FW Electric hammer - Robo Challenge (no name yet)

[craig_colliass]

I think this should be an interesting robot to build, and follows the path of making featherweight versions of heavyweight icons.
the only difference this version is based on a heavyweight that didn't work properly. NOT JOHN'S FAULT I hasten to add.
The only disadvantage, this robot could only work properly on the Robo Challenge arena, as it is the only steel floored arena in the UK. I don't know are the floor panels bolted down enough? or the floor superstructure strong enough not to warp?

I hope to have a new Seraph robot for the UK champs too, that will be a sword or hammer. The difference is the ground clearance on it will be about 120mm and not less than 1.2mm

Good luck with the build Grant looking forward to fighting it soon.

[Flag Captured]

based on a heavyweight that didn't work properly.

Is this Beta? Why didn't it work properly? I've heard it about and that it was supposed to be going on Battlebots or something, but never heard anything more than that!

[psychostorm]

The steel floor panels in the battlebox weren't stuck down so Beta kept moving them. In addition, to the point that the magnets removed pretty much all the ground clearance.

[Flag Captured]

Ah yeah, I did hear about it pulling panels up... I'm guessing that put a real strain on the motors then too, with all that lack of ground clearance.
Did it ever actually fight at all?

[grant_ploughbot]

Beta has sadly never fought in battle so It's quite difficult to know how effective it is. I'm sure it would be pretty awesome though! John was told the floor was a set thickness of steel and it turn out it was much thinner in layers and so the magnets just pulled the floor fight up and stuck it so it couldn't drive!

When I started the design on this one I wanted an electric hammer and started working on designs completely different to Beta as I don't want to make a copy of another robot. I was almost set on a flywheel design using a brushless motor to spin a flywheel and a Y shaped axe shaft with hydraulic caliper's built in to clamp onto the flywheel to work as a clutch. After working things out weight wise it still appears that the cam system that Beta uses is still the best option. Funnily enough Mortis uses a very similar system effectively.

I've made a number of alterations to try and improve the design over whats currently been done, such as having a much larger change in gear ratio (varies from around 22:1 down to 5:1) to give the mag a much easier time starting up. I've also made the ae arm longer, and the swing angle far higher so that I can put more energy overall into the weapon and make use of that larger change in ratios. It means I need to go with a short and stubby hammer head to get the extra movement, but I like the way it looks.

I''ve been trying to make it as far from Beta as I can, however the facts are that the way John designed beta is the best way to do an electric axe! This is the prototype version for my brushless one, using a system of clutches for rapid direction changing etc - but that's going to take abit of work!

[Flag Captured]

Sometimes though it's difficult to deviate from the norm and be effective - in much the same way that many robots copied the general style of Chaos 2 because that was the most effective way to do a back-hinged flipper! Still, this looks like it'll be a beast of a machine once it's all finished! So many featherweights now that I really would not like to fight!
Does it actually rely on the magnets to run, or is that just for stability?

[grant_ploughbot]

When running at full power it looks like it will need about 90kg of downforce to stop it jumping off the floor. If it does jump you loose all the effective power which would be ashame. I'll test running it on 6s with no magnets and a longer tail for events without a steel floor though and see if it can still be powerful enough for what Id like

[shakesc]

After reading the Beta website there is some nice engineering that went into that bot, well beyond what I have access to. Would be nice to see something along those lines running

[grant_ploughbot]

I've spent a couple of day's working on the machine now since the gears arrived from HPC. I had a last minute change of mind and increased the MOD of the gears to 1.5 on the first stage and MOD 2 on the second as opposed to Mod 1 and 1.5 respectively. Looking at them now I think it was a good idea!

The bulkheads were just a fraction too large to fit on my mill, so Kane and Ant were able to machine these out for me from the CAD files I sent over. They've done a great job.

IMG_2326.jpg

As you can see above the main gears are mostly machined out and have keyway's in. There's some lightening holes to put on them still but that will be done tonight. Test fit of the weapon motor, gears and prototype cam's all seem a good fit.

I'm now machining the gear cover that holds the bearing for the shaft on the first stage of gearing.

IMG_2328.jpg
IMG_2330.jpg

Just completed the back face here.
IMG_2333.jpg

More to update on tomorrow

[Flag Captured]

That looks far too nice and shiny, nice work! What thickness/grade of aluminium is that? Looking at options for machining bulkheads for one of my machines soon, looks like it'll stand up to all that hammer (pun slightly intended)