Mini Mulcher Design Overview: 1-lb Antweight Combat Robot
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- Опубліковано 14 бер 2020
- This video will be a design overview video for my new Antweight combat robot Mini Mulcher! Mini Mulcher is inspired by the story of the 1995 combat robot The Mulcher, a bot built for the 1995 Robot Wars in the US before Battlebots even existed. It sounds nightmarish on video and in concept. Since I was given a couple lawnmower blades for free, it was only fitting to use them as a robot weapon! They weigh a bit over 5 ounces each making them fitting if large for a 1-pound antweight robot. This design overview video is pretty long because it covers literally every aspect of the design and how I made the decisions about each of those aspects. It includes a full cost breakdown and a look at the specs for every component. This is the first in what will become a series of several tutorial style videos documenting the build and the whole process of constructing, modifying, testing, modifying again of the bot and its design.
If you're really interested in designing your own bot and building from scratch, this will be a great guide to get you started! Antweights and Beetleweights are both great for first builds as they are relatively cheap, use lots of 3D printed and off the shelf parts, and there are numerous competitions for them to fight in. This combat bot will cost under $250 to build, including more than two complete sets of parts for spares! 3 weapon motors, 5 drive motors, two batteries, four ESCs, etc.
BOM for Mini Mulcher (incl. links to every part)
bit.ly/MiniMulcherBOM
Blank BOM Template:
bit.ly/BOMTemplate
Original Mulcher Video
bit.ly/MulcherDemoVid
Team Panic RX Video
• The best rx for antwei...
Podcast Episode of Behind the Bots which everyone should listen to:
bit.ly/BehindTheBotsBlacksmith
Just 'Cuz Robotics Website: justcuzrobotics.com/
Just 'Cuz Store: justcuzrobotics.com/shop
=========== Social Media ===========
Instagram: @JustCuzRobotics
/ justcuzrobotics
@bloodsport_battlebot
/ bloodsport_battlebot
Bloodsport Facebook Page:
/ bnsrobotics
Behind The Bots Podcast FB:
/ behindthebots - Наука та технологія
This robot can actually be about $40 cheaper than I thought! If you use a $27 4-pack of SimonK 30A ESCs with BEC built in it replaces the $45 ESCs and $11 of BEC I had found. I also found a cheaper and better BEC option and discovered I'll need to use a removable link since the switches I got are way too large for the bot. All changes are reflected in the BOM.
did u ever link to the blank bow google sheets?
am i missing something.
@@ianross2352 Nope you aren't, I must have forgotten it!. This video is a year old and you're the first to ask about that haha. I just updated the description, but I'll put the same link here. bit.ly/BOMTemplate
Looks like a great time to use a herringbone gear pattern to avoid the thrust forces of a helical gear.
I might switch to that later on, but the root of the gear teeth has the same surface area for a helical gear like I have now. Herringbone is basically two half width helical gears with left hand and right hand helix stacked.
@@JustCuzRobotics Yep the left and right hand helixs thrust forces cancel each other out, instead of pushing the gears apart axially.
Which is why I used them on Draconid. Here however I expect I'll need the gears to tolerate some axial misalignment so for now at least I'll leave them as helical.
Sorry personal bugbear here. Stop using round holes to save weight a round hole generally combines max structural damage with min material removed. So think about the widest part of the circle the section at that point in going to be the failure point so any thing closer to the tip that has more cross section, triangles cut radiused triangles. Anyway good video and really nice design just no more circles ok.
Horizontal spinner type Bot, would a weapon exponential power curve setting (throttle) improve the driving control and weapon spin up for attack?
I'd probably go with the SaintSmart TPU for a combat robot body. It's a quite hard TPU.
I have been thinking of experimenting with TPU for the chassis. Sainsmart appears to sell Shore 95A TPU. There are a few cheap TPU filaments that are even harder, and the harder it is, the faster you can print as well. PRILINE TPU is like $23/kg, shore 98A. For now I'm just prototyping with PLA since it's dirt cheap though. And the wedges and forks will definitely be better if they are more rigid.
For the forks, does their range let them flip up into the blade?
Nope! They should not be able to pivot more than 30 degrees up
Team Just 'Cuz Robotics I didn’t expect a reply that fast, thanks for clearing it up. Also mind if I ask what direction the bar will be spinning? It wasn’t really clear in the video, the seemingly default direction it seemed like it was moving in the cad model was counterclockwise. Just based on lawnmower blade bar, each hit will pop the bot up. Then again I just don’t really know a lot of about robots and up they hit.
@@raspberryslush Yeah Fusion was being dumb and it defaults joint animations to a certain direction. In reality, it will spin clockwise looking down with the sharp 'downwards' edges of the blade pointing the correct way.
Was the CAD file ever available?
Not for the full robot. I never actually managed to compete with it yet and didn't want to release the design unless I knew there wasn't any sort of fatal flaw to it.
I finally competed with it and won't you know, there was a fatal flaw with it: The servo drive sucks. Already working on a thorough redesign!
Blade mounted at an angle will make it very difficult to turn the bot.
Maybe. In theory at just 5 degrees it should have less than 9% of the gyroscope forces of a vertical spinner in that sense. Guess we will see!
@@JustCuzRobotics as a 1lb FBS builder, I can tell you that even a 2 degree out of plane gyro moment on a 2 bladed weapon will cause severe mauler tendencies, especially with 2wd. it will proably be stable up to around 4k RPM
@@CamdenWallraff I expect I'll have some issues, but I think the very low speed/acceleration of the drive will make it less likely to flip out. I'm sure it'll go crazy after every hit but I'll just need to find a way of self righting.
Um... why does it look like the animation is running backwards?
The blades make no sense running that way.
Yeah... "Animate Joint" in Fusion doesn't let me pick the direction. I think I've gotten it right since then lol. This video is rather old.
Just a smidge of constructive criticism, all kindle speaking is only coming through 1 speaker. I had my right headphone in and heard "Here's what al kindle said" and then heard nothing.
Interesting... I pulled that audio clip into Audacity to cut it down instead of doing it in the video editor like everything else so I must have not noticed that either it imported or exported in mono. I'll keep an eye on that in the future.
Oh, this is all far too reasonable and sensible!
I'd much rather see a vertically-spinning lawnmower blade. True, it would only cut grass one piece at a time, but as a combat robot it'd avoid all that nasty pinball ricochet stuff that so bedevils horizontal spinners.
And then there was... Apex in Robot Wars. Remember when it exploded and trashed the arena's inner wall? Yikes! Go vertical, peeps; horizontal is bad for my nerves. ;-)
Let me know next time you see a 9 inch tall antweight robot!
@@JustCuzRobotics Is that a height restriction for the weeny weight class? Ah, well, no problem.
You could either go for a smaller diameter weapon (a chunky drum), or - and this is my preferred solution - mount the original long-bladed weapon vertically and simply raise the arena floor several inches to stay within the rules.
The physics in your universe may vary.