RCCrawler Forums

Custom Trendz Inc. · 06-03-2006, 02:10 PM

Hi, i am running a Moped V16R esc. And i have a hitec 945mg servo in front and a crap Futaba FP-S14B in back until i get my z650m in. Will having that weak servo in the back lead to it drawing more amperage from the BEC than usual? Its just this esc has 5v at 3amp BEC and i would think that is enough for 2 servos. So does that weak servo draw more amperage because it has have less power and alot of strain?

tkruger · 06-03-2006, 03:50 PM

An electric motor (like the one in the servo) will draw the most amps when it is closest to or at its stall point. As to if that servo will draw more amps than the front one I am not sure. The rule that I go for is to have enough amps available to cover both servos at thier stall points.

Custom Trendz Inc. · 06-03-2006, 03:54 PM

thanks, where do i find out how many amps my Hitec 945Mg draws and my JR Z650M draw?

JohnRobHolmes · 06-03-2006, 03:56 PM

A weaker servo will draw less amperage.

Stronger servos have a higher gear reduction combined with a lower wind motor. At stall the low wind motor pulls the highest amperage.

JohnRobHolmes · 06-03-2006, 03:57 PM

Quote:

Originally Posted by Custom Trendz Inc.

thanks, where do i find out how many amps my Hitec 945Mg draws and my JR Z650M draw?

Good luck finding that. Servos are rarely rated at stall amperage. The easiest way to find out would be an inline ampmeter, wired in with a harness.

Custom Trendz Inc. · 06-03-2006, 04:09 PM

but do you think i will be fine running GP3300's on a 5V/3A rated esc? I will be running a Hitec 945mg in front which is 122oz at 4.8v and a JR Z650M in the rear which is rated at 142oz at 6v.

Custom Trendz Inc. · 06-03-2006, 04:10 PM

and would running a 3300uf cap help it any because someone told me it would.

dezfan · 06-03-2006, 04:44 PM

I really don't know what's going on w/ your set up? I ran two 200+ oz. servos w/o issue?

Custom Trendz Inc. · 06-03-2006, 04:45 PM

idk what the problem is, might be the crap servo or something. It was glitchy and once i setup my trim on the servo it worked excelent. But since the rear is having so much strain its making everything glitch.

JohnRobHolmes · 06-03-2006, 05:52 PM

Sounds like a cheap servo causing a problem.

It could be many things though. You can either try a new servo, or stick a RX pack on, or both. No way to figure it out without trying new stuff.

Custom Trendz Inc. · 06-03-2006, 06:40 PM

well i am getting the case for my z650m tommorow so ill see if that is the problem.

max to crawl · 06-03-2006, 07:57 PM

i used to run the jrz650m servos.......kept burning up one in the front(3 servos @$54).....switched it to a hitec 5945 in front and the jr lasted maybe 2 minutes in the rear, it had a glitch for some reason........now i have both hitecs and no more issues. no more jr servos for me...
it has been my experience that the lighter torque servo will draw more current than that of the higher torque. ( on a Y-harness) and burn themselves out.

Custom Trendz Inc. · 06-03-2006, 08:17 PM

hmm i hope my rear doesnt burn out :(

Custom Trendz Inc. · 06-04-2006, 07:43 PM

well now i am running the z650m and the 945mg on a y harness and i get crazy glitches when i turn. Whats the problem? I just cant find the problem, the esc and servo glitches only when the servo's are under load.

tkruger · 06-04-2006, 08:16 PM

Quote:

Originally Posted by Custom Trendz Inc.

well now i am running the z650m and the 945mg on a y harness and i get crazy glitches when i turn. Whats the problem? I just cant find the problem, the esc and servo glitches only when the servo's are under load.

Check if all of your connections are tight. If there are any areas of your wires that are frayed this may also cause it. Does any part of your y-harness or the servo wire run along one of the power wires to the motor or the battery? If so that may also cause electrical interference. If that is the can run the wires elsewhere.

Also try connecting a receiver pack just to see if that eliminates the problem. If it does it may be that the ESC cannot handle the two servos at once or the receiver is not transferring the needed power. To test if it is the receiver try plugging the rear servo into the 3rd channel (if you have one).

dezfan · 06-04-2006, 08:21 PM

Is your Receiver antenna touching anything that can conduct electricity? Can you reposition it or switch it out for another receiver?

hvydty1 · 06-04-2006, 08:28 PM

What is the BEC rating on the Moped? If it is under 6 volt, that is your problem.
You have two high torque servos trying to to turn massive tires drawing alot of
power from a small esc, and the small esc is glitching cause it can't keep up with the load it is beeing asked to deliver. What kind of truck are you running? How big are the tires? You're probably gonna have to switch to a reciever pack or a nitro regulator instead of trying to let the esc BEC try to power your rig.

dezfan · 06-04-2006, 08:37 PM

Quote:

Originally Posted by hvydty1

What is the BEC rating on the Moped? If it is under 6 volt, that is your problem.
You have two high torque servos trying to to turn massive tires drawing alot of
power from a small esc, and the small esc is glitching cause it can't keep up with the load it is beeing asked to deliver. What kind of truck are you running? How big are the tires? You're probably gonna have to switch to a reciever pack or a nitro regulator instead of trying to let the esc BEC try to power your rig.

The MOPED is rated at 5V (3A) and handles the two (2) 200+ oz servos on my Clod w/ twin 55t lathes fine? And he is having the same problem w/ a receiver pack.

hvydty1 · 06-04-2006, 08:41 PM

Saw that now, everyone posted while I was typing. lol

Custom Trendz Inc. · 06-05-2006, 04:05 PM

their is wayy more glitching when the servo's are under large ammounts of stress.

