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Thread: Lotus RC T580 reports from RCG

  1. #1

    Lotus RC T580 reports from RCG

    Browsing the LotusRC T580 thread on RC groups, first reports have been coming in from the Testers, and some well balanced reviews (after the initial "looks its so shiney" box opening events)

    Here is a well written review, commenting on the good and no as great parts, over all very positve.

    Note that there is an issue around the Motor controls, and the T580's are being retrofitted in the field with bigger capacitors on the power supply circuit. Without these capacitors, the voltage regulator circuits (powering the brains of the Quad) tend to meet an early demise - magic smoke escapes.

    The review is from these two posts

    Reports by user "Kisssys"

    The Review Part 1
    "I got a chance to play with my T580 this week and it's been fun. I decided since I watched the video and it's suppose to be ready to go I'd put it together without reading the manual. I saw the Futaba type connectors which I had to trim so I looked up the channel order on the net so I'd get those right.

    I didn't like the props not having a nut for the props to tightened up against so I went to lowes and got a bag of 4-.7mm nuts to run down to the bottom of the 4mm thread. I wasn't sure what that little plastic spacer did so I left it out, when I had a top bearing start to walk out of the motor I put them back below the 4mm nut. I tightened the props against the nut and then tightened the prop nut down to the prop. This has worked ok so far. Lock tite may be in the future but I can see problems there also. If the Spinner nut you put lock on doesn't give first you will be turning down on the bearing and motor housing. The bell is not strong enough to press the shaft out so if you need to you should support it on the inside of the housing so you don't bend the supports going to the outer ring of magnets. Yes their is a story to come about that.

    I was given a DX8 for some other testing I'm doing so I installed the AR8000 RX and a TM1000 telemetry system with temp sensors on the FC board regulator and on a row of Fets on the top esc. I have to switch them back and forth since you can only read one at a time. I hooked up the voltage wires to the flight pack wiring and installed a rpm sensor to one of the esc's. I don't have a spektrum rpm sensor so I rewired a eagle tree sensor and tried it. Gives a lot of garbage readings at times but It looks like 2600 rpm at a hover at 1.3kg. Someone might confirm what rpm their hovering at. I set
    the pole count to 14. Horizon is out of the official version, sorry Andy.

    As per Jim's recommendation I installed an extra 2000uf cap to the esc input. I looked at the voltage with my scope at half throttle and didn't really see anything scarry with or without the cap. My Tek468 is not exactly high bandwidth so that doesn't mean their's not something their blowing the regulator so I put the cap in anyway. I have flown the quad now about 20 flights and the temp readings seem normal flying in the 20C weather we're having. I let the unit set with it turned on for 20 minutes and the FC regulator went from 20C to about 58C. I was amazed that when I flew it in the sun that the temperature actually drop about 15degrees. It was cooler outside so the drop was probably do to that and a little cooling from the little vents on the bottom of the case. After 15minutes of flying the esc temp went up to 80C which isn't too bad I guess. Maybe an issue flying on a hot texas afternoon.

    I set the DX8 flight pack warning to 10.3 volts and it consistantly comes on about 20 seconds before the low battery warning on the T580 starts to beep.

    Even with the trip for nuts at Lowes it only took about an hour to get it flying( I did the telemetry stuff the next day). Since its suppose to work with any 4 channel radio I've been flying it with the defaults that are set in the DX8. It flys well enough that a cheap radio could in fact fly this with no problem. The pitch and yaw are so good I wouldn't have to change a thing. I would like to change the bottom of the pitch curve to prevent pulling off the power to much in decents. Sensistivity around the hover point is very good and this is where I usually spend some time with the throttle pitch curve, not needed on the T580. The Yaw is exactly how I want yaw to work, fast enough rotation rate and it does what I want when I want. Pitch and Roll are a bit sensitive without expo but still perfectly flyable.

    Other than the props not staying tight I think that the mechanical design is sound. My thoughts on the motor and it's mounting and the prop threaded insert on a later post.

    It does not hover well in the wind and in forward flight and mine has a pitch porpoise that is very noticeable. It's does well in calm air, holds altitude within a couple of feet.

