Mismatch after AutoMatch
#1
Video 
JimDrew;47010367 Wrote:Did you change the EPA after doing the AutoMatch?  You can’t do that.  You have to make sure that you set the end points prior to the AutoMatch and not change them afterwards.  You can change the trim,  but not the end points.

It could be that you are over-driving the surface,  and the hinge line is binding.  What servos are you using where you would need to unplug the slave?

Please note that we are not using RCGroups anymore for support.  Please use our direct support forum here: 

https://www.xtremepowersystems.net/forum/

Never touched anything after the automatch. Just plugged the slave back in and moved the surface with the aileron stick like normal. Checked for hinge limits and there is no mechanical resistance at all.
Also, wouldn't the match current jump if there was binding? It was perfectly normal throughout.
I didn't need to unplug the slave servo. It said to do that in the instruction manual. The servos are Futaba a700's. They don't have built in failsafe. They free wheel with power and no signal.

Video of Movement
Reply
#2
Unless you are using certain servos that have a failsafe that holds the servo in position on signal loss, there is absolutely no reason to be unplugging any servos.  You MUST have all servos plugged into the X24 during the AutoMatch process or it won't actually work.  Do you have both servos always plugged in when you start going through the AutoMatch setup and then the AutoMatch process?  Also keep in mind that you can't swap servo ports for the servos after an AutoMatch.  So, if you were using ports D1 for the Master and E1 for the Slave, you can't then swap the ports (ie. put the Master in E1 and the Slave in D1).
Reply
#3
(04-25-2021, 08:53 PM)XPS Wrote: Unless you are using certain servos that have a failsafe that holds the servo in position on signal loss, there is absolutely no reason to be unplugging any servos.  You MUST have all servos plugged into the X24 during the AutoMatch process or it won't actually work.  Do you have both servos always plugged in when you start going through the AutoMatch setup and then the AutoMatch process?  Also keep in mind that you can't swap servo ports for the servos after an AutoMatch.  So, if you were using ports D1 for the Master and E1 for the Slave, you can't then swap the ports (ie. put the Master in E1 and the Slave in D1).

Both servos were plugged in during automatch. The auto match worked perfectly. I watched both servos go through the entire process. Once complete, the instructions say to unplug the slave. That's as per the instructions. Then it says to exit the menu until you get the green led. I did that. Then it says to you can plug the slave back in and move the surface as per normal operation. I did that and that's when I took the video showing the current shooting up near the end of travel for right aileron movement only. I did not move servo leads, change ports or anything like that after the match. I just plugged the slave back in as per instructions and them moved the surface normally with my radio as per the video.
Reply
#4
Those instructions (in blue on page 36 of the manual) are only for when using servos that have a failsafe when the signal stops.    Only follow instructions on that page if you have servos that have a failsafe that can not be disabled.  Otherwise, follow the instructions starting on page 37.  You stated you are using Futaba servos, so do NOT follow those instructions on page 36 as those do not apply to you.

You should retry the AutoMatch (following the instructions starting on page 37), leaving the servos plugged in.  Make sure you make no adjustments to the EPA in the X24 or your transmitter afterwards.

You could try u plugging the slave servo and looking at the max current and then doing the same with just the slave servo.  Maybe there is a mechanical binding issue at some point during the throw.
Reply
#5
(04-26-2021, 11:25 AM)XPS Wrote: Those instructions (in blue on page 36 of the manual) are only for when using servos that have a failsafe when the signal stops.    Only follow instructions on that page if you have servos that have a failsafe that can not be disabled.  Otherwise, follow the instructions starting on page 37.  You stated you are using Futaba servos, so do NOT follow those instructions on page 36 as those do not apply to you.

You should retry the AutoMatch (following the instructions starting on page 37), leaving the servos plugged in.  Make sure you make no adjustments to the EPA in the X24 or your transmitter afterwards.

You could try u plugging the slave servo and looking at the max current and then doing the same with just the slave servo.  Maybe there is a mechanical binding issue at some point during the throw.
Copy that Jim. I will do as you suggest. I will report back shortly.....
Reply
#6
So re-did the automatch and it completed it no problem. I then tried the aileron and sure enough it started drawing lots of current when I went to right aileron. Left was ok. So as you suggested I disconnected one servo at a time and moved the active one through full aileron movement no problem. Did the same thing with the other one. No binding.

I did notice one thing when moving just the slave servo in the direction it was binding when they were both connected: as I got to the last 1/5th of my right aileron stick, the servo stopped moving for the amount of stick movement remaining. As if it reached it's endpoint. When doing the automatch, this did not happen at all. My transmitter end points are set to +/- 110 from the beginning and I have not changed them. Nor did I touch any other settings at all. I followed the instructions on page 36. I then un-plugged D1 and E1 and plugged them into two separate channels on the receiver (after disconnecting the sbus feed from the receiver to the X24) I then did a manual old school match with the servos on two separate channels using the same parameters for 45 degree through, just as I did with the X24, and it worked. I did that just to see if I was missing something in the process.

