RCCrawler Forums

DRCMAN · 01-05-2007, 11:47 AM

Ok here is how i got more power to my rx for running High torque servo's.

I had an old 3-step tamiya speed controller that already has bec circuitry. Here is the link to them from tower http://www2.towerhobbies.com/cgi-bin...?&I=LXKAL6&P=7

First you can eliminate the motor leads and the wiring for the resistor. They are not needed because the new esc heat sink does takes care of that.

Next splice/solder on female tamiya connector (leaving enough slack to get to your batt or esc. You will need to lock the selector into the neutral position as shown in the tower link. (I removed the nut and the bushing sleve, then tightened the nut all the way down.), shrink wrap/tape up the msc. You are now done wiring. If there is no bec switch with the msc add one, this will let you turn off the power to the esc. The reason for the Female tamiya connection is to allow for running of one batt and not adding more weight. Connect batt to the male end/the new female end to the esc and the futaba conn. to the bat slot on the reciever. "!!!! DO NOT TURN ON YOUR ESC ORIGINAL POWER SWITCH !!!!" THAT WILL FRY YOUR ESC ! I have tested this and it works great. I run a 3300 mah/nimh batt and get over an hour of runtime.

This is a picture of the circuitry.
http://home-and-garden.webshots.com/...00130556rHISAH

Big Mike · 01-05-2007, 11:53 AM

Your last image is'nt working, DRC. I hope you can fix it cause I'm real interested in your setup.
Hopefully it's a wiring schematic?

DRCMAN · 01-05-2007, 12:33 PM

Big Mike the picture is up now. Not much of a schematic just eliminate extas. I was getting frustrated and poor trying to get a solution and answers. I dug into some old rc stuff and new the bec worked great from this msc. I can put together a schematic and post it up if you need.

skellyo · 01-05-2007, 12:51 PM

This is about the same price and much easier to use alternative:

http://www.starluckrc.com/catalog/pr...roducts_id=120

Big Mike · 01-05-2007, 01:39 PM

That's ok, the pic told me everything I needed to know. Thanks, dude.
The other device does look a little more simplified.

DRCMAN · 01-05-2007, 01:48 PM

Skellyo, I definitely agree price wise. I'm going to look into that, I just used what was on hand. the only advantage to the MSC is no charging and no extra batt's. I was working on a schematic of this thing and once you eliminate the un-needed wiring it's almost a direct wire to the rx.

This is a picture of the solder side.

http://home-and-garden.webshots.com/...00130556JxPHXw

DRCMAN · 01-05-2007, 01:52 PM

No problem Big Mike. Just wanted to toss that Idea out there. I'm going to look into that other setup also. the weight is almost nill and it's plug and play.

Thorsteenster · 01-05-2007, 02:00 PM

so really then, you could just splice a switch and plug inline with the battery wires, or solder em on with deans

Jeckler · 01-05-2007, 02:07 PM

There's no "circuitry" involved in this setup. All you're doing is shoving a full 7.2 volts into your receiver. Good luck to those who try this.

RC Rock Hugger · 01-05-2007, 02:18 PM

Quote:

Originally Posted by Jeckler

There's no "circuitry" involved in this setup. All you're doing is shoving a full 7.2 volts into your receiver. Good luck to those who try this.

It is no different than the old mechanical speed control, direct battery voltage to it to the receiver.

Jeckler · 01-05-2007, 02:37 PM

That connector was added when the usual pack in a Tamiya car was a 5 cell (6 volt) in a hard plastic case, around 1982. The "hot" 6 cell was an upgrade. My M-03L from 10 years ago came with a MSC as well, but not that BEC connector, because by then 6 cell packs were the norm. So you either went back to a seperate RX pack, or upgraded to an ESC to avoid burning up your stuff. Why do you suppose ESC's only come with a 6 volt BEC, or even 5?

