The adventures of an antweight robot building nerb

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Dazmund
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The adventures of an antweight robot building nerb

Post by Dazmund » Tue Jan 23, 2018 8:07 pm

As Mr. Garrison from South Park once said - there are no stupid questions, just stupid people.

As a long time Robot Wars fan and someone who was in a John Findlay cardboard antweight workshop, I had a bit of free time over the Christmas period to do a mock-up cardboard antweight flipper robot (within the 4-inch cube parameters). But then, after browsing the Nuts and Bots store this month and noticed the NanoTwo ESC & receiver were being sold, I ordered one along with 30mm wheels and motor mounts, there was no going back - I'm building an antweight robot for the first time, and one that is within the current rules and hopefully will be combat-ready.

Since then, I ordered a high-torque Turnigy servo, and 5 180mah LiPos with safety bag and balance charger from Hobby King, Tamiya on/off switches from Robot Shop, and a Devo 7e transmitter and two 6V 300rpm motors from eBay (the latter of which will take bloody ages to get here as its a cheap overseas order but I'm in no rush). I will also get numerous fixings from places like Leyland SDM, RS Components and Screwfix (the latter two being 5 minutes from where I live). Any other bits I need for things like soldering and cutting I can get from a friend or sort out in workshops or services in my area. The only thing I haven't got yet is chassis and armour material, though I am considering getting 1.5mm polycarbonate and some kind of metal. If push comes to shove, I may go the 3D printing route.

I've been taking advice from this forum, Alex and Rory's NanoTwo suggestions, and the antweight building video from Team Panoramic in terms of what to buy and how to put together stuff. All the internals will definitely fit in my flipper bot, which I intend to make it wedge-shaped along the lines of Eruption, Gravity, RONNY and some of the Oink bots. That said, here comes the questions...
  • My servo is the Turnigy S306G-HV, and I have no clue what to do in order to mount it to the body of the inside of a robot, nor how to attach the motor end to the flipper arm. What steps should I take in order the have it properly fastened?
  • I bought a few 3mm nuts, bolts and washers. Will they be useful in any way such as armour attachments or are they too thick? I know Alex has recommended 2mm bolts for antweights here though.
Any advice or feedback would be very welcome. When I get my bits together, I'll post a build diary and I am likely to ask more questions again!

Paulmchurd
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Re: The adventures of an antweight robot building nerb

Post by Paulmchurd » Tue Jan 23, 2018 11:05 pm

Hello,

I made a polycarbonate clamp. Thin strip over the top of servo and a screw at either end of the servo into the base of the chassis.

I’ve also used a mix of 3mm and 2mm screws. I found 3mm a little bulky when fiddling around with the inside of the robot. They seemed to get in the way. Only a tiny bit bigger, but you notice it. On my next build I’ll definatly just go for 2mm bolts.

They also weigh a small amount more.

Check out my build page. I made a wedge flipper.

Paul

Dazmund
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Re: The adventures of an antweight robot building nerb

Post by Dazmund » Wed Jan 24, 2018 12:26 am

Thanks Paul. I just checked your build. One question that I was going to ask was how one would go about hinging the flipping arm onto the main body, and you used some kind of wire or rod to do so. What's it made of and where did you get it?

Paulmchurd
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Re: The adventures of an antweight robot building nerb

Post by Paulmchurd » Wed Jan 24, 2018 7:50 am

A few people just use a bolt at either end of the robot. I used a push rod. Recommended by Peter on this forum.

https://www.ebay.co.uk/itm/CARBON-FIBRE ... 2749.l2649

Really strong.

Dazmund
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Re: The adventures of an antweight robot building nerb

Post by Dazmund » Wed Feb 07, 2018 7:19 pm

Here's my progress so far as detailed in my blog and Twitter video. Now to start thinking of body and internal construction...

https://itsaneverydaystory.wordpress.co ... ectikeant/

https://twitter.com/dazmundmonkey/statu ... 9714099200

Dazmund
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Re: The adventures of an antweight robot building nerb

Post by Dazmund » Sat Mar 24, 2018 6:54 pm

After plenty of trail and error, I have managed to cut the pieces of my polycarbonate armour and plan to put them together using Araldite epoxy and joining with screws and 1mm polycarbonate pieces. I just wanted to ask out there how do you paint polycarbonate? Acrylic? Spray paint? Specialist paint? Do I scratch up the surfaces for a more durable coat?

The whole building process has been slow due to the weather preventing me from working outside (I don't have a shed or workshop or well ventilated place to work in) and I'm getting regular work, but once the body work is put together, expect another build diary... and a couple more questions too.

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MarkR
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Re: The adventures of an antweight robot building nerb

Post by MarkR » Sun Mar 25, 2018 5:29 pm

You can also bend PC quite easily at room temperature or with moderate heat (I think). I am currently trying with 1mm polystyrene (the non-expanded variety) which seems quite amenable to bending with a carefully constructed (timber) jig and hot air gun.