06-03-2006, 02:10 PM	#1
Custom Trendz Inc. Rock Stacker Join Date: Mar 2005 Location: Wethersfield, Connecticut Posts: 64	Drawing more power? Hi, i am running a Moped V16R esc. And i have a hitec 945mg servo in front and a crap Futaba FP-S14B in back until i get my z650m in. Will having that weak servo in the back lead to it drawing more amperage from the BEC than usual? Its just this esc has 5v at 3amp BEC and i would think that is enough for 2 servos. So does that weak servo draw more amperage because it has have less power and alot of strain?

06-03-2006, 04:44 PM	#8
dezfan I wanna be Dave Join Date: Dec 2005 Location: Happiness is a warm AK. Posts: 12,563	I really don't know what's going on w/ your set up? I ran two 200+ oz. servos w/o issue? Last edited by dezfan; 06-03-2006 at 06:14 PM.

06-04-2006, 07:43 PM	#14
Custom Trendz Inc. Rock Stacker Join Date: Mar 2005 Location: Wethersfield, Connecticut Posts: 64	well now i am running the z650m and the 945mg on a y harness and i get crazy glitches when i turn. Whats the problem? I just cant find the problem, the esc and servo glitches only when the servo's are under load. Last edited by Custom Trendz Inc.; 06-04-2006 at 07:54 PM.

06-03-2006, 03:50 PM	#2
tkruger Pebble Pounder Join Date: Jul 2005 Location: Greece Posts: 154	An electric motor (like the one in the servo) will draw the most amps when it is closest to or at its stall point. As to if that servo will draw more amps than the front one I am not sure. The rule that I go for is to have enough amps available to cover both servos at thier stall points.

06-03-2006, 03:54 PM	#3
Custom Trendz Inc. Rock Stacker Join Date: Mar 2005 Location: Wethersfield, Connecticut Posts: 64	thanks, where do i find out how many amps my Hitec 945Mg draws and my JR Z650M draw?

06-03-2006, 03:56 PM	#4
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	A weaker servo will draw less amperage. Stronger servos have a higher gear reduction combined with a lower wind motor. At stall the low wind motor pulls the highest amperage.

06-03-2006, 04:09 PM	#6
Custom Trendz Inc. Rock Stacker Join Date: Mar 2005 Location: Wethersfield, Connecticut Posts: 64	but do you think i will be fine running GP3300's on a 5V/3A rated esc? I will be running a Hitec 945mg in front which is 122oz at 4.8v and a JR Z650M in the rear which is rated at 142oz at 6v.

06-03-2006, 04:10 PM	#7
Custom Trendz Inc. Rock Stacker Join Date: Mar 2005 Location: Wethersfield, Connecticut Posts: 64	and would running a 3300uf cap help it any because someone told me it would.

06-03-2006, 04:45 PM	#9
Custom Trendz Inc. Rock Stacker Join Date: Mar 2005 Location: Wethersfield, Connecticut Posts: 64	idk what the problem is, might be the crap servo or something. It was glitchy and once i setup my trim on the servo it worked excelent. But since the rear is having so much strain its making everything glitch.

06-03-2006, 05:52 PM	#10
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	Sounds like a cheap servo causing a problem. It could be many things though. You can either try a new servo, or stick a RX pack on, or both. No way to figure it out without trying new stuff.

06-03-2006, 06:40 PM	#11
Custom Trendz Inc. Rock Stacker Join Date: Mar 2005 Location: Wethersfield, Connecticut Posts: 64	well i am getting the case for my z650m tommorow so ill see if that is the problem.

06-03-2006, 07:57 PM	#12
max to crawl Newbie Join Date: Jan 2006 Location: kansas city Posts: 24	i used to run the jrz650m servos.......kept burning up one in the front(3 servos @$54).....switched it to a hitec 5945 in front and the jr lasted maybe 2 minutes in the rear, it had a glitch for some reason........now i have both hitecs and no more issues. no more jr servos for me... it has been my experience that the lighter torque servo will draw more current than that of the higher torque. ( on a Y-harness) and burn themselves out.

06-03-2006, 08:17 PM	#13
Custom Trendz Inc. Rock Stacker Join Date: Mar 2005 Location: Wethersfield, Connecticut Posts: 64	hmm i hope my rear doesnt burn out :(

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06-04-2006, 08:21 PM	#16
dezfan I wanna be Dave Join Date: Dec 2005 Location: Happiness is a warm AK. Posts: 12,563	Is your Receiver antenna touching anything that can conduct electricity? Can you reposition it or switch it out for another receiver?

06-04-2006, 08:28 PM	#17
hvydty1 Quarry Creeper Join Date: Feb 2006 Location: Angier N.C. Posts: 387	What is the BEC rating on the Moped? If it is under 6 volt, that is your problem. You have two high torque servos trying to to turn massive tires drawing alot of power from a small esc, and the small esc is glitching cause it can't keep up with the load it is beeing asked to deliver. What kind of truck are you running? How big are the tires? You're probably gonna have to switch to a reciever pack or a nitro regulator instead of trying to let the esc BEC try to power your rig.

06-04-2006, 08:41 PM	#19
hvydty1 Quarry Creeper Join Date: Feb 2006 Location: Angier N.C. Posts: 387	Saw that now, everyone posted while I was typing. lol

06-05-2006, 04:05 PM	#20
Custom Trendz Inc. Rock Stacker Join Date: Mar 2005 Location: Wethersfield, Connecticut Posts: 64	their is wayy more glitching when the servo's are under large ammounts of stress.

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