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250 Class Electric Helicopters 250 Class Electric Helicopters manufactured by Align, Tarot, SYMA, Airhog, Chaos, HK and similar. |
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08-15-2016, 09:51 AM | #21 (permalink) |
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Join Date: Feb 2015
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Glad you are making progress. Not sure if its just the video but the heli doesn't sound as smooth as a 250 should. How is the gear mesh? What does the log say as far as vibes? Assume you will always have a slight bit of tail wag with a 250, every one of them has a tiny bit, you really can't tune it all out without impacting other aspects.
And get that thing outside! |
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08-15-2016, 12:42 PM | #22 (permalink) |
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Join Date: Jul 2013
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I thought it was a little noisy aswell.
If i increase my throttle curve past 70 i get a flutter sound once blades are under load...... i tweaked things further and seem to have made it worse. My tail servo wasnt properly centred so redid it to get centre, and reset up tail pitch. also gave it a tiny bit more collective pitch. I remounted the gyro aswell... not anywhere near as stable as it was.... When i got the kit, the tail belt pully felt a touch notchy, but it smoothed out once i turned it by hand with the tail belt attached for a few minutes, This is possibly the noise, ill be ordering an align pully with bearing blocks and hex bolts for it. The blades were involved in a tipover, though while look undamaged maybe there is a problem with them (ive got a set of carbon blades coming to replace them) Also got a set of plastic KBDD 40mm tail blades to put on. Gear mesh i checked using a thin strip of paper, i can run the paper through the gear and it comes out zigzagged. im using the copterx motor, maybe those are noiser aswell. |
08-15-2016, 12:57 PM | #23 (permalink) |
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Join Date: Feb 2015
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Again, videos are hard to go by for sound, but it doesn't sound like tail noise, sounds more like the main. You can always remove the belt and see what it sounds like when you spool it up. Unbalanced blades will also make more noise. A clean running 250 will sound like dremel tool, very smooth noise.
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08-15-2016, 01:22 PM | #24 (permalink) |
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Think ill check the motor aswell, ive heard of them coming with bad bearings.
Im putting on an align main shaft and main gear so will run the motor on its own, then with the new blades gear and shaft but without tail belt on and then with everything on. Edit: Someone mentioned to me that they had a strange noise until they added gripping washers to the motor mount so im gonna try that aswell. Last edited by bazsound; 08-16-2016 at 01:02 AM.. |
08-16-2016, 04:30 AM | #25 (permalink) |
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Join Date: Jul 2013
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remounted the gyro with 2mm thick mounting foam tape doubed up. its loctite mounting taape and this stuff realaly sticks well. gyro is way more solid.
The tpe i was using befor wa 5mm tick andd very spngy so there was a lsme movement possibe. and as an extra measure i used a velcro strap (with a strip of foam taape under the strap to stop vibrations) Gyro is rock solid. also fitted the 40mm kbdd tail blades i got last week. feeling confident this is going to be decent so going oout the field where i have more space and softer landing |
08-16-2016, 07:54 AM | #26 (permalink) |
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Join Date: Jul 2013
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i got it in the air for a full minute!
its quite widy, flying my v977 was quite challancing. the field has its grass cut but not short enough for the little 250 so had to use a sheet of plywood as a landing taking off pad. not really that big of a target for landing. after some tweaking and truying different things noticed that swash was way off again. what...... again... hooked up to computer, reset trims and leveled it again as close as i could in the field by eye, rechecked and adjusted zero pitch. bumped my throttle up 5 points and eased off the collectiove. after a few mmore tries a gust of wind cought the heli and lifted it into the air, had some tail wag and carefull set it down on the grass hit throttle hold. despite the grasse beeing a little too long, if you land in the right spots perfectly level it doesnt get cought. switched to rate mode and flew for 30 seconds in rate mode then the tail kicked out hard and wagged. set down bacck into HH and got in the air and kept it there, really stable. howevver the controlls are really soft. i have this issue wwith the cx-3x2000 giro despite uit seeing the full range of my tx (ive adjusted it with subtrkm and endpoints) i only get 20 points either side of the stick for full range of swash movement. if i increase the servo trim up more the servos will bind, swash is moving close to full tilt. so it looks like my gyro mount is working well., theres