Team Eventorizon: Build Diary

[RogueTwoRobots]

I'm slightly disturbed that The Riddler's been at a couple of your wheels...

[grant_ploughbot]

I'm guessing those are the ones that melted too much from the Laser? What sort of power did you need to cut through that plastic hub?

[Eventorizon]

Why So many wheels? Spares?

Two order mess ups on my part

I'm slightly disturbed that The Riddler's been at a couple of your wheels...

Those 2 wheels are not perfectly modified. One is at a slight angle but still centred and the other is about 1mm loose.

I'm guessing those are the ones that melted too much from the Laser? What sort of power did you need to cut through that plastic hub?

I did 6 perfectly, 2 were slightly off. The uni has a 120W Laser cutter but as the material would simply melt back together if we did it in one pass I put so it would cut at 5x the speed and thus a 5th of the depth. Re just repeated the cycle until we cut all the way through. We have to turn them over as well which is tricky as the focus of the laser goes out the deeper we cut.

I am going to be modifying the rest tomorrow. So if anyone wants any unmodified ones they better say now.

[Eventorizon]

Armour Question.

Binky has the same 2mm Grade 2 Titanium that Conker 2 had. After what happened in Conker's fight against LS4 I am concerned that Binky's armour is just a massive accident waiting to happen.

We got hold of some 1.2mm Grade 5 Titanium, enough to redo the armour maybe 3 times. But I don't think its enough. Is simply doubling up the armour a good idea or should we source some thicker Ti To go round the bottom edge (Say 3mm G5)

We were planning to add a rim to the edge of the Ti base to bolt the armour to like LH3 to stiffen the whole machine up after LF3 broke our welds by tossing us through the air!

[typhoon_driver]

Thicker is always better and single piece over layered. Put some 8mm HDPE on the outside of the ti and it will absorb a lot of the impacts.

[Eventorizon]

Finally had a little time to assemble my Banebots motors.
2013-06-28 13.35.31.jpg
Oddly I came across 2 problems.
In one motor the plastic fan is not perpedicular to the shaft so it feeps rubbing on the magnets but I am sure that will wear in with time. (I have tried moving it with a screw driver and it hasn't made a difference.)
The other issues is that one of the gearbox's was supplied with the wrong MOD gear for the gearbox's I am using, so I will have to get on to BB and discuss that.

[Eventorizon]

Hardox for the Weapon and armour arrived while I was away. 4mm Hardox 500 for the armour and 20mm Hardox 500 for the weapon. Still on the list is a sheet of 3mm Titanium (Grade 5 or above), 20mm Aluminium for the bulkheads and weapon mount (2014, 7075 or Alumec) and then various diameters of Titanium bar for supports and shafts.

[Eventorizon]

Made some progress today now that I have an income.

Ordered all my RS parts today totalling around £130. Thats all the belts, pulleys and bearings for the drive and weapon.

Also bought a sheet of 0.140 inch (3.556mm) Grade 5 Titanium off ebay. Annoying its coming from Israel so that will be £76 including import tax.

This goes alongside the Hardox, the ESC's drive motors, wheels, hubs, batteries, and receiver.

All that is missing is the Aluminium for the Bulkheads, the Weapon motor and the weapon ESC!

And I am now onto version 3.14.2. 200mm wide weapon, 25% more force than 720 (In theory) and 13kg in CAD.

[Andy]

All sounds brilliant goodluck with the build

[Eventorizon]

Got quite a few interesting bits of news...

Firstly David W is selling us Hells Angel which will give us a chance to have our first look at pneumatics. Spinners are all well and good but in the end they are just a big motor and a lump of metal so it will be fun to get on with something a little trickier.

The current plan is to re purpose the chassis, reconfigure the internal layout to make it smaller (David has said this is possible) and then build a nice new chassis with some better armour. This machine wont be for competitions but give us something that is interesting for audiences to watch at live events and heavyweight meets.

Secondly we have taken a stock check of everything we have... and it is a lot. We have enough electronics to build 2 whole machines so we will be building a second whiteboard machine, either pneumatic or with a linear actuator, so that we can both rumble at the heavyweight events.

Thirdly, as beetles are definitely on the up I have concepted not only a few beetle machines but a beetle arena...

Beetle Arena 01.jpg Beetle Bar Spinner.jpg

[Conker 2 & 3 are in there for scale along with the beetle concept]

The arena is around 400kg when built and is 2m x 2m x 1m with 10mm Polycarbonate on every side and a 4mm thick steel floor. Finally there is a 200mm tall 4mm thick kickboard round the edge and a door at either side of the arena. The arena would actually serve as both a Beetle arena but also as a featherweight testing and demonstration area. In the same way you can demo/test a single heavyweight in the RoboChallange arena you could demo/test a single feather in the Beetle arena. There are currently no rules about this and I feel that it is something that aught to be talked about and decided upon.

As for the beetle machine we are going with the 1.5kg limit to match Iron Conkers so this machine has a 3mm Grade 5 Ti base, 1.2mm Grade 5 armour and is fitted with a 100g bar. Doesn't sound much but inside are 3 3S 1000mAh lipos. Two in series, giving 22.2V, power a HK-2520-1360Kv brushless motor which directly drives the bar. So, in theory, the bar will do 30'000 RPM. I doubt that we would ever go anywhere near that, mainly because of engagement, but its nice to know its possible.