I wonder how many receiver manufacturer's really suggest that their stuff run on over 8 volts (fully charged 6 cell Nimh pack).

mazdaparts · 01-05-2007, 03:29 PM

Not only are you putting battery voltage to the RX, but you are also getting battery voltage to the servos. Might need to put a resistor in line to drop the voltage. Only bad thing about that is it will drop to low when the battery dies.

thatguy · 01-06-2007, 12:00 AM

Quote:

Originally Posted by Jeckler

There's no "circuitry" involved in this setup. All you're doing is shoving a full 7.2 volts into your receiver. Good luck to those who try this.

why ?works fine with a bec rx. thats what the bec does dropes the voltage from 7.2 to 6 inside the rx.

drzjohn · 01-06-2007, 01:26 AM

This is an up to date way of doing it,I have one on the way! I will post up when I have tried it.http://cgi.ebay.co.uk/3A-Switch-Mode...QQcmdZViewItem

skellyo · 01-06-2007, 10:33 AM

Quote:

Originally Posted by RockShocker

Here's a place in US (Georgia) you can get 'em for $25 +s&h.
http://www.starluckrc.com/catalog/index.php?cPath=65

Umm, I think you meant to link what I already posted:

cheap BEC power fix.

RockShocker · 01-06-2007, 10:44 AM

Sorry man,wrong thread.

DRCMAN · 01-06-2007, 02:51 PM

Hey guys. I went to the lhs old school elec. guru last night and got this info. The switch used on the old tamiya style msc's had circutry built in to drop the voltage from 7.2v to 6v. He also said that the rx does drop the voltage but will eventally take a toll since I'm getting over an hour of runtime. He also suggested tapping of of five cells in the 7.2 bat and running that through a switch then into the batt. conn on the rx via a univ. conn.. The switch will allow power shutoff to the rx when needed. Just a F.W.I.

01-05-2007, 11:47 AM	#1
DRCMAN Quarry Creeper Join Date: Apr 2006 Location: Pittsburgh Posts: 412	cheap BEC power fix. Ok here is how i got more power to my rx for running High torque servo's. I had an old 3-step tamiya speed controller that already has bec circuitry. Here is the link to them from tower http://www2.towerhobbies.com/cgi-bin...?&I=LXKAL6&P=7 First you can eliminate the motor leads and the wiring for the resistor. They are not needed because the new esc heat sink does takes care of that. Next splice/solder on female tamiya connector (leaving enough slack to get to your batt or esc. You will need to lock the selector into the neutral position as shown in the tower link. (I removed the nut and the bushing sleve, then tightened the nut all the way down.), shrink wrap/tape up the msc. You are now done wiring. If there is no bec switch with the msc add one, this will let you turn off the power to the esc. The reason for the Female tamiya connection is to allow for running of one batt and not adding more weight. Connect batt to the male end/the new female end to the esc and the futaba conn. to the bat slot on the reciever. "!!!! DO NOT TURN ON YOUR ESC ORIGINAL POWER SWITCH !!!!" THAT WILL FRY YOUR ESC ! I have tested this and it works great. I run a 3300 mah/nimh batt and get over an hour of runtime. This is a picture of the circuitry. http://home-and-garden.webshots.com/...00130556rHISAH Last edited by DRCMAN; 01-05-2007 at 12:27 PM.

01-05-2007, 12:33 PM	#3
DRCMAN Quarry Creeper Join Date: Apr 2006 Location: Pittsburgh Posts: 412	Big Mike the picture is up now. Not much of a schematic just eliminate extas. I was getting frustrated and poor trying to get a solution and answers. I dug into some old rc stuff and new the bec worked great from this msc. I can put together a schematic and post it up if you need. Last edited by DRCMAN; 01-05-2007 at 12:38 PM.

01-05-2007, 01:39 PM	#5
Big Mike I wanna be Dave Join Date: Oct 2006 Location: Martinsburg WV Posts: 2,781	That's ok, the pic told me everything I needed to know. Thanks, dude. The other device does look a little more simplified. Last edited by Big Mike; 01-05-2007 at 01:42 PM.

