tony
New Member
Posts: 23
|
Post by tony on Aug 2, 2018 18:06:35 GMT
AC 6DOF System: 2017 Board and 2018 Kickstarter Board (presently using), WJ200-2Hp Drive, 1Hp Black Max Inverter Duty Motor, Iron Horse Gearbox 60:1, WWII 1942 North American AT-6 Texan Windshield, Canopy and Pilot's Chair all restored with hand made replica forward and side instrument panels, 3 AOC 40" Ultra 4K, HD Curved Monitors, etc...
0. Always wear a ground strap when working on the AMC or any sensitive electronics. Get spare UDN chips just in case you need one. They blow out if you look at them the wrong way. 1. Placed a 0.1uF Electrolytic Capacitor directly on the analog outputs of the AMC (AMC side) to the Inverter's analog inputs. 2. Switched over to AEAT SSI 12Bit Sensors. After doing this we still had noise on the AMC analog outputs, thus number 1 above. This was the biggest improvement in 1.5 years as far as smoothness for flying. The caps did not stop the percolating noise, but the arms hold the platform rock steady now! 3. A motor jerking or kicking is not always a noise or firmware issue. It can be a torque limiting issue with the drive. Manual Torque Boost helps, reducing weight, moving the CG, etc... 4. Put hard stops in and adjust torque limits B040 - B045. 5. Put 6 limit switches in series wired back to the inverter inputs. Any one limit switch triggered, all drives will trip. 6. Put 3 E-Stop switches in parallel wired back to the AMC Kill Input. The input is programmed for bringing the platform home. 7. Input 5 C005 on the WJ200 Set to function 19 PTC Thermistor Thermal Protection. Connect to terminal [5] and [L]. 8. Input 7 C007 on the WJ200 Set to function 12 External Trip Option, NC Limit Switches in Series. Use C017 to Invert C007s Logic. 9. Output 11 C021 on the WJ200 Set to function 13 Thermal Protection Signal . C031 puts Output 11 in active state. Can use LED Indicator. 10. Output Alarm Relay C026 on the WJ200 Set to function 10 Torque Limit Signal. C036 puts Output Alarm Relay in active state. Use Piezo Alarm here for Torque Limit Detection. Keep adjusting Torque Limit B040 - B045, Torque Boost A041 - A043, weight, cg, etc...until only a slight beep ocassionally on demanding platform positions.
I DO NOT recommend anyone try anything discussed here. Severe injury or death may result. This machine can bend solid 3/4" steel like nothing. BTW, we are a couple of very sick old men and a young wizard working on this, so we may be sans replies. Be well.
|
|
|
Post by Trip Rodriguez on Aug 5, 2018 20:06:22 GMT
Tony, thank you for posting!
My sim is very similar to yours, so this should be a great help.
The main thing I'm still trying to figure out is the motors jerking or kicking. I will check out the Manual Torque Boost, can you go into detail on what your findings were as to where it is best to have your CG? I'm also seriously thinking about reducing weight...the problem there is the cost of getting an aluminum upper frame put together.....
What about gearbox backlash? Have you had problems, and if so have you solved them? I gave up on the springs idea, at least for now. They were noisy and didn't seem to do much good. After much tinkering I wound up doing two things. I have my middle of travel point significantly lower than it's supposed to be (which causes some issues but helped immensely), and I put rubber vibration isolating mounts between my cockpit and the upper hex frame.
I also may have to look into the thermal protect stuff, I have nothing like that in place.
Trip
|
|
tony
New Member
Posts: 23
|
Post by tony on Aug 6, 2018 2:32:14 GMT
Hi Trip, Been following you and your Killer Machine for years! Awesome to hear from one of my heroes of Hexapods! {:>) Yes the kicking....if you take the person out of the cab and fly it with the joystick and its smooth as butter...then you put a person in and it starts bucking...It's the weight! We have an 8020 upper/lower platform. I think re-distributing the weight/cg will help...if all motors are chipping in the same...you can see it in the Amp draw on the display. THE Biggest thing was by chance placing a 0.1uF, 50V Electrolytic Capacitor on the AMC 0 to 10V output. WOW. A small 50 cent part made all the difference. We did convert the AMC to 12bit SSI input and 12Bit analog output. We are using helical inline gears, so the AMC has to always work to keep it steady. No seemingly backlash problems of note. Riddle me this...now that we converted to 12-Bit SSI Inputs and 12-Bit Analog Outputs, how do we convert the BFF calculations (they are in 8-Bit) to 12-Bit. Is there a file or something I am missing. I don't know how to enter it in the BFF or INI file. I have the conversions, do you just put them in. It is working now with 8-bit BFF? ? Thanks Trip!
|
|
|
Post by Trip Rodriguez on Aug 6, 2018 7:03:14 GMT
Thank you for the kind words, but I'm no hero! All the people here on the internet who helped me achieve my dream despite the fact that I had no clue what I was doing are the heroes!
