Andron4000 HW crusher build

[Andron4000]

We did consider a clamp arrangement, like brake pads on a car, however I think we'll struggle to resist the forces applied to the arm by the crushing hydraulic cylinder.
We are currently working on the design of the locking mechanism. We have struggled to get a fast acting shot bolt that is strong enough and think we may be better going for a ratchet mechanism.
IMG_7540.jpgIMG_7544.jpgIMG_7545.jpg

We should point out again that this is our first robot. We all have no idea and are working things out as we go along so really appreciate the feedback!
I will go and have a look at buddybox now and save an RC setup

[daveimi]

You're sketches look like mine when I'm working out how I'm gonna put a robot together lol.

[Andron4000]

They are a bit rough at the moment, we are just trying to get our ideas down so the team all agrees and are on the same page before we move to modelling.

[Andron4000]

Hello Roboteers.

Lots of progress!

We received our Hydraulic unit today from relatedfluidpower.com
Attachment 6204Attachment 6205
They have been very helpful in helping us select the right unit and configuring it to be suitable for combat.
The solenoid driven valve, mounted on top has 2 positions for forward and reverse, rather than the usual 3 with the default position being all ports blocked.
The reservoir also draws from the centre instead of the bottom, which allows the unit to deal a little better with being inverted, or operate off centre.
It should give us our 8tonnes using a 80mm bore cylinder

We have also started converting our concepts into models.

Attachment 6206 Attachment 6207
This is the wheel. The idea is we waterjet the 'jigsaw' hub out of alu, and the complimentary tread shapes out of pu or rubber.
When the pieces get damaged they can then be switched out easily.

We have elected to go for the NPC-T64s for the drive (they are currently sitting in customs!), and decided to mount the wheels on separate bearings so the gearmotor will not see any side loading.
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The next stage will be to choose a cylinder so that the weapon arm can be designed, concept shown above.
We also still have to decide on RC components and batteries/ chargers etc.

[MattLampitt]

This is very interesting... I'm making a feather and due to the rules of most tournaments not allowing high speed spinners and too many flippers everywhere I wanted to do something else. A crusher is oen of my preferred options. However I'm not convinced they have a place anymore due to hardox.... so I have a question, what tip pressure would be required to pierce hardox of maybe 3mm to 5mm,, and what material would your tip have to be to accomplish this?? Anyone know? Or done it? Lol

[Andron4000]

The yeild strength of hardox is 1000MPa, which is more than double a decent grade of mild steel.
In our practical tests, for penetrating 3mm Rhs we peaked at about 2 tonnes, and for 5mm wall peaked at about 5 tonnes.
If we assume about double penetration force for hardox? I have no idea how it would react once the leading edge of a spike/ beak is driven through.
For the spike we used EN36, as it was a good compromise between hardness and impact resistance.
It did pretty well and didnt dull too much.
In my opinion, on a feather weight hydraulics will not be effective once scaled down.
With our hydraulic system, we have taken a very long time sourcing a pump system which can provide our flowrate and pressure and be light enough. Wet it will weigh about 12.5kg and provide ~8 tonnes at the tip with 200mm stroke in 6 seconds.
I have not investigated smaller systems, but think the applications would be limited, so these may be hard to come across and expensive.
There are definatly other ways to get that much force, with gearing electric motors, lead screws, or levers and pneumatics for instance, but we certainly couldnt think of a viable way, and we tried pretty hard to stay away from hydraulics!
For a feather weight, the lead screw, like a car jack may be an idea

[Andy]

There are featherweights that have a few tonnes of force behind them, i think they're yet to fully penetrate hardox in practice though

[MattLampitt]

I was thinking mechanical yeah, I have a heavy van (Renault trafic) and was changing the tyre the other day... Put the 19mm socket in my 18v makita lxt and lifted my van with ease with the scissor jack, motor did even get warm and these things are good for 2 tonne (not sure what the drill could achieve), was thinking could get 4 at the tipp if levered 1:2

im having little play around at the moment, etc but if someone can just slap a 2or3mm hardox plate on that completely rules out my weapon I may not bother lol

[Liftoff]

Done some calculations and as Andron said, does not look promising in a feather. Using Hardox 450 with a tensile strenght of approx 140kgf/mm2, punching a hole 1mm in dia in a 5mm thick plate will require approx 1.75 tonnes, but it gets worse, you have to have a claw to pierce through, which my guess would need to be at least 10mm in cross section and getting wider the more it penetrates...the force required is progressive, so with a 10mm claw to start punching through you need at least 5 tonnes with a progressive increase in force the further you go in....

[maddox10]

With enough power you'll start deforming the opponent before penetrating.


Also, most machines ain't hardox boxes.
Hardox sides are normal, top and/or bottom, less so.