01-05-2007, 11:53 AM	#2
Big Mike I wanna be Dave Join Date: Oct 2006 Location: Martinsburg WV Posts: 2,781	Your last image is'nt working, DRC. I hope you can fix it cause I'm real interested in your setup. Hopefully it's a wiring schematic?

01-05-2007, 12:51 PM	#4
skellyo Quarry Creeper Join Date: Jan 2006 Location: Orlando Posts: 224	This is about the same price and much easier to use alternative: http://www.starluckrc.com/catalog/pr...roducts_id=120

01-05-2007, 01:48 PM	#6
DRCMAN Quarry Creeper Join Date: Apr 2006 Location: Pittsburgh Posts: 412	Skellyo, I definitely agree price wise. I'm going to look into that, I just used what was on hand. the only advantage to the MSC is no charging and no extra batt's. I was working on a schematic of this thing and once you eliminate the un-needed wiring it's almost a direct wire to the rx. This is a picture of the solder side. http://home-and-garden.webshots.com/...00130556JxPHXw

01-05-2007, 01:52 PM	#7
DRCMAN Quarry Creeper Join Date: Apr 2006 Location: Pittsburgh Posts: 412	No problem Big Mike. Just wanted to toss that Idea out there. I'm going to look into that other setup also. the weight is almost nill and it's plug and play.

01-05-2007, 02:00 PM	#8
Thorsteenster I wanna be Dave Join Date: May 2006 Location: Arlington, VA Posts: 3,377	so really then, you could just splice a switch and plug inline with the battery wires, or solder em on with deans

01-05-2007, 02:07 PM	#9
Jeckler Rock Crawler Join Date: Jan 2004 Location: Round Rock, TX Posts: 597	There's no "circuitry" involved in this setup. All you're doing is shoving a full 7.2 volts into your receiver. Good luck to those who try this.

01-05-2007, 02:37 PM	#11
Jeckler Rock Crawler Join Date: Jan 2004 Location: Round Rock, TX Posts: 597	That connector was added when the usual pack in a Tamiya car was a 5 cell (6 volt) in a hard plastic case, around 1982. The "hot" 6 cell was an upgrade. My M-03L from 10 years ago came with a MSC as well, but not that BEC connector, because by then 6 cell packs were the norm. So you either went back to a seperate RX pack, or upgraded to an ESC to avoid burning up your stuff. Why do you suppose ESC's only come with a 6 volt BEC, or even 5? I wonder how many receiver manufacturer's really suggest that their stuff run on over 8 volts (fully charged 6 cell Nimh pack).

01-05-2007, 03:29 PM	#12
mazdaparts Quarry Creeper Join Date: Jul 2005 Location: Oran, MO Posts: 347	Not only are you putting battery voltage to the RX, but you are also getting battery voltage to the servos. Might need to put a resistor in line to drop the voltage. Only bad thing about that is it will drop to low when the battery dies.

01-06-2007, 01:26 AM	#14
drzjohn Rock Crawler Join Date: Jan 2006 Location: Derbyshire UK Posts: 623	This is an up to date way of doing it,I have one on the way! I will post up when I have tried it.http://cgi.ebay.co.uk/3A-Switch-Mode...QQcmdZViewItem

01-06-2007, 10:44 AM	#16
RockShocker Newbie Join Date: Nov 2006 Location: RedRock near BedRock Posts: 44	Sorry man,wrong thread.

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01-06-2007, 02:51 PM	#17
DRCMAN Quarry Creeper Join Date: Apr 2006 Location: Pittsburgh Posts: 412	Hey guys. I went to the lhs old school elec. guru last night and got this info. The switch used on the old tamiya style msc's had circutry built in to drop the voltage from 7.2v to 6v. He also said that the rx does drop the voltage but will eventally take a toll since I'm getting over an hour of runtime. He also suggested tapping of of five cells in the 7.2 bat and running that through a switch then into the batt. conn on the rx via a univ. conn.. The switch will allow power shutoff to the rx when needed. Just a F.W.I.

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Thread: cheap BEC power fix.