SPEKTRUM PROBLEM OR NOT?
01-16-2008, 08:42 PM
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SPEKTRUM PROBLEM OR NOT?
To get a flight in at our Frosty-Fingers, New Years fun-fly day I put together a Park Zone FW 190. It only took seven minutes to attach the stab and set the elevator throw. Then, with a previously charged, supplied, NiMh battery the airplane was ready to go. It was a piece of cake to fly that day but I was a bit inhibited by the 3-channel mode-2 transmitter.
Back at the shop I planned some upgrades. First of all, I would fit a Spektrum RX and convert the airplane over to Mode-1 using my Spektrum-module-converted 8103. I also cut and hinged the previously fixed rudder to give me full four-function control. (Once you really find your rudder you can’t do without it!)
There was a snag. The speed controller for the 360 geared motor was also an integral part of the supplied three-channel 27 MHz FM RX. So an E-Flite 30 Amp BRUSHED ESC was purchased. The RX was bound, the connectors were compatible and the LIPO upgrade was well received by the brushed/geared motor.
The first test flight went very well indeed. Flying on my native mode gave me a better feel for the FW190. It also allowed for much longer and smoother rolls. Loops were bigger and more impressive. Low passes were performed with a lot more confidence.
The second flight, with a new pack, was a bloody disaster. About two thirds of the way through the 6100 receiver shut down the throttle and gave the FW 190 a classic swan-dive into the deck. Quite a nasty prang and not well received by yours truly. I took the bits back to the shop and did an autopsy.
I was thinking, “Oh no! The anti-Spektrum-pundits were right after all, had the RX reacted to a dip below 3.5V etc. Maybe it was a range problem? etc. etc. etc.” (You’ve heard it all in this forum.) I left the whole 2.4 GHz radio system switched on all the way back to the shop/store. It’s only 4 miles and more importantly it was all still working.
I did some voltage tests and found out that the BEC was only delivering 3V. The 6100 was driving three programmable Spektrum digital servos and had worked well for almost 2 flights. The voltage between the RX and the BEC was a variable but low 3V. Once in a while it did not connect to the TX when switched on and off. A red flag to say the least!
Further investigation of the LIPO battery in another Park Zone warbird showed that the battery still had a lot of charge in it. If the battery had been low the motor should have quit and the radio should have stayed connected. Did I have a bad ESC? If that was the case then someone was going to get a stimulating service call from me the next day that was for sure!
To be sure of my facts I dialed up the pdf of the manual for the brushed ESC in question. To my abject dismay I discovered that the output from the BEC was only rated at 3V. I can only surmise that it was designed for a system that only needed a 3V supply to a proprietary receiver. Choking on my own ineptitude for not checking the specifications I grabbed a BEC with a 5.1V output and installed it in parallel to the ESC LIPO supply.
All now worked well and I could not force a range or disconnect error out of the 6100. I ran the LIPO down and the prop stopped but BEC continued to drive the RX etc.
Upon reflection, I could have avoided the error but I never imagined that an ESC would have a BEC RX voltage output that low. It was not a minimum output but a specified steady output. My experiences for the last few years have been with BRUSHLESS motors and their ESC/BEC output. I have become used to their RX voltage supplies. Now that I am working more with indoor models I will be paying much better attention.
My afterthought was about how willing I was to readily blame the Spektrum system when it was clearly my fault for not providing enough voltage to the 6100. My deeper afterthought was that if I had also converted to a brushless motor and ESC I would not have had any problems because they seem to be fairly well sorted out these days.
For now I will stay with brushed motor in the Park Zone FW190 because it has plenty of power with the Park Zone LIPO upgrade option. If the brushed motor “degrades” I will readily fit a 480 E-Flite brushless motor.
I posted this in the Spektrum thread in case it helps other experimenters.
Regards
Eric.
