Andron4000 HW crusher build

[Eventorizon]

Its up to you but many robots have dual power setups. Both of our Featherweights have separate looms for the drive and weapon. For example, mine has a single 5S drive and dual 6S in series, giving 12S for the weapon. The only point they meet is at the receiver but that is only so the weapon ESC gets its signal, the RX gets power from a BEC in one of my drive ESC's.

If you are happy with 2 drivers then 2 isolated systems would be fine too, nothing against it. Many teams do this so that they can one member focusing on drive and the other focusing on the weapon. Most of the house robots probably have 2 so that they can respond faster and be more effective; imagine 1 person trying to control all of Sir K's functions! It also helps with trouble shooting and can stop electrical issues damaging other components, just make sure you label everything neatly

[Andron4000]

Hello Guys,

Does anybody know why the RobotMarketPlace is showing the NPC-T64's as discontinued? We have tried to conact them and had no reply.
We contacted NPC directly to place an order after seeing this, but were told for international orders to use the robot market place.
Since this is our only supplier for these and they are showing discontinued, we have decided to go for the T74's in case we need more in the future.

We have managed to find an all in one 24v hydraulic unit from Flowfit. They have been very helpful and have work with us and helped us figure out exactly what we need in terms of valves, gauges etc.
Mini 130 Hydraulic Power Unit

• 24Vdc 2.2kW motor c/w start solenoid
• 2.7cc/rev pump
• Pressure line check valve
• Pressure line relief valve set to 200 bar
• Cetop 2 interface fitted with 4 way 2 pos P to A & B to T then crossover directional valve 24Vdc
• 2 litre plastic reservoir
• 5 L/min @ 200bar

We are using it to run a 75mm, 200stroke cylinder which should give 8 tonnes. All of the components are rated to 240bar (apart from the pressure relief) so there may be scope to over-volt the motor and get more from the pump.

This is our electric circuit so far

CIRCUIT SCHEMATIC.JPG

In terms of the shot bolt, we did think about using a small hydraulic cylinder, but did not want to complicate the hydraulic system, so are now looking at an electric actuator.


http://www.ebay.co.uk/itm/DC24V-20mm...-/262478235663
ebay, elect actuator.jpg
This will not have to take any forces directly, as we can use it to drive a shot bolt.

[Andron4000]

False alarm!
We have had a reply from the robot market place, and the NPC T-64s are shown as discontinued as a result of a 'website error'.
They have assured us that there are plenty on hand, and no plans to discontinue.

[NKT]

If you're custom making the arms, I'd suggest having some sort of clamp to tighten the arm, rather than the shot bolt. For one, it will clamp at any point, and for two it is easily freed up after use, and for three, you won't end up struggling to reset it during the fight for a second go.

In fact, am I missing something of is it a single shot weapon?

[maddox10]

Even with 2 of those batteries in parallel, the max amp is "only" 320A.

I know that the ampflow will draw that and more if stalled.

And running 2 seperate RC setups. Why? Most of us that tried simular setups just use a buddybox.

[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

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.


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.
Capture1.JPG
Capture.JPG


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.