HELP ! MMP + Spektrum RX = cutting out ?
 

So I went and bought a MMP to run my Ballistic 4.5 550 in my Hyper and it will cut out for a second when I hit the throttle or turn alot under throttle . You can see the light on the RX go out like its loosing power .

I have tried a glitch buster cap but that really didnt help , I have the latest software in it also .

Am I going too have to get a BEC also ? I was running a Novak Havok Pro before this and I NEVER had this problem ?

I also run 4 Mamba Monster systems WITH Spektrum RX's in different R/C's and they do not have this problem either !

I've heard of this on a few forums - sometimes the glitch buster was enough other times its taken a BEC...

Open the rx case and check for sand in the case, silica sand will short it out. I have had it happen multiple times

I have tried it with 3 different Spektrum RX's and all of them do it ?

Are the motor and power wires routed well away from the rx?

Yep , I have been doing this for a few years so I am not a newb .

This has really disapointed me since I have had great luck with Castles products in the past ..... Like I said I have 4 Mamba Monster systems and they work just fine with the Spektrum RX's . I think the issue is with the MMP's BEC or maybe something in the software ......

I have exact the same problem with my Tekin r1 esc and airtronics FHSS-2 receiver on 3s. My UBEC arrives tomorrow and hope it solves the problem.

I dont feel I should have too buy anything else to run this ESC , it has a built in BEC that should be able to handle any servo or RX its used with IMO .

I hope there is a fix for this soon , I dont want too have to spend MORE money when I could have bought a different ESC in the first place that I knew worked instead .

If you are running 2s the voltage could be dipping under acceleration. BECs need around 1-1.5v higher than the output to run right. So, if your BEC is set to 6v, anything much lower than 7v at the battery could cause the BEC to dip below what the rx needs. You could try setting the BEC to 5 or 5.5v and see if that helps. I would keep the glitch buster cap in there too; it may not noticeably help, but it does smoothen the voltage and reduce any noise.

Hmm , tried lowering the voltage on the BEC and it seemed too help a little but it still cuts out and hesitates pretty badly . I guess I will try an external BEC next . :grrrrrr: Either that or sell it and take a loss to buy a different ESC .....

Are you using 2s? I'll assume you are. No matter what BEC you use, you still need a battery with 1v-1.5v higher than the BEC rating. 2s being at 7.4v doesn't leave much leeway for voltage drop. The only real solutions for 2s usage are:

- Use a better battery that doesn't dip as much under load (higher C rate)
- Use 3s. Of course, that would require gearing and maybe even a motor change to keep speed/rpm in range.
- Lower the BEC to 4.8v or 5v to allow more leeway. Even then, if your battery voltage is sagging a lot, this won't help much.

For 2s applications where battery sag is going to happen no matter what you do, I would actually suggest using a linear LDO (low voltage-dropout) regulator. You may be able to find one capable of 3A+ and less than 1v dropout (BGMicro.com used to have some), but would be easier to use a lower current LDO regulator (like 100mA) and add a pass transistor to get 3A+.

BrianG , why would Castle put this thing out if it wont run on 2s properly ? Its a 1/10 controller and MOST 1/10 scale cars run 2s ? I am using 30c batteries so they should be able too supply enough power .

I even tried an 8000mAh 25c battery and it still does it ? Never heard of this with the Mamba Max so whats different now ?

I really can't answer the purpose of the design, but what I said does stand. It's simple electronics and math, and they don't lie.

I know from experience that Spektrum receivers do tend to be finnicky with regards to power. Usually, adding a ~10,000uF capacitor (glitch busters) eliminates the problem.

Another potential issue could be the servo. If it is binding, very high torque, etc (basically pulls a lot of current), it could be causing the BEC itself to drop out, which causes the spektrum rx to hesitate.

