Epic Robotics

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EpicentrE
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Epic Robotics

Post by EpicentrE » Thu Jul 05, 2012 9:35 pm

Well, since everyone else has one of these fancy threads, I wanted one too!

Firstly, hi! For those of you who don't know me, my name's Scott/EpicentrE, and I've been building ants for around 9 years now, with a few breaks along the way. I like to put a huge amount of thought into my robots, and usually spend an age refining designs over a long period of time before actually getting round to building anything. I also never like taking the simple option, meaning I quite often end up with something too complicated that doesn't perform as it should, but I enjoy that challenge. I love pushing boundries, thinking outside the box (cube?) and seeing what I can achieve within the constraints of the class.

Meet the most recent versions of my two main robots, Void and Zenith: (click for supersized versions!)

ImageImage

You can read more about them, and their previous versions, on my brand spanking new website at http://www.epicrobotics.co.uk

For those of you who know me, it's great to be back, and for those of you who don't, I look forward to meeting you. I hope to see you all at events very soon :).
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk

razerdave
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Re: Epic Robotics

Post by razerdave » Thu Jul 05, 2012 10:21 pm

Very Nice site scott :)

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Re: Epic Robotics

Post by Remote-Controlled Dave » Fri Jul 06, 2012 6:04 am

Mmmm....Zenith
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Cavecrusher
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Re: Epic Robotics

Post by Cavecrusher » Sat Jul 07, 2012 9:29 pm

Damn, I must attend a AWS again soonish. Robots are looking awesome...

EpicentrE
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Re: Epic Robotics

Post by EpicentrE » Wed Jul 25, 2012 4:04 pm

I've started work on Void 8, here are a couple of terrible quality pictures from my phone. I'm building a 'custom servo' using a Pololu HP motor and potentiometer controlled by a Baby Orangutang, which was looking quite impressive, but I was seeing how far I could push it and broke part of the printing, so I need to re-order the part before I can carry on.

ImageImage

And I've finally gotten round to ordering the parts for a new version of EP, my flea, which I've had designed for a few years now. As there's so many people building fleas I didn't want to miss out :).

Image

With a 6.6mm thick chassis and 8mm diameter wheels, I think it might qualify for the thinnest robot ever.
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk

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Re: Epic Robotics

Post by Remote-Controlled Dave » Wed Jul 25, 2012 5:24 pm

Mmm...pancake flea. Despite my "notorious hatred of 3D printing" :P they are looking awesome.
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Re: Epic Robotics

Post by razerdave » Wed Jul 25, 2012 5:48 pm

I have to ask:

Void 8 has 4 wheel drive, but the front ones are much smaller than the rear ones. What ratio are you using for the 2 to get them to run together, so the front isn't fighting the back.

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Re: Epic Robotics

Post by EpicentrE » Wed Jul 25, 2012 9:16 pm

razerdave wrote:Void 8 has 4 wheel drive, but the front ones are much smaller than the rear ones. What ratio are you using for the 2 to get them to run together, so the front isn't fighting the back.
The back motors are Pololu HP 100:1s on 37.5mm wheels, and the front motors are 30:1s on 12mm wheels. This works out to exactly 1.319m/s each on 12.6v, assuming the published figures are reasonably accurate (and I'm hoping they are)!

I worked it out using my motors spreadsheet on Google Docs, which I think I posted an age ago but has probably got lost on the forums. Anyone may use it for their own calculations if they wish :).
Last edited by EpicentrE on Wed Jul 25, 2012 9:46 pm, edited 1 time in total.
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk

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earthwormjim
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Re: Epic Robotics

Post by earthwormjim » Wed Jul 25, 2012 9:30 pm

Holy Cow,Scott!
Image

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Re: Epic Robotics

Post by Remote-Controlled Dave » Wed Jul 25, 2012 10:07 pm

Scott, does Void actually NEED a flipper? I know you're famously hold backish with the weapon, and I think you used it once at the last AWS (not including self righting). I know its a nice feature to have, but could you not do something else with the weight?
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EpicentrE
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Re: Epic Robotics

Post by EpicentrE » Wed Jul 25, 2012 10:29 pm

Dave26 wrote:Scott, does Void actually NEED a flipper? I know you're famously hold backish with the weapon, and I think you used it once at the last AWS (not including self righting). I know its a nice feature to have, but could you not do something else with the weight?
I didn't use the lifters on Void 6 or 7 very much because they didn't work very well. On 6, IIRC the lifter didn't really go high enough and because of the scoop, opponents fell off it easily. On 7, I tried a different mechanism using a slider, and again, the lifter was quite slow and didn't really go up high enough. In the CAD designs they looked fine, but they didn't really work as expected.

I've always wanted a weapon on Void, but the last couple of designs just havn't worked out so I've ended up not using it much, as you said. With trying something different on Void 8, I'm hoping to actually get a proper flipper back (rather than just a lifter), and if everything goes to plan it will actually perform triple-duty as a lifter (something pneumatics or springs can't do) and a nomme...grabber.

The design ethos I'm following with Void at the moment is focused on control. I want great control of the robot through 4wd, good quality controllers and a gyro (possibly - still working out the details of that one), and I want to be able to control the opponent, whether it's flipping them over, carefully lifting them in a certain way in order to gain an advantage, or trapping them. Void's always been intended to be a great all-rounder, so this vision fits in quite well with that.

I'll be as interested as anyone else to see how well it actually all works in the end ;).
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk

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Re: Epic Robotics

Post by EpicentrE » Thu Jun 27, 2013 10:41 pm

So as has happened to me a few times in the past, I came back to build Void after a short period, looked at the design, and realised it was terrible. So I scrapped it and started again.

Going for a slightly different body shape this time, tracks made of lego pneumatic tubing (softened and roughed up), and a 3-part mechanism that lifts, grabs, and grabs & lifts (if that makes sense), all with one servo.

Just put the Shapeways bits together today, and it's coming together nicely. Will try to post some regular updates, as it may motivate me to not leave it until the last second before the AWS!

Image
(Click for supersized version)
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk

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earthwormjim
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Re: Epic Robotics

Post by earthwormjim » Fri Jun 28, 2013 6:10 am

That looks amazing. Incredibly well thought out design.
I look forward to seeing it for real!
Image

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Re: Epic Robotics

Post by haz » Fri Jun 28, 2013 9:23 am

looks like it needs joysticks :P
Very cool though, love it!

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Re: Epic Robotics

Post by EpicentrE » Tue Jul 02, 2013 7:49 pm

So I played around with the Lego pneumatic tubing I had intended to make the tracks from, but it turned out it was more rigid than I had originally thought, and wouldn't wrap around the smaller pulleys without bowing out in a way that would've increased the ground clearance significantly. After panicking a bit, I managed to find some 4mm rubber thong (not what you're thinking - apparently it's used for making jewellery), which is much more pliable and, while still not able to perfectly wrap around the pulleys, it was much better.

I tested some different lengths of belt to see how much current the motor was drawing, and although i was able to get the belt almost completely wrapped around the pulleys, that setup was drawing almost an amp at 6v, and so I had to go to a slightly longer one, which is the one you see pictured. I also decided to drop the voltage down from my planned 3 cells to 2, as I'm a little concerned about the current draw, but I'll still get 1.3 m/s on 2 cells so it should be ok. It now draws 700-750ma on 8v, which is still high, but the motor doesn't go beyond warm even with constant running for a few minutes, so I'm hoping it'll be ok.

Image
(Click for supersized version)
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk

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