How To: Installing an MPI voltage regulator

[Grizzly4x4]

Originally Posted by Unholy

The specs on that volt reg are printed backwards everywhere.

The input is 4.8-16 and the output is 4-8.4

I have tested it up to 12 volts input, but didn't have anything above that to test with.

I run 8 cell packs through mine with the output regulated to 7 volts no problem.

I mean think about it... how could the output be more than the allowable input?

I noticed that but did not want to make any assumptions and pass it along as fact. Glad to hear that it's working well on 12V.

I got a response from MPI this morning. I was told that as long as 20 watts power dissapation is not exceeded then the regulator will be ok.
Based on that I have come up with a recommendation: On a crawler it would be good to have the abitity to pull approximately 5 amps through the circuit. Based on this, the voltage drop across the regulator should not exceed 4.1 volts. This means that in order to run 11.1 input volts the output voltage should be 7 volts. I have had good luck running 7 volts to Hitec servos but not JR servos.

I have updated the original post with this information.

Originally Posted by cartronicshn

Thanks Grizz , i've had a regulator from MPI sitting here for over 6 months because i had no idea how to install it , i will hook it up to my mambas 25 and tower pro 995, i can know run 6-8 cells safely right?

You should have no problem running this setup with a 9.6V input voltage Cart.

[Grizzly4x4]

Originally Posted by kris

I have 4 of these all running on 3cell lipos. I run 1 for each servo on my super and run them to the steering servo on my SW2 and the Hustler2.2 the bec from Mamba max runs my winch servo on the Hustler. There has been a few times after runnig 3 packs in a row through my super you could probaly grill a burger on it but it still works, very good product you will be happy after doing this.

I had been considering buying this ever since I saw it at Hobbytown. Then I saw it tucked away in your Hustler 2.2 and went right out and bought it.

[kris]

Originally Posted by Grizzly4x4

I had been considering buying this ever since I saw it at Hobbytown. Then I saw it tucked away in your Hustler 2.2 and went right out and bought it.

I could have probable got away with just the bec from the Mamba max on the Hustler but I over build everything.If it is sitting on the counter I can hold the front tires and swing the rig like a windsheild wiper and knock everything on the floorthe super has 2 to keep the amp draw lower through the reg.

[roktoy]

Nice writeup Griz and a good explanation on the power capability.

I've been running the ACC234 on 9 cells with two robot servos without a problem.....but I typically don't use both servos under a lot of stress simultaneously. Output is set at ~6 volts.

Jay

[Grizzly4x4]

Originally Posted by roktoy

Nice writeup Griz and a good explanation on the power capability.

I've been running the ACC234 on 9 cells with two robot servos without a problem.....but I typically don't use both servos under a lot of stress simultaneously. Output is set at ~6 volts.

Jay

Thanks Jay. Glad to hear that it is holding up to that kind of stress. A 4.8V voltage drop and dual robot servos must give it a pretty good workout.

I fully agree that you can stress this more than what I recommended but I would rather give a conservative recommendation for people who want to be safe.
Having people post up their experience is great because then others can see what has been working. Thanks to Unholy, you and Kris for adding some great information.

And thanks to everyone for the compliments, I hope this proves useful in one way or another to everyone.

[Unholy]

I'm running 2 5995s as well...
and I stress them both all the time!

I'm running at 7 volts to the servo with a 9.6 volt pack driving it.
They pull about 4.5 amps at stall... each.

No problems!

[Tanis]

Thanks for the update Griz, I won't be worried about my 9.6v setup now. I run a 5995 steering servo with a TP995 dig servo on my 2.2TXT, set at 6v so far. I am going to up the reg to 7v to get some more power, as both servos are rated up to 7.2v, to lower the amp draw like you explained, as I can never have enough steering power.
Thanks again for the info.

Nathan

[racerx]

I have also been running one of these on my super for a while with 2 1/4 scale hitec servos with it set to put out 7 volts.... Hey Kris, you got a recipe for them burgers?