The Mamba Max uses a linear regulator, which is good up to 2s (sometimes 3s if the servo load is small). Linear regulators are generally pretty darn tough and can handle all kinds of abuse gracefully. But above 2s, the internal BEC should be disabled and an external switching BEC should be used to keep it from thermalling. The MMPro uses a switching BEC. From experience, this BEC can supply a little over 2A before it drops-out.

I installed an UBEC today and the problem solved...

Well , I also went too the LHS and picked up a CC 10a BEC , put it in and it seems to have cured my problem ? So why cant the BEC in the Mamba Max Pro do the job ? Is there some kind of fault with them ? I am using a high torque servo (JR 9100T) but I use that servo in all my 1/8th scales and the MMP ESC is the only one that is giving me trouble .

An ultra HT servo such as the 7955TG or 7950TG I've shown to pull 4amps at stall... The MMP bec is just not comping... An extra CC bec is a pain but compared to what we used to do its a small price to pay

That servo is known to be a current eater :lol:

I'm following but what I want to know is; if using the 7950TG and MMP with a 2s setup could you get away with just adding the 10,000uf 10v cap or should you still put in a CC BEC because of the HV servo. If that's the case would changing the servo make then an external BEC unnecessary?

I personnaly would rather have a cc bec on my ten than a cheesey servo.
just my .02

:lol: I guess I should've been more specific. I was thinking instead of using the 7950TH to switch to my 7955TG which isn't HV. In that case would I still need an external BEC on 2s? And is it ok to put say 3 x 4600uf 10v caps in series to be closer (well actually way over) to BrianG recommended 10,000uf 10v? Thanks BrianG for a reply.

i actually had problems with a similiar servo.Not the hitec 7955tg,but the hobbico ct170,or cs170,anyway basically the same servo per the specs.So i would say no. BEC should solve your problems.Buy the cc bec pro so we can get some feedback on it.I've been concidering one.

:lol:You buy Hobbico servos and use the word cheesy in your other post:rofl:
And please post help according to a person's application. I'm using a 2s setup why would I want a CC BEC PRO that doesn't even make sense. Like I said I'll wait for an answer from BrianG, thank you!

A 7955 and 7950 both pull about the same at stall from my tests - You could try adding the extra 10000uf capacitor however thats about as big or bigger than a CCBEC...

I've done tests etc and already put up results of the CC BEC Pro - I use one on my comp super (crawler)

I would just go with a medium size digital servo. I run a futaba s9551 low profile servo in my 1/8 buggy because of the problem. Despite only 122 in-oz of torque, it gets the job done. The JR9100s causes bad glitching and the spektrum s6040 makes a complete joke out of the bec all together. One twitch of the steering and the esc resets itself.

But seriously though, Castle needs to get their act together on this. This has been a problem from day one and I have not heard a word from them addressing it in the last 6 months. I've posted complaints here twice.

I've gotten replies such as:
"It only seems to be a problem with a particular servo." Not the case. Seems to be any high power digital servo that is causing the problem and it put me back $80 to find that out.

"You probably have a bad chip." Maybe two? in each of my escs that seem to be working normally otherwise?

"A power cap should solve the problem because it's the current spikes created by the servo when it changes direction." Been there, done that. No go.

Face it, it's time that Castle takes some heat on this. They could at least be proactive and let people know what is going on. When I people who are newer to the hobby running into this problem and have gone painstakenly out of their way to pinpoint it without luck, it really gets me.

THANK YOU ! You said EXACTLY what I was thinking ! There is obviously SOMETHING not right with these ESC's !

I was running the same setup with 2 other ESC's and neither of them had this problem running 2s ?

Why should we have too buy an external BEC to run 2s when its a supposed to be a 1/10 ESC and MOST 1/10's run on 2s ?