    If the wind is blowing it jumps around a lot and the altitude hold is poor. I have not done the foam shrink fit trick on the MPX yet but will. I've got some video to edit before I keep going on this so more later.


    and Part 2
    "I think the T580 fly's very well right out of the box. I have never had much luck with my UAVX's with large props and low rpm, the T580
    seems to do fairly well other than the porpoise in forward flight that I mentioned in a previous post. It's so quiet you can hardly hear it when
    its a few hundred feet away.

    I've done a number of full throttle climbs and rapid descents as I opened up the flight test window(getting closer to a crash). It climbs straight up
    with no roll, pitch or yaw correction so I've got a pretty evenly powered craft. When I bring the throtte up slowing to get the esc's to start, my front and
    left right motor's come up right away. My aft motor run's a little in reverse until I stir the sticks a little and it will kick in. This is typical of I2C esc's
    and may or may not indicate a problem. Since I'm getting full power from the slow to start motor I'm ignoring it's lazyness.

    Fast descents are always wobbly to some extent and the T580 is no different. I did have a couple of recoverys where I let the throttle get to low and
    it did a couple of wild gyrations until the motor's got back up to speed. The big props and slow rpm can slow up pretty quickly so caution in pulling
    off the power too far. For FPV flying I like to switch in a second throttle curve that will not allow me to pull the power all the way off. If you do that
    you have to remember to switch it off before you land. It's idle up for a multi-rotor.

    I spent some time down low to the ground over the grass giving it strong inputs one way or the other to test the self righting response and whether I could
    trigger a flip as some have experienced. If I bump the stick enough for a 20 degree change and let it go back to center, it comes back to level very quickly.
    It does at times overshoot slightly before settling back to normal. It comes back fast enough that it concerned me enough to keep playing with it. I found
    if I give it a quick bump to the left and then a quick bump to the right I could get it to flip. I was low to the ground over the grass and no harm was done. This
    was my first indication of how sturdy the props are and that the esc's limited the current until they shut down. I've got a half dozen Turnigy Plush I2C modified
    controllers in a box that burnt up from just bumping the ground so the T580 controllers faired well.

    I didn't have a camera onboard at the time so went back in the house and put my Gopro on to do another test. I did it again and got it on video. Since I was so close to the ground when I generated the flip the video just looks like a couple of wiggles and then its back on the ground so that was a waste but it once again proved how strong the props are. Unfortunately the motor shafts did not fair so well. The front and right motor shafts broke, one at the unused snap ring slot and another at the end of the threaded portion of the shaft. The braking of the shaft is a good news bad new thing I guess. I guess I would rather change a broken prop but a bent shaft would take more time to fix. I think they will need to have a good stock of motor shafts.

    Since the T580 has no provision to change PID's or update firmware it seems that you must fly it exactly the way it comes. Any modifications you make
    that might change flight characteristics may or may not be successful. If you want to play around with PID's their are lots of better choices.

    With that disclaimer I will proceed against my advice.

    I'll get new shafts when I get the chance but it's a good chance to try out unthreaded shafts and a standard collet prop adapter. This would solve the prop slipping issue but allows unsuitable props to be installed. Having reverse threads on 2 motors and props would be the best solution IMHO but
    would probably be too costly.

    More later!!


  2. #2

    Thumbs up

    t580 = NO NO NO!!! but ont take my word for it get one and try to fly in wind with a camera

    prime example of too much wind

    my t580 flipped and broke from hovering over my bed in the test flight bedroom

  3. #3
    i agree- the slightest breeze and she gets upset, i broke 1 motor shaft and 2 props with a slight breeze (must have been a curry ! )


  4. #4
    yep its a real shame too that they just WONT listen to ideas to fix things prime exaple

    April/May lotusrc told by multiple users esc's overheat almost a whole flying season later they say they have made ""NEW"" esc's??? an for these new esc's to work you gotta drill holes in your t580 dome till it looks like swiss cheese SOME FIX hiden in the last pages of the thread is a comment that basicly says new esc used but had a minor mishap?(sounded like a flip from the ""NEW"" ESC'S to me)

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