still vibration in the rotor somewhhere. if i hold the tail find and spool it up theres a distinct fast pulse. im still using the stock blades , gear and mainshaft a deliverys not here yet. This little heli flys so different from the v977, even trhough the 250 is still small its alot more stable (even in its current setup not being perfect) just sits there in the air. I think i may need to take it out of beginner mode. The tail wag i dont think ill get rid off, its probably a combination of the cheap copterx servo and the slop in the tail linkages, i the slider mechanism for binding and its smooth as butter. free in both directions. Looked around for loose screws, seem to be holding up fine. Need to reprogramm the esc, low voltage cuttoff is set a ttadd too low. 3v..... I think ill just go ahead and replace the tail gear pulley with the align part, i know this is a suspect area where there could be vibrations (although there was still vibration after tail motor stopped) due to it felling slighly notchy out of the box. over the next few months will probably see this becoming mostly an align heli, really want it to be in good condition and well setup, no subpar parts. Planning n upgraig it with the DFC head aswell. Edit: so it was brought to my attention in amongst a thread on RCgroups.com i think, either a general cppterx thread or maybay a tailwag thread, and in there i find out you should use the closest hole to centre on the servo horn. Im on the 2nd..... Also my hitec servo is just about the same as the copterx, no better. hitec hs55, same speed ever slo slightly more torque. guess ill just order some metal gear servos that are faster Last edited by bazsound; 08-16-2016 at 12:10 PM.. |
08-17-2016, 08:07 AM | #27 (permalink) |
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Looks like the 250PRO mainshaft is not really a direct fit for the copterx (does it fit the align trex?)
shafts are exactly same size but the integrated colour is a little further up, this results in the thick part of the shaft sticking out from the bottom bearing by about 2-3mm. Align main gear is much nicer than the copterx gear, it actually lines up pretty well with the stock tail gear, its off just a little but not as much as with the copterx gear. Had to take a break as wasted an hour trying to get the 250pro shaft installed. Only way i could get it to work is if i had a spacer to go between the colour and top bearing. Carbon fibre blades on, those look great! Think im gonna have to replace the main shaft bearings, there not notchy but donig feel as smooth as they did. Before i fitted all the parts, i tried my heli to see if moving the hole in the servo horn position had worked. But i couldnt get the heli off the ground. Kept sliding to the left, never done that before. Strange, laminate floor but i was able to get it in the air without it doing that. |
08-17-2016, 09:36 AM | #28 (permalink) |
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Right were really getting somewhere now.
Carbon Fibre blades fitted. Align main gear fitted (much better aligment with the tail gear) I couldnt use the 250PRO mainshafts, the built in colar on them seems to be 2-3mm higher. when isntalled i can see that theres that amount sticking past the bottom bearing. It would need a spacer between the color and top bearing. Also installed the new links, thought they were too big but actually they are the perfect size. Reset everything, recentred servos and adjusted links to level swash. Adjusted blade to swash links to get 0 pitch on both blades, checked them at 3 points around swash . Everything looks close enough. Spool up, smoother. Gets light on the skids as expected, no sliding to the left. had trouble getting it in the air without it darting around. Some tweaks later. I fainly got a few inches of the ground, tail wag while not gone instantly better and im running higher gain, too low it wags, too high it wags. It seems way more locked in. cyclic control seems a bit weird, its like nothing then a jerk, i cant seem to get full stick range to map to full swash travel... tried diferent levels, from beginner to expert, all it does it speed up the swash movement, beginner mode the swash moves slower even if you move stick quickly, expert the swash moves exactly with the stick. I did discover a big problem, the copterx shaft isnt spinning true, on spooldown i was hearing a clicking. Turns out that if you looked at the screw on holding the gear onto mainshaft it was wobbling aswell as the washer, which was creating a scuffing and clicking noise. ANNOYING. Need to get the 250SE mainshafts then. Edit. seems the only mainshafts are the ones with integrated colar.. I need mainshaft bearings anyway, so ordered a set of main bearing blocks. If it turns out its an error in the frame mounting point for the blocks, where can i get spacers that fit the main shaft (not spacers for the bottom of shaft as they are slightly smaller, one that can sit between collar and bearing) |
08-19-2016, 03:32 AM | #29 (permalink) |
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Turns out i had the mixer arms the wrong way making them extend out too far.
Should have swapped it round when i put them back on and thought it just didnt look right. |
08-19-2016, 01:38 PM | #30 (permalink) |
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Ive made another error.