I love Castle's products but after this experience I dont think I could recommend the MMP to anybody who wants to run 2s on it :diablo:

Well , its still cutting out just a tiny bit when you hit full throttle from a dead stop WITH the external BEC ! :cry:

Tried going too an ACE 1015 servo also but that didnt help either :grrrrrr:

Man I was hoping not to have to buy another ESC but I dont like the way the MMP runs the Novak 550 motor :no:

I was going too try a cap with the BEC next but I dont want too spend anymore money trying fixes too get this thing to run correctly :no:

If you are running an external BEC and its still dropping out it has NOTHING to do with the ESC.

I'm guessing that your batteries are dumping massively and causing the issue.

Whatever , I am using 5200 Mah 30c batteries that are fairly new and a 8000 Mah 25c battery that is about 3 months old .

These batteries work great in everything I own except the truck with the MMP in it .

The motor and batteries also worked fine with the 2 other ESC's that were in the truck before ?

It's safe to run the 7955TG on 2S unregulated lipo. It's the same servo as the 7954SH but with titanium gears instead of steel gears.

No thats a 7950TG.... A 7955TG is a 6V servo...

I'm not sure what it is then (dodgy RX) but if you've run a Castle Bec and it still cuts out you've ruled out the ESC being the issue...

Indeed. That's what's on the box. But the 7955TG can have 2S unregulated lipo without problems. Ask all the nitro guys. They run all run 2S lipo's with 7955TG servo's without any problems.

I mailed Hitec about it and it's true. The 7954SH is a 7955TG under the HV serie, but with steel gears and cheaper. And you don't lose your warranty if you run the 7955TG unregulated ;-) HITEC FTW :D

Just give that baby a lipo 2S lipo and it will be faster than ever :D If you don't feel safe about it, use the search in the nitro section of RC tech. (sry rc monster, but they have very big nitro section. NP to remove the last sentence if this isn't allowed).

I've got a JR9100S in my XXX-T running a MMP, along with a Spektrum SR3100 receiver... don't have any glitching.

I didn't mention that I was running 6s lipo in a 1/8 scale. The same esc in a 2s powered b4 runs the 9100s w/o glitching, but still drops the bec voltage enough so that my personal transponder doesn't always count laps, even with a power cap added.

I did some more running on it and it seems that the external BEC has fixed the problem , what I was seeing was hesitation from the motor , the RX was staying on all the time and not going out . Changed settings too sensored only and now its smooth .

I have the same problem with the MMP and a Savox 1258 servo. (I tried 2s 3s and 4s - I always get this cutting out!) This has to be a software problem --- castle can you fix it ?

No official statement in this case ?

hmm, I got too of these ESCs coming in to use with some 8.5 ballistics, now I am worried.

I just came back from the track after testing the 7955TG and didn't experience the same hesitation at all. I did let my buddy drive and he got a glitch. I installed a CC BEC and took out the 7950TG and there was according to him still a slight glitch. Well, after talking a bit I believe my glitch is still ESC related and have a hunch that it's my fault after all. You see at my track some of the other guys who run electric use reverse (as to not have to wait for the turn marshall if your up against a wall or pipe) and I followed suit a couple of races back. I believe my ESC is simply stalling due to the reverse setting. Too bad it got real late because I definitely wanted to test it out. But, anyways the reason I'm sharing this is to hopefully get some feedback as to the possibility of the reverse setting being the culprit. And for those of you experiencing this glitch; Do you have the reverse setting on?

Well an update on my last thoughts...NO...glitch still there!:diablo:
But, I do feel I came up with a real solution.:whip:
First I'm going to use the MMP internal BEC to power my receiver and transponder, in other words plug it directly into the radio with all wires still in the plug including the red wire.
Second, I'm going to use the CC BEC to power just the HiTec 7945TG (just got it), so basically connect both the CC BEC and servo wire into a heavy duty servo Y adapter and before plugging it into the radio disconnect the red wire since the servo is what needs to be powered with a signal wire but the CC BEC just needs to be grounded back to the ESC.

I don't know if anyone has suggested this fix or tried it but theoretically it is sound and should work. I'll post up my results.