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Post by sgmason on Sept 5, 2012 13:59:40 GMT -4
Ac, things just keep going down hill for me on this helicopter. I got to thinking that that jitter I mentioned might be just because the battery was low so I decided to charge up my other pack. I had it stored in the basement at storage charge, can't remember what exact voltage right now but it was 3.8-3.85V. I took the battery out and low and behold one cell is swollen. Yes it was just a zippy, but I haven't even really used them yet . I am charging the one I started my set up with to see what happens with it, but it looks like I get to fully discharge the bad pack and toss it. I will take a picture of it later and post it along with the jitter video I took later. I just want to try it out with a fully charged battery too to see if that was the problem.
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Post by sgmason on Sept 6, 2012 10:31:39 GMT -4
Ended up getting too busy last night to upload anything, but I have it done now. First up the vibrating blades and servo. I planned on switching the cyclic servos around to see if that solves the problem. The servos are Hyperion Atlas DS20X SMD Coreless Digital on the cyclic and the vibration only happens when the blades are approximately 90° from the boom and only if I flick the elevator stick, no vibration on the aileron stick or if I move the stick without letting it snap back to center on the spring. I did notice there is what I would call a fair amount of slop in the linkages on the head, yet next to nothing on the servos. Now the battery pack. This is what I think I get from buying Hobby King Zippy batteries. The pack has been charged and discharged twice on my Accucell 8150, never flown, and stored at 3.8V per cell. The battery never got hot or warm to touch while charging and discharging. To the best of my knowledge it has never been dropped either. This is not the battery that was in the helicopter when I burnt up the original ESC either, that one is fine. It is only the one cell that appears to have gone south, but I guess it is as good as any reason to go to an 8s set up. The destructive side of my wants to fully charge the pack and puncture it just so see how much fire I can get out of a 6s pack , but the sensible side of me doesn't want to risk ruining anything
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Post by osidak on Sept 7, 2012 10:54:24 GMT -4
I am using those same packs and they have been great - hell I have even attempted to kill it (not meaning too though) and they are still happy - the servo jitter is not good I would start by disconnecting all the linkages and see if you can make it happen. I wonder if something is binding in your head causing them to freak out
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Post by sgmason on Sept 7, 2012 11:25:00 GMT -4
I was a little shocked when I saw the battery all puffed up like that. I chalk it up to a bad cell that got through, not that all Zippy packs are bad. I am sure that there are some Zippy packs are perfectly matched and are darn near indestructible. With the number of them that they sell there will be some bad that slip through, I just happened to get one. I was just going to switch the position of the servos to see if it cured the problem, but I haven't gotten around to it yet. Pulling the links off the servos might be a less time consuming option through. Just the movement of the head feels like it has slop in it, whether it is that I have stretched the links or it is something else I don't know I am still leaning pretty heavily towards a Black Widow FBL setup, before shipping to Canada it is under $200 so it would be about the same cost as each of my previous crashes.