Best to message Ian about 12bit output from BFF. Maybe Thanos too. This question is over my head for sure! Let me know what you learn because I believe I'm running 12bit also on the AMC. I'm still using the old sensors though, have not upgraded them.
Can you show me (picture if possible, or a drawing) your capacitor installation? You are talking about putting them (6?) on the Analog Setpoint 0-10V?
I am always trying to get the sim smoother for flying. I'm looking at aluminum now, but how to pay for it is another story! =P
|
|
tony
New Member
Posts: 23
|
Post by tony on Aug 6, 2018 17:01:00 GMT
Not pretty but just tie the negative to ground and the positive to analog 1 - 6. Yes, 1 cap for each analog channel. I soldered a jumper wire to the caps to make it a little easier.
|
|
|
Post by Trip Rodriguez on Aug 7, 2018 4:10:24 GMT
Not pretty but just tie the negative to ground and the positive to analog 1 - 6. Yes, 1 cap for each analog channel. I soldered a jumper wire to the caps to make it a little easier. Thank you! I will try to make this mod as soon as possible and let you know my results. That is a whole lot prettier than what I have hidden inside enclosures! =P I have another idea for the weight issue. I think I'm going to try using bungee cords up to the ceiling from the cockpit to partially support the weight of cockpit and rider. I think I'm going to try this first before investing in aluminum to make a new upper hex. If I wind up making an aluminum frame afterward, I figure the bungee's will still potentially be helpful. Edit 1: Actually I think I'm going to try adding bungee's on pulleys to the gearboxes, to help counter the weight of the platform, and also to try to eliminate backlash problems. I definitely feel that I'm getting some bumps from backlash so I've been wanting to fix that too. If I get this idea to work, I'll be sure to post about it!Edit 2: After thinking about it using the bungee's and pulleys to prevent backlash in the opposite direction of the load will not work because of the increased force from the load during accelerations. Removing the backlash therefore is going to require I pull the other way, effectively increasing instead of reducing the load on the motors during upward movements. =( Back to trying to suspend part of the platform weight from the ceiling I guess.
|
|
tony
New Member
Posts: 23
|
Post by tony on Aug 7, 2018 14:09:38 GMT
Hi Trip, Just a couple of ideas for you....I've seen pictures Gokan, Gohan (spelling???) posted with special keyway he had made to gid rid of his backlash. Also, can't think of the parameter right now but it may be A091/092 or B091/092. You can change you linear accel/decel ramp to a S-Curve....just some thoughts. Edit: It is Gokhan motionsim.freeforums.net/thread/224/backlash-problem-solved
|
|
|
Post by Trip Rodriguez on Aug 7, 2018 19:13:51 GMT
Hi Trip, Just a couple of ideas for you....I've seen pictures Gokan, Gohan (spelling???) posted with special keyway he had made to gid rid of his backlash. Also, can't think of the parameter right now but it may be A091/092 or B091/092. You can change you linear accel/decel ramp to a S-Curve....just some thoughts. Edit: It is Gokhan motionsim.freeforums.net/thread/224/backlash-problem-solvedThank you sir. I'll check out the link. I did go to S-curve, about a year ago I think and it didn't seem to help much if I recall. I think I'm still on it. One other thing, I ordered the caps. Could you possibly explain what their function is installed as you recommend? I just like to understand these things. =) Trip PS- Nevermind about explaining the function of using caps here, I found Thanos explanation of this on the thread you linked and the cap function is just as I guessed. Thanos said: On the amc1280usb board there are two lines of 5v and Gnd. You can attach on them a few electrolytic capacitors to cover a wide range of noise: 0.1uF 1uF 10uF 100uF 1000uF Watch the polarity of electrolytic caps to be correct. You can solder them on female headers and plug them one at a time to find the best combination with less or no noise.
|
|
|
Post by Trip Rodriguez on Aug 8, 2018 5:57:45 GMT
I will try to explain the things that bother me with my sim that I'm trying to solve:
1- When moving flight stick suddenly forward or back the movement of the platform is a big "kick" that does not feel like flight at all, more like a car hitting a big bump! If I tune to where this is not an issue, I don't get enough cue for "normal" pitch movements. I want to smooth this so it feels like an aircraft. I think both pitch and heave cues (if I isolate axes) tend to cause this, but mostly heave if I remember right. If I tune it for nice cues during normal pitch maneuvers, when I yank the stick the sim moves much too hard.
