T_Y's Build Log

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T_Y
Posts: 141
Joined: Thu Mar 15, 2018 12:51 am
Location: York

Re: T_Y's Build Log

Post by T_Y »

It's been a while since I've updated this blog, so let me talk about what I've been up to in the past year.

Precussive Maintenance 3 will never see combat. That's because it has been replaced with Percussive Maintenance 4: A New Spanner!

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I've returned to the gear-driven roots of PM2. I moved away from tht design because of the gear slip issue, but I've made a number of changes to ensure it doesn't happen again. The first is that I've significantly increased the tooth size on the gears, the second is a redesign of the chassis 3D printed parts so that now I can print the upright supports for the axe mechanism flat on the print bed. This will eliminate an issue with PM2 where a significant impact on the axe could delaminate the upright support near the base. I've tried to make sure that the tolerances are as tight as possible to reduce any slack in the system. The total gear ratio is 4:1, coupled with the 0.06s KingMax servo, so while it still won't do any real damage, it has a bit of a kick to it now.

https://youtu.be/qCle3EgDfVc

Another new thing I'm using in PM4 is the receiver/ESC. I'm using a Malenki Nano in this, and so far I'm very happy with how it performs in testing. For now I'm using a FlySky FS-i6 to control it, but I think I can buy a multi-protocol board for the Devo 7E that will let me use AFHDS 2A on it.

I've also been working on improving my mechanum wheel efforts. I tried updating Error 404 to improve its traction by using several coats of spray-on latex onto the rollers, but this didn't seem to make a huge difference. In an attempt to make mechanum wheels more viable, I decided to make a new bot with an active weapon.

Image

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Introducing PLA+ is a Perfectly Legitimate Choice of Material! I managed to add a lifter to the mechanum wheel setup by pulling ESCs out of cheap high voltage servos and adding resistors in place of the potentiometers (thanks for the help Peter!).

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Another change is I've made the wheels smaller - this does make them more fiddly to put together! Another change is that I've used heat shrink on the rollers to give them a tire (I can't claim credit for that idea - that goes to Adam Wrigley). It turns out this is actually a great solution to the traction issue - now, it has plenty of pushing power!

https://youtu.be/EK9aDvCdeEE

With the hope of events in the near future, my next task is to prep my bots - Make sure they're all still working, buy and print spare parts.
Thomas - Approximation Robotics

Ants:
Percussive Maintenance 4: A New Spanner
Have You Tried Turning It Off and On Again?
Runtime Exception
PLA+ Is a Perfectly Legitimate Choice of Material
Stack Overflow (WIP)
Stack Underflow (WIP)

Beetles:
Déjà Vu
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MarkR
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Re: T_Y's Build Log

Post by MarkR »

The mecanum wheel robot is amazing.

Getting a 4wd + mecanum + active weapon in 150g is a good effort. I hope it does well.
Robots: Betsie - RaspberryPi controlled flipper bot with gyro stablisation - too clever for her own good?
Stacie - tidy flipper; 4wd driven by hair bands
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LimaHotel
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Re: T_Y's Build Log

Post by LimaHotel »

PLAPPYAPPLECOM! YEEAAHH!
Jiggy Sawdust
Jammin' Good with Weird and Flippy
The Pushbot from Mars
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peterwaller
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Re: T_Y's Build Log

Post by peterwaller »

That is one nice robot can't wait to see it in combat.
T_Y
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Location: York

Re: T_Y's Build Log

Post by T_Y »

Thanks all! Hopefully I'll be able to meet you guys at events soon!

Progress is going on the manufacture of spare parts. I have a full set of spares for the three I intend to bring to the next event (PLAPIALPCOM, PM4, RE). I probably want extra sets of wheels for PLAPIAPLCOM because they're exposed.

BBB recently released their red escs, which look perfect for use in PLAPIAPLCOM. I'm going to see if I can redesign it using those (though probably not for Robodojo next month), alongside N10s from Nuts and Bots to make the robot smaller, which will reduce the weight slightly and hopefully let me add side panels.

I also upgraded my Maker Select Plus to have an all-metal hot end, so once I get an enclosure sorted out, I can think about using other materials.
Thomas - Approximation Robotics

Ants:
Percussive Maintenance 4: A New Spanner
Have You Tried Turning It Off and On Again?
Runtime Exception
PLA+ Is a Perfectly Legitimate Choice of Material
Stack Overflow (WIP)
Stack Underflow (WIP)

Beetles:
Déjà Vu
T_Y
Posts: 141
Joined: Thu Mar 15, 2018 12:51 am
Location: York

Re: T_Y's Build Log

Post by T_Y »

Version 2 of PLAPIAPLCOM is complete! Test video here: https://youtu.be/9299wu4GJw8

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One of the things I didn't manage to do with the previous version was add side armour panels to protect the wheels against horizontal spinners. With this version, I have managed to do this, by using N10s from Nuts and Bots and Red ESCs from Bristol Bot Builders, allowing me to narrow the wheelbase.

