Electric retrac battery question
06-22-2015, 07:33 AM
#1
Electric retrac battery question
Looking for advice from some modelers using elec retracs.I will be using a set of Robart 635 elec retracs in my new project and I was wondering if I can run a tap to one (or both) of my A123 rx packs or do I need to have a separate battery. Robart says the gear can be hooked up to the rx but I would not consider that option.
Thx
Vin...
Thx
Vin...
06-22-2015, 08:39 AM
#3
My Feedback: (2)
Join Date: Jun 2004
Location: Sailing in the Eastern Caribbean
Posts: 4,047
Likes: 0
Received 1 Like
on
1 Post
The problems arise when you get a jammed wheel or gear door resulting in a continued high current draw from the stalled retract motor. You need to do some sums based on the draw from a stalled retract unit and your reserve battery battery capacity.
Me, anytime I used electric retracts I used a separate battery and worried a little less.
Me, anytime I used electric retracts I used a separate battery and worried a little less.
06-22-2015, 08:42 AM
#4
The problems arise when you get a jammed wheel or gear door resulting in a continued high current draw from the stalled retract motor. You need to do some sums based on the draw from a stalled retract unit and your reserve battery battery capacity.
Me, anytime I used electric retracts I used a separate battery and worried a little less.
Me, anytime I used electric retracts I used a separate battery and worried a little less.
06-22-2015, 08:43 AM
#5
My Feedback: (57)
The problems arise when you get a jammed wheel or gear door resulting in a continued high current draw from the stalled retract motor. You need to do some sums based on the draw from a stalled retract unit and your reserve battery battery capacity.
Me, anytime I used electric retracts I used a separate battery and worried a little less.
Me, anytime I used electric retracts I used a separate battery and worried a little less.
06-22-2015, 08:46 AM
#6
My Feedback: (57)
The problems arise when you get a jammed wheel or gear door resulting in a continued high current draw from the stalled retract motor. You need to do some sums based on the draw from a stalled retract unit and your reserve battery battery capacity.
Me, anytime I used electric retracts I used a separate battery and worried a little less.
Me, anytime I used electric retracts I used a separate battery and worried a little less.
06-22-2015, 09:01 AM
#7
My Feedback: (2)
Join Date: Jun 2004
Location: Sailing in the Eastern Caribbean
Posts: 4,047
Likes: 0
Received 1 Like
on
1 Post
Most likely to occur on take off and more common in grass strip operation than smooth runways.
06-22-2015, 09:13 AM
#10
My Feedback: (24)
Join Date: Dec 2001
Location: Fond du Lac,
WI
Posts: 2,234
Likes: 0
Received 0 Likes
on
0 Posts
Hi Vin:
I keep battery lead for my electric retracts separate, just in case a transient spike occurs during the retract cycle. I have electric Robarts in my Eurosport 635's as does my buddy Dave. I use a Hobbico LiFe from Tower LXDVCA 6.6v/1300ma/10C for $22 and change. Current draw per cycle is about 15 mAH.
Tom
I keep battery lead for my electric retracts separate, just in case a transient spike occurs during the retract cycle. I have electric Robarts in my Eurosport 635's as does my buddy Dave. I use a Hobbico LiFe from Tower LXDVCA 6.6v/1300ma/10C for $22 and change. Current draw per cycle is about 15 mAH.
Tom
Last edited by Tom Antlfinger; 06-22-2015 at 09:41 AM.
06-22-2015, 09:14 AM
#11
My Feedback: (1)
Join Date: Dec 2001
Location: Fort Wayne, IN
Posts: 3,759
Likes: 0
Received 0 Likes
on
0 Posts
There are no limit switches, they shut down when a preset current draw is reached. no matter if they are stalled part way or all the way in. no current is drawn after they stop. That is how all electric retracts work. No worries if you don't need the extra weight, just plug 'em in to the RX.
06-22-2015, 11:27 AM
#14
My Feedback: (7)
There are no limit switches, they shut down when a preset current draw is reached. no matter if they are stalled part way or all the way in. no current is drawn after they stop. That is how all electric retracts work. No worries if you don't need the extra weight, just plug 'em in to the RX.
06-22-2015, 01:28 PM
#15
And just FYI, Behotec got it right from the start by using an encoder that counts revolutions on the jackscrew for travel limits. Current draw is only used in a stall situation or as a backup if the encoder ever fails.