[razerdave]

Those batteries, in my opinion, will not be enough. I know other spinners with the same size and they are not man enough to handle weapon and drive at the same time. You have the voltage in there, but I fear, not the capacity.

[Ellis]

You can easily get the 630w that that Scorpion produces at 4s, and even 3s with a little bit of searching. 6s seems completely unnecessary.

This, at 4s, produces over a horsepower and with 1.5:1 at that voltage would spin a 100g bar to ridiculous rpm in no time. I'd expect it to do it at a 1:1 ratio and just 3s, too. You could buy four and have enough left over for a spare set of pulleys for the price of one of those Scorpions. Of course, NTM motors don't represent the epitome of quality, but they're very easy to work with, and as I say you could have spares galore. Epoxy on the magnets wouldn't be a bad idea, but otherwise it should last the robot's lifetime just as well as the Scorp, for much less money, you claw back some weight, and it drops the need for at least one lipo.

If it weighs just 100g I'd run 3s, making life even lighter and easier.

Edit: Forgot the link lol: http://www.hobbyking.com/hobbyking/s...rehouse_.htmll

[Eventorizon]

Ah, you have all beaten me to it.

That beetle setup is just plain stupid I have now decided. No idea what I will change it to but something that isn't so... stupid.

[Eventorizon]

Not strictly about robots but defiantly linked...

I am now half way through Axminster's 5 Day Engineering course and things are looking good!

They have had us making parts with as many different techniques on them as possible and using as many different tools as possible.

2013-10-23 16.37.48.jpg

Right to left: Centre Punch (Untempered), V joint cutter missing its 5 cutting tips (machined them now but no pic), bar with 2mm Left hand thread, 2mm Right hand thread, 2mm double start thread and M16 thread with matching bolt (Very happy with the M16, no back lash what so ever!)

The last 3 parts are for a small grinding tool for finishing shafts and threads.

I have also taken the opportunity to get some help with Binky.

2013-10-23 13.39.02.jpg

The front scoops have just been cut off with a band saw but with their supervision I will be making a piece to fill in the gaps, making the front dead flat, which will be welded in before we face of the front with a mill to get a flat surface.

They also have the tools to modify Binky's disc. The 3 inner spikes will be cut off and ground back and then 1-2mm will be taken off the inner spokes on either side. If there is time about 3-44mm will be taken off the inside of the main ring on both sides. The aim is to reduce the weight to 3kg from 3.6kg. The weapon will still retain a very high inertia but will spin up faster and give us the 600g we need elsewhere.

They have also suggested some ways of restoring Binky's teeth. The best one seems to be using something similar to stick welding to build up a hard deposit on the teeth which can then be ground down.

[Eventorizon]

Since the champs has now been announced I thought I would be the first to announce the progress of this years machines...

Binky is defiantly going to be making the list. After a mix of small issues last year she should be considerably better this time around. Most of the changes have been to the chassis and armour. The front armour and bulkheads have been reshaped to expose the disc so that we now don't have to get robots up onto the old front blade to hit them. To go with this the base has been stiffened with some triangles just in front of the wheels. The armour has been bent back into shape and has been rewelded on the outside with welds on every seam now on the inside too.

The reason for all this structural modification is to stiffen up the chassis. In the immediate aftermath of the first melee we had believed that 720 had bent our base plate so out wheels touched the ground. After reviewing all the angles we concluded that it was actually the rough landing from Little Flipper that had done us in. The landing was so hard that we snapped a major weld on the armour which was keeping everything flat and square. With this rigidity gone the 2mm Grade 2 Ti simply flex and and allowed the centre of the machine to ground out. 720 shoved us onto a join in the floor and that was all it took for us to be counted out.

The electronics remain the same as well as the drive system. The only changes are to the motor mounts which have been reprinted to interoperate brackets that hold the motors in place as well as mounts that hold the TZ85's away from the front of the machine.

Conker 3 on the other hand is just a pile of bits.

The Hardox and Titanium for the armour have been done for some time. The bulkheads are away being machined and should be back by the end of next week. The weapon should be back any day now from being cut too. Motor, batteries, esc's and the other electronic parts are all ready to go in. Parts that are missing are the Titanium bars for the top and front wheel mounts.

There will also be some experimental parts on the machine. The internal mounting for the batteries, ESC's and other parts will be 3D printed in ABS. This will not only be very lightweight but allow for compact and safe spacing of components. This will also include motor supports for the Banebots gearbox's so they don't get damaged.

But the biggest gamble will be the 3D printed HTD timing pulley and wheel mount units. Again printed in ABS, they will be printed with 100% fill and provide a much lighter and compact method of mounting the wheels. The rear mounts will have a central Keyway printed straight onto them to match the shaft of the Banebots gearbox's while the front will have recesses to take needle roller bearings.

Depending on what happens in testing I may have to include metal pins that run through the wheel units as the laying method of FDM modelling will leave them susceptible to sheering. The pins will help take the loadings that will be put on the in combat.

The final note is that Conker 3 will actually be underpowered. It will fight this year on 4S for drive and 10S for the weapon rather than 5S and 12S. This is simply because we would rather reuse the batteries we have which are lighter and then mess around for next year with the more powerful system when we know how the machine performs.

If you have reached this point... Thanks for reading :-D and see you at the champs!