Conundrum Mk1r2 - Team Robotic Death

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

With A123's having a limited current burst i'm looking at LiPo's which can provide +200A, but what is the verdict on them and are they worth buying because I know some US competitions have started to pull them out of there larger weight classes like the 30lb's. Mainly due to venue issues like fire and large plumes of smoke which would set of a venues alarms meaning an evacuation of the building and canceling a show.

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

Quick idea of the rough spec so far..

• - 4kg Drum (we'll see)
  - Around 5hp brushless weapon motor
  - Bosch 35w's for the drive motors, rate limited
  - 3800mAh 8S 29.6V LiPo (see post above)
  - 200A Brushless ESC
  - Milled Ali & Nylon chassis

..think that's about it.

[Mouldy]

Re: Conundrum Mk1r2 - Team Robotic Death

What brushless esc you going for? and what gear ratio from what motor?

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

The motor is only a low 170Kv so with 8S it's only going to be running 5000rpm so i'll leave it at that I think. But going back to the battery issue I might go for a smaller controller as alot of these brushless motors never really reach there peak power unless you spend £££'s on a big brand like Plettenberg or Neu. The one i'm waiting for is rated 5500w but it will realistically reach 4000w if i'm lucky.

[Mouldy]

Re: Conundrum Mk1r2 - Team Robotic Death

what esc and voltage?

Id suggest running the motor below its rated voltage..

I ran my old scropion 6s motors on 6s and 2 of the 3 phase wires melted themselfs

Id suggest getting an esc rated a fair bit over what you'd expect to pull.

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

The motors max voltage is 48v, a 8S battery provides 29.6V so it will be running just over half the max rated voltage. R/C aircraft forums report a peak of 125A.

Flight Power EONX 30 8 Cell Pack

• Voltage: 29.6V
  Cont Discharge: 30C (114A)
  Burst Discharge: 60C (228A)

As parts arrive i'll have more details as at the moment untill key conponents show up I don't know if i'm going to fit them all in the weight.

[grant_ploughbot]

Re: Conundrum Mk1r2 - Team Robotic Death

The new range of Flight Power Batteries dont sound all that great from recent reports (reports of using cheaper cells). The newer Hyperion G3 cells would probably be your best bet, or the new Thunder Power 45C cells, although abit pricey.

Always get a higher capacity than you would generally use, just to make sure your dont over discharge them and and up ruining the cells. Its not dangerous, just not good for longevity at all.

Go as high a voltage as you can on the motor, I would probably look at 10cell and gear it down a fraction. Brushless dont like un nessasary loads especially on start-up, so a better gear ratio would help your motor alot i think.

[Mouldy]

Re: Conundrum Mk1r2 - Team Robotic Death

Would agree with grant Ive owned flight-power, thunder-power and Hyperion from experience id say thunder power are the best, Hyperion a close second and flight power..were pretty pants.

the new thunder-power 45c range look awesome, there pretty light as well.

8s sounds like a good plan... i don't think 10s is needed, i've been ok running on 4s until now!

If you haven't already checked out ESC's take a look at castle creations new ice line. Ive just had two ICE 160HV's arrive, i know of people using the ICE100's and from what Ive seen they seem to be the dogs, the inbuilt data logging will be very helpful as well helping to maximize your machine... but they come at a cost. but the service castle offer is second to none.

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

I've been looking at all sorts of different cells Thunder-Power 45c's would be nice but I cannot easily source a single 8S pack in the UK.

TP-3800-8SP45

• Voltage: 29.6V
  Max Continuous Current: 171A
  Max Burst Current: 342A

I had look at the Castle Creations Ice range and read some poor reports with bigger brushless motors, the 160 Hv is only rated at 160A burst not it's constant current. Also they a note that the burst current is with a 5mph air flow. So for the price your getting more tech but less spec, I cannot justify the amount of money to another decent brand of controller with the full spec.

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

Ok a drum motor has arrived but I think I under estimated the size of this thing, its a Turnigy 80-85-B and I think I may have gone alittle overboard. Looks like this motor is going onto my pile of rusting bot parts and i'll go find a sensible Scorpion motor.

[joey_picus]

Re: Conundrum Mk1r2 - Team Robotic Death

Heh :P That happens sometimes, you could always sell it to one of the other spinner guys and get some of your money back...or build something else, when I started with ants I accidentally did the opposite and ordered a motor that was too small, so I just scaled the robot I was building down to fleaweight size

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

Right i'm back on top of this, i'm going to shelf Conundrum Mk2's design with the drum and wedge and skip straight to my next idea which is a completely different concept but still using a spinning drum.

I'm still looking for a suitable battery and still welcome to suggestions it's going to be a squeeze. But if I can build around an EV Warrior and 24v BotPacks with mild success i'll be able to use this monster brushless. Not sure about gear ratio yet.

ESC i'm looking at the moment is the Jeti Spin 200, overkill maybe but i'd rather spend money on a decent one than worry about burning out a medium cost controller in battle. I can always scale down and sell on parts if needs be.

I have also sourced a nice aluminum tube for the drum. I started thinking about Hardox but I don't see any simple way of forming it into a balanced tube. The Ali tube has a 1 thick wall so I can see what weight I have left then I can mill it to suit and fit some heavy duty teeth. Again i'm welcome to suggestions to what material to use for the teeth.

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

Jeti Spin 200 is going to be dropped, other than Castle Creations Ice range what other contollers should I look at?

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

Finally decided on a weapon controller, mainly because it was a bargain. It is a Castle Creations Phoenix ICE 200. The controller was on sale on a US website I stumbled across and I got it for under £185 inc shipping from the US. Sadly it was the last one as they was having a clear out sale otherwise I would have got some spares.

Also received the Bosch 35w's, is there a brass gear mod or something for these motors to make the gearbox's more reliable?? I recall something like that. Also waiting for the Sabertooth to arrive so I can start mapping out the internals.

Most of the parts are coming together now. Only problem is i've contacted all the Thunder Power suppliers in the UK and none of them can get me the 8s pack I would like so i'm wondering if I can order it from overseas.

[robotic_ants]

Re: Conundrum Mk1r2 - Team Robotic Death

All the parts so far, just need some batteries and material to start work...