Spektrum DX-7
05-26-2007, 10:46 AM
#2078
RE: Spektrum DX-7
You guys will get a kick out of the latest addition to our evaluation of 2.4. This was literally "from the trenches". Said a lot for the robust capabilities of Spektrum's DX-7. Needless to say it certainly got the evaluation teams attention ! ! !
http://004edc4.netsolhost.com/ss_results.htm#D7eval While we are in the middle of an evolutionally change in our hobby for the better, like everything else...what is will be better tomorrow.
http://004edc4.netsolhost.com/ss_results.htm#D7eval While we are in the middle of an evolutionally change in our hobby for the better, like everything else...what is will be better tomorrow.
05-26-2007, 12:51 PM
#2079
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RE: Spektrum DX-7
ORIGINAL: aerobob
What really is going on is that the RX "remembers" the control surface positions (including throttle) that are held at the time the bind button is pressed. Then, after binding, when you first turn on the Rx (if the TX is off), the "no signal" settings that were stored at the binding is where everything goes to. When you turn on the Tx after that, of course the RX then goes to the current transmitted signal.
If you then LOSE the TX signal for some reason, the RX will again return all the settings to those that were stored at Binding.
I think that's what Spektrum calls "Smart Safe", but I've found it to be pretty useless in gas aerobats.
What really is going on is that the RX "remembers" the control surface positions (including throttle) that are held at the time the bind button is pressed. Then, after binding, when you first turn on the Rx (if the TX is off), the "no signal" settings that were stored at the binding is where everything goes to. When you turn on the Tx after that, of course the RX then goes to the current transmitted signal.
If you then LOSE the TX signal for some reason, the RX will again return all the settings to those that were stored at Binding.
I think that's what Spektrum calls "Smart Safe", but I've found it to be pretty useless in gas aerobats.
05-26-2007, 01:21 PM
#2080
RE: Spektrum DX-7
Bob, I thought only the throttle will return to the bound position and ther surfaces will remain at last know?
That's been my experience also. The throttle will go to fail safe position and all other surfaces remember last good signal. The other settings are only remembered at switch on... bind with gear down.
bigbird
05-26-2007, 03:27 PM
#2081
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RE: Spektrum DX-7
Maybe I'm confused with the AR9000 that I'm playing with.... it's a little different.
ORIGINAL: skorman
When signal is lost, only the throttle returns to its fail safe position. All other channels hold their last position when the signal was lost.
ORIGINAL: aerobob
What really is going on is that the RX "remembers" the control surface positions (including throttle) that are held at the time the bind button is pressed. Then, after binding, when you first turn on the Rx (if the TX is off), the "no signal" settings that were stored at the binding is where everything goes to. When you turn on the Tx after that, of course the RX then goes to the current transmitted signal.
If you then LOSE the TX signal for some reason, the RX will again return all the settings to those that were stored at Binding.
I think that's what Spektrum calls "Smart Safe", but I've found it to be pretty useless in gas aerobats.
What really is going on is that the RX "remembers" the control surface positions (including throttle) that are held at the time the bind button is pressed. Then, after binding, when you first turn on the Rx (if the TX is off), the "no signal" settings that were stored at the binding is where everything goes to. When you turn on the Tx after that, of course the RX then goes to the current transmitted signal.
If you then LOSE the TX signal for some reason, the RX will again return all the settings to those that were stored at Binding.
I think that's what Spektrum calls "Smart Safe", but I've found it to be pretty useless in gas aerobats.
05-26-2007, 03:29 PM
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RE: Spektrum DX-7
Yep.... I think you're right.... see my other confused post....
Gotta quit playing with different flavors of stuff.
"Shameless Sales Plug" - I have my Spektrum Dx 7 with two receivers for sale at a VERY good price, if anyone is interested. I'm flying the 9303 w/ Spektrum module and AR 9000 now... all works wonderful.
Gotta quit playing with different flavors of stuff.
"Shameless Sales Plug" - I have my Spektrum Dx 7 with two receivers for sale at a VERY good price, if anyone is interested. I'm flying the 9303 w/ Spektrum module and AR 9000 now... all works wonderful.
ORIGINAL: bigbird007
That's been my experience also. The throttle will go to fail safe position and all other surfaces remember last good signal. The other settings are only remembered at switch on... bind with gear down.
bigbird
Bob, I thought only the throttle will return to the bound position and ther surfaces will remain at last know?
