Team MedBots

[Max]

Thanks, output shaft is 20mm stainless steel rod- I think I will have to support it at the far end but not sure what wheels I'm using yet so if I don't use much of the shaft then I may get away with it.

[Ellis]

Both the gearbox and ram look great, nice work!

[Max]

Just wondering, is it acceptable to have a mechanical linkage to activate the dump valve? Eg. You have to pull on a piece of wire to open the dump valve? Or pull on a lever connected with linkages?

[maddox10]

As long the dump can be activated by hand.

[Liftoff]

Just wondering, is it acceptable to have a mechanical linkage to activate the dump valve? Eg. You have to pull on a piece of wire to open the dump valve? Or pull on a lever connected with linkages?

I hope so as my dump valve is essentially a safety/pressure release valve, operated by a cable. I think it should be fine as long as I dont get my hands inside the robot or remove any access panels.

[Max]

The piston and rod weigh 700 grams- do you think that's ok?
And here's a picture:

[maddox10]

Should work fine. On the other hand, the rod is a tad narrow to my taste.

But that's my own idea.

[Max]

Thanks Mario, I'll bear that in mind.
Just before I order some batteries- how many fights should I expect at an event, assuming there are 2 shows? I'm getting SLAs so won't be able to charge them during an event.

[razerdave]

Why can't you charge them during an event?

[maddox10]

If you don't drop out due damage, expect 3 fights at least.

meaning, with your drive, @12V, 30ah+. And that's a tad on the low side.

[maddox10]

Why can't you charge them during an event?

No money for chargers I guess. Or to difficult to remove the batteries.

[Max]

The problem is as Mario says I can't afford loads of chargers to charge them all and they will take ages to charge I imagine, easier I imagine to do what the saint team does and just have a battery pack per fight. I am still considering hobbyking lipos, there a good price as long as I can charge the packs between fights as I can't afford more than one set of packs.

[Max]

Here are some pictures of the layout I'm planning:


I think it is very large but I'm not used to heavyweights! Also as it is pneumatic but not a flipper it has to be quite flat to make it invertible so it has become very large.

[maddox10]

You're planning to run the Bosch 400's @12V. That gives you 2 realistic options for LiPo. 3S or 4S. (5S is 18.5V, right in the ballpark for "overvolting", but then the gearratio is a tad low). A 8000mah pack will probably see you trough a fight.

This means you need 1 Imax B6 AC , cost, less than £50 delivered at your door. And that one can charge the 4S 8000mah pack from "safely flat to full" in less than 2 hours.

Pricetag together, a tad more than 1 45Ah gelcel or AGM SLA without charger.
Difference in weight..... huge. 1 kg compared to 12 kg.

[maddox10]

4 kg of CO2. That's 2000 liters of gas @1 bar @ roomtemperature. Your ram uses per stroke 27 liters. That means 60 strokes at least(not counting losses due liquid CO2 venting). In a 3 minute fight it's an action every 3 seconds (or 6 if it's double acting)

I would say, use only 1 main storage bottle if size is bothering you.