2- When sim moves downward for large "heave" cue I get a shudder/vibration. I'm basically certain that this is from backlash in the gearboxes. Backlash is pretty small in the gearbox, but with the 160mm long torque arm it becomes an issue. One gear box has significantly worse backlash than the others, I think I slightly deformed the gear inside by accidentally loading it against an immovable object *whistles innocently*. There is no backlash in the fit of torque arm to shaft and no play elsewhere, the backlash is internal to the gearboxes. I tried using springs but no luck,
3- I sometimes get a large unexpected "bump". I suspect it might be random sometimes, but I know that there are certain times with certain motion profiles where it will happen. For example, in my current XP11 Cessna 172 profile if I roll hard while climbing there will be a sudden big "bump" (in the roll axis I think) toward the end of the maneuver when I'd expect the motion to be small and slow. I run Ian's BFF software on a separate dedicated computer. This computer is an old intel i7 920 CPU, and testing shows that one of the CPU cores is often maxed out just running BFF. Is it likely some of the "bumps" could be from when the CPU can't keep up, then suddenly tries to catch up?
4- EMI I don't think this been an issue with the sedate profiles (cessna 172) I've been using lately but I'm about to go back to DCS and try to tune for jet fighters which reminds me that when I was using very fast cues previously the motion felt "bumpy" and/or "mechanical" Maybe gearbox backlash, but maybe EMI too. The first step is probably the 12 bit sensor upgrade Thanos suggested, but after that there also may be EMI issues. Sadly I do not have access to a scope, and do not have the knowledge to use one. I hope to get one some day, it would be great for my antique cars (Chevy Corvair) as well! My EMI shielding: My power cables from VFD's to motors are in metal flex conduit. Position sensors are run with shielded home security system wire. AMC is located in a steel enclosure, but that enclosure does have a couple holes in it. VFD's are not shielded, but are not very close to anything but the AMC enclosure (it is about one foot from the nearest VFD). I suppose the USB cable from the PC to the AMC could be an EMI weakness, the AMC end of the USB cable comes out of the enclosure fairly near the VFD's (12" to 14" to nearest VFD I would say).
Note: Money is a major concern for me, my "disposable" income is only about $100 per month at this time and even that I should generally be putting toward paying off debt left from my ex-wife. Don't worry too much, I should be debt free in a couple years (except for mortgage) I just want you to be aware that I cannot easily do things like upgrade the PC running the motion sim to solve the CPU issue so I'd want to be pretty sure that it is an issue.
|
|
|
Post by hexpod on Aug 8, 2018 13:15:57 GMT
Well, what do you call noise? What are the exact symptoms of your electromagnetic noise? Whatch what I had with the analog 8bits here: youtu.be/tozRznH530AThis issue has desapered after a simple sensor upgrade to the 12bit SSI. Concerning the kicks with the motion cues, you should maybe go and see on simtools side, as the new IK plugin we developed ( heXpod.xyz ) takes little resources and is smooth like butter by now. Good luck!