Here is the anti-horizontal configuration:

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In terms of events soon, there is BotFest 4 on the 24th July and Robodojo on the 25th, but it looks like I probably will be busy on the 24th. It's been 18 months since I've gone to an event, I'm itching to get back into the arena!
Thomas - Approximation Robotics

Ants:
Percussive Maintenance 4: A New Spanner
Have You Tried Turning It Off and On Again?
Runtime Exception
PLA+ Is a Perfectly Legitimate Choice of Material
Stack Overflow (WIP)
Stack Underflow (WIP)

Beetles:
Déjà Vu
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TeamScrewUp
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Re: T_Y's Build Log

Post by TeamScrewUp »

That armour configuration looks absolutely lovely. Nice work!
Daaa
Manta ray (2WD wedge bot)
Nom (Grabber)
Arena Sweeper (Undercutter)
FORCE WALL (Front-hinged Flipper)
T_Y
Posts: 141
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Location: York

Re: T_Y's Build Log

Post by T_Y »

I went to BotFest and Robodojo a couple of weekends ago, so it's time for an event log! This one will cover some general remarks followed by a Robodojo report, as I'm waiting for BotFest footage to be uploaded first before I write up that event.

Robodojo footage here: https://youtu.be/YvnPG7cjgX4

So I decided it would be a good idea to go to two events on consecutive days - BotFest 4 on Saturday followed by Robodojo on Sunday. And I had a great time!

Here is the lineup pre-events - Runtime Exception, Percussive Maintenance 4 and PLAPIAPLCOM. Each bot had a anti-horizontal spinner and anti-overhead configuration, but the anti-overhead configurations were not needed (though there was a potential overhead saw bot at BotFest that worried me!).

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===== General Remarks =====

This was the first time I'd been in an arena for ~18 months, the last being Robodojo back in February 2020. It was great catching up with everyone at the events. Typically, I don't do too well at events, and with a full team of untested (in combat) robots, I didn't know how I would do. But against all my expectations, I ended up with an overall positive win/loss ratio at each event! I came away from BotFest with 7/5, and Robodojo 5/4.

BotFest was done with 8 round robin heats, with the best performing bot from each heat going into a single elimination bracket. Robodojo ended up being 4 rounds where each robot fount in a 1v1 with another. The was one bot that unfortunately could not compete, so each of my bots got a bye in the first 3 rounds (not included in the win/loss count).

===== Runtime Exception =====

At Robodojo, Runtime picked up 1 win and 2 losses. It first fought against Crumbs!, which was also present at BotFest. I think it was originally a lifter but due to damage at BotFest it was only a pusher here. After a bit of back-and-forth fighting the ground game, I managed to get under Crumbs! and flip it, followed by a good push towards the pit, and managed to flip it over the barrier.

Its next fight was against Botlerone, a triangluar drum spinner, but unfortunately had been experiencing problems all day and so couldn't fight.

In round 3, it fought the new version of Rammstein. You can see in this fight in particular I had trouble controlling Runtime, so I didn't get many opportunities, and the fight ended with me ricocheting off Rammstein into the pit.

In the final round, Runtime fought Stewie. I managed to get one good flip on Stewie that nearly threw it into the pit, but he managed to escape and pit me.

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Overall, I am happy with the design of Runtime Exception, I just need to make some minor tweaks. I want to get some BBB ESCs with braking to help reduce oversteering - the fast BBB motors plus 30mm wheels results in a very twitchy (and reasonably fast) robot. I could also move the wheels back so it doesn't beach itself on a flip, but it didn't seem to affect me much in fights.

===== Percussive Maintenance 4 =====

At Robodojo, PM4 came away with 2 wins and 1 loss. It first got a bye against Botlerone.

Its second fight was against Crackers. The improved reliability of the weapon mechanism results in a persistent hammer like Blacksmith, as I got many swings of the hammer in. The fight was a fairly long back and forth until I managed to corral Crackers into the pit (hammering it all the while).

PM4 next fought Crumbs!. Again, the improved reliability of the weapon allowed me to get many hits in. Unfortunately, I couldn't control Crumbs! very well and I got pitted with about a minute left on the clock.

Finally, it fought Baby Dead Bod, another BotFest participant that was a powerful horizontal spinner. I attached the aluminium armour package, but laziness/design flaw meant that each panel was only held in with two screws, which resulted in Baby Dead Bod ripping the lower screw out and spinning the left cheek around so it blocked my axe from firing. It got VERY close to taking out the KingMax servo, as it also blew through the bracket right next to it. Luckily for me, I managed to keep the remaining right cheek in the way for the most part, until it gyroed itself into the pit.

Image

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Again, I am happy with how PM4 is shaping up. I have an axe bot that is controllable, persistent with its axe, and reliably self-rights. I just need to acutally fasten the aluminium with more screws (the mount points are there but I didn't think I'd need them...).

===== PLAPIAPLCOM =====

This is the one I really want to talk about, as it's been occupying my thoughts since it was first built. I really wanted to prove to myself that I could make the mechanum wheels viable after seeing the potential of them in Error 404, and I feel vindicated by its performance over this weekend, managing 2/1 at both events.

The larger arena at Robodojo really let me show off the manoeuvrability of PLAPIAPLCOM. The first fight was against Ant Crackers, where I started off strong by flipping it over. However, a loose wheel meant that it fell off during a pushing match, unbalancing PLAPIAPLCOM and forcing me to drive diagonally. It also meant my forks were no longer scraping the floor, so I struggled to get under Crackers. At one point, Crackers nearly pitted me but I managed to get out of it by flipping him back over. Eventually, it managed to take advantage of my missing wheel and push me into the pit. The wheel issue was simply solved by adding a blob of hot glue to the end of the shaft (I probably should have done this from the start...).

The second fight was against Rammstein. I managed to get a few grabs with my lifter, but couldn't quite manoeuvre it into the pit. At one point, it managed to shove PLAPIAPLCOM quickly across the arena, but the pit guard prevented me from going in. Eventually I managed to get Rammstein stranded on its side, propped up against a wall.

PLAPIAPLCOM then got a bye against Botlerone.

The final fight was against Ant Smash, a vertical spinner. I was unsure of how I would do, as none of the armour configurations are particularly effective against vertical spinners. I attached the side polycarbonate panels in the hope that they would take the sting out of hits and save the wheels, but left the forks on. Luckily, I managed to get under it and flip it, preventing it from getting damaging uppercuts, and the polycarbonate panels stopped the blade before it could touch the wheels. Atfer a bit of back and forth, I got it into the pit.

During the fight, one of the rollers came off the wheel. It looks like the blob of hot glue that I had used to secure the brass rod wasn't very good. I'll probably need to check all the other wheels to make sure they're done up properly.

-----

I am very pleased with the progress I've made with mechanum wheels since the harebrained idea from 2019. It is definitely a viable option, and I actually think it's faster than all my other bots because of the wider diameter of the wheels compared to my other bots. Now I just need to get used to using the strafing more effectively.

===== Future Plans =====

I am very happy with the current ant team. Aside from minor tweaks to the designs and printing off more spare parts, I think my focus will be on getting a beetle together. It's essentially a scaled up version of PLAPIAPLCOM! If all goes to plan, it should be ready to hopefully take with me to RoboNerd. The next event after that I believe is Robodojo 26th September, which is a beetle/ant combined event.
Thomas - Approximation Robotics

Ants:
Percussive Maintenance 4: A New Spanner
Have You Tried Turning It Off and On Again?
Runtime Exception
PLA+ Is a Perfectly Legitimate Choice of Material
Stack Overflow (WIP)
Stack Underflow (WIP)

Beetles:
Déjà Vu
T_Y
Posts: 141
Joined: Thu Mar 15, 2018 12:51 am
Location: York

Re: T_Y's Build Log

Post by T_Y »

AWS 62 was good fun as always, and it was great seeing some people for the first time in 2 years at Ant Freeze!

My performance was about standard for me at larger tournaments. PLAPIAPLCOM got my best result at an AWS at 3/2 (though that includes a bye), PM4 got 2/2 including a bye, and Runtime went winless. I came out of the event with no damage to repair aside from some replacement 3D prints that PM4 needs after the gladiator, so I'll get that done for Robodojo next Sunday, which will be the last event I go to this year.

I have a couple of ant projects lined up in between Robodojo and 2022 events. There's a couple of minor tweaks to PLAPIAPLCOM's armour configs I want to do, and I may do a V5 of Percussive Maintenance, to make it a bit faster and better at pushing/winning the ground game. In terms of new robots, I am working on Stack Overflow, a grab-and-lift robot I've been prototyping (a video of which is on the Approximation Robotics Facebook page - oh yeah, I never mentioned it here, I now have a Facebook page!). I should get that ready for Ant Freeze, which will let me enter 3 bots - PLAPIAPLCOM in the flipper category, Percussive Maintenance in the axe category, and Stack Overflow in the freestyle category.
Thomas - Approximation Robotics

Ants:
Percussive Maintenance 4: A New Spanner
Have You Tried Turning It Off and On Again?
Runtime Exception
PLA+ Is a Perfectly Legitimate Choice of Material
Stack Overflow (WIP)
Stack Underflow (WIP)

Beetles:
Déjà Vu
MySolderIsOlder
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Re: T_Y's Build Log

Post by MySolderIsOlder »

I did enjoy watching those Mecanum wheels in action as PLAPIACOM skittered around the arena. Poetry in (omni-directional) motion!
Stuart (Anthony's dad)
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