other alternatives to pneumatics

[jamietoeg]

I was browsing through previous threads about making a pneumatic featherweight flipper but after discovering the difficulty and danger I think I have decided against that idea. My next choice would be a lifter robot but I wondered if it would be possible to use some kind of motor (please give model and make) to be able tho throw opponents out of the arena without using pneumatics. I also plan to make this flipper back hinged on a relatively cheap budget.

[Eventorizon]

Have a look at the Tormenta 2 and Tormenta 3. They use a heavily geared down motor to act as a lifter to toss opponents out the ring. Tormenta 2 used a dewalt drill and gearbox combo while Tormenta 3 uses a more advanced brushless motor and a 64:1 off the shelf planetary gearbox.

Tormenta 2 build thread - http://www.fightingrobots.co.uk/thre...d-diary/page25

Tormenta 3 doesn't seem to have a build thread but there are some images of the internals floating around.

https://www.youtube.com/watch?v=y6nsj7W9LmM - Probably not the best example, but here you can see how Tormenta does a flick as it drives at the wall to try and toss opponents out.

Sewersnake/Stinger is the heavyweight machine that Tormenta 2 and 3 are based on, so look at their fights and there is also a video explaining what is inside Sewersnake. In effect its just a heavily geared down motor connected to a long arm/scoop.

[R9000]

There has been discussion recently of a spring-loaded weapon like Diotor's, that's wound back by a motor and released. Perhaps not the most reliable or easy to make, but neither are pneumatics.

[maddox10]

Electric axes are done in the past, with succes.

With the right motor/gearratio combination an electric flipper is possible

[R9000]

Maybe it's a crazy idea, but perhaps a flywheel-powered flipper could be a thing? You know, where you have an internal flywheel that's built up to speed with a brushless motor, and then you dump that energy into a flipper through some kind of clutch. It would also have a nice internal gyroscopic effect.

[Eventorizon]

Maybe it's a crazy idea, but perhaps a flywheel-powered flipper could be a thing? You know, where you have an internal flywheel that's built up to speed with a brushless motor, and then you dump that energy into a flipper through some kind of clutch. It would also have a nice internal gyroscopic effect.

Those are an absolute pig to make even for an experienced roboteer. There are only a handful of robots in the world that use that kind of system.

[R9000]

Yeah I know the energy transfer would be quite a problem with so much acceleration, the clutch and any drive train would have to be rock-solid. Plus there's a spool-up time. Which robots use them?

[jamietoeg]

Thanks for the reply. I had heavily reaserched tormenta 1 but hardly taken notice of tormenta 2. It's great to know that this idea is possible and that many have done it in the past. I'll hopefully try and take a look at some of these robots you mentioned as I think I previously seen some of sewer snake and the insides but didn't pay close attention to it. One question that I would like to ask is do you think that a cordless drill motor combined with some 6 MM chain would hold enough power to compete with some of the other flipper out there? And is it worth using 2 motors for increased power?

best regards
jamie

[R9000]

Thanks for the reply. I had heavily reaserched tormenta 1 but hardly taken notice of tormenta 2. It's great to know that this idea is possible and that many have done it in the past. I'll hopefully try and take a look at some of these robots you mentioned as I think I previously seen some of sewer snake and the insides but didn't pay close attention to it. One question that I would like to ask is do you think that a cordless drill motor combined with some 6 MM chain would hold enough power to compete with some of the other flipper out there? And is it worth using 2 motors for increased power?

best regards
jamie

I don't think a drill motor would make a flipper as much as a lifter. Two motors would definitely increase the power, but you'd have to connect them carefully so they don't run at different speeds or in different directions.

[jamietoeg]

Thanks fr the reply. Do you think that the Argos value range of motors would do it or would you go more upmarket for something like dewalts. Are chains also a good way of attaching the motors and do you know a good eBay link/store where I can buy them and sprockets?

[maddox10]

For a weapon I would look to heavier duty brushless motors.

[jamietoeg]

For a weapon I would look to heavier duty brushless motors.

Do you think that would work as you would need to constantly change the direction? Would you use a relay for this and can you suggest some of these motors and where you can find them for a price preferably lower than £30 per motor? Sorry for my limited knowledgeable of electronics.

jamie

[maddox10]

Brushless motors can't work with a relay, for those you need an dedicated ESC.

And, no, £30 won't cut the cheese

[jamietoeg]

Overall for a first robot do you think it's worth just trying to build a lifter and after I'm a bit more competent trying to u se pneumatics for my second? I know you need a special brushless esc but I'm thinking that connecting the outputs of the esc to a relay would allow you to change direction by swapping over 2 wires. What motor do you think would do it and what gearbox would you go for if I was still going for an electric flipper? Sorry for all the questions😀

[Liftoff]

I'd definitely go with an all electric robot for a first, and while a simple pneumatic setup is not that difficult to build, you would need to get more experience first, and someone with knowledge in pneumatics physically guide you.