Back at the shop I planned some upgrades. First of all, I would fit a Spektrum RX and convert the airplane over to Mode-1 using my Spektrum-module-converted 8103. I also cut and hinged the previously fixed rudder to give me full four-function control. (Once you really find your rudder you can’t do without it!)
There was a snag. The speed controller for the 360 geared motor was also an integral part of the supplied three-channel 27 MHz FM RX. So an E-Flite 30 Amp BRUSHED ESC was purchased. The RX was bound, the connectors were compatible and the LIPO upgrade was well received by the brushed/geared motor.
The first test flight went very well indeed. Flying on my native mode gave me a better feel for the FW190. It also allowed for much longer and smoother rolls. Loops were bigger and more impressive. Low passes were performed with a lot more confidence.
The second flight, with a new pack, was a bloody disaster. About two thirds of the way through the 6100 receiver shut down the throttle and gave the FW 190 a classic swan-dive into the deck. Quite a nasty prang and not well received by yours truly. I took the bits back to the shop and did an autopsy.
I was thinking, “Oh no! The anti-Spektrum-pundits were right after all, had the RX reacted to a dip below 3.5V etc. Maybe it was a range problem? etc. etc. etc.” (You’ve heard it all in this forum.) I left the whole 2.4 GHz radio system switched on all the way back to the shop/store. It’s only 4 miles and more importantly it was all still working.
I did some voltage tests and found out that the BEC was only delivering 3V. The 6100 was driving three programmable Spektrum digital servos and had worked well for almost 2 flights. The voltage between the RX and the BEC was a variable but low 3V. Once in a while it did not connect to the TX when switched on and off. A red flag to say the least!
Further investigation of the LIPO battery in another Park Zone warbird showed that the battery still had a lot of charge in it. If the battery had been low the motor should have quit and the radio should have stayed connected. Did I have a bad ESC? If that was the case then someone was going to get a stimulating service call from me the next day that was for sure!
To be sure of my facts I dialed up the pdf of the manual for the brushed ESC in question. To my abject dismay I discovered that the output from the BEC was only rated at 3V. I can only surmise that it was designed for a system that only needed a 3V supply to a proprietary receiver. Choking on my own ineptitude for not checking the specifications I grabbed a BEC with a 5.1V output and installed it in parallel to the ESC LIPO supply.
All now worked well and I could not force a range or disconnect error out of the 6100. I ran the LIPO down and the prop stopped but BEC continued to drive the RX etc.
Upon reflection, I could have avoided the error but I never imagined that an ESC would have a BEC RX voltage output that low. It was not a minimum output but a specified steady output. My experiences for the last few years have been with BRUSHLESS motors and their ESC/BEC output. I have become used to their RX voltage supplies. Now that I am working more with indoor models I will be paying much better attention.
My afterthought was about how willing I was to readily blame the Spektrum system when it was clearly my fault for not providing enough voltage to the 6100. My deeper afterthought was that if I had also converted to a brushless motor and ESC I would not have had any problems because they seem to be fairly well sorted out these days.
For now I will stay with brushed motor in the Park Zone FW190 because it has plenty of power with the Park Zone LIPO upgrade option. If the brushed motor “degrades” I will readily fit a 480 E-Flite brushless motor.
I posted this in the Spektrum thread in case it helps other experimenters.
Regards
Eric.
01-16-2008, 09:30 PM
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RE: SPEKTRUM PROBLEM OR NOT?
Very well put!
I like it when facts are presented verses blind speculations based on ???.
We are in the hobby to have fun and if there is a problem let's work it out so every one benefits.
Thank you,
Tony
I like it when facts are presented verses blind speculations based on ???.
We are in the hobby to have fun and if there is a problem let's work it out so every one benefits.
Thank you,
Tony
01-17-2008, 10:33 AM
#3
RE: SPEKTRUM PROBLEM OR NOT?
One thing to keep in mind is that batteries don't particularly care for cold temps.