I also use 2mm bolts and nuts, they are fiddly but effective.

You might be able to weld some of these plastics using the pipe welding compound available from DIY and plumbing shops. That's normally used for (Polypropylene?) waste pipes. Pipe weld isn't kept on the shelves, but is generally an "under the counter" product which you have to ask for.
Robot: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?

Dazmund
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Re: The adventures of an antweight robot building nerb

Post by Dazmund » Tue Mar 27, 2018 8:52 pm

While I'm sticking with 2mm nuts and bolts to hold things together, as well as the epoxy bonding (along with super glue to temporarily hold things in place), is it possible to weld/melt polycarbonate together using a soldering iron? I just bought cone tips for mine for precise jobs.

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MarkR
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Re: The adventures of an antweight robot building nerb

Post by MarkR » Tue Mar 27, 2018 9:20 pm

I haven't tried a soldering iron. To be honest, I doubt it, soldering irons are too hot and too localised for that kind of thing... but if you manage, do please post the results.

More likely would be a "soldering rework station" hot air gun, which can apply extremely hot air to a very localised area. But it's very easy to get it wrong and turn the whole piece into a gooey mess.
Robot: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?

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Rapidrory
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Re: The adventures of an antweight robot building nerb

Post by Rapidrory » Tue Mar 27, 2018 11:00 pm

Heating polycarb makes it quite brittle. I always just cold fold and bolt together chassis. Superglue works for a while, but eats the polycarb and it will fail after a few months.
Rory Mangles - Team Nuts

Robots: Nuts 2 and many more...

NanoTwo Motor Controllers: https://nutsandbots.co.uk/product/nanotwodualesc

Dazmund
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Re: The adventures of an antweight robot building nerb

Post by Dazmund » Wed Apr 04, 2018 4:45 pm

Well, it took a while, but I finally had time over the past week to finish up my robot. I didn't bother with epoxy in the end and used glue and double-sided tape to hold panels into place while I bolted them on. It's wonky, over-designed for a first robot, the soldering is bad and the internals are place a little slap-dash, but for a nerb, I'm pleased with it. Yes, I called it #ProjectIkeAnt, but I have christened it "Flipper The Priest". I will do a proper picture of Father Jack underneath the weapon and peel off the front cover when I get the chance to finish it.

Image

Paulmchurd
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Re: The adventures of an antweight robot building nerb

Post by Paulmchurd » Wed Apr 04, 2018 7:14 pm

Looks awesome. Rugged and raw is the best look. If you have some spare grams maybe protect those wheels from spinners

Dazmund
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Re: The adventures of an antweight robot building nerb

Post by Dazmund » Thu Apr 05, 2018 7:31 pm

Cheers Paul. I am around 10-15 grams underweight, but I won't bother putting wheel protection for now as it has been too much of a faff to put this thing together! Too much time to make little adjustments right now and I'll have to learn to keep my front end facing my opponents. Besides, I'm not entering any events yet unless they are a little closer to London... and when I get round to building another one!

Dazmund
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Re: The adventures of an antweight robot building nerb

Post by Dazmund » Sat Aug 04, 2018 9:44 pm

It's been 4 months since I posted anything here, but Flipper the Priest was finally completed last month.

Image

After sorting out the soldering (because I didn't have the time to do it since the last post) it's now properly working, though it can be a temperamental thing - much like how Father Jack Hackett was! It's not the quickest, or has the most powerful flip, but it does the job and is still good for a first try. This, along with the Hexbug toys, make great entertainment for kids, young people and those with autism - I work with them in my regular jobs. Expect a blog post or two along with a video of Flipper the Priest real soon.

Now, my next intended robot will be fairly basic and easier to build in comparison. It'll be made with a Zumo tracked chassis, a polycarbonate front plow and will use DasMikro speed controller. I'll be looking around for tips on that ESC in this forum, and anticipate it melting upon some use...

Dazmund
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Re: The adventures of an antweight robot building nerb

Post by Dazmund » Wed Aug 29, 2018 1:49 pm

I've got the parts for building my next robot called Watta Doze, and it's simply a Pololu Zumo track-bot chassis with a static polycarbonate scoop. It should be a lot easier to put together than Flipper the Priest. I've got a transmitter and receiver (GoolRC TG3 3-channel), a 180mAh LiPo, 2 300rpm 6V motors... and a DasMikro 2s6a dual speed controller with mixing.

Now I'm once again going to need some help, especially since my soldering is so gammy at best and the last speed controller I used was the NanoTwo. I've got an idea of how to connect the motor and battery wires, but the terminals meant for the Futaba connectors for the receiver I have absolutely no clue about that. If there's anyone nice enough out there to give instructions or diagrams on how to hook those up, I'd be grateful!

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