Team MedBots

[Ellis]

The ESCs don't take power from a BEC. A BEC is a bit of extra kit on some speed controllers purely meant to make the need for a separate battery to power the rx unnecessary (BEC = battery eliminator circuit).

Also, this may seem a silly question, but you're sure you're not just feeling the slight delay between fwd/rev that Electronize speedos have, due to being relay based?

[Max]

Well I'm charging up the batteries to check that isn't the problem, I am pretty sure it's not just the delay as I am keeping the motor at the same speed and it just stops suddenly then starts with lots of sparking

[Max]

Here's a video of the problem:

Just to explain what's going on- to begin with I have to motors going full speed forward, then after looking at both wheels I put it into full reverse then back into full speed forward, during the jittering I am holding the stick on the transmitter in one position never changing speed or direction, the wheels just stop.
At the end I quickly how the insides trying to show the flashing/sparking inside the motors caused by the starting and stopping.

[plargen]

might be worth popping off the case and seeing if there is anything odd going on inside the esc like something loose or some metal filings etc..

[Ellis]

Well I haven't a clue, really. By the sound of it those motors aren't on a flat battery. Could be radio issues I suppose... have you got an alternate radio set you can try the setup on? If on a different tx/rx combo it still happens then that narrows the diagnosis some.

Edit: suggestion of opening the ESCs up and having a look is a good one. It's very odd that the motors stop dead, since Electronizes don't have braking. Sort of suggests the motors are being sent reverse polarity for a split second, stopping it dead, then continuing as normal? Don't know!

[Max]

I'll have a look at the electronizes this evening, I've had a rethink on the layout for the heavyweight, I've dropped one of the main tanks and replaced the other with a longer thinner bottle.

I have lost the 'ideal' flow setup from the buffer like I had before but this way is much more compact so can be better armoured. I'll make the pipes from the buffer to the ram 3/4" rather than 1/2" to increase flow around the bends. Is it true that a 90 degree bend halves the flow, I find that hard to believe

[maddox10]

For practical purposes, you can say that a 90° corner halves the flow.

[Max]

Is there any way of reducing that loss, like swept elbows?

[Danjr1]

Here's a video of the problem:

Just to explain what's going on- to begin with I have to motors going full speed forward, then after looking at both wheels I put it into full reverse then back into full speed forward, during the jittering I am holding the stick on the transmitter in one position never changing speed or direction, the wheels just stop.
At the end I quickly how the insides trying to show the flashing/sparking inside the motors caused by the starting and stopping.

I had the exact same problem, which I sorted by changing the motors but it was a trial and error fix. I never worked out why it was actually happening but electronize said it wasn't the ESCs. I've never had the problem again after switching to hacked tz-85s.

[maddox10]

yes, large radiï bends are one solution. Another , and that one I prefer, is to eleminate any corner.

Now, from main tank to buffer isn't the issue, from buffer to valve, and from valve to ram, that's the part you need to look after.