From what I've been reading and seeing with my electric powered foamies, that information is correct. While I don't use NiMH or NiCD batteries nearly as much (they are only in a couple of glow models I keep around) any more, they did not seem to be as susceptible to cold temps as the Li-Po's used on my foamies. I've not flown my gassers with the Li-Ion setups in the cold enough to get a good idea of what the effect is on them but I'm sure they'll have a reduced capacity as well.
I'll be switching to the A123 batteries for my fuel powered models and in doing some research on those and the new FMA chargers I got for them, FMA warns about temperatures and Li-Po batteries. They even have a cold weather charge mode which IIRC, does not try to charge the batteries to full capacity.
Just for curiosity's sake, you may want to check into what other manufacturers or vendors might have to say about cold weather operation?
Good experience report, gives all some more information about possible trouble spots with our models. Thanks for posting...[8D]
From what I've been reading and seeing with my electric powered foamies, that information is correct. While I don't use NiMH or NiCD batteries nearly as much (they are only in a couple of glow models I keep around) any more, they did not seem to be as susceptible to cold temps as the Li-Po's used on my foamies. I've not flown my gassers with the Li-Ion setups in the cold enough to get a good idea of what the effect is on them but I'm sure they'll have a reduced capacity as well.
I'll be switching to the A123 batteries for my fuel powered models and in doing some research on those and the new FMA chargers I got for them, FMA warns about temperatures and Li-Po batteries. They even have a cold weather charge mode which IIRC, does not try to charge the batteries to full capacity.
Just for curiosity's sake, you may want to check into what other manufacturers or vendors might have to say about cold weather operation?
Good experience report, gives all some more information about possible trouble spots with our models. Thanks for posting...[8D]
01-18-2008, 12:52 AM
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RE: SPEKTRUM PROBLEM OR NOT?
ORIGINAL: Zeeb
One thing to keep in mind is that batteries don't particularly care for cold temps.
From what I've been reading and seeing with my electric powered foamies, that information is correct. While I don't use NiMH or NiCD batteries nearly as much (they are only in a couple of glow models I keep around) any more, they did not seem to be as susceptible to cold temps as the Li-Po's used on my foamies. I've not flown my gassers with the Li-Ion setups in the cold enough to get a good idea of what the effect is on them but I'm sure they'll have a reduced capacity as well.
I'll be switching to the A123 batteries for my fuel powered models and in doing some research on those and the new FMA chargers I got for them, FMA warns about temperatures and Li-Po batteries. They even have a cold weather charge mode which IIRC, does not try to charge the batteries to full capacity.
Just for curiosity's sake, you may want to check into what other manufacturers or vendors might have to say about cold weather operation?
Good experience report, gives all some more information about possible trouble spots with our models. Thanks for posting...[8D]
One thing to keep in mind is that batteries don't particularly care for cold temps.
From what I've been reading and seeing with my electric powered foamies, that information is correct. While I don't use NiMH or NiCD batteries nearly as much (they are only in a couple of glow models I keep around) any more, they did not seem to be as susceptible to cold temps as the Li-Po's used on my foamies. I've not flown my gassers with the Li-Ion setups in the cold enough to get a good idea of what the effect is on them but I'm sure they'll have a reduced capacity as well.
I'll be switching to the A123 batteries for my fuel powered models and in doing some research on those and the new FMA chargers I got for them, FMA warns about temperatures and Li-Po batteries. They even have a cold weather charge mode which IIRC, does not try to charge the batteries to full capacity.
Just for curiosity's sake, you may want to check into what other manufacturers or vendors might have to say about cold weather operation?
Good experience report, gives all some more information about possible trouble spots with our models. Thanks for posting...[8D]
Regards,
Eric.
01-18-2008, 07:55 PM
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RE: SPEKTRUM PROBLEM OR NOT?
Eric, this information of yours is great to have. Points out how important it is to preserve the system when troubleshooting, and then rechecking the operating specs of things when we find something out of spec. I only have one e-power bird right now, but knowing that there "could" be an ESC supply voltage problem is a good thing to put on the "I'd better be sure" checklist.
