Boner

[typhoon_driver]

Ok quick update. I have since writing the above posts decided to run boner on 10s. Mainly for one reason. I was taking a look at hobby king and stumbled over these batteries

http://www.hobbyking.com/buddy.asp?code ... 27C3E15B91

Now granted the specs may be inflated but boner only ever drew the big current for a split second before settling down to a few amps on the drum. So two of these in series should do the business. If anyone happens to buy via this link you will get the same packs cheaper too.

Still in two minds about the brushless esc. I may go for an el cheapo option or stick with the castle creations and get the blown one repaired.

[PJ-27]

El cheapo all the way! Plus then you can seriously over spec at little cost.

http://www.hobbyking.com/hobbyking/stor ... ouse_.html

Was keeping that Jem to myself. Bargain!

[typhoon_driver]

No good i'm afraid, 7s max

[PJ-27]

Sorry you did say you wanted to upgrade to 10s.

[typhoon_driver]

Yup, 7s seems to be the limit for el cheapo controllers. I'm treating these batteries as an experiment. They should give a better performance than the hyperion I was using previously purely on the greater voltage but i'll need to see how they handle the power demands. I'm not overly sure on the figures they quote for discharge but time will tell.

Gonna bring both along to the champs so I can run in a few combinations should it be required.

[PJ-27]

I thought the drum was already running at a good RPM. Seems to have good bite, can throw and keeps on hitting. Why so keen for the voltage upgrade?

[typhoon_driver]

Well it's a motor that's rated for 10s as is the esc so I wanna see how the two of them run on 10s. Plus the lipo were cheap and we shall see if they give the performance they promise. A fair few good reviews of them but time will tell.

Also got my eye on another motor but again time and bank account will tell. It's something very special though

[Eventorizon]

Can I ask what motor & esc you are looking at?

I am still a little confused when it comes to Brushless motors. Simply going bigger doesn't always mean more watts or torque.

For example: an sensored In runner I am looking at is 2650KV but is 4S max, where as a HK40 is 800Kv but can go to 10S. Both ultimately end up with about the same speed; 28'860 and 29600 rpm. But the HK40 is 120g heavier, so which way round is better? Can anyone shed some light?

[typhoon_driver]

Currently I use a scorpion 4035 motor. These come in a number of KV ratings and tbh I can't remember which I have in boner as it's rubbed off. This motor is an outrunner, ie the magnets in the outer can rotate along with the shaft whilst the copper coils in the center remain static.

Inrunners as the name suggests rotate internally with the magnets sitting in the center of the motor.

For a given voltage generally an outrunner will spin slower than an inrunner. You will also get more torque from an outrunner than an inrunner (generally). These both mean that an outrunner is usually better for combat robots as they require less gearing to get a useful rpm range for a disc or drum.

The power of the motor will be given in the specification. The 4035s give around the 4 to 5hp range (same as a big magmotor!) and peak even higher.

The controller i'm using atm is a Castle Creations Phoenix Ice 2 160HV ESC. A very nice controller that has a data logging feature that means that i can download the data from the controller after the fight and see the current draw, voltage, temperature and rpm of the motor during the fight.

[Eventorizon]

Out runner it is then! We need more torque than speed most of the time.

Though I spotted a machine with HK40's for drive which was interesting. Will took them at an event in germany I think?