That's been my experience also. The throttle will go to fail safe position and all other surfaces remember last good signal. The other settings are only remembered at switch on... bind with gear down.
bigbird
05-26-2007, 09:33 PM
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RE: Spektrum DX-7
I finally got up the nerve to try the Spektrum AR7000 in my 1/4 scale model of the Hanriot HD-1. Part of my concern was the aluminum cowl and the aluminum skin (.012 litho plate) that covers the front area of the fuselage where the rx is located. The main rx is under the pilot seat and the satellite has a 12" extension and is back about where the 5 is on the fuselage side. Worked flawlessly. I was careful to watch the rx battery voltage, and I also had one of those little Spektrum voltage protectors installed. Previously I've flown the model with a JR 10 channel dual conversion PCM rx, but with all those flying wires there were always one or two glitches each flight. The Spektrum was rock solid.
Thanks to all who contribute their experiences to this thread, as I tried to read most of the reports and learn from others to minimize the risk....
Randy
Thanks to all who contribute their experiences to this thread, as I tried to read most of the reports and learn from others to minimize the risk....
Randy
05-26-2007, 11:02 PM
#2084
RE: Spektrum DX-7
G'day Randy,
I was worried about battery voltage, on my Katana, have already lost one, due to battery failure.
I had a 1700Mah, 4 cell nicad, in it, so I just added an extra 1100Mah, 4 cell pack & switch, plugged it into my gear slot, in the RX, & also bought & installed a West, battery monitor, the monitor shows what your lowest in flight voltage got down to, has never got below 4.8volts, yet, & that is reading the voltage drop spikes, highly recommended system.
See web sites, http://www.westonuk.co.uk/index_176.htm
&, http://www.rcbatteryclinic.com/
Just scroll down the left side of the Battery Clinic page to see Parrallel Operation, = reliability & more flight time.
I was worried about battery voltage, on my Katana, have already lost one, due to battery failure.
I had a 1700Mah, 4 cell nicad, in it, so I just added an extra 1100Mah, 4 cell pack & switch, plugged it into my gear slot, in the RX, & also bought & installed a West, battery monitor, the monitor shows what your lowest in flight voltage got down to, has never got below 4.8volts, yet, & that is reading the voltage drop spikes, highly recommended system.
See web sites, http://www.westonuk.co.uk/index_176.htm
&, http://www.rcbatteryclinic.com/
Just scroll down the left side of the Battery Clinic page to see Parrallel Operation, = reliability & more flight time.
05-27-2007, 09:05 AM
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RE: Spektrum DX-7
Thanks Allan,
I looked at parallel battery arangements but with the plane being built and there already being another pack and switch for the onboard glow driver, there just wasn't much extra room. I did order a couple of 5 cell packs from
http://www.hangtimes.com/giantrxpacks.html
whose products were recommended earlier in this thread. The model seldom gets flown and when it does three flights a day is about maximum. Plenty of time for topping up the batteries between flights.
Parallel packs and switch arrangements are a future consideration though. Fromeco offers some products that look pretty nice.... http://www.fromeco.org/
Randy
I looked at parallel battery arangements but with the plane being built and there already being another pack and switch for the onboard glow driver, there just wasn't much extra room. I did order a couple of 5 cell packs from
http://www.hangtimes.com/giantrxpacks.html
whose products were recommended earlier in this thread. The model seldom gets flown and when it does three flights a day is about maximum. Plenty of time for topping up the batteries between flights.
Parallel packs and switch arrangements are a future consideration though. Fromeco offers some products that look pretty nice.... http://www.fromeco.org/
Randy
05-27-2007, 09:37 AM
#2088
RE: Spektrum DX-7
If you really want to know if your battery setup is up to snuff -or if your servos are setup correctly---
purchase a simple little voltmeter by EXPERT.
available in 4.8 or 6 v.
weight is a few grams -plug it ANYWHERE into system which sees battery power with switch ON.
use a Y if needed to get there .
The little LCD display zips up to full when battery is full.
now move each servo full travel -watch the meter-
Basically-the meter sees actual voltage in entire circuit that the battery feeds.
So for example --if the battery reads high when nothing is moving - yet drops quickly when a certian servo moves - -you are seeing a "problem" with that servo or linkage.