Thanks for posting all the details. Very helpful info.
Thanks for posting all the details. Very helpful info.
01-18-2008, 08:15 PM
#6
RE: SPEKTRUM PROBLEM OR NOT?
Did digital servos come with that little model?
or
did you switch over to them
the rinkydink BECS (in the ESCs)can be pretty unforgiving
Some of the EFlite ARFS included the "afterthought" notes which caution about using the internal BEC -especially if you upgrade servos
I have been hitting the small /medium electrics , pretty heavily for the past while and one thing I would suggest to anyone who is considering upgrading motor , prop size, servos, servo loads - above the stock kit setups -- beeeee careful- get a discreet BEC (switching type) -or upgrade to a new ESC/BEC which is a switching type. The wee ones are very current sensitive
If you have fiddled with these things for a while , you may note that there are cautions about not exceeding 3 ,small servos-on some ESC setups.
That tip should be read "Danger Will Robinson!! get a better ESC/BEC
Having said all that -- EFlight has a spiffy new 40 amp ESC with internal switching BEC- works like a champ !!
I use it in this model with a EFlite480 and 4 A123 cells as shown -It is a rocket -for about 5-7 minutes.
or
did you switch over to them
the rinkydink BECS (in the ESCs)can be pretty unforgiving
Some of the EFlite ARFS included the "afterthought" notes which caution about using the internal BEC -especially if you upgrade servos
I have been hitting the small /medium electrics , pretty heavily for the past while and one thing I would suggest to anyone who is considering upgrading motor , prop size, servos, servo loads - above the stock kit setups -- beeeee careful- get a discreet BEC (switching type) -or upgrade to a new ESC/BEC which is a switching type. The wee ones are very current sensitive
If you have fiddled with these things for a while , you may note that there are cautions about not exceeding 3 ,small servos-on some ESC setups.
That tip should be read "Danger Will Robinson!! get a better ESC/BEC
Having said all that -- EFlight has a spiffy new 40 amp ESC with internal switching BEC- works like a champ !!
I use it in this model with a EFlite480 and 4 A123 cells as shown -It is a rocket -for about 5-7 minutes.
01-18-2008, 11:29 PM
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RE: SPEKTRUM PROBLEM OR NOT?
I took out all of the FW190 Park Zone equipment except the brushed motor. I already had a 6100 RX so I purchased 3 Spektrum 285 digital servos. (Incidentally they are programmable).
The main goal being to move over to my Mode-1 TX. The secondary goal was to add a rudder. The supplied TX has a slider for the throttle and only one dual gimbal stick on the right, so I could not mode-one-modify the TX.
I ordered an E-Flite 30 amp ESC without taking any note of the BEC rating - My big mistake. Interestingly enough the current E-Flite brushless equivalents all have plenty of voltage for the 6100.
I wanted to report that there were also two significant pieces of data that I should not have ignored. They may also help you all.
1. During installation/conversion I did observe that the servos were a bit wimpy and prone to what I would call micro-jitters.
2. Before the fatal flight the RX undid its lock with the TX a couple of times after I switched on. Then it was just fine - famous last words.
The data was there and I missed it. Maybe it was the excitement of the crowd or my desire to go chase a Park Zone Spitfire that had previously launched.
Either way the low servo performance during the install was a big clue. My current set-up has a separate E-Flite 5.1V BEC. What a big difference. These little servos are pretty awesome. They snap to the TX commands and feel strong. I hear them do the digital “groan” but they do not “dance”. Also I now have much bigger throws as the power of the 285’s bend the molded hinges to new limits. The low servo performance is/was a clear indicator of a shortage of juice.
In addition any unusual system start up of a DSM system should have been investigated. In my own defense I had no external switch/jack through which I could monitor the RX voltage, but I should have used a servo extension lead while the airplane was on the bench. Also I had not seen the servos in action other than with the BEC of the brushed speed controller so I did not know what to expect.
