7 inch quad build thread. Start to finish

Not yet, need the frame, which arrives on Tuesday.
Cheers
Steve :slightly_smiling_face:

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One thing I’ve wondered about self building a new quad is when you physically put the unit together do you have to balance the weight distribution to allow it to fly true? Or do you make adjustments to the motor speeds to compensate for weight distribution? :thinking:

Ideally you lay it out, mainly the battery position, for balance on the centre of thrust point.
In reality this does not work out so the flight controller compensates i.e. controls motor speeds to keep the gyro level (in straight flight)
Some motors work a bit harder, they may get a bit warmer, but nothing to cause undue concern. Unless of course you have it way out in which case back to the drawing board :smile:
Cheers
Steve :slightly_smiling_face:

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Very interesting thanks for the insight Steve :grinning:

on this very subject …

Here’s my first piece. A TBS nano diversity receiver.
This will take 2 antenna’s, for the front and rear of the drone, to get the best control reception no matter which way the drone is facing.

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Here’s some photos of my new 7" build (not flown yet)

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And my second part. A 6s 4000mah lipo. It’s massive sitting next to a regular 4s 1500mah.
I can also use it as a field charger :+1:

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I’ve been looking at those as well. Not sure my frame is actually long enough.

Not sure if mine will be :laughing:

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Eeer No.
Length is OK but width to wide for the straps to fit properly
148x38mm plate space
Dimensions: 50x44x140mm (without wires and connectors)

Frames arrived today :grinning:
Should start basic build on Sunday

Hi Steve. I wouldn’t worry about a bit of battery overhang. This is my (possible) solution to the battery question.

Homemade Li-Ion 6S pack using 6 x 18650 Sony VTC5A cells @ 2600mAh and rated at either 25A, 30A or 35A continuous current depending upon which specs you read. I won’t be using it for my maiden flight though as haven’t used the battery yet and want to gauge how much current the quad draws first.

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Thanks Neil
I’m sure Karl @notveryprettyboy will get it fitted.

One of my battery options is an 18650 pack also, but like you I’ll bench test and maiden with Li-Po’s to start with.

Jees. My lipo is 600g :man_facepalming: But 400a burst 200a continuous. Maybe a little too heavy…

Hi Neil
Yours looks sweet :+1:
Those T-Motors are quality, I’ve used them on 450mm quads in the past.
I’m opting for the ESC’s on the arms as well, and if you don’t mind I’m going to knick your position for the capacitors on the arms.
Cheers
Steve :slightly_smiling_face:

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I looked at using the VTC6 cells but the VTC5A on paper have a higher current rating - though with a lower capacity. As you say a bit of testing will need to be done which is why I only made up one pack. Some commercially available VTC6 pack do state some very high continuous current ratings and C values - I saw a pack with a 100C rating which would mean 300A - that’s just ridiculous for a 18650 VTC6 cell. This is what I found spec wise:-

Sony / Murata VTC6 18650 Battery Specifications:

  • Nominal Capacity: 3120mAh
  • Rated Capacity: 3000mAh
  • Max Continuous Discharge Current for temp. up to 80 degrees Celsius: 30A
  • Max Continuous Discharge Current: 20A
  • Nominal Voltage: 3.6V/3.7V
  • Full charge Voltage: 4.2V
  • Internal Impedance 13 mΩ measured by AC 1kHz
  • Diameter 18.45mm max +/- 0.05mm
  • Length 65mm max +/- 0.05mm
  • Weight: 47 g Average
  • Positive terminal: Flat top
  • Color: Green
  • Battery Type / shape: 18650 / Cylindrical
  • Made in Japan
  • Manufacturer: Sony Energy
  • Intended use: Power Battery packs

So that’s 30A continuous for temps up to 80 degrees. If my battery got to 80 degrees I’d be running away. To be fair most Lipo packs also have ridiculous C ratings. It seems the C rating is more of a marketing gimmick than anything real these days.

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I debated a long time on where to put the capacitors. On 7" arms there was room to put them on the end of the ESC and that made the soldering easier (I’ll do anything to make soldering easier). I actually soldered the capacitors on the top and the wires on the bottom - the iFlight Slick ESCs I used has solder pads on both sides.

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I’ve got the DYS ARIAS and they also have double sided pads. I’ll be following your lead on this :laughing: