jdn181

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First Quad - Eachine 250 Racer
« on: May 30, 2016, 03:22:39 am »
Hi all! Got my first quad last month (Eachine 250 Racer) and already modified the hell out of it. Hope was to use this for a bit of search and rescue, but the flight times aren't exactly where I want them to be so this first one is turning out to be more of study into quads, configs, and instruction for my next build (large quad with a target flight time of around 30min or so). I got the 250 racer because it was cheap(-ish), and powerful (to carry some additional items). Here's what I've done thus far:

Good to see another E250 racer here. Got mine last month and already did the following:

1) Replaced stock CC3D with Revo Mini (in hopes of using GPS modes like position hold, return to home, flight path follow. More on this below)
2) Replaced gps that came with Revo Mini (peice of shit) with M8N. (The M8N is LIGHT YEARS better than the small oplink one. Hands down!)
3) Replaced Flysky i6 with Flysky i10.
4) Smathering of 3D printed parts
5) Added a left and right facing Runcam Owl cams
6) Added FPV camera switcher
7) Added minimOSD on top of existing OSD. (I can turn off the existing OSD in the VTX with the botton on top of the quad, but I keep it on to verify the voltage I'm getting from the minimOSD).

Wee bit heavier now but can still get 8 to 10min flight time with a 2200mAh 3S Lipo. Still hovers fine at 50% throttle too. Spent the last couple days dialing in the altitude hold settings and working on getting the GPS modes to work. On getting the GPS modes to work....yeah they dont. I learned on my own (and verified by others after doing some reading) that the damned magentometer on the Revo Mini is too susceptible to the electrical interferance on the racer. Arming/flying using the complimentary sensors works fine, but as soon as I throw it into GPS sensors and then Position Hold mode the magentometer goes nuts, goes red, and I cant arm.

On my last attempt I re-calibrated the magentometer by clicking Save 5 times, then moved the entire quad around in the air whilst using oplink connection (so no wires attached between quad and laptop). After doing this if the quad is sitting level the Mag status is green so I can arm and take off, but as soon as I get the props moving the mag sensor goes red again. So I'm following the  threads on remote-mounted magnetometer pretty closely now. The M8N GPS has an on-board compass, but there isn't any way to connect it to the Revo mini FC. Yet. I'm hopeful that the developers will figure out a solution soon. Other than that I'm very much happy with the entire package.

jdn181

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Re: First Quad - Eachine 250 Racer
« Reply #1 on: May 30, 2016, 03:45:54 am »
Some pics...

The landing gear is held on with zipties right now, but that's because I'm waiting for some 2.5mm x 10mm screws to come in mail. The landing gear was added to protect the small tray mounted underneath the quad in between the landing gear skids. I ran out of space inside the quad for additional electronics, so this little compartment holds the power supplies for the two runcam owls and the camera switcher board.

Re: First Quad - Eachine 250 Racer
« Reply #2 on: May 31, 2016, 06:35:24 am »
i have a similar frame... (E-Turbine) and the same Flight controller. Same problems... Whorks like a charm in manual but when i switch to PosHold it flyes like s**t.
I even bought the same GPS (m8m) no luck. I compiled the latest version of GCS that supports AuxMag. But i can't properly calibrate the thing.
I gave up with GPS for the time beeing and now i fly manual :) or at least i did... ( waiting for a new revo, burned the old one ;) )