MKS X8 servos in an E5

[Thunder Fighter]

Hi again guys, I was planning on putting MKS 665/669 servos in my E5 Stretch but they were out of stock at my local shop and several weeks away, so I was given a great deal on a set of MKS X8 servos. For sure these are overkill but I can always move them to a 700 or larger heli later.

My problem comes with getting them to fit in the E5 frame. The tail servo looks fine, although I found my servo mount bolts were all 10mm not 8mm so I needed to either use the mounting rubbers or shorter bolts to stop them bottoming out on the frame side as they were tightened up. The Aileron and Pitch servos touch in the centre of the frame but it looks like if I use both the rubbers and an additional alloy spacer it should work ok. Due to the larger boss in the servo you need to use the MKS arms, I will use the plastic arms for now as they have a 20mm hole, but I might change to the 2mm threaded balls (as used on the tail servo) as the stock 3mm do not leave enough thread out the other side of the arm to get a nut on the securely and I'm not that happy about just threading these into the plastic and using CA to hold them there.

The Elevator servo is more of an issue. Using the stock Elevator mount, with no rubbers, the ball is still too far to the left of the frame when mounted on the top of the MKS Arm. Additionally the servo case now interferes with canopy by about 5mm. So looking at the problem I think if I grab 4 additional alloy mounts and stack 3 on each side using longer screws I can move the servo inboard and mount the ball on the under side of the arm and get it centred. Has anyone else solved this issue, have you spaced out the canopy and just lived with the elevator arm being off centre?

//Dennis.

[Thunder Fighter]

So it looks like it has worked ok. For the elevator servo I used 2 additional mounts each side of the servo and drilled out the outside threaded hole in them. Then used some 2.5 x 15mm cap screws to pass through the 2 mounts and screw into the third mount. I left off the servo rubbers from this servo and it looks like the elevator link will be vertical when using the 2mm threaded ball link. I still need to centre the servos, cut the arms and get the links on but it looks pretty good. The servo is also well back from the canopy now.

For the pitch and aileron servos I used one additional thin alloy servo hold down between the servo and its mount, but also needed to use the rubber grommets to keep the servo cases from touching each other in the middle of the frame. It looks a little ugly with the grommets on there and I may get some thicker servo hold downs and remove the rubber as an option but with the current setup the geometry looks pretty good.

Another change I have made to make the fitting of the electronics easier is raising the ESC tray with some of the 6.5mm brass standoffs I found in the Synergy parts at the shop, to bring it up to being almost level with the top edges of the frame. I have done this because my ESC (Hawk 120) is the same width as the outside dimensions of the frame so would not sit down between the frame sides. The other advantage of this is that I can mount my Rx pack under the ESC plate, rather than under the frame but I will have to wait to see where it balances before I work out the best place to mount it.

I will post some pictctures to show these mods when I have time.

//Dennis.