Now - put a battery in the plane which is old or vey small or weak. and look at the meter - as you move the sticks - the meter will rapidly drop .
OR- stall a servo -again the meter drops .
The SIZE of a battery is important as is the IMPEDANCE--which is a fancy way of saying how easily the battry will release current.
Example a 2700ma pack with high impedance (these are common as fleas on a dog ) is a terrible choice for a model with 3D or active flying .
You would be better off with a 1400 ma pack with extremely low impedance .
tho the number of flights seemingly would be far less --in actual practice-the 2700ma pack would quickly be choking power (voltage)to low and very possibly below rx operating threshold.
This tiny readout will tell you more than a whole roomful of test equipment and $$chargers .
Why?
Simply because it shows what is happening AS it happens.
I use one of these a 6 v model-and a 2300 ma, A123 dual cell pack - NO reg -for my planes - until the cells hit under 3 volts - the current available will melt wires.
when ready to take off -I look into canopy at the meter - and move the sticks - IF for some reason the meter takes a dump- something is wrong - low cells stalled servo -whatever .
THAT kind of info simply is not available from stuff sitting on your shelf.
purchase a simple little voltmeter by EXPERT.
available in 4.8 or 6 v.
weight is a few grams -plug it ANYWHERE into system which sees battery power with switch ON.
use a Y if needed to get there .
The little LCD display zips up to full when battery is full.
now move each servo full travel -watch the meter-
Basically-the meter sees actual voltage in entire circuit that the battery feeds.
So for example --if the battery reads high when nothing is moving - yet drops quickly when a certian servo moves - -you are seeing a "problem" with that servo or linkage.
Now - put a battery in the plane which is old or vey small or weak. and look at the meter - as you move the sticks - the meter will rapidly drop .
OR- stall a servo -again the meter drops .
The SIZE of a battery is important as is the IMPEDANCE--which is a fancy way of saying how easily the battry will release current.
Example a 2700ma pack with high impedance (these are common as fleas on a dog ) is a terrible choice for a model with 3D or active flying .
You would be better off with a 1400 ma pack with extremely low impedance .
tho the number of flights seemingly would be far less --in actual practice-the 2700ma pack would quickly be choking power (voltage)to low and very possibly below rx operating threshold.
This tiny readout will tell you more than a whole roomful of test equipment and $$chargers .
Why?
Simply because it shows what is happening AS it happens.
I use one of these a 6 v model-and a 2300 ma, A123 dual cell pack - NO reg -for my planes - until the cells hit under 3 volts - the current available will melt wires.
when ready to take off -I look into canopy at the meter - and move the sticks - IF for some reason the meter takes a dump- something is wrong - low cells stalled servo -whatever .
THAT kind of info simply is not available from stuff sitting on your shelf.
05-27-2007, 09:42 AM
#2089
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RE: Spektrum DX-7
Those are handy.... Maxx Products sells 'em, too. Interestingly, LONG before the DX7 and it's "reboot" voltage.... my JR PCM R955 rx's would "see" equally-low voltage spikes on my pattern setups. Five digital JR servos, on a piped OS 1.60.... when running, holding it in place, stirring the sticks (8411 and 8231 digital servos) absolutely drove the thing DOWN into the red.... was it low enough to cause problems? Evidently not.
The 2.4 Spektrum stuff appears to just be more sensitive to voltage stability on the RX. Just something we have to learn.
The 2.4 Spektrum stuff appears to just be more sensitive to voltage stability on the RX. Just something we have to learn.
05-27-2007, 09:55 AM
#2090
RE: Spektrum DX-7
Bob -after I really got into checking operating levels -using the meter - I threw away (really) almost every pack I had.
It beacame obvious that "weak" servos were simply weak batteries.
It beacame obvious that "weak" servos were simply weak batteries.
05-27-2007, 09:58 AM
#2091
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RE: Spektrum DX-7
Amen to that. There are so many BAD, really BAD, NIMH cells out there that it's a miracle we don't have more airplanes falling out of the sky everywhere.
Or... maybe they are?
Or... maybe they are?
ORIGINAL: dick Hanson
Bob -after I really got into checking operating levels -using the meter - I threw away (really) almost every pack I had.
It beacame obvious that "weak" servos were simply weak batteries.
Bob -after I really got into checking operating levels -using the meter - I threw away (really) almost every pack I had.
