Need response from a Castle tech for MMM question

[TruckBasher]

My V2 has about 2 hrs of total runtime before it give up....I hope this is just an isolated incident and that my way of driving is the cause....

I definitely think that MMM will soon be more reliable...but I think they need to redesign the whole BEC+Brains setup.....

This mod is good but I think (just my opinion), that once those components are remove the MMM has reduced its efficiency to limit voltage going to those IC....either that or I fried the one doing the limiting...worst is I killed the main brain because of incorrect voltage....

Originally Posted by TruckBasher

My V2 has about 2 hrs of total runtime before it give up....I hope this is just an isolated incident and that my way of driving is the cause....

I definitely think that MMM will soon be more reliable...but I think they need to redesign the whole BEC+Brains setup.....

This mod is good but I think (just my opinion), that once those components are remove the MMM has reduced its efficiency to limit voltage going to those IC....either that or I fried the one doing the limiting...worst is I killed the main brain because of incorrect voltage....

Did you run it on 4s or 6s

[TruckBasher]

I only run it on 6S A123 close to 5S lipo....

btw the voltage im talking about is the BEC supplying the ICs and Brain

[lincpimp]

Looks like I will be doing the mod. One of my 2 V2s died, and I would like to get it running, if only to use as a backup...

I think I will stick to a rx pack, as that is already setup nicely in the lst, complete with an on/off switch. And the addl weight is neither here nor there in that heavy truck.

I may also call castle, and see if they will send me a replacement v2 with a mailer. Save me a few bucks on return postage maybe??? What is their number for things of this nature?

[jhautz]

Does anyone know what the max voltage the MMM "brains" can run on? I was thinking about doing this mod to my dead V2, but instead of using an external BEC or Rx pack I was thinking about running the whole thing on a plug that would tap into the main pack balancing plug and just run it off of 2 cells in the main pack. I know my servo and Rx can handle the 2s voltage, its just a matter of if the MMM brains can take the full 2s charge voltage. Would 8.4V fry it?


Before anyone points out that I will be draining 2 cells and creating an imbalance..... I know. But I have an excelent charger that balances the cells perfectly no matter how badly they are out and I run a high enough LVC setting that I dont think it will be a problem.

[jhautz]

Brian,

How is your OPTO modified controller doing? Still running OK?

I was on the phone with a CC tech this morning and what he was telling me seems fishy. He told me that on my V2 that has a misbehaving BEC (sometines works and puts out 6.4v and sometimes only 2.0v depending on what it feels like doing), if I disconect the red wire on the Rx cable and power the Rx with another power source that the MMM will run. He said the the "brains" run on 3.2v on another circut and that the internal BEC wount effect that. It doesnt seem right to me, otherwise why wouldnt all of us just be able to run the controller with a RX pack or external BEC when the when the internal BEC fails. I told him what he was explaining didn't make sense based on what I saw in my totally failed units. If what he said was accurate the LEDs should still lite on the MMM unit itself even without a Rx plugged into it. But he insisted that the internal BEC should effect the Barin board.

I still think he doesnt know what he is talking about. I will do some playing tonight to confirm it.

I'm right... Right?

BTW... I asked him about doing the "OPTO Mod" on it and he said that it would void the warantee. Wouldnt make any exceptions either.

[BrianG]

Mine runs ok for the little I do. Since I'm still waiting to decide what lipos I'll be running in my MBX5/Corr truck, I haven't made a permanent batt tray, and so I just run on 4s a little here and there. So, not a whole lot of use.

What the tech said about using an external source doesn't sound right. If the on board BEC fails, it could be pulling down any external supply. Of course, it depends somewhat on what went wrong.

[jhautz]

What about the whole BEC not having anything to do with the brains of the unit. Seems wrong to me.

[BrianG]

Dunno about that either. To me, the BEC would bring the battery voltage down to ~6v, and then there would be an onboard regulator for the 3.2v supply. It's the only thing that makes sense considering how these things act when they fail.

[Arct1k]

I think the BEC must do the majority of the step down - One thought though is that the Brian board may still be able to operate at 2v whereas the servo and rx can't....

Just as a precaution - I'm going to give up on running with the BEC powering the Servo/RX and use an UBEC. I'll leave the fan off the MMM as it shouldn't run anyway...

[TruckBasher]

What that tech is saying doesn't make real sense....unless the brains has its own power source or something to regulate and step down the higher voltage input from our batteries. highly doubt it

[BrianG]

Plus, why else would the brains work via the castle link, but not off the battery? The Castle link provides the needed 5v to power the brains.

[lincpimp]

Well, I did the Bec removal mod and my dead V2 is alive again...

Hope it lasts! I will bash it extra hard. I am trying to run the truck hard to break any weak points, including the electronics. I will say that the hacker 11xl on 6s will easily launch the lst 2 feet in the air and flip it 2 or 3 times from a standing start... Way too much power, just like I like it. Plus the motor stays around 150f. I may step to a 1521, but I am not sure if it will make much difference.

[George16]

Originally Posted by lincpimp

Well, I did the Bec removal mod and my dead V2 is alive again...

Hope it lasts! I will bash it extra hard. I am trying to run the truck hard to break any weak points, including the electronics. I will say that the hacker 11xl on 6s will easily launch the lst 2 feet in the air and flip it 2 or 3 times from a standing start... Way too much power, just like I like it. Plus the motor stays around 150f. I may step to a 1521, but I am not sure if it will make much difference.

Good to hear that.

Anyway, are you using a UBEC or Rx pack?

I talked to a rep from CC last night (I have to call at least almost midnight due to time difference) and asked about doing the BrianG mod.

So anyway, I'll be doing Brian's mod but instead of a UBEC(just ordered Dimension Engineering's Sport BEC), I'll be using one of my 6V rx packs from nitro revo. If it doesn't work, I will be shipping a dead MMM to CC and wait a couple of weeks for the replacement ESC to arrive unless Lutach's 10S Chineses ESC arrives first.

[lincpimp]

Originally Posted by George16

Good to hear that.

Anyway, are you using a UBEC or Rx pack?

I talked to a rep from CC last night (I have to call at least almost midnight due to time difference) and asked about doing the BrianG mod.

So anyway, I'll be doing Brian's mod but instead of a UBEC(just ordered Dimension Engineering's Sport BEC), I'll be using one of my 6V rx packs from nitro revo. If it doesn't work, I will be shipping a dead MMM to CC and wait a couple of weeks for the replacement ESC to arrive unless Lutach's 10S Chineses ESC arrives first.

I decided to use a rec pack, as i really do not feel like soldering up anything right now! I may invest in a novak regulator and use a 2s lipo pack, but atm I will be using a IB nimh pack...