06-22-2015, 01:46 PM
#16
My Feedback: (1)
Join Date: Dec 2001
Location: Fort Wayne, IN
Posts: 3,759
Likes: 0
Received 0 Likes
on
0 Posts
Big bubbles, no Tribbles..........May all your Tribbles be little ones.........Scotty to Captain Kirk........LOL
All Of the "New " electric designs don't use no stinking limit switches.............
All Of the "New " electric designs don't use no stinking limit switches.............
06-23-2015, 05:59 AM
#17
Vincent , I have electric retracts in a few various planes and have set up each one differently based on needed nose weight etc. I have ESM gear , r
Robart gear and Down and Locked all three use and over-current protection . I have setup power through the receiver, seperate power and shared power via Batt share. All setups have worked well with no problems of lost or reduced power to the receiver. If you are using enough battery and your retracts are setup and maintained within reason you shouldn't have problems with either setup you choose. Because of the over current protection the retracts will stop before the voltage drop is enough to interfere with the receiver. The key is to be sure you have enough battery to start with . You haven't said how many mah your packs are but if they are both 2300 to 2500 mah a123 packs then you will have enough battery for several flights on almost any 50 to 60cc warbirds with elect. retracts.
Robart gear and Down and Locked all three use and over-current protection . I have setup power through the receiver, seperate power and shared power via Batt share. All setups have worked well with no problems of lost or reduced power to the receiver. If you are using enough battery and your retracts are setup and maintained within reason you shouldn't have problems with either setup you choose. Because of the over current protection the retracts will stop before the voltage drop is enough to interfere with the receiver. The key is to be sure you have enough battery to start with . You haven't said how many mah your packs are but if they are both 2300 to 2500 mah a123 packs then you will have enough battery for several flights on almost any 50 to 60cc warbirds with elect. retracts.
06-23-2015, 07:15 AM
#18
Vincent , I have electric retracts in a few various planes and have set up each one differently based on needed nose weight etc. I have ESM gear , r
Robart gear and Down and Locked all three use and over-current protection . I have setup power through the receiver, seperate power and shared power via Batt share. All setups have worked well with no problems of lost or reduced power to the receiver. If you are using enough battery and your retracts are setup and maintained within reason you shouldn't have problems with either setup you choose. Because of the over current protection the retracts will stop before the voltage drop is enough to interfere with the receiver. The key is to be sure you have enough battery to start with . You haven't said how many mah your packs are but if they are both 2300 to 2500 mah a123 packs then you will have enough battery for several flights on almost any 50 to 60cc warbirds with elect. retracts.
Robart gear and Down and Locked all three use and over-current protection . I have setup power through the receiver, seperate power and shared power via Batt share. All setups have worked well with no problems of lost or reduced power to the receiver. If you are using enough battery and your retracts are setup and maintained within reason you shouldn't have problems with either setup you choose. Because of the over current protection the retracts will stop before the voltage drop is enough to interfere with the receiver. The key is to be sure you have enough battery to start with . You haven't said how many mah your packs are but if they are both 2300 to 2500 mah a123 packs then you will have enough battery for several flights on almost any 50 to 60cc warbirds with elect. retracts.
06-23-2015, 09:19 AM
#19
My Feedback: (134)
Not sure about the battery usage of other gear but the Behotec 50 size retract and electric brakes on my Comp Arf Viper use very little juice per flight. I am using a dedicated 3 cell LiPo for the gear but only for the weight. On a typical outing of 4-5 flights I will only use 200-250 mah. In fact only charge it ever 4th or 5th time out. Now that I know what the usage of this gear is I certainly would not think twice about using one of my flight packs to also power the gear. Also, the Behotec gear let you set a low voltage gear safe level to drop the gear if you ever get into a low voltage condition.
06-23-2015, 02:35 PM
#20
Vincent you will be fine with the dual setup 2500mah a123 cells with just running the retracts off of the receiver . If you want more security but still only 2 batt packs, power your gear from the second leg off of a Batt Share . You will have 2 pack redundancy for the receiver and the gear power will be isolated from the receiver too. This is the setup I use in my 1/5 scale Zero and I get 8 10 minute flights before I get to my 40% reserve point and time to recharge
Last edited by CK1; 06-23-2015 at 02:39 PM.
06-24-2015, 01:43 AM
#21
I used to use a separate battery now I don't on my Electron ER40 and ER50's. All run of turbine battery.
Retract servos (for mechanical retracts) & electric brakes run off my turbine battery on my BVM Sabre.
My next model will use the turbine battery for landing lights as well. It's there already, why not use it?
John.
Last edited by Boomerang1; 06-24-2015 at 01:45 AM.
