Team Eventorizon: Build Diary

[Ellis]

For science!

[Eventorizon]

Has it been heat treated? Could be warped... Just see how bad it is, if you can still drive it I wouldn't worry for now.

And yeah bolt it down next time... If you see my YouTube, 360s first spin up the robot had a large industrial container weighing it down, and 720 got bolted in my vice in my workshop.

It was case hardened but at 35mm thick at the outer run and 12mm in the centre I doubt it would have warped by almost a whole millimetre.

And yeah I will strap it down. I cant actually clamp it cos of all the sloping armour panels but we will get come ratchet bets and lock it to a paving slab. Or just stand well, well back and see what happens... the garden is big enough.

Though snow may make all of this obsolete... its only got 3mm of ground clearance.

[typhoon_driver]

The disc is statically balanced but not dynamically balanced so it will pass the balance on the bench test but when you spin it up the imbalance in weight along the shaft causes vibration. Just spin it up and stand back.

With a disc that big you will have bigger issues not flipping whilst turning due to the gyro forces.

[cavecrusher]

One tooth is chamfered left and the other right. Would that do it?

The disc is statically balanced but not dynamically balanced

Seems to me like that's the problem

[Eventorizon]

Today I was able to run a full 'bench' test of Binky [I ran a basic test on friday but I couldn't go to full throttle as the top was not on] and there is one serious problem.

Once the ESC was armed, the moment I moved more than about 3 meters away the disc went straight to full throttle. Thankfully the machine was clamped to a metal plate so it wasn't going anywhere but the only way to stop it was to get within a meter and regain the signal; and then pull the link when the disc had slowed down to a speed that didn't make it sound like a jet engine.

This didn't happen the first test even when I was a full 8-10 meters away. I think it was the armour blocking the signal as it was fine in the other test.

We are using a Spektrum DX6i and an Orange receiver, neither of which seem to be fail safeing properly.

Does anyone have any suggestions on how to solve this?

[Mouldy]

Didn't you have this issue last year during tech check? What channel is your disc on, on your tx? Im pretty sure only the throttle channel failsafes on a dx6i.

Re bind it with the throttle in the down position.

[Eventorizon]

Same problem. Different machine.

The ESC for the disc is on the throttle channel. I will do a rebind with the stick down and see what happens.

Oddly enough the drive motors stopped. I don't think the TZ85A have fail safes in them. Either that or they were bound in the centre with no movement applied.

[Ellis]

The tz85s do failsafe, after about a second. :)

[Eventorizon]

The tz85s do failsafe, after about a second.

Good enough I think as no one is going to be in the arena 1 second after Cease is called.

Also, how do you slow down something with this much inertia? It takes 2 minutes for the disc to come to a stop from full speed. I don't think driving your machine into the wall is a valid technique unless its in run away. I know some teams use electromagnetic breaking but how do you even build a system like that?

[grant_ploughbot]

Regardless of the ESC's having failsafe's, most 2.4ghz RX's mean that it will never activate.

In failsafe mode certain RX's have programmable failsafing on all channel's, and others only on the throttle (they keep sending some form of signal out the other channels and very rarely just cut the signal completely which is is what makes ESC failsafes work).

Just to clarify, the channels that failsafe are nothing to do with which TX you use. All TX's can failsafe on all channels with the right RX.