If I ever do go to a brushless motor like an E-Flite 480, I will be sure to test the output value of the internal BEC that comes with ESC or just stick with my new little friend the separate BEC.
Regards,
Eric.
The main goal being to move over to my Mode-1 TX. The secondary goal was to add a rudder. The supplied TX has a slider for the throttle and only one dual gimbal stick on the right, so I could not mode-one-modify the TX.
I ordered an E-Flite 30 amp ESC without taking any note of the BEC rating - My big mistake. Interestingly enough the current E-Flite brushless equivalents all have plenty of voltage for the 6100.
I wanted to report that there were also two significant pieces of data that I should not have ignored. They may also help you all.
1. During installation/conversion I did observe that the servos were a bit wimpy and prone to what I would call micro-jitters.
2. Before the fatal flight the RX undid its lock with the TX a couple of times after I switched on. Then it was just fine - famous last words.
The data was there and I missed it. Maybe it was the excitement of the crowd or my desire to go chase a Park Zone Spitfire that had previously launched.
Either way the low servo performance during the install was a big clue. My current set-up has a separate E-Flite 5.1V BEC. What a big difference. These little servos are pretty awesome. They snap to the TX commands and feel strong. I hear them do the digital “groan” but they do not “dance”. Also I now have much bigger throws as the power of the 285’s bend the molded hinges to new limits. The low servo performance is/was a clear indicator of a shortage of juice.
In addition any unusual system start up of a DSM system should have been investigated. In my own defense I had no external switch/jack through which I could monitor the RX voltage, but I should have used a servo extension lead while the airplane was on the bench. Also I had not seen the servos in action other than with the BEC of the brushed speed controller so I did not know what to expect.
If I ever do go to a brushless motor like an E-Flite 480, I will be sure to test the output value of the internal BEC that comes with ESC or just stick with my new little friend the separate BEC.
Regards,
Eric.
01-19-2008, 09:12 AM
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RE: SPEKTRUM PROBLEM OR NOT?
I mixed my JR and Spektrum speak for a moment - Here is what I used.
They offer two versions, here is one of them.
SPMDSP60 by Spektrum
This programmable servo allows you to customize your radio installation even further to help enhance over all performance.
MainIn-DepthProducts 6.0 Gram Super Sub-Micro Digital Prog Servo
Key Features
Digital
Programmable (Airplane, Helicopter, Tail-Rotor)
Universal connector
Includes complete mounting hardware
Includes an assortment of servo arms
Overview
The DSP60 offers superior speed, torque and precision for the class, and includes complete mounting hardware and an assortment of servo arms. You can optimize its performance for specific applications like airplanes, helicopters and tail rotors, by adjusting the end points, gain and even direction using the Digital Servo Programmer (SPMDSP- sold separately) The DSP60 is ideal for smaller electric models like 3D profile foamies and micro-helis.
Specs
Type
igital Programmable
Torque:13.2 oz/in @ 4.8V
Speed:.09 sec/60 deg @ 4.8V
Dimensions (WxLxH):.90 x .39 x .74 in (23 x 10 x 19mm)
Weight:.21 oz (6 g)
Motor Type:Coreless
Connector Type:Universal
Voltage:4.8V-6.0V
They offer two versions, here is one of them.
SPMDSP60 by Spektrum
This programmable servo allows you to customize your radio installation even further to help enhance over all performance.
MainIn-DepthProducts 6.0 Gram Super Sub-Micro Digital Prog Servo
Key Features
Digital
Programmable (Airplane, Helicopter, Tail-Rotor)
Universal connector
Includes complete mounting hardware
Includes an assortment of servo arms
Overview
The DSP60 offers superior speed, torque and precision for the class, and includes complete mounting hardware and an assortment of servo arms. You can optimize its performance for specific applications like airplanes, helicopters and tail rotors, by adjusting the end points, gain and even direction using the Digital Servo Programmer (SPMDSP- sold separately) The DSP60 is ideal for smaller electric models like 3D profile foamies and micro-helis.
