Peter Wallers Robot Ramblings

[peterwaller]

I finally seem to have a track molded in the softer 00-30 rubber that stays in place on continuous high speed rotations.

The round teeth are 3 mm long and the holes in the inner mold are 2 mm deep so you get 1 mm of rubber under the the insert and 2 mm of teeth to engage in the drive wheels.
Here are the two parts of the mold and the insert.

This produces a track that is a little thicker than necessary so I am printing a new mold to try and reduce that by 2mm.

[Rapidrory]

Looks good! Was just watching this and thought you might find it interesting; gecko tape tracks could be pretty awesome :L https://www.youtube.com/watch?v=9XQfYKYO380

[peterwaller]

That is certainly interesting although I have got some Gecko tape but haven't found it as good as soft rubber.
Scott has had more success with it and I believe he used it on his latest tracked robot at the last event.

[EpicentrE]

Your moulded tyres are definitely better than the tape I use, I'm just lazy

[Rapidrory]

The other possibility I've been looking at is slick silicon wheels with a brush pushed against them to keep them clean.. could even have a tiny rotating brush!

[peterwaller]

Reducing the thickness by 2 mm proved a little too much as the rubber between the treads was almost non existent so the final tracks are 1 mm thinner.
Here are the tracks on the old Defiant chassis ready to go on my measuring rig the yellow box is to ensure the sloping front of the robot doesn't get under the spring balance which gives more download on the chassis effectively increasing the weight.

The chassis as is weighs just 107 gms and as can be seen in the video peaks at around 300 gms of push.
https://youtu.be/BMYZaKrMKhI

[peterwaller]

Having improved the tracks I decided that the chassis although virtually intact was looking a bit tired so I decided to give it a bit of a spruce up (It was made in 2012).
Having made the tracks purple I decided to invest in some matching ABS for a new chassis and track drive wheels.
Here is the finished robot sporting 1.5 mm polocarb armour weighing in at 112 gms so is still likely to be part of a cluster.

Although the sloping front on the old chassis looked more streamline, robots did have a tendency to drive straight over so hopefully this should help stop that.

[AntRoboteer]

Love the boxy shape actually. Looks awesome!

[peterwaller]

That's funny you should say that I have been trying to convince myself it looked good for a couple of days but rather failed.
So I have been experimenting with some better looking scoops and came up with these 3D ptrinted ones.


The white one is a sample of High Impact ABS I was given which has a breaking resistance of 37 Kj per sqm as opposed to 26 for normal ABS.
Unfortunately I only had enough for one scoop but it prints better than normal ABS but only comes in the one colour.
I also have some PLA 3D850 which has a value of 40, (normal PLA 20) comes only in clear and that is at the moment printing so that may be used depending on how it comes out.
Unfortunately you appear to have to order it from Spain here is the link: http://smartmaterials3d.com/en/9-tienda-smart

[HugoIsOnFire]

Awesome Peter , did it increase the weight compared to your boxy polycarb scoops? i might get my scoops 3D printed out of ABS (curtsey of Shakeys 3D printing service) for Propellant, but it depends