|
|
|
Post by hexpod on Aug 8, 2018 14:46:46 GMT
Well, what do you call noise? What are the exact symptoms of your electromagnetic noise? Whatch what I had with the analog 8bits here: youtu.be/tozRznH530AThis issue has desapered after a simple sensor upgrade to the 12bit SSI. Concerning the kicks with the motion cues, you should maybe go and see on simtools side, as the new IK plugin we developed ( heXpod.xyz ) takes little resources and is smooth like butter by now. Good luck! Another benefit of the heXpod plugin is the benchmark loop feature where you can test on the heave axis different kinds of loops in a repetable way (speed, amplitude, pause time). This can be a big help to properly set up your acceleration/velocity/PID Whatch here: vimeo.com/263733345Cheers
|
|
|
Post by Trip Rodriguez on Aug 9, 2018 6:51:28 GMT
Well, what do you call noise? What are the exact symptoms of your electromagnetic noise? Whatch what I had with the analog 8bits here: youtu.be/tozRznH530AThis issue has desapered after a simple sensor upgrade to the 12bit SSI. Concerning the kicks with the motion cues, you should maybe go and see on simtools side, as the new IK plugin we developed ( heXpod.xyz ) takes little resources and is smooth like butter by now. Good luck! Another benefit of the heXpod plugin is the benchmark loop feature where you can test on the heave axis different kinds of loops in a repetable way (speed, amplitude, pause time). This can be a big help to properly set up your acceleration/velocity/PID Whatch here: vimeo.com/263733345Cheers That sounds great about the SimTools update! Once I complete some other mods I'm going to start playing with both BFF and SimTools to see what kind of results I can get. About your video concerning the 8 bit sensors: I don't think I'm having oscillation problems, but I have been running very low PID for smoother motions for a very long time. I run something like 12/0/0 but even at high P settings (60 plus) I have no oscillations at all with the platform sitting still. Just to clarify my above post, the vibrations I was mentioning in my previous post are totally invisible they are so small (see here, in this video I'm feeling the vibrations but you can't really see it www.youtube.com/edit?o=U&video_id=Q1RuGWJ_GVM) , but I feel them and they annoy me a lot. Looking on the motion sim barely appears to be moving, but in VR the motion cues feel huge! My sim can move a lot more than this. The "jerks" are very small too, but they feel really big. Here is a video just a few seconds long where you can see the mystery bump, just before my friend says "what was that?", reacting to having felt it. www.youtube.com/watch?v=-UXny49vrIQTrip
|
|
tony
New Member
Posts: 23
|
Post by tony on Aug 9, 2018 14:47:07 GMT
I get the bump/crunch/heavy hit or whatever it is once and a while. I think it is related to torque limiting. What about turbulence in BFF? I don't know how to turn it off. It says "\B" to turn it on but I see no indicator telling me it is on for sure. Could that be it? BTW: I bought a 1 Channel Scope Assembled for around $20.00 on Amazon. I always have had it on #6 Inverters Analog Input. Man, it used to be noisy....and now it is a straight line! Thought: could the math like Hexpod has said give a bogus calc at certain angles and then everything is out the window? We are doing 12bit I/O on the AMC. Maybe the 8bit BFF is impacting somehow? IAN/Thanos, how do we update the BFF file for 10 12 or whatever bit we need? Thanks
|
|
|
Post by Trip Rodriguez on Aug 10, 2018 7:59:29 GMT
I don't think it's anything like that.
The recorded turbulence in BFF actually doesn't exist in most of the BFF modules, I think it's in DCS but definitely not in X-Plane.
I'm strongly suspect that the "bump" I get once in a while is EMI or some fault in my hardware somewhere. I'd like to find out if it's always the same actuator that does it for starters.
|
|
|
Post by Trip Rodriguez on Aug 16, 2018 18:33:00 GMT
Another benefit of the heXpod plugin is the benchmark loop feature where you can test on the heave axis different kinds of loops in a repetable way (speed, amplitude, pause time). This can be a big help to properly set up your acceleration/velocity/PID Whatch here: vimeo.com/263733345Cheers That sounds great about the SimTools update! Once I complete some other mods I'm going to start playing with both BFF and SimTools to see what kind of results I can get. About your video concerning the 8 bit sensors: I don't think I'm having oscillation problems, but I have been running very low PID for smoother motions for a very long time. I run something like 12/0/0 but even at high P settings (60 plus) I have no oscillations at all with the platform sitting still. Just to clarify my above post, the vibrations I was mentioning in my previous post are totally invisible they are so small (see here, in this video I'm feeling the vibrations but you can't really see it www.youtube.com/edit?o=U&video_id=Q1RuGWJ_GVM) , but I feel them and they annoy me a lot. Looking on the motion sim barely appears to be moving, but in VR the motion cues feel huge! My sim can move a lot more than this. The "jerks" are very small too, but they feel really big. Here is a video just a few seconds long where you can see the mystery bump, just before my friend says "what was that?", reacting to having felt it. www.youtube.com/watch?v=-UXny49vrIQTrip Hexpod, was it you that answered my email yesterday or someone else? I sent you a PM on this forum, I have some questions so contact me if possible. The software looks great, I can't wait to try it! Trip
|
|