| Home |
| Search |
| Today's Posts |
|
|
|
#1
July 28th 03, 10:24 PM
|
|||
|
|||
|
|
#3
July 29th 03, 02:55 AM
|
|||
|
|||
|
On Mon, 28 Jul 2003 22:24:11 +0100, Paul Burridge
wrote: On Mon, 28 Jul 2003 13:20:27 GMT, (John Crighton) wrote: The rich guy is stunting around and decides to buzz me at low level about 20 feet above the ground. His model flies over me and then nose dives into the ground near by. I could here his servos twitching away as I walked past the wreckage. After I retrieved my model and switched off my transmitter, I stopped by the little gathering at the wreck site. The rich guy was operating his servos OK and scratching his head. " I spend thousands on my model and that ******* John Crighton comes here every weekend with 50 dollars worth of homebuilt junk and flies. It just isn't fair." "Moan...grumble..moan." I didn't try to explain that his receiver got swamped. His mates put the crash down to pilot error at low level, and that was that. John, what in your experience causes this 'servo-twitching'? In that incident with the rich guy, he was a few hundred yards away from his model and my transmitter, only 20 feet away. even though it was on a different channel upset his signal. Therefore his servos twitched and his model crashed. I've observed it myself at close hand many times. Waving a transmitter with a fully extended antenna beside the model will cause a bit of servo twitching. The signal is too strong. That is why you see people doing close range testing with the antenna retracted. The last time it happened, we cured it by isolating the die-cast box the rx was mounted in from the chassis. I still can't figure out why this worked, as I'd have thought grounding it *ought* to solve the problem. I would have thought that grounding the RX to the box would be good practice also. Not having a circuit to guide you, maybe you were grounding a spot on the PCB that should not be grounded. But in this instance, grounding it *created* the problem and isolating it solved it! Sometimes when I see those servos behaving like they've got a mind of their own it almost makes me believe in the supernatural. You got some good advice from John R Strohm in regards to fitting decoupling capacitors across the servo supply leads. I am assuming that your R/C gear is operating from its own battery supply not the main driving motor supply. Using the same battery for the radio and main driving motors could cause servo twitching. Pity there isn't one of these fighting robot clubs here in Sydney. I would like to have a go. Paul you will have to put some pictures up somewhere so we can have a look. Regards, John Crighton Sydney |
|
#4
July 29th 03, 12:55 AM
|
|||
|
|||
|
"Paul Burridge" wrote in message
... On Mon, 28 Jul 2003 13:20:27 GMT, (John Crighton) wrote: The rich guy is stunting around and decides to buzz me at low level about 20 feet above the ground. His model flies over me and then nose dives into the ground near by. I could here his servos twitching away as I walked past the wreckage. After I retrieved my model and switched off my transmitter, I stopped by the little gathering at the wreck site. The rich guy was operating his servos OK and scratching his head. " I spend thousands on my model and that ******* John Crighton comes here every weekend with 50 dollars worth of homebuilt junk and flies. It just isn't fair." "Moan...grumble..moan." I didn't try to explain that his receiver got swamped. His mates put the crash down to pilot error at low level, and that was that. John, what in your experience causes this 'servo-twitching'? I've observed it myself at close hand many times. The last time it happened, we cured it by isolating the die-cast box the rx was mounted in from the chassis. I still can't figure out why this worked, as I'd have thought grounding it *ought* to solve the problem. But in this instance, grounding it *created* the problem and isolating it solved it! Sometimes when I see those servos behaving like they've got a mind of their own it almost makes me believe in the supernatural. R/C servos are EXTREMELY sensitive to trash on the power supply leads. Grounding the box probably coupled some trash into the ground lead to the servo. I don't know what you have in your system, but I'd start by investing in a few small 250 uF (nominal) capacitors and put them directly across the servo supply leads. Use Y-harnesses to hook them in if you don't feel like modifying a cable. |
|
#5
July 29th 03, 02:55 AM
|
|||
|
|||
|
On Mon, 28 Jul 2003 22:24:11 +0100, Paul Burridge
wrote: On Mon, 28 Jul 2003 13:20:27 GMT, (John Crighton) wrote: The rich guy is stunting around and decides to buzz me at low level about 20 feet above the ground. His model flies over me and then nose dives into the ground near by. I could here his servos twitching away as I walked past the wreckage. After I retrieved my model and switched off my transmitter, I stopped by the little gathering at the wreck site. The rich guy was operating his servos OK and scratching his head. " I spend thousands on my model and that ******* John Crighton comes here every weekend with 50 dollars worth of homebuilt junk and flies. It just isn't fair." "Moan...grumble..moan." I didn't try to explain that his receiver got swamped. His mates put the crash down to pilot error at low level, and that was that. John, what in your experience causes this 'servo-twitching'? In that incident with the rich guy, he was a few hundred yards away from his model and my transmitter, only 20 feet away. even though it was on a different channel upset his signal. Therefore his servos twitched and his model crashed. I've observed it myself at close hand many times. Waving a transmitter with a fully extended antenna beside the model will cause a bit of servo twitching. The signal is too strong. That is why you see people doing close range testing with the antenna retracted. The last time it happened, we cured it by isolating the die-cast box the rx was mounted in from the chassis. I still can't figure out why this worked, as I'd have thought grounding it *ought* to solve the problem. I would have thought that grounding the RX to the box would be good practice also. Not having a circuit to guide you, maybe you were grounding a spot on the PCB that should not be grounded. But in this instance, grounding it *created* the problem and isolating it solved it! Sometimes when I see those servos behaving like they've got a mind of their own it almost makes me believe in the supernatural. You got some good advice from John R Strohm in regards to fitting decoupling capacitors across the servo supply leads. I am assuming that your R/C gear is operating from its own battery supply not the main driving motor supply. Using the same battery for the radio and main driving motors could cause servo twitching. Pity there isn't one of these fighting robot clubs here in Sydney. I would like to have a go. Paul you will have to put some pictures up somewhere so we can have a look. Regards, John Crighton Sydney |
| Reply |
| Thread Tools | Search this Thread |
| Display Modes | |
|
|
Similar Threads
|
||||
| Thread | Forum | |||
| Ten-Tec filters | Boatanchors | |||
| 'other' Kenwood SSB Filters : YK-88S1 and YK-88S2 | Equipment | |||
| 'other' Kenwood SSB Filters : YK-88S1 and YK-88S2 | Equipment | |||
| 'other' Kenwood SSB Filters : YK-88S1 and YK-88S2 | Equipment | |||
| FS: New Crystal Filters $25.00 | Boatanchors | |||
Hybrid Mode
