Team MedBots

[Max]

Hi,
With the champs coming up I have started my last minute panic so instead of starting lots of threads I'll put my questions here and if your lucky you may even get to see pics or even a video of my bots once I'm back from holiday!
But first the questions;
1) what rate can I charge a 12v Nicd 2200mah or 2400mah battery?
2) can I charge 2 of said battery in parallel so I can change both batteries at once between fights?
3) if I've got a 11.4 4000mah 25c lipo battery don you think I should use a 100A fuse or a 80A fuse (I'm using 2 drill motors and speed 900 replica)
Thanks :P

[PJ-27]

Re: Team MedBots

7.8.3 Fusing A fuse rated below the maximum burst discharge of the battery must be fitted.

Find out what your battery outputs and get a fuse below that.

[archie2000]

Re: Team MedBots

if the fuse blows your robots dead
make sure it's well protected.

[psycho_fling]

Re: Team MedBots

with the bateries i think you can only charge in series and that depends on if your charger can cope with that many cells

for charging i would charge between fights at maybe 2amps the higher the number the the faster the pack will charge but continous fast charging isn't good for the long term health of the battery when at home i would do a discharge charge cycle at much lower figures

[Max]

Re: Team MedBots

I've spent the last 2 days in a metal workers working on centrifuge and have just spent 4 hours trying to do the wiring this morning but still not finished, this is going to be tight or the champs and I still gt to finish of. Invictus

[Max]

Re: Team MedBots

Somebody tell me the £25 transmitter from giantcod failsafes! Do I need an external failsafe?

[maddox10]

Re: Team MedBots

Hi,
1) what rate can I charge a 12v Nicd 2200mah or 2400mah battery?

Depends on the quality of the pack. but 0.5C (1.1 or 1.2A) seems safe enough.

2) can I charge 2 of said battery in parallel so I can change both batteries at once between fights?

Preferably not. Also, with the pricetag of a charger these days, why bother?

3) if I've got a 11.4 4000mah 25c lipo battery don you think I should use a 100A fuse or a 80A fuse (I'm using 2 drill motors and speed 900 replica)
Thanks :P

4000mAh * 25= 100 000 mAh= 100A. That is what the rules say, so it seems good enough for me. Also, it would surprise me that the LiPo pack has a burst of 25C.

[RogueTwoRobots]

Re: Team MedBots

Somebody tell me the £25 transmitter from giantcod failsafes! Do I need an external failsafe?

From what I remember, it doesn't technically failsafe. It does output zero signal when you turn the transmitter off though, so you can use external failsafes. If you're using Electronize controllers, some have them built-in. If not, I'm pretty sure I've got a few failsafes with me that I'm not using so I could probably lend you any if needed.

[Max]

Re: Team MedBots

I've been trying to diagnose the problems we had at the champs, I've found that the magnets in the speed 900 replica in centrifuge had shattered, does anyone know a way I can rescue them because I can't even figure out how to open them? I called electronize and they said that most probably one of the relays has blown in my esc but said they would fix it free of charge (apart from postage) which I thought was great seeing as it came with a note when I bought it saying it would cost £20 to have them fixed! But I can't figure out what has happened to the real speed 900 in invictus. It is not spinning at all. I've checked the relay is working, there is a current going through the motor and a voltage. I guess it's burnt out but I'm not sure why can anyone confirm? Again if anyone know what I can do to mend it, it would be great as that will be £36 to replace!

Annoyingly I've realised the reason the spare motor I was given didn't fit in centrifuge was just down to the mount being put othe wrong way round so it most probably. Would have worked but I would be very limited with my steering as the relay in the electronize had broken.

Any help or advise will be greatly appreciated!

[Max]

Re: Team MedBots

On the real speed 900 the 2 terminals don't conduct between the 2 of them if you understand

[Max]

Re: Team MedBots

Started work on making a mockup of my new pneumatic flipper but it seems very large.
Here are some pics to show you the shape/size:
[attachment=1:1yhvlgju]flipper photo 1.jpg[/attachment:1yhvlgju]
[attachment=0:1yhvlgju]flipper photo 2.jpg[/attachment:1yhvlgju]

the dimensions are 550mm long, 300 wide (excluding the wheels) and 200 high.
i was thinking of making all those bulkheads out of 15mm hdpe (it wont be against spinners) or possibly having middle 2 bulkheads as wood then hdpe for the other ones; then i thought a 3mm aluminium lid.

Do you guys think thats sound ok and in the weight limit? also what do you generally think of the design?

[jonny]

Re: Team MedBots

i like the design, it's very long though. Try and make it more compact. Also i wouldn't recommend having the bottle at that angle, the liquid co2 will go to the valve (unless you have a dip tube). As regards to the bulkheads i'd just have 2 really strong bulkheads in the centre and mount everying to those, then have have thinner side armour. Ram size btw?

[Max]

Re: Team MedBots

That's a good point about the bottle angle. I'll flip it round so it's at the other angle and run a long tube back to the back. The ram is 125mm stroke, 63mm bore I think (looking at the product code on the side)

[Max]

Re: Team MedBots

I am thinking about re-building centrifuge and I thought that at the champs the bar lacked any real power or speed. I was thinking I would increase the weight of the bar ( if possible around the outside) and then changing the motor. But I wasn't sure what motor would be best out of:
Real speed 900
2 replica speed 900s
1 or depending on weight 2 car fan motors
A electric scooter motor
Or if anyone knows of any other motors which are quite cheap but powerful?

Also does anyone know the weight of a car fan motor?

[PJ-27]

Re: Team MedBots

A couple of tons.....

I dunno actually, I'd say 1.5-2kgs, they're pretty heavy but super powerful. Our 3.2kg drum could spin up to full revs on a 2:1 ratio in less than 2s, so you wouldn't need 2.

As for the el'cheapo Speed900 from eBay I use one in BitzaWood. That spinds up 1.5kgs in a couple of seconds on a 2:1 ratio so pretty pleased with that.

Just remember that cheapo ones are only rated to 12v, whereas real Speed900s can do 24v. Our fan motor happily took 25.2v.