt worry about running out and buying power tools left right and centre.

A welder, whilst a nice toy, is only useful if you use it correctly. True I taught myself to weld but I always use a bolt to support a weld in some way as I am never 100% confident in my welding skills.

To be honest, If you have a power drill, a good set of drill bits, a set of screw drivers and something to cut with (hack saw, jigsaw, grinder etc) then you are pretty much sorted. Everything else is just a bonus.

What makes building bots interesting is seeing what you are able to do with the resources and knowledge available to you.

FYI my arc welder was £30 out of macro and has yet to fall to bits

Hmmmmm...what type of saw should I buy for cutting metal?

a metal cutting saw :)

really the best you could get is the slow torque metal chop saws with the coolant on them, they are probly the best, a normal metal chop saw works fine aswell, or probly the best and most verstile kind of saw is a grinder do angles chops saws cant do. but you could also use a hacksaw if your not lazy :)

Nothing like a quality hack saw with a bi-metal http://www.sandvik.com/Sandvik

Hard to imagine a feather part that could not be cut with a hacksaw.

Does the sciccor jack screw directly Into the drill motor?

Probably not reliably.
But that makes roboteers inventive.

The scissor jack wont screw onto a drill motor without some sort of adaption - the simplest thing I can think of is to keep the chuck for the drill motor, put the jack all the way in and tighten the chuck, then drill a hole all the way through and put a bolt or pin (or similar) through the setup to prevent the scissor jack thread from turning independantly of the motor.

EDIT: Wow, just realised the forum clock is at the right time now :)

(Message edited by K_C_R on January 21, 2007)

Thats a really good idea.Thanks!

Depending on what material the scissor jack is made of, it might be difficult or tedious (or both!) to drill all the way through it. If so, another idea might be to only drill through the chuck until you hit the jack, thread the drilled hole to take a bolt, and tighten the bolt to press against the scissor jack thread. It wouldnt 100% guarantee the jack from turning independantly but it would give maybe 80-90% resistance, which hopefully would mean that unless the jack got jammed and the drill still tried to turn, it should be effective to keep the drill and jack rotating together.

Another lifter Idea is a four bar lifter . They might be a bit difficult to build but it would be a quite effective lifter.
http://www.fightingrobots.co.uk/discus/messages/13/5336.html?1168748439http://www.fightingrobots.co.uk/disc...tml?1168748439

Yeh,the four-bar lifter is the one i wanted most.
Going takin a look it that link :)

Yeh,the four-bar lifter is the one i wanted most.
Going takin a look it that link :)

As some people know i am building a feather with a pneumatic axe.I was just wondering do you need a speed controller for your weapon?

Thanks.

Dan.

Pneumatics are operated by valves and these are operated electronically but are either on/ off.

You would use something like http://www.technobots.co.uk/acatalog..._157.htmlthese

As Kane said.... you simply switch the valve on/off via a Radio control switch.

Speed maybe set by adding restrictors to one or both exhaust ports of your valve.

Note:- You will not be able to vary the ram speed whilst driving.

Would a pico switch do this?(Off gimson robotics.)

Thanks.

Dan.

Yes ... Ive got one on my Feather.