After lurking on here for almost a decade, I've finally built something

[natybug]

Having spent close to half my life reading this forum, and after multiple failed attempts at starting, I finally ordered the parts to start making a bot....in March 2020. After a long wait I finally have access to my uni's maker space, and here's the result!




https://www.youtube.com/watch?v=Q-1lK79UEPU

The wiring is a mess, it's all just PLA for now, and it doesn't quite drive straight, but hey its a start. Really enjoyed making it and already having ideas for many more.

[Kyro]

nice work... whats it printed in? also do you have spares?

the flipper arm looks a bit thin if i had to nitpick, but everyone loves a 4bar

[Dazmund]

I do love 4-bar lifters and would love to make one should I ever know how to 3D print and design. Is there enough spare weight to put on more armour such as polycarbonate?

[natybug]

Thank you guys!
Currently its just 1-2mm PLA, although it was more just a prototype; any recommendations of what to print in for a combat ready version would be appreciated. No spares currently but will definitely be making/buying some soon. Now that you mention it yeah the arm could really use some bulking up, and the extra mass should help it to wiggle itself off its side better too. It currently weighs 137g, so still have some room to play with to do that and add some polycarb armour too, at least on the front wedge.

[haz]

I'm so happy to see you make something! I expect a second and third will be following on quickly - they're addictive once you're over the hurdle.

I would second most of the comments made so far, all good stuff.

Even a material that is less desirable like PLA can still be decently used. I would make sure that there is a polycarbonate "skin" over any area likely to get impacted hard. You can sort of make a thicker PLA frame with attachment points to bolt polycarbonate panels to. That way you can keep your existing geometry and increase resistance!

Love the lifter design and I hope you keep the yellow. Happy building!

[T_Y]

Ooh, 4-bar lifter! Always like seeing more of those being made.

Seconding haz's suggestion of polycarbonate panels bolted on to the chassis. This is what I do - I use PLA+ brackets and mostly polycarbonate (I like to use 1.5mm if I can spare the weight, but you could probably go thinner), and they hold up okay, I just make sure I have plenty of spare parts ready. I know that people like to use ABS or some of the more esoteric materials, but I haven't had any experience with those.

One thing to look out for is ways you can get stuck. If your sides are flat, you might get stranded on them by a control bot, you could add some curved raised section to help avoid this, or slope the sides.

Another thing that most people do is add acetate to the front of the robot to get under the opponent.

[natybug]

Alright, so taking onboard some of the advice given, I've redesigned to have bolted on polycarbonate for the front and sides, and also increased how sloped they are (currently it can barely get itself off its side with the arm, but only if I time it right with it swaying). I'm also trying having the whole front scoop be mounted to the lifter arm, giving me a bigger lifting area. I have the new base printing now, picture to come tomorrow.

[natybug]

Version 2! The silver plates are just placeholders until my polycarbonate order arrives (although honestly I'm kinda digging the silver/yellow combo)



The sides are now about 60° rather 80°, so it can't balance there anymore, although this has sacrificed the wheel covers. Not sure which is a better tradeoff but the exposed wheel should mean I can still escape getting stacked against a wall.

The "polycarbonate" sides are 1mm currently, but there's space for 2mm. The front plate is 2mm. I wanted to allow some flex in the sheets to absorb blows, but I'm not sure it's rigid enough right now. Once I have actual polycarb (and enough bolts for all of the holes) I'll see how it goes.

The lifter arm has been bulked up, doubling the thickness of the arms, but despite all these changes I've somehow shaved a gram, so I can bulk everything up a bit more. The batteries I have a fairly big too so I can look for smaller ones if I need to save weight later.

I still need to grab some acetate for the front, and tweak a few more bits, but it's really coming together now

[haz]

Looking much stronger already!

Only thing I can think to say is try and fold over the edges on the lifter plate. This makes it harder for spinners to catch and pull the panel off.