In the gyro my collective trim was all the way down at 45 to get 11 degrees pitch. Just found out that if you are below 60 you need to move in on the servo arm (servo arm too long) whoops |
08-20-2016, 12:50 PM | #31 (permalink) |
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So its looking like my servos may be giving too much deflection as i discoverd that having the collective range at 45 is too low.
tried moving in a hole on the servo arm, not much help, cant go in anyfurther or it will bind on the servo. After lots of searching it looks like my servos could be 180 degree servos and not 90 |
08-22-2016, 03:51 PM | #32 (permalink) |
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Replaced main bearing blocks (with included bearings) with align versions.
No surprise there, quality much better. not only looks much nicer but feels slightly heavier. and also the bearing is almost flush with the bearing block, the copterx bearings were resesedd by a few mm. After lots of seraching i found that you need shhims (spacers) to make up for any play if htere is any, but i didint know that and hadnt ordered the spacers, but when i fitted the blocks and tested the main shaft there was no extra mainshaft protruding below the bearing like i did with align pro mainshaft with the copterx bearing blocks. once all fittetd and the mainshaft installed (including the spacer between the lower breaing block and maingear plus the washer between the maingear and screw) there was a slight grab every rotation when rotation the main blades to check the 1 way bearing. backed of the screw a quarter turn and the bearing was free. So no shims required, that is a bit of luck!!!! I checked the copterx shaft, it was defiantly bent, showed a very obvious curve when rolling on a flat surfice. Align shaft is straight, align breaings feel very smooth. Looking into my FBL cyclic and collective issue i finaly found another usefll piece of info. so it turns out that the fbl CONVERSION from the flybarred SE possed a problem. which resulted in the issue im having (this was with the align which was obviojlsy coppied to copterx) using the same head resulted in too much pitch range. theres an extension piece from tarot that addressed thge issue, that basically extends the blade gripps. theres also a tarot headessembly that has this extension alreadyt implemented.# So basically i need either the mikido blade grip extensions, or the tarot FLB head which has the ball links on the head further out or as a hack way to put spacers on the servo so that i can use the inner balls on the servo arms so as not to bind on the servo, but that throws out the geometery as the links will now all be at funny anglyes |
08-22-2016, 06:19 PM | #33 (permalink) |
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Location: Fullerton, CA
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In a post above, you mentioned that you were going to upgrade to the Align DFC rotor head. If so, all I recall doing is installing the DFC main shaft, the DFC rotor head, and the DFC arms. All the servo links remain the same as the stock SE ones, as far as I can recall. So, I am uncertain about needed any extension pieces that you mentioned in your previous post.
Honestly, I would upgrade the Align swash plate, too. I had nothing but trouble with the CopterX swash and rotor head, and since upgrading to Align parts the heli consistently flown just great.
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08-23-2016, 12:35 AM | #34 (permalink) | |
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Quote:
with the FBL controller set in the recomended range of 70-80 i get 25 degrees of pitch, After much searching i found a post on helifreak where someone else had the same issue, and that it turned ouit to be a commen issue with fbl conversions, there was 2 solutions, either use mikido blade grip extensions to to get the ball link further out from the head, or use the tarot head which has greater distance from head to the ball link. Can find niether in the UK, mikido blade grip extensions dont seem to exist, and tarot head only in the us Edit, Gave up on the copterx gyro, reflashed firmware to earlier versins and started getting massive twitchy when trying to set it up. flashed back to 2.4 and then it wouild not set the gyro direction. yaw corrections would move the swash plate. Had to reset to default and flash again. then the viiolent twitches started happening (seems to happen when hooked to usb) Manged to tweak it to make it fairlys table to hover, i had to increase the cyclic gains on the pots very high and now its more responsive around centre stick and can get it to hover fairly well. Tail is ok but drifting counter clockwise now and the slight was is still present (crap servo) https://www.youtube.com/watch?v=ijEkZZbN-yY This is probably the longest ive hovered in my tiny dinning room, and also the highest ive gotten. Ive got more confidence in finer control now that its setup like this. going to take it out tomorrow see how it feels in more space. I wont be doing anything taxing though until i get my kbar. I also moved in 1 hole on the cyclic arms, i did try going another hole in but i got binding and the links were at extreme angles. even though this reduced the throw (its 3 holes in from outside of arm) and could increase the collective into the 70 range, and cyclic to 65, still only getting full cyclic range on the sticks through 40%-60% going from 60-100 abd 40%-0% does nothing. Even tried putting the cyclic upto 100 obvioiusly this would cause binding but still same result (disconnected links and still only getting the full movement mapped over that tiny range of stick movement) The new bearing blocks and mainshaft have greatly reduced vibrations, theres still some vibration in the tail but its not pulsing like it was before. Its also still seems noisy. Last edited by bazsound; 08-23-2016 at 09:45 AM.. |
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08-23-2016, 12:54 PM | #35 (permalink) |
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Still, I am unsure why there is any difficulty. The DFC upgrade corrected all my issues connected with the CopterX rotor head and swash.
