4 tonne @ tip Electric crusher idea

[MattLampitt]

Ok so.... scissor jacks...
changing a wheel on my van the other day, put the scissor jack under my van, took out my impact wrench with 19mm socket to drive it instead of using the crappy manual way.

This incredibly simple 18v setup lifted my van in seconds with no problem at all.
so it got me thinking... how could I use this to run a crushing weapon.
a simple leaver setup at 1:2 would give you 20cm of travel on the crushing arm at twice the force applied by the jack.
the full travel you get is roughly 40cm and it takes my drill about 4 seconds to do that.
but it's a hell of a ballache to make this work in a fixed location e.g., inside a bot.

then i saw this...
https://www.ebay.co.uk/itm/391560570218

is this the answer or at least on the way to an answer to a 4 tonne tip pressure electric crusher??

i thought I'd post here instead of just going out on a whim and trying it.
I also wish to ask about another method.... as seen here: http://www.fightingrobots.co.uk/thre...ghlight=Lifter

his method for gripping the bot is interesting. I would want to change it slightly to run a piercing weapon but Would I be able to produce much pushing power if I used my impact 18v wrench to drive it?? (Compared to the jack) It has a rpm of 1600 and torque of 440. Also I think having the impact effect would help it pierce into stuff.

so thoughts or advice anyone?

[adamclark]

or go for a hydraulic version
http://www.ebay.co.uk/itm/172241880214

[typhoon_driver]

Wow it's funny how history repeats itself.

This was a standard go to for many featherweights back in the day. The issues are simply that jacks are heavy and too large to fit into a featherweight. You would be much better designing a custom crushing mechanism using a linear actuator if you want to go electric.

[MattLampitt]

Hahah I guessed it must have been tried before or at least thought about. I did do a search but nothing came up other than using the thread to make a actuator. Which I did think about but can't imagine there would be anywhere near enough force generated.
The one in the link above weights 5kg.

[Giles]

The mechanism I used in Mantis could barely crush a cardboard box. It was mainly designed as a grabber, not a crusher. That being said, the same mechanism with a different lead screw pitch and bigger than 550 size motor could probably do something useful. It's essentially a bare bones linear actuator.

[MattLampitt]

i was thinking of a 20mm diameter piece of thread with a high thread count.. and running it directly from this: http://www.makitauk.com/products/cor...ct-wrench.html

i think the "impact" side of things would really help with penetrating stuff too as it's not so much a continuous pressure but constant hits each time. 2200per minute to be exact.

the problem I'm seeing though is for as much force this will produce it will recive back down the shaft to the gearbox which it isn't designed for..
so would maybe have to put a sprocket on the base of the thread and use the drill (also with sprocket attacked) to turn it. So the force isn't put back into the drill motor/gearbox then.

Its something I would like to test out, but really don't know what upward kg force it would produce. I think it would be a fair bit as these impact wrenches are beasts.

[Giles]

The lead screw in mine was hollowed out so that the gearbox shaft could fit inside of it. This lead to the shaft getting bent eventually by impacts. The gearbox itself didn't suffer any damage, as the lead screw sat against a bearing and nylon spacer. If the gearbox had a large enough output shaft, it might be ok, but I would recommend using an indirect approach instead of doing what I did with the direct gearbox connection.