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Post by osidak on Sept 7, 2012 14:41:43 GMT -4
fbl will not solve a hinkey servo so i would start with disconnecting the cyclic servos and see if they still jitter. if they do then start unplugging each servo one at a time to see if one is throwing some electrical interference or something
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Post by sgmason on Sept 7, 2012 14:59:57 GMT -4
I don't think the servo is the problem, but if it is, I would replace it. The FLB idea is simply because there is less mechanical links involved. That and I am enjoying the simplicity of the MCPX and its FLB head First thing will be to pull the servo and give it the flick test to see if it jitters on center all on its own with just a servo arm on it. Then I will try it on its own with a load connected to the arm. then i just start adding things in till I find the problem. I should be able to rule out the servo in the first couple of tests
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Post by sgmason on Sept 7, 2012 23:33:40 GMT -4
I did the testing and moving around of my servos, even swapped out all the horns to take that out of the equation and about the only thing I can come up with is that they just aren't strong enough. The servos in question are Hyperion DS-20x SMD and the specs are at www.hyperion-world.com/products/product/HP-DS20x-SMD. I am positive that I have the BEC PRO set for 6V so I should be getting a torque of 8.0kg/cm, but as soon as I add the weight of the head I start getting the vibrations, more so when the blades are put on. Loosening off the spring tension on the Tx made the vibration lessen but it is still there if the stick is released and allowed to return to center on its own. I don't think switching to a FLB head alone will solve the problem so it looks like I will be upgrading my servos as well. Tomorrow I will double check the voltage settings on the BEC PRO, but if I am right about having it set properly it looks like I will be saving up over the winter to spend a few hundred dollars on new, stronger servos. Its a good thing I still have the MCPX to play with in the mean time, because by the time I get this sorted out I should be getting really good at flying a CCPM helicopter
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Post by Valkman on Sept 8, 2012 4:48:48 GMT -4
I just looked the torque on them seem to be fine so power I don't think is the issue and there is no load on them in the vid anyway. Another thing you could try is to remove you gyro to see if that is giving interference. Then maybe the ESC and BEC. These are quick things to do. Next is how loose is your sticks on your TX? If you flick it and the sticks keeps bouncing the servos will of course do the same. Last and not least thing I can think of and it is the biggest and it means the servos are not centering right which means there is an issue more than likely with the pot or something.
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Post by sgmason on Sept 8, 2012 9:46:45 GMT -4
The only thing plugged into the Rx right now are the cyclic servos and the two leads from the BEC PRO. It almost seems like the elevator servo is fighting to get to center and hold it, and it does that no matter what servo I physically put in that position, not just change the channel on the Rx. I thing that all the cyclic servos are doing it at the same time, its just most noticeable in the elevator position. I just finished my first cup of coffee, and am going to go get the second once I finish writing this reply. Then I am going to go through the programming of the BEC PRO and the servos to make sure I didn't forget something there. Here is a screen shot of what I can program with Servo Commander, if you see anything I should adjust feel free to make suggestions. For the record that is just the default screen and not necessarily how my servos are set, but it could be because I didn't do anything to them other than test them, but I could have knocked something out of wack Well I am off for coffee #2 and to dig out the cable to connect the servos to the programmer
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Post by sgmason on Sept 8, 2012 11:41:07 GMT -4
OK I have gotten that extended blade/servo buzz down to almost nothing and I can attribute that to the spring in the Tx stick. I adjusted the servo dead band to 0, added tension to the cyclic stick springs, and backed of the servo mounting screws 1/2 turn. The last part was in the Tx manual warning not to over tighten the screws and to use both the rubber dampers and brass inserts. I had the screw cranked down. I can't use the inserts because they were too small fit the screws for the servo nuts. I am going to go hunting on my next heli parts order to try and find some inserts that will work with my screws and nuts.
I will post a video of what is going on now later in the day or tomorrow, I have a few things to do around here first., like have breakfast ;D
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Post by sgmason on Sept 18, 2012 18:40:27 GMT -4
Well I over did it on the weekend and my hands are useless right now, add in the rain today and there wasn't much for me to do, so I went back to work on the 600.
I got tired of trying to wedge in the flybar lock that I bought so I decided to make my own out of a piece of 1" plexiglass and some brass rod. I pull the button off the head made some measurements and went to work with the bandsaw, drill press, belt grinder, files, taps and dies. First was drilling a hole for the button screw to go through and hold everything in place, then I eyed up where I needed to drill the holds for the rods. I tapped the holes for the rods then threaded two pieces of brass rod to fit the holes. With that laid out I was able to mark the shape I needed to give clearance for the blade grip links, and cut/file the excess material away. the way it works is I screw it down in place of the button, then thread the rods down and adjust till the flybar is level and not able to move.
I removed the head again and re-leveled the swash, more of a double check than anything. After remounting the head I mechanically tweaked the linkages till I had 0° at 50% throttle.
Right now I actually have more pitch throw than my gauge can measure, but I am going to knock that back in the swash/pitch settings. I am thinking about +/-11°.
