Goblin 570 First Build

[Smoggie]

Can I just use a 12s pack since most are 2 6s connected together

They are all just two 6S packs wired together in series. There are hardly any chargers that can charge a 12S pack, so no point manufacturers offering such a battery. You would usually charge the two packs in parallel as 6S packs (so a 6S capable charger will do the job)

You can sometimes get 12S 'stick-packs' but they are just two normal 6S packs pre-joined with heatshrink. They still charge as 2 x 6S packs.

 

[leedude1]

As you mentioned Smoggie I'm definatly running 6s for convenience. I ordered the 21t tail speed up gear so I can run a lower headspeed . Figured I'd keep it around 2100-2200 max.
My first goblin so really not sure what's these babies feel like in comparison to my others.

 

[Nicholas Pomarico]

They are all just two 6S packs wired together in series. There are hardly any chargers that can charge a 12S pack, so no point manufacturers offering such a battery. You would usually charge the two packs in parallel as 6S packs (so a 6S capable charger will do the job)

You can sometimes get 12S 'stick-packs' but they are just two normal 6S packs pre-joined with heatshrink. They still charge as 2 x 6S packs.

Definitely going to get 2 6s packs and join them together, for sure easier to find and I can get the cable to hook them up in series

 

[Smoggie]

Definitely going to get 2 6s packs and join them together, for sure easier to find and I can get the cable to hook them up in series

You dont need any special cable. Sure you can buy series harnesses but i wouldn't recommend them because they add unnecessary connects and wire length.

Two ways I would recommend:

1. Use single pole 'bullet' type connectors. This way you dont need to do anything special at all. You connect the black wire of the ESC to the black of one pack, and the red ESC wire to the red of the other pack.. then you take the 'spare' black and red wires from each pack and connect together. Job done. This is the simplest way and has least number of connectors and shortest overall cable length. But the downside is that it is possible, if you are careless, to connect the + and - of a battery together and cause a short circuit... which is no fun!
2. Use normal 2 pole connectors and solder up to ESC this way: Take two 2-pole connectors (EC5 or XT90 or whatever you prefer). Solder the black ESC wire to the negative pole of the first connector. Solder the red ESC wire to the positive pole of the second connector. Now take a length of wire (same gauge as ESC wires and about 3" long) and solder it between the 'spare' poles of the two connectors. Now you just plug your packs in as normal. This is the safest and most 'foolproof' solution.

 

[leedude1]

I went with option #2 on the 700 set up. Here's a visual if using an external BEC... I used because it allows me to have the 6s packs available for other birds if necessary (although it is better to leave them paired for use in the one 12s application if possible) . Also, I have provided the link for the schematic to set up a jumper so you dont need to have the 12s to set up your electronics.

https://www.rc-help.com/attachments/20190706_082234-1-jpg.21949/

https://www.rc-help.com/attachments/20190705_220621-1-jpg.21944/

 

[leedude1]

Smoggie, a question for you my man . Im working through my 570 build and need to shorten the shaft on my Scorpion 4025.
Im looking to Dremel it... do i need to create a heat sink of some sort when doing this? I've never had to cut one down but am assuming a lot of heat is generated... any advice or best practices here would be appreciated. Gonna tackle it tomorrow night.

 

[Smoggie]

Heat is not a big issue but what you need to do is put the motor in a zip-lock plastic bag, poke the shaft through the bag and seal with tape. This prevents metal filings from getting into the motor.

 

[leedude1]

Got it. Thanks

Had to put another flat on the shaft also... came out pretty good. First time for everything.

 

[leedude1]

Almost done with my build and was trying out the battery tray and christ I cant get the tray in all the way... is it meant to be this tight? Anyone else have this issue, before I start trying to sand down the carbon fibre tray.

UPDATE: Never mind guys, I just slid it it in and out a thousand times,and backed out the screws on the frame sides an 1/8 of a turn to relieve a little pressure.. finally able to get it to seat properly.

 

[Smoggie]

UPDATE: Never mind guys, I just slid it it in and out a thousand times,and backed out the screws on the frame sides an 1/8 of a turn to relieve a little pressure.. finally able to get it to seat properly.

It might be that the screws are a hair too long and stick into the slot where the tray slides. If so adding a washer under the screw head will fix it.

 

[leedude1]

Hey guys, just for reference.

It turned out that I was strapping down my battery onto the tray too tightly and that was causing the tray itself to bow. That bowing was causing the additional friction and difficulty in getting the tray slid in all the way. Slacking those straps a tad enabled proper functionality.
I was checking screws and frame tightness and just couldn't figure out why without the battery all was good and smooth. I finally noticed it when I got the battery on for the 5th tine and had an moment while kicking myself in the ass . Lol.

Anyway all good.

NB: This bird is really nice in the air boys. I'm impressed with the visibility of it (my first Goblin) and the flight characteristics overall are excellent.

I do find however that you really have to be on top of cheeking this bird regularly as fasteners do back out, more so that on any of my other birds. Like the tail boom screws at the bottom of the frame... as they go into nylock bolts (that come pre-mounted in those small carbon plates) I can't lock-tight em but I find I need to tighten them every couple of flights as they do start to lossen. The manual does say to lock tight them, but I feel this was probably when bolts may not have been nylocks and perhaps just regular bolts but they didn't update the manual accordingly. You guys lock tight em anyway?


Also those small carbon plates, has anyone permanently fixed them to the boom interior? Say, once fitted and properly positioned..with JB-weld or epoxy or something else to avoid the inevitable movement of them? They are really not my favorite part I must say. lol