[run2jeepn]

Just ordered me one....I have an 8cell pack running the truck and one MG945 servo. Now Tower stats that the MG945 can handle 7.2v's. How would I go about running that to my servo? Also I run a 2nd servo for my Dig. Is there a way to not run 7.2v to it. I don't think it would handle it. It's just a cheap Traxxas one....I'll reread all of this again and try to figure it out, but it starts to run toegther on me. Crappy thing is just ordered a 6 cell RX pack from CBP's...Ohwell. I'll use it on something esle I guess.

[Grizzly4x4]

Originally Posted by run2jeepn

Just ordered me one....I have an 8cell pack running the truck and one MG945 servo. Now Tower stats that the MG945 can handle 7.2v's. How would I go about running that to my servo? Also I run a 2nd servo for my Dig. Is there a way to not run 7.2v to it. I don't think it would handle it. It's just a cheap Traxxas one....I'll reread all of this again and try to figure it out, but it starts to run toegther on me. Crappy thing is just ordered a 6 cell RX pack from CBP's...Ohwell. I'll use it on something esle I guess.

When I first set mine up I had the steering servo running off the voltage reg and my dig servo running off the BEC power so yes it can be done very easily.

All you need to do is make a wiring harness. I still have mine so I will post up pics of it tonight. It's alot easier to explain in pictures than words.

[JohnRobHolmes]

I just made such a harness for a customer. This particular one doesnt have a plug installed for the servo regulator or voltage source of choice. It is fairly easy to see how to seperate servos and RX/ESC power. The BEC runs the RX and ESCs, while the Voltage Reg supplies power to only the servos. Pics explain easier, I agree.


This was made with 20awg extensions, and will be powering two 5955's on a clod. The power is routed in parallel between the two servos.

[MrNatural420]

Damm top 10 thread...Whole thing needs to be a STICKY...except this post

[Grizzly4x4]

Originally Posted by MrNatural420

Damm top 10 thread...Whole thing needs to be a STICKY...except this post

Glad you like it.

Thanks for posting that John.

Here is the harness I made from a standard Y-harness. This could also be used to power the steering servo off of an RX pack. Of course you would want to leave the power wire in the ESC to RX connector if you do this. That's how the dig servo would get power.

[run2jeepn]

Thanks a million guys. Should help out alot...I'll post pic's of my set up when done.

[Cloak]

JRH: You have me confused with your pic compared to Griz's. Is it not necessary to have the black (ground?) wire go to the receiver?

I think I'm going to try and make me one tonight so I can give it a try on my clod and just plug that in to a 6V rx pack.

This also explains how I can power my lights w/o having to mess with tapping my bec or hitting my main battery too.

[JohnRobHolmes]

The black going to the receiver is not necessary. The servos only need signal from the RX. More than one way to skin a cat.

[Grizzly4x4]

Originally Posted by johnrobholmes

The black going to the receiver is not necessary. The servos only need signal from the RX. More than one way to skin a cat.

I agree 100%. The servo will get ground through the power connection.

Cloak, I just left the ground wire in my harness because it doesn't hurt anything.

[Cloak]

Fair enough. Just making sure I understand the reasoning for it.

[EeePee]

Attention! Attention!

Mamba 25 ESC owners, this is a must do mod.

I went with the ACC134 model, the non adjustable version, 6 volts out, $19.50 price tag.

When I bought the MIP CVDs I made some adjustments to the steering set up to maximize the throw. Swinging a longer servo horn takes more effort as does steering the tires when using the included wheel wideners. I instantly noticed a lack in power from my Airtronics 361 servo. And from what I can remember the Mamba 25 is only a 5 volt, 1.5 amp BEC circuit.

After plugging the MPI regulator in, it's night and day. The steering power difference is not even comparable.

The only downside is I lost the ability to use the on & off switch on the Mamba 25.

[Grizzly4x4]

Originally Posted by EeePee

The only downside is I lost the ability to use the on & off switch on the Mamba 25.

Why? Did you not remove the power wire from the Mamba RX plug? That's why I removed mine, so I could still use the switch. Everything you said is true though, night and day difference.