That is as far as I have gotten so far, but after supper or early tomorrow I will start setting the pitch and throttle curves. Going by the Finless bob Curves 101 video, he suggests -1°to -3° for point one on the pitch curve and the full 11° at point 5 on the curve for normal with 50% being 0° point 2 half of the pitch between points 1 and 3, while point 4 being half of the pitch between points 3 and 5.
The curve for normal would be something like this: 1: 40%=-3° 2: 45%=-1.5° 3: 50%=0° 4: 75%=5.5° 5: 100%=11°
I am not sure exactly what the % would be at the first point I just used 40% because it was simple to split up ;D
IU would be a full liner curve 0-25-50-75-100
Also based on the Finless Bob video my throttle curve would be
Normal:
1: 0% 2: 50% 3: 80% 4: 90% 5: 100%
IU
1: 100% 2: 90% 3: 80% 4: 90% 5: 100%
The Normal throttle curve is taken right from the video, but I modified the IU curve a touch so that it matched the upper part of the normal curve so there is no jump in head speed when the switch is thrown.
Being that i have no intentions of putting this in the air in the next few days at least, feel free to make suggestions on these settings. I am going to figure out where that -3° is after I have supper and I will modify the pitch curve when I have it.
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Post by sgmason on Sept 18, 2012 22:21:51 GMT -4
OK I think I got this nail down this evening. I limited the pitch to +/-11° then went to work on the pitch curve Normal 1: 32% = -4° 2: 41% = -2° 3: 50% = 0° 4: 75% = 5.5° 5: 100% = 11° IU is same as I stated in the previous post 0%= -11°, 100% = 11° I also set the throttle curves up the same as the previous post. Next is to set up the gyro and clean up the wiring. I also have to fix my training gear. I cracked two of the legs the last attempt so I am going to cut some dowels to insert into them and use some of my high end marine epoxy to glue things back together. After that it is just a thing of waiting for a nice weekend day and I can give it a test hover with the flybar head and the 6s battery. It has to be a weekend because school in back in session so I can't fly there during the week and I don't have the level hard surface at the local park to take off from, its all long grass. I have been taking off from my hand there with the MCPx
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Post by sgmason on Sept 19, 2012 17:26:28 GMT -4
All thats left is to tidy up the wiring and have a nice day to try fly on. The gyro set up went off without a hitch, pretty much just getting it centered and setting the limits. It seems to be working in the right direction which is always a plus I even got my training gear more less fixed today. I just picked up 4 driveway markers cut them to length, and drilled a small hole so I could screw the ball ends to the rods. I still need to epoxy the screws in for security, but that is a 10 minute job and 24 hours of curing time.
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Post by sgmason on Oct 7, 2012 10:50:01 GMT -4
Still not sure if I am going to get this in the air this year, but it will be going FBL soon, then the 8s setup sometime in December or January. With only 1 battery right now and knowing I am switching from 6s to 8s the long walk for 4 minutes just doesn't seem worth it when i can break out the MCPx and fly it almost anywhere.
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Post by sgmason on Feb 5, 2013 13:57:44 GMT -4
Well I finally have BW head on the way, thanks Chris. Not new but good enough for me ;D Next up will be the new motor, FLB control unit and a couple 4s packs to power the bird. I have pretty much decided on the Ikon/MSH unit for the bailout function So I still have a few dollars to spend before this is done. Recently we got a hobby store, that sells Align, in the immediate area so parts are going to be easier to get. They also have a nice 450 super combo sitting in the store and that caught my eye. I may just break down and pick that up before I finish the 600's conversion to FLB and 8s. Why? Because the price is right and the parts are cheaper than the 600. Also I can get a nice scale fuse for it a lot cheaper than I can for the 600. I have to hurry up and get the wings built for my homemade Cub so I can have my table back when I start working on the 600 again. This summer should turn into a busy yet fun one because my RC stable has out grown my bike collection, and there will be a proper flying field within 20 minutes of home with people that can help me in person ;D Not that I don't get help here, but hands on instruction is needed some times We have a beautiful day here today. It is cold, but the sun is so strong that you feel the heat on your face. I think I am going to charge up a couple batteries for the MCPx and go play outside later this afternoon
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