Featherweight Discs

[jamesb]

Featherweight Discs

Tantrum managed to have a huge weapon and fast drive, but controllable at high speed on both weapon and drive, nope, one or the other Im afraid, once the disk is up to full you must drive slow.

As for spinup time, youll find Ewan that if you are a spinner, every other feather comes straight for you to stop you spinning up, if you can avoid 1, the others will get you. You need to say not more than 3 seconds to a damaging speed, 4 to 5 max for full speed.

Eds putting a LEM in?
sucka fruckin rick rastardly.....
(trantslates to doh!)

[ewan]

Featherweight Discs

a) the motors run at 1100rpm when overvolted on 150mm wheels, this= 19.3mph or so, near enough to 20mph.
b) I simply said ed is the best roboteer ever on one condition, and that is that he can put a lem in a feather at 24v or over and still provide the power, dont think he can though
c) I think I may have to work on disc speed, the speed Im aiming for is above 3000rpm, but that means I need a BIG motor for enough torque.
Cheers, Ewan

[blazerbotics]

Featherweight Discs

no dis-respect to ed, put ed manages to create these high power robots (vortex, storm 2 etc) by having the money to pay for it. Why bodge when you can have to profesionally made? Most of us dont have the money, therefore have to bodge!

As far as i know the LEM spinner is just a rumour, I cant see it possible. How do you get a 3Kg motor, strong enough supports, batteries that can last a fight, and supply the current required and then have someway of controling it; all into 12kg? I personally dont see it possible, but hey, prove me wrong!

[ewan]

Featherweight Discs

Just to ask but will the 1500rpm rule come into play at all?
Cheers, Ewan

[Mouldy]

Featherweight Discs

Im looking forward to see a feather with a big disc motor inside rip itself apart. After a while im sure this rumored robot will do so if it hit an unmovable object on full power after a bolt or 2 were to shake loose......

regards
Dave moulds
Team Turbine

[spinnerboy]

Featherweight Discs

Unless of course the builder has half a clue and builds a good bot...

[Mouldy]

Featherweight Discs

Its Ed... think of your own ending to this sentance :P

regards
Dave moulds
Team Turbine

[fwsorg]

Featherweight Discs

And Ed has quite a bit more than half a clue when it comes to spinning featherweights. As for big batteries, not really hugely necessary as the lem wont draw a huge amount once the disc is up to speed- a really efficient big motor like that will probably only need of the order of 5A once the disc is up to speed. Remember that (and this is fairly over simplified) if his disc has, say, a theoretical kinetic energy of 2kJ at its intended speed, and the lem is something around 3kW power, that means its 3 thousand joules per second, and the disc will only need 2 thousand joules of energy put into it. So youve got a motor providing 3000 joules per second trying to give 2 thousand joules of energy into a disc- so the disc will spin up very quickly. Once the disk is up at full speed, only frictional losses will dissipate its energy when its just spinning, so the LEM really has only to keep it topped up with enery- not a partiularly arduous task, so the lem wont be using that much power at all, therefore little current. The only 2 big factors I can see being a pain are simply the fact that LEMs are heavy by featherweight standards, and of course it has to be built stong enough to take the rather massive knocks, but in terms of batteries, they only have to be able to cope with the spin up. Once the disc is cruising, there shouldnt be a huge problem.

[geoff]

Featherweight Discs

Well!
I have Just read through this thread and all I can say is we are all in the seriously deep poo if Ed gets this LEM powered spinner of his up and running.
I speak from 1st hand experience of building LEM powered spinners for heavyweights and that LEM130 is one SERIOUS motor! We use one to drive the disc on our heavy and it is a killer, (If you need evidence, ask Stu, He has seen it used in anger!) Now, if you put that sort of power into a feather the only problem I see is how the hell are you going to hold it down. If we assume that the motor weighs around 3.25Kg add say 3Kg for a disc plus 24V worth of battries, 1.3Kg in NmHI or 2Kg for Ni-Cad, then you need a drive system of some discription, maybe another 2Kg Thats around 9.5Kg, leaving 2.5Kg for a chassis capable of holding the impact from the disc and some armour (that last bit is hard enough in a heavy, let alone a feather!) Good luck Ed, I would love to see it!
Ewan, yes its possable to build a feather with a powerful, nimble and quick drive train plus a very respectable 4500 RPM 2.5 Kg vertical disc, we have! Mind you, to get it to drive anywhere near as good as we wanted took 4 years of heavyweight building experence and a top of the line programable Vantec speed controller! (Sorry, that makes an H5 look like a toy!) Even then we still have problems sometimes making tight turns with the disc at full chat due to the giroscopic effect. The whole machine can tip over at about 45 degrees before slowly comming back down! (you canna change the laws of physics Jim!!) The point Im to make here is that spinners be they heavy or feather weight are not as easy to get right as some people think, even a featherweight one can be leathal and I do mean LEATHAL if not properly built. I Have been in a workshop with a heavyweight robot when a blade weighing only about 1/2KG parted company with a disc spinning at 5000 RPM Fortunatly it landed inside the robot but the damage was horrendus and I was scared s**tless! So, to all you guys out there, keep building those spinners but PLEASE, PLEASE be careful and if in any doubt get it checked by someone who knows what they are looking at!

I wish everyone a very Happy New Year and productive but above all SAFE roboteering,
Geoff,
Team Scorpion.

[tim_jones]

Featherweight Discs

Ok its time to put the cat among the pigeons.

When considering the rate of improvement in feathers, it is possible to envisage a need for 2 classes at some point in the future.

How about

Class 1. The bodgers
Class 2. The machine toolist/ contract the work out brigade.

Regards

Tim

[storm]

Featherweight Discs

Sorry, that makes an H5 look like a toy!

Actually the H5 runs rings around a Vantec in terms of handling - what do you think is at the heart of Storm II, H5 technology

Having used Vantecs for all our previous robots, H5 knocks the spots off it !



Ed
http://www.stormrobot.comhttp://www.stormrobot.com

[geoff]

Featherweight Discs

Ok Ed, maybe that statment was a bit strong, sorry. But I like my Vantec!
In the interests of a fair comparison, please may I be really cheeky and ask if I can have a little drive of Storm II at some point?
That said, sorry Ed, but I still cant quite see how you are going to get that LEM in a feather!! But I admit I will be seriously impressed (and worried!)if you do!
Geoff.

[storm]

Featherweight Discs

There seem to be all sorts of rumors circulating regaring what were up to Geoff !

Suffice to say that I do have a spare LEM and nothing to do with it..... and I do have a CAD model of a LEM powered feather spinner though.

Ed
http://www.stormrobot.comhttp://www.stormrobot.com

[robotwars]

Featherweight Discs

im not scared..... ill fight anything !!!!!! you know me

My 160kw Truck motor powered at 8 million volts new feather will take anything on, yes its 12kg aswell.
And runs upside down, and is made of plactic, and also is painted pink.

CCCOOOMMMMMEEEE OOOONNNNN !

jonno

[spinnerboy]

Featherweight Discs

go jonno u big brave man u..