So why won't the slave servo move the same as it did when it went through the automatch? This is very disconcerting.
Reply
#7
Well, you definitely found the problem. It sounds like you have the center of this servo really far off from dead center (1500us). If you drive a servo beyond it's pulse limits (less than 800us or greater than 2200us) the servo will just free wheel, and the AutoMatch would go through. However, during normal use at the end they could definitely fight.

Are you using the servo reverse option for the slave channel? What is the CENTER value for the master and slave servos? They both should be very close to 1500us. What servo group number are you using? What are the endpoint values you are you using for the master?

Again, do NOT follow the instructions on page 36 - they do not apply to you. Follow the instructions on page 37 and later.

You are the only person ever have a problem with the AutoMatch feature (that wasn't a mechanical binding issue at the very end of the AutoMatch). We have not had anyone report what you are seeing, so we are a bit stumped. Other than a pulse limit, the only thing that might cause this would be a defective X24. The AutoMatch table is stored in the flash memory. If you changed which group was used for that match (like trying it on the other aileron group that works) and you see the same issue then it would rule out a faulty X24.
Reply
#8
(04-26-2021, 03:34 PM)Robert Wrote:
(04-26-2021, 11:25 AM)XPS Wrote: Those instructions (in blue on page 36 of the manual) are only for when using servos that have a failsafe when the signal stops.    Only follow instructions on that page if you have servos that have a failsafe that can not be disabled.  Otherwise, follow the instructions starting on page 37.  You stated you are using Futaba servos, so do NOT follow those instructions on page 36 as those do not apply to you.

You should retry the AutoMatch (following the instructions starting on page 37), leaving the servos plugged in.  Make sure you make no adjustments to the EPA in the X24 or your transmitter afterwards.

You could try u plugging the slave servo and looking at the max current and then doing the same with just the slave servo.  Maybe there is a mechanical binding issue at some point during the throw.
Copy that Jim. I will do as you suggest. I will report back shortly.....

(04-28-2021, 02:35 AM)XPS Wrote: Well, you definitely found the problem.  It sounds like you have the center of this servo really far off from dead center (1500us).  If you drive a servo beyond it's pulse limits (less than 800us or greater than 2200us) the servo will just free wheel, and the AutoMatch would go through.  However, during normal use at the end they could definitely fight.

Are you using the servo reverse option for the slave channel?  What is the CENTER value for the master and slave servos?  They both should be very close to 1500us.  What servo group number are you using?  What are the endpoint values you are you using for the master?

Again, do NOT follow the instructions on page 36 - they do not apply to you.  Follow the instructions on page 37 and later.

You are the only person ever have a problem with the AutoMatch feature (that wasn't a mechanical binding issue at the very end of the AutoMatch).  We have not had anyone report what you are seeing, so we are a bit stumped.  Other than a pulse limit, the only thing that might cause this would be a defective X24.  The AutoMatch table is stored in the flash memory.  If you changed which group was used for that match (like trying it on the other aileron group that works) and you see the same issue then it would rule out a faulty X24.

The center on the master is -159. I did reverse the master and slave using the servo reverse option on the X24. Servo group is group #2. Master endpoints are 83.6 and 108.8.

With regards to the pulse limit, I noticed that when it asked to move the stick to the max in both directions (just prior to starting the automatch process), that those numbers were definitely less than 2200us and greater than 800us. They were 1924 and 944 respectively.

So I will start again from scratch by resetting all geometry mechanically first (for both master and slave) ensuring that center for my master and slave is close to zero as I can get it. Then I will re-do the automatch. And, I will follow the instructions on page 37 and later.

I will report back.
Reply
#9
The center being only -157 should not be an issue. If it was something like 800 or more then that could be a problem. I doubt that your end points are the issue either.

I would try changing the group, just to see if this is a hardware problem with the X24’s flash memory. The method/code is the same for any setup and since one side works perfectly we can only assume that unless we are missing something, this would have to be a hardware problem. The slave servo positions are stored in flash memory during the AutoMatch process, and those positions are used as a look up for the master servo position. If slave servo stops moving it can only be due to the servo reaching its maximum pulse position, or the table data is empty. However, when this occurs I would expect the slave servo to freewheel and not try to hold position.
Reply
#10
We were going through your info again and noticed that you have reverse set for both master and slave. That would be an extremely rare case where the servos arms are on opposite sides. You could try setting these both to normal (not reversed) and reverse that channel in your transmitter that controls this ailerons. That would be the normal way to setup the system.
Reply




Users browsing this thread: 1 Guest(s)