Specs
Type
igital ProgrammableTorque:13.2 oz/in @ 4.8V
Speed:.09 sec/60 deg @ 4.8V
Dimensions (WxLxH):.90 x .39 x .74 in (23 x 10 x 19mm)
Weight:.21 oz (6 g)
Motor Type:Coreless
Connector Type:Universal
Voltage:4.8V-6.0V
01-19-2008, 09:16 AM
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RE: SPEKTRUM PROBLEM OR NOT?
These are pretty good as well.
DS285 Digital Hi-Speed Sub-Micro Servo
Key Features
Ultra-precise centering and movements
30% Faster than the previous version
Weighs only 8.5 grams
Specs
Typeigital Hi-Speed Sub-Micro
Torque:17 oz/in @ 4.8V, 19 oz/in @ 6V
Speed:.18 sec/60 degrees @ 4.8V, .14 sec/60 degrees @ 6V
Dimensions (WxLxH):0.45"x0.87"x0.85"
Weight:.32 oz
Bearing:n/a
Motor Type:3-pole ferrite
Gears:Nylon
Application:Electric aerobatic planes, sailplanes, micro-helis and other special applications
DS285 Digital Hi-Speed Sub-Micro Servo
Key Features
Ultra-precise centering and movements
30% Faster than the previous version
Weighs only 8.5 grams
Specs
Type
igital Hi-Speed Sub-MicroTorque:17 oz/in @ 4.8V, 19 oz/in @ 6V
Speed:.18 sec/60 degrees @ 4.8V, .14 sec/60 degrees @ 6V
Dimensions (WxLxH):0.45"x0.87"x0.85"
Weight:.32 oz
Bearing:n/a
Motor Type:3-pole ferrite
Gears:Nylon
Application:Electric aerobatic planes, sailplanes, micro-helis and other special applications
01-23-2008, 05:16 PM
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RE: SPEKTRUM PROBLEM OR NOT?
Just as a little follow up. we had a balmy 37F today in South Jersey.
So the Spektrum upgraded FW 190 was taken down to the field with a couple of fully charged 2200 mAh LIPO's. Switch-ons were pretty close to immediate with 5.1 V now flowing from the separate BEC. Range test were performed and the little 6100E stayed talking all the way through them.
There was only a 5 mph wind and with a little wind-break cover from the van it was almost pleasant to stand out there.
The airplane was flown to great heights and also way out over the ploughed fields. As unscientific as my tests may have been it was pleasing to not have a repeat of the previous outing. The baby Spektrum servos were also much better in response. Their increased power and gave bigger control throws.
I also converted a T-28 over to a 6100 receiver last week. This time I tested the voltage from the included ESC/BEC at the R/X pins while the brushed motor system was on. Running the brushed motor had no effect on the 4.8 V R/X voltage. So we will keep our fingers crossed for that test flight.
Regards,
Eric.
So the Spektrum upgraded FW 190 was taken down to the field with a couple of fully charged 2200 mAh LIPO's. Switch-ons were pretty close to immediate with 5.1 V now flowing from the separate BEC. Range test were performed and the little 6100E stayed talking all the way through them.
There was only a 5 mph wind and with a little wind-break cover from the van it was almost pleasant to stand out there.
The airplane was flown to great heights and also way out over the ploughed fields. As unscientific as my tests may have been it was pleasing to not have a repeat of the previous outing. The baby Spektrum servos were also much better in response. Their increased power and gave bigger control throws.
I also converted a T-28 over to a 6100 receiver last week. This time I tested the voltage from the included ESC/BEC at the R/X pins while the brushed motor system was on. Running the brushed motor had no effect on the 4.8 V R/X voltage. So we will keep our fingers crossed for that test flight.
Regards,
Eric.
