Need a new BL-Controller for my Savage

[mt_enthusiast]

my MGM160 has the brake/reverse problem, but the new ones fix that. I can get mine up to par too, but I haven't sent it back yet. Metal man got his updated and so did GriffinRU. My nephew actually drove through a deep puddle by mistake. I was afraid I was going to have a replacement cost, but once the controller dried out, it was fine.

[Dafni]

Going into full reverse if you keep holding the trigger is exactly what it is supposed to do. Just release the trigger when the truck has stopped, it's easy. It won't go into reverse if the truck is still rolling.

Just release the trigger.

btw, I never use full brake anyway, it would flip my trucks over. (set EPA)

Originally Posted by Dafni

Going into full reverse if you keep holding the trigger is exactly what it is supposed to do. Just release the trigger when the truck has stopped, it's easy. It won't go into reverse if the truck is still rolling.

Just release the trigger.

btw, I never use full brake anyway, it would flip my trucks over. (set EPA)

NO, I would expect that the controller acts like in this description (it's from MGM):

CAR mode forward / backward [A1]:
If the car is at standstill, then by moving the throttle from neutral the car will go backward or forwards. If the car is moving then by moving the throttle backwards the car will brake. The brake is proportional, that means the further the throttle is from neural the more intensive the brake is. The intensity of braking in the max throttle position may be set in parameter "B". When braking the car will stop, and not start moving backwards until you move the throttle to neutral and then again backwards. Connected braking lights are turned on when braking.

-- Dave

[Dafni]

Ah, I see. That's the "double throw reverse"! Some ESCs have this. They only go into reverse if you go to neutral first.

I prefer the "single throw" types, such as the EVX or the BK controllers. If you found this describtion on a MGM product, I would guess they'll act that way.
The downside is well known: if your car is still rolling, and you want to brake again, it goes into revers too. That's why I prefer the single-throw types!

DAF

[MetalMan]

Originally Posted by Attila

NO, I would expect that the controller acts like in this description (it's from MGM):

CAR mode forward / backward [A1]:
If the car is at standstill, then by moving the throttle from neutral the car will go backward or forwards. If the car is moving then by moving the throttle backwards the car will brake. The brake is proportional, that means the further the throttle is from neural the more intensive the brake is. The intensity of braking in the max throttle position may be set in parameter "B". When braking the car will stop, and not start moving backwards until you move the throttle to neutral and then again backwards. Connected braking lights are turned on when braking.

-- Dave

I would actually disagree with MGM's statement about this. Just this weekend I was doing speed runs with my Rustler and MGM Compro 12012 (newest version as far as I am aware) with 4s Lipo and a Feigao 540 12s. Since its BEC is putting out the full battery voltage (I know, it's strange) I have to use an external BEC. The XUS Hobby UBEC induces glitching, so my range isn't the greatest. Anyways, to maximize my acceleration distance I had to brake as late as possible. Most of the time when I hit full brake when going full throttle, it resulted in the tires spinning in full reverse while my car was going 50mph! Obviously that isn't a good thing, and was very annoying. I've also noticed that the MGM is finnicky in general. Sometimes going from a low throttle position to neutral causes it to do the brake thing (no "freewheel") like the older versions did, even though I have it set so that it will "freewheel".

Now to the likes: fully adjustable acceleration and braking, and a LVC for Lipos that kicks in at 3.1v/cell with a hard or soft cutoff, or no cutoff at all.

[Dafni]

Hmmm, metalman, the LVC is nice. Very nice indeed. But the going into reverse is bad! Might tear your rusty in two one day :026: And the BEC giving the batt voltage...well, what can I say. Strange.

Freewheel is a must for me, too.

Thank you for the honest report!

Originally Posted by MetalMan

... Most of the time when I hit full brake when going full throttle, it resulted in the tires spinning in full reverse while my car was going 50mph! Obviously that isn't a good thing, and was very annoying. ...

Sounds as if your controller is in Boat mode:

"BOAT mode forward / backward [A2]: ...The direction of motor revolutions is reversed immediately upon moving the throttle the opposite way." (MGM)

-- Dave

[Dafni]

I doubt it, Attila, like I know our Metalman.
This problem was mentioned by other users, too.

Anyway, did you get the double-throw VS single-throw idea?

I was in contact with BK yesterday. I asked them about the "brake/backward-problem". Here is what BK answered (short version):


"Breaking is a short-out of the motor. When you are breaking all phases of the motor are under positiv voltage. That's also the reason why MGM controllers are burning some times.
When you hold the trigger in break position for more than 1.8sec. the stress peaks are so high that when switching to forward mode the motor could blow up.
That's the reason why 99% of the (racing) drivers like the behaviour of the BK controllers. Nobody would ever break for more than a second."


Ok, maybe a "racing driver" would not break longer than a second. But I driving a Savage and I am bashing for fun and not entering a race contest...

-- Dave

[GriffinRU]

I will say BK sales people are not correct...

If BEC on MGM controller outputs full battery voltage, then BEC part is damaged. See my earlier report on MGM's BEC failure.

As far as updated versions of MGM ESC, I haven't had such problem yet. But I was not using BEC from the very start either (memories of blown servos...).

You should be able to apply brakes as long as you want, motors back EMF should be well below FET's voltage limit. But if you have noisy/glitches in receiver part then you signing for disaster yourself. Use good power connectors and good UBEC (most times bad capacitor on UBEC or ESC part can create problems).

Artur