It beacame obvious that "weak" servos were simply weak batteries.
05-27-2007, 10:49 AM
#2092
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RE: Spektrum DX-7
Yep. We're all getting an eduation now. I think I will pick up one of those volt meters myself. Being able to check realtime could alert you to a bad servo.
05-27-2007, 02:20 PM
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RE: Spektrum DX-7
I have two of those Jenerally Reliable 5 cell 2700ma nimh battery packs that at the time seemed to be the best way to go...new this year too.....I have one of those LED voltage monitors also....time to go play with it a bit.....
Randy
Randy
05-27-2007, 02:26 PM
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RE: Spektrum DX-7
I hope yours are better than mine that I've tried in the past. Two different brands of 2700mah. Had such high internal resistance they would drop almost a cell's worth just from sitting a day or two. When swirling sticks with digitals, they were horrible. It was actually scary the first time I watched the voltmeter. I thought things were so "good"; all that "capacity"..... just wasn't usable.
Good luck!!
Good luck!!
ORIGINAL: V2PLUS10
I have two of those Jenerally Reliable 5 cell 2700ma nimh battery packs that at the time seemed to be the best way to go...new this year too.....I have one of those LED voltage monitors also....time to go play with it a bit.....
Randy
I have two of those Jenerally Reliable 5 cell 2700ma nimh battery packs that at the time seemed to be the best way to go...new this year too.....I have one of those LED voltage monitors also....time to go play with it a bit.....
Randy
05-27-2007, 09:17 PM
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RE: Spektrum DX-7
More un-scientific testing....Apparently the Fromeco Badger rx fail-safe switch allows you to read system voltage through the charge jack with the system switched on..a nice feature.
So, with a Hobbico ESV in the charge jack ( an additional load), and a Fluke multimeter in one of the aileron outputs, I plugged in a variety of batteries (one at a time!) in various stages of discharge. The system continued to function until about 3 volts were reached....this was not absolute as the battery voltage dropped rapidly from about 3.5 to 2.9 were everything stopped working. Although, the bind LED's were still lit on both main and satellite rx's at 2.9 volts
With the normal onboard 5 cell 2700ma JR nimh pack providing power, the voltage at rest with the system on was 6.2 volts, with the ESV plugged in the charge port and the system on it was 5.9 volts on both meters, and the lowest I could get with 4 digital servos..3 HS-5945's and a 5985 was 5.7 volts, on both meters again, this wiggling all the sticks and loading the elevators (2 servos) with my free hand. I'm sure I haven't charged this battery in over a week.
I really don't know if this means much but it has bolstered my confidence in the system as I have it installed in my Yak....much better than just wondering what may be going on with the power supply to the rx....
Maybe now I'll try something similar on the Hanriot, which has an 1800ma 4cell nicad pack....no Fromeco switch though....
Randy
So, with a Hobbico ESV in the charge jack ( an additional load), and a Fluke multimeter in one of the aileron outputs, I plugged in a variety of batteries (one at a time!) in various stages of discharge. The system continued to function until about 3 volts were reached....this was not absolute as the battery voltage dropped rapidly from about 3.5 to 2.9 were everything stopped working. Although, the bind LED's were still lit on both main and satellite rx's at 2.9 volts
With the normal onboard 5 cell 2700ma JR nimh pack providing power, the voltage at rest with the system on was 6.2 volts, with the ESV plugged in the charge port and the system on it was 5.9 volts on both meters, and the lowest I could get with 4 digital servos..3 HS-5945's and a 5985 was 5.7 volts, on both meters again, this wiggling all the sticks and loading the elevators (2 servos) with my free hand. I'm sure I haven't charged this battery in over a week.
I really don't know if this means much but it has bolstered my confidence in the system as I have it installed in my Yak....much better than just wondering what may be going on with the power supply to the rx....
Maybe now I'll try something similar on the Hanriot, which has an 1800ma 4cell nicad pack....no Fromeco switch though....
Randy
05-28-2007, 07:05 PM
#2100
RE: Spektrum DX-7
Hmmmm. After searching horizon, all I see is the 300...
Hey Dick, this thing looks essentually like a Hobbico voltwatch for 4.8 and 6v, any idea how they differ?
Thanks
bigbird
Hey Dick, this thing looks essentually like a Hobbico voltwatch for 4.8 and 6v, any idea how they differ?
Thanks
bigbird