Here are a couple of pics of my most recent 250 build: Starboard: Port: As you can see, the servo links are stock. Only the DFC parts are different. The shorter DFC main shaft will correct any grip link/pitch issues, and the rest is taken care of in your receiver setup and by adjusting the servo links. Meanwhile, you mentioned that your pitch is 25 degrees. By this, do you mean there is roughly 12 degrees of negative pitch and around 12 degrees of positive pitch?
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08-24-2016, 12:17 AM | #36 (permalink) | |
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Quote:
25 degrees positive, 25 degrees negitive if i am on the last servo arm hole when the collective trim in the gyro is set to 75 to get 12 degrees needed it to br brought down to 45 . Im now on the 3 hole in wich is the closest you can go without causing the rear servo arm to hit the anti rotation bracket I havnt measured the pitch since moving in 2 holes but it seems better. someone on youtube mentioned that with FBL systems the sticks dont map to swash movement like a flybar heli. I did put the cyclic trim to 100 but stick movements were the same. my only comparison is a v977, but that fbl system acts a bit different as when the throttle is off, the gyro is off (gyro doesnt keep swash plate level unless motor is running) on that stick movement translates to equal swash movement. It seems to be flying in a hover well now i have the cyclic gains much hgiher |
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08-24-2016, 06:30 AM | #37 (permalink) |
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got it outside in light wind.
Much better! its still far from flying nice but its controllable and not unpredictable. It still feels pretty soft around midstick but was able to hover it quite well. Plenty of power, pitch pumps made it shoot up fairly quick, and i was probably only bumping upto +75 on the pitch. Tail was kicking out but no compensation has been set. Tail wag is slight not bad for a rubbish servo. quick rudder inputs and stopping at centre though cuase pretty bad bouncing, get 3-4 wags before the tail stops. Theres also a random drift in the tail so constantly having to correct the tail (could just be needing adjusted in rate mode since i reset the tail) Not sure what the headspeed but it doesnt soiund like other 250's. Motor is a 3400kv copterx motor, even at 97% its just sounds like its cruising along. |
08-24-2016, 03:41 PM | #38 (permalink) | |
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Quote:
but its still a little nosiy, i ran the motor by itself with no main gear attached. I think it may need to be balanced. Also after running through the headspeed calculator, with my moter 3400kv at 3s theoretically should be 5000rpm headspeed at full throttle! My current throttle curve equates to 97% (+90 on devo tx range -100 to +100) i upped it to 95% 15t pinion. something says to me this is no where near 5000rpm just doesnt sound like its screaming. |
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08-25-2016, 07:53 AM | #39 (permalink) |
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Well my PID tunning made things worse i think.
Multiple tail bounce when doing rudder jabs (returning stick to centre without bouncing the stick) still gives bounces. I got the tail pretty locked in by increasing the gain, it still wags a bit now and then but seems bettery. Cyclic feels worse after increasing the agility and tweaking the PIDS . Twitchy and seemed to glitch a little. Think i need to go back to middle of the range works best range as it was OK there, and go through the guide again. |
08-28-2016, 03:30 PM | #40 (permalink) |
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I realize now I've been commenting on your thread at RCG as well.
I've read people state the 3M outdoor mounting tape provides the best vibration isolation for the controller. I use two or three layers of the stuff and it seems to do the job. A main shaft out of true will cause a ~lot~ of vibration. It doesn't take much. Even if you can't obviously see it's out of true it can be too much. You seem to be having a lot of problems with parts on that heli. I've read these clones can lead to a lot of futzing around with parts getting things to work right. It's possible to get them going well, but people end up replacing a lot of the parts with genuine Align stuff. I have an Align 250 DFC myself and have experienced only a small fraction of the issues you seem to be running into. I'm sure you can get it worked out, but there's something to be said about paying the premium for a name brand kit. I've been tempted to go with a clone myself, the Tarot 450 was a definite possibility for a time, but I ended up going name brand on a 450. Not that it solves all the problems, but they do require less futzing around than the clones. |
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