New Skyjib X4 Build

[Cheshirecat]

Hello. well after a lot of planning and what seemed like ages looking a a next to useless WK-M and Zenmuse in it's box my SJX4 Frame finally arrived, I have Been busy putting it together, I am still waiting for the Herkules III to arrive from Germany (hopefully early next week) and a big thumbs up to Andy of multirotorcraft for taking the 2 Hour drive to personally deliver the frame to me + the invaluable build tips (Thanks Andy) that's what I like good old fashioned customer service. Well not a lot else I can do without the ESC so I had better buy some props, batteries and a decent charger . View attachment 12626 No idea why my return key does not work on this forum????

 

[baja-king]

Nice...

How much did the SJX4 cost from multirotorcraft?

 

[Cheshirecat]

Hi. The price from Andy at Multirotorcraft was exactly the same as I would have paid online at Droidworks, plus UK VAT of course but folks here were saying to budget 25% for import duties if I went direct so all in all probably worked out roughly equal plus now I have the backup of somebody with 40 Years RC experience. Showing me the mangled X4 in the back of his car where the pilot had ignored the Lipo warnings (Two snapped arms, a totally mangled AV200 - god knows what happened to the camera and a very bent crash cage) focuses the mind on procedures and sticking with them.

 

[Droider]

Take your time and really enjoy the build, building your own does give you an incredible sense of achievement but most importantly respect for your machine which becomes part of you and like any part of you you dont want to harm it..

Keep us posted

Dave

 

[Cheshirecat]

Cheers Dave, I will be taking each step carefully, I am excited about seeing it lift off for the first time but as you said it wont be at the risk or harming it.

 

[Cheshirecat]

Well i took Dave's advice... I have certainly been taking my time but she is nearly ready for a basic test.

View attachment 12897

Lots a faffing around in this department, if i moved stuff once i must have moved it 10 Times, well balanced though.

View attachment 12898

She is getting fat with the 8300's on board mind

View attachment 12899

I guess i had better think about getting a NEX7 for the Zen! was let down by the T-Motor carbon prop supplier so i have some Xoars for the time being, i rather like they way they look but it looks like the hubs need a small tweak on balance, pretty close though.

View attachment 12897

Once she is dialed in i will work on something a bit more permanent for the wiring,

View attachment 12900

With the Futaba 7008 on S-Bus am i right in thinking i will have to trade something like IOC switching on X3 for the retracts??


Cheers

 

[Cheshirecat]

And the moral of the story is!!!

If you make a plan stick to it....Damn it.

The plan was, put on the props, take it outside and run it up to just under 50% Throttle, check for no nasty noises, everything running smoothly and in teh correct direction, make some clamp meter current measurments and take the Motor / Battery temps after the test.

That part went well......But then i went off piste and started checking effect of controls with the X4 flexing against its suspension left/right/forward/back etc... the plan called for it to be tethered to a turntable when i did this whilst light on it's feet at 50% gas.
Net result it tipped over backwards faster than i could react and i broke 4 Props with no spares on hand, that scuppered my planned maiden flight for Sunday.

New props on order and fortunately these were Wooden Xoars rather then the Cabon T-Motors i plan to operate it with (once i have finished breaking props) :dread:

 

[Cheshirecat]

Well this time i tethered it to a turntable and all appears well (left / right / back / forwards and yaws correctly) so looking good that way.
A couple of questions though.

I was testing it in Atti Mode and noticed that at just past the 50% throttle mark the motors pick up revs and it keeps going up despite not increasing the throttle, is this because the WKM is effectively trying to take off and getting a bit confused because the tethers are preventing this?
Another question about the LiPos for those flying sky jibs with the battery plates, i am not too convinced about the ability for the velcro straps to stop the LiPos sliding back and forth, do you guy's add anything extra to hold them in place? I am running 8300 6S and the tips of the 15 Inch props are not that far away, i also seem to be having a hell of a time trying to get the rig balanced with the LiPos on, without them the balance is spot on but as soon as they go on it all goes wrong. Not massively out but it does slowly rollover when checking balance centered around the booms. i can get balance across one pair of booms but then the other two are out and when i put that right the opposite goes out. Sheesh! we are talking mm in difference 1 or 2 mostly...How much should i worry about this??
I know this thing should be off the ground by now and i am probably being a big wuss but would like to double check everything before it commit it to the ravages of gravity for the first time, you advice keenly anticipated.

 

[baja-king]

Hi Ches, it's better to take your time - fail to prepare, prepare to fail and all that.
In answer to your first question the WKM is not trying to take off but it is trying to level - what you are probably seeing is the WKM responding to resonances and vibes etc. BTW I always check mine on the turntable in manual mode, that way I know that the motor output is relative to stick input...

Second question - the lipos. I use 3M Dual Lock (industrial Velcro) between the lipo and the battery plate to stop them sliding... As to balance, I only ever fix them by eye and the Skyjib flys perfect...

Steve

 

[Cheshirecat]

Thanks Steve....Manual mode to test without the FC getting involved makes perfect sense.

I did have Velcro to stop sliding but took it off again as i found it prevented me attempting to tweak the position of the LiPos, i think i will put it back as i can see an agressive manouver (planned or otherwise) causing the LiPo to move (or worse) having seen your SJ fly i feel a bit more comfortable about the balance situation.

Thanks

 

[Cheshirecat]

Yeeeees! feeling a bit like an over excited 2 year old right now.
The SkyJib just flew for the first time.
2 Flights in Atti and 1 in GPS Mode.... wind here today is 16-17 MPH and she did very well in a tight space in GPS Hold. Motors. Herkules and LiPos all "just" warm to the touch so no dramas there.
It was in the air for around 7 Minutes (no gimbal at this stage) and i called it a day at 23.1 Volts under load so i make that about 60% of the battery capacity used so 10 Minutes looking achievable with 16600mAh on board.

Going to see how much the charger puts back in each pack to confirm my working out.

Proper chuffed..... camera on order can't wait to get the Zen up and running and get some footage shot .