T_Y's Build Log

All things antweight

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T_Y
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Re: T_Y's Build Log

Post by T_Y »

With AntFreeze 7 in a few weeks, I've been busy getting the team ready.

HYTTIOAOA had little in the way of repairs. All that needed doing was to get some slightly larger wheels printed off and attached, to help prevent the drive issues I had in the fight against RBMK.

For PM2, I tweaked the design slightly, using a flat front panel instead of the composite-angle shape I previously had, this should remove some bite points on the front. I've added a small skid on the front which makes it drive a bit straighter now its not dragging the front along the floor. The aluminium shield is now a fixed shield.

Most of my efforts have been in getting Error 404 ready for Antfreeze 7, and I can happily report that it will be competing! I've swapped out the electronics, so now I'm using BBB's motor/esc combination kit, which by coincidence fits perfectly into the chassis!

Image

All the mixing is done on my Devo 7e, so that reduces the amount of circuitry inside the bot. I've redesigned the wheels to get larger rollers, which now mean that the bot rests on the rollers throughout the entire rotation of the wheel, without hitting the wheel hub.

And...

https://youtu.be/IcWAUvbGQnI

It works! Strafing left and right is a little inconsistent, but I'm happy to take this into a fight now. It is pushing up against the weight limit though, so I might have to drill some holes in the side arms of the wedge.

Image

I've also got a variant plough for ground-scraping,

Image

This event is the first that I've managed to get all competing bots ready with more than a day or two to go. So now all I'll be doing is prepping spare components- it takes a long time to print off these wheels, at around 4 hours per wheel + rollers!

Image

Can't wait for AntFreeze 7!

As a side note, I've decided to take the plunge into making a beetleweight. Naturally, it's going to be a scaled up version of Percussive Maintenance...
Thomas - Approximation Robotics AKA "the one that does the mechanums"

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LimaHotel
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Re: T_Y's Build Log

Post by LimaHotel »

You get some truly massive spanners...
Hpw far up the weight categories do you reckon PM could go?
A grabber? I CHALLENGE IT WITH JIGGY!
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LimaHotel
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Re: T_Y's Build Log

Post by LimaHotel »

Also E404 - How much pushing power does it have? I'd imagine that the Mechanum wheels do not offer the best grip?
A grabber? I CHALLENGE IT WITH JIGGY!
T_Y
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Re: T_Y's Build Log

Post by T_Y »

The spanner I've picked up for PM BW clocks in at around 150g. Realistically, I think I won't be able to build anything bigger than a beetleweight with my current workspace/tools, but it would be nice to see Percussive Maintenance bigger at some point in the future!

E404 has basically no pushing power due to the mechanum wheels (it fails to push my other bots unpowered, which are 130-140g), so I don't expect a good performance from it! But it's mainly there as a proof of concept, as an interesting thing to make.
Thomas - Approximation Robotics AKA "the one that does the mechanums"

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MarkR
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Re: T_Y's Build Log

Post by MarkR »

That Mecanum wheels bot is amazing.

Is there any kind of rubbery glue that you can apply to the wheels which will give them more grip? Maybe rubber solution glue or something?
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jes
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Re: T_Y's Build Log

Post by jes »

You can 3d print a mould and a hub and cast some 2-part silicone rubber onto the hub using the mould. That's how I made wheels, it's not that hard. Peterwaller's thread has some more detail on it as well.

Although, given that you would have dozens of them to make, you might consider making a mould that can cast several at a time with sprues in between, to save yourself some effort.

The mecanum wheels look amazing btw, nice work.
T_Y
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Re: T_Y's Build Log

Post by T_Y »

I think given the curved shape of the rollers, casting silicone tyres onto them might be a bit tricky, I'd have to think about it and see what could be done. I was thinking of some sort of tape or paint-able latex which may do the trick.

Any attempt to add tyres to the rollers is going to need a modification to the wheels anyway, as they barely have enough clearance to rotate as it is.
Thomas - Approximation Robotics AKA "the one that does the mechanums"

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Kyro
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Re: T_Y's Build Log

Post by Kyro »

latex gloves... cut some up into strips and glue onto each roller?

would provide grip without adding too much weight or thickness... just, it would take a while... but if you start now you will only have a few left to do by the time antfreeze finishes :p
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EddieJ
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Re: T_Y's Build Log

Post by EddieJ »

T_Y wrote: Mon Jan 27, 2020 11:16 pm I think given the curved shape of the rollers, casting silicone tyres onto them might be a bit tricky, I'd have to think about it and see what could be done. I was thinking of some sort of tape or paint-able latex which may do the trick.

Any attempt to add tyres to the rollers is going to need a modification to the wheels anyway, as they barely have enough clearance to rotate as it is.
Fire me the STL for the roller part in a PM, and I will 3d print you some rubber rollers on the DLP machine. This needs to be at maximum effectiveness :)
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T_Y
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Re: T_Y's Build Log

Post by T_Y »

Kyro wrote: Tue Jan 28, 2020 12:03 am latex gloves... cut some up into strips and glue onto each roller?
That's a good idea - I might look into this after AntFreeze.
EddieJ wrote: Tue Jan 28, 2020 4:34 pm Fire me the STL for the roller part in a PM, and I will 3d print you some rubber rollers on the DLP machine. This needs to be at maximum effectiveness
That would be awesome, thanks!
Thomas - Approximation Robotics AKA "the one that does the mechanums"

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