Quick Q on 3-Axis Setup

Discussion in '3 Axis Gimbal' started by Zach Beggs, Jun 6, 2013.

  1. Zach Beggs

    Zach Beggs Member

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    Are you guys velcro-ing your mondo stingers and HDMI converters? I realized they get really fricking hot, so my trusty double-sided sticky tape has me wondering it will melt or the adhesive would melt.

    By the way, which side are you sticking the velcro or tape to your stinger? On the circuit side or on one of the metal walls?

    Thanks!!

    Zach
     
  2. Josh Lambeth

    Josh Lambeth Well-Known Member

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    I would zip-tie it... no issue of it coming off that way.

    josh
     
  3. Zach Beggs

    Zach Beggs Member

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    Hey Josh, what part of the MK board am I gluing these heat sinks to? The BLs are the 3 black squares right? I noticed the silver adhesive cannot touch a lead, does that include solder?
     
  4. Gary Haynes

    Gary Haynes Administrator
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    Yes to the black squares. Silver should not touch any electrical connection point. I did the heat sinks on top and bottom. Quite frankly really couldn't tell much difference other than some peace of mind. What have others experienced?
     
  5. Cris Olariu

    Cris Olariu Member

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    Same thing here Gary. I only placed heat sinks on top, and haven't noticed any difference. But it makes me feel better. :)
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    The peace of my mind was indeed the only substantial change I noticed. I suspect there will be some cooling benefit just because of the larger radiative surface, but it wasn't a huge drop. It certainly doesn't hurt, but it's not quite the night and day difference I thought might occur....

    Andy
     
  7. Cris Olariu

    Cris Olariu Member

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    Zach, I use 2 zipties for the video downlink. Which HDMI converter are you using? I just ordered one from QC, and also got the little bracket that mounts it to the tilt boom, so I was hoping I didn't need anything else for it...
     
  8. Zach Beggs

    Zach Beggs Member

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    Cris - that bracket was the most fustrating piece to put on, then the arms were stopping the servo from sliding back. I took it off... :/

    Andy, I've been hearing that the heatsinks do wonders, won't know until I try! :)

    I had Riley at QC solder my bullet connectors, is it okay if the black wire hits the side of the heat sink? I'm thinking of glueing heatsinks just to the underside. What do you think?

    [​IMG]
     
  9. Zach Beggs

    Zach Beggs Member

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    *bump

    Do I need to re-solder these bullet connectors to make room for heat sinks?

    Thanks for your time :)
     
  10. Jason Smoker

    Jason Smoker Active Member

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    Zach I have put heat sinks on top first and notice a little difference but when I put them on the bottom, and tried again the temp drop 15degrees!! :) Zach you may need to re-solder them when you get your heatsinks you have a pretty good idea weather there gonna fit or not!
     
  11. Sam Slape

    Sam Slape Member

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    Zach, mine were the same as yours and I resoldered before putting the heat sinks on the top. Top only right now but have not had a chance to fly with them yet.
     
    Zach Beggs likes this.
  12. Cris Olariu

    Cris Olariu Member

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    I only have heat sinks on the top. And I had to resolder the connectors, but not all of them. I have every other one going to the outside of the board basically.
     
  13. Sebastian Meredith

    Sebastian Meredith Active Member

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    Top and bottom for me ... the cooler the better!
    After frying one BL in the past, the few extra grams of weight for a couple of extra heat sinks is definitely worth the peace of mind!
     
  14. Cris Olariu

    Cris Olariu Member

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    Sebastian -

    Did you raise the BL board any higher in order to accommodate heat sinks on the bottom? I'm not sure the way I have it setup now would allow for enough room for bottom heat sinks. Plus I think raising it would put less strain on all the cables going around the board (that would prolly mean raising the FC board as well).

    Any thoughts anyone?
     
  15. Jason Smoker

    Jason Smoker Active Member

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    Chris you could do that way or just change to a slightly less smaller bolt , mine are 5cm shorter than the ones your meant to use and it just looks like i have cut it off on top of the press nuts! :)
    with mine there is still enough space for cable etc to run through too!
     
  16. Zach Beggs

    Zach Beggs Member

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    I've seen mixed videos on the 3-axis gimbal and just wanted to double check with y'all on 2 things.

    - Servo Buzz: "OK" or does too much buzz mean over-stressed servos?​
    - Servo Belts: tight belts or how much slack? Because the belts or flexible, if think even when their tight they have slack, so it's hard to tell how much is enough.​

    - Pan Axis: Balanced = will stop at an angle while being hung vertically (and while the belt is attached to the pan servo)​

    Thanks Everyone!
     
  17. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Zach:
    There's usually some whining noise from the servos, but, if in doubt, remove the belts and assess how much load the servos are having to move -- sometimes, if pulleys or axles drift out of alignment, there can be a surprising amount of mechanical resistance.

    As to the belts, push with your fingertip at the mid-point of belt between the servo pulley and the large pulley -- you should see about 2-3 mm of deflection before you feel resistance.

    Pan axis: Yeah, it's hard to remove the pan belt so you're correct.

    Andy.
     
  18. Zach Beggs

    Zach Beggs Member

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    Thanks Andy!
     
  19. Zach Beggs

    Zach Beggs Member

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    Heat Sinks
    For the heatsinks on the bottom of the PDB -- is it normal for the heatsinks themselves not to fit perfectly on the BLs? One of the two transformers (I think they're transformers) are in the way and pushes the heatsink slightly diagonally. I noticed the heat sink would be over leads because of this.

    Is this ok?
     
  20. Sebastian Meredith

    Sebastian Meredith Active Member

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    Some nice clear images that might assist in answering your question.

    image.jpg

    image.jpg
     

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