Flipper (pneumatic) VS Lifter (electric)

[billy breach]

Hi All,

I€™m building a feather and I€™m contemplating using a electric lifter, on it€¦.However I€™m tend to think a pneumatic flipper would be better.

I know my skills are limited so I€™m leaning towards an electric lifter but I€™m concerned that it will be to slow to lift (without the other robot managing to get away before I€™ve lifted it).

Can anyone advise/ give me their opinion on what is better?

Also I was looking for advice on what the electrical and mechanical mechanism would be to create an electric lifter. I€™m looking for a lifter to be as fast as possible, so any ideas on how to construct a fast electric lifter? Would a window wiper motor be any good with a metal arm fixed to it?

Any suggestions would be great

Thanks
billy

[maddox10]

Re: Flipper (pneumatic) VS Lifter (electric)

A fast lifter or slow flipper needs 1 thing from the setup. Motorpower. Volts * amps.

And you can achive that by combining the right motor with the right gearratio.

A window-wiper motor... Several problems.
1) the fuse in my car for the wipers is a 10A one. Meaning the most you can get out of such a motor is 120W.

2) overvolting is asking for a broken wormgear wheel. Most, if not all wipermotors use a hard plastic wormwheel. It can't handle overvolting nor heavy shocks.

I learned that lesson with Project I and II where the wipermotor was used as a big steering-servo-motor to control the back wheel.

[billy breach]

Re: Flipper (pneumatic) VS Lifter (electric)

so a good heavy motor and good gearing is the answer. Would it be cheaper than pneumatics or sound the same.

[maddox10]

Re: Flipper (pneumatic) VS Lifter (electric)

Heavy is a no no in a feather. But light and powerfull is most of the time equal to expensive.

On the cost. A simple RC switch and relais that are strong enough to control the used light and powerfull motor are about equal in pricetag to a RC switch and valve setup.

Cost of gearing depends on your capability to scrounge, beg or find cheap, useable gears ,sprockets, chains, belts and assorted stuff.

In the end, the BIG advantage of using pure electric power is that you can extend the range easely by adding more amp-hours in Battery.
Something very difficult with a custom build pneumatic setup. (the bottles available come in only a few, large sizes)

[RogueTwoRobots]

Re: Flipper (pneumatic) VS Lifter (electric)

Hi Billy,

Check out this video and see what you think for the speed of an electric lifter;

http://www.youtube.com/watch?v=TnX9CZfSaz4

[billy breach]

Re: Flipper (pneumatic) VS Lifter (electric)

thanks for the input guys, thats starting to get me to think now...electric or pnuematic. That wee lifter was a lot faster than what i thought it would be...........and great idea about the threaded rod and a drill motor.

Would something like this work?

[ewan]

Re: Flipper (pneumatic) VS Lifter (electric)

You'd be better off using a threaded rod in that kind of set-up - your drawing would put large demands on the motor gearbox which most small ones couldn't handle. You can still get fast lifting speeds with a threaded rod - 'ploughbot' being a good example

[billy breach]

Re: Flipper (pneumatic) VS Lifter (electric)

what would I need to change in that set up to make it a.threaded rod idea?

[billy breach]

Re: Flipper (pneumatic) VS Lifter (electric)

Would a set up like this work then?



a drill motor linked direct to a threaded rod, which is fitted inside a tube. On the tube it has a nut welded to it in order for it to go up and down the threaded rod.

if this would work...... any ideas how to connect a drill motor to a threaded rod without welding it?

[jonny]

Re: Flipper (pneumatic) VS Lifter (electric)

turn an adapter for 3/8 unf thread 1 side and the thread for the threaded rod you want to use on the other

[billy breach]

Re: Flipper (pneumatic) VS Lifter (electric)

i see. I dont have a milling machine etc.....can anyone make and adapter for me?

[RogueTwoRobots]

Re: Flipper (pneumatic) VS Lifter (electric)

There are only a couple of ways to attach the rod to the drill motor without welding, but with the rotational forces that will be going through the connection, welding will most likely give you the strongest connection.
One alterntive is what Jonny just mentioned; have a shaft collar (basically a bit of thick-ish wall metal tube) that has one half threaded to suit the thread on the output shaft of the drill motor and the other half threaded to suit the rod. You could then put some grub screws through the wall of the collar to press down against the joints once they've been threaded, just as an extra form of security.

Another option is to keep the chuck on the drill motor and put the threaded rod into that (if it's too large in diameter, see if you can get it lathed down to a suitable size) and then tighten the chuck. This won't be strong enough on its own, but if you then dill all the way through the chuck and the threaded rod (say 5mm diameter) and then put a pin or 5mm bolt through it, it will prevent the chuck from loosening and the threaded rod from falling out.

[typhoon_driver]

Re: Flipper (pneumatic) VS Lifter (electric)

say you want to use 12mm threaded rod. Buy a small block of mild steel off ebay for next to nothing. Drill and tap an M12 hole through one side and drill and tap a 3/8unf hole the other. To make sure they line up, you could drill a pilot hole right through the block.

You don't need fancy machining centers to make parts, just a bit of imagination and some basic tooling

[billy breach]

Re: Flipper (pneumatic) VS Lifter (electric)

thanks for all the help guys.....would the above design work though? and would a 12v dewalt xrp drill (running on 18v) be a better option for the lifter motor and gearbox?

[typhoon_driver]

Re: Flipper (pneumatic) VS Lifter (electric)

Should do yeah. As for the drill motor, I can't say but a standard argos 10 quid motor would be more than up to the job, anything bigger is just for boasting purposes