2. Hemple 25% Xtreme Decathlon Build Log (Updated 11/17/2017)


1/14/2017 – Well, the build is complete but I lost all of my build pictures.  I’ll summarize briefly and say that the build was the typical ARF build.  Only one major issue caused by an inadvertent manufacturing error.

DLE55 Rear Exhaust
Xoar 23 x 8 prop
Hitec HS-7954SH servos for the control surfaces
Hitec HS-5645MG servos for the flaps and throttle
Spektrum AR8000 8-Channel Receiver
Fourtitude V2 20oz fuel tank
Redwing RC LiFe 2,100mah receiver battery
Redwing RC LiFe 1,450mah ignition battery
RCEXL ignition optical kill switch
Hemple 4″ rudder servo arm

The manufacturing error is with the strut support braces that were formed incorrectly leaving one side too short to match up with the factory mount location.  This required that I open the covering along two wing ribs on each wing and install a new blind nut about a half inch toward the leading edge. It was very fortunate that there was just enough ply to securely hold the blind nut.


The DLE55 rear exhaust engine fit nicely using the DLE standard standoffs necessitating just a minor trimming of the bottom of the motor box for clearance of the stock exhaust and I was able to mount the cowling at the recommended 6 1/4 inches.

The provided hardware is fine except for the rudder pull-pull cable.  It was not plastic coated so working with it I made a mess of the cable so I replaced it with the Dubro 4-40 kit.  I used the left over cable for the tail flying wires.

Although the factory supplied tail wheel springs would have worked, I used my preferred silicone fuel line instead.


Locating the fuel tank and batteries required a mounting tray setup as I just could not get my hands inside the fuse to use Velcro or plastic ties to secure them in place.  A CG check determined that the batteries for the receiver and ignition needed to be located up front and there was enough room next to the fuel tank after offsetting the tank location a bit. I simply cut a thin piece of ply and used Velcro to attach the batteries, which are stacked, to one and the fuel tank to the other.  Then I slid them in place and used screws on each end to secure them.  Simply remove the screws and pull out the tray for maintenance.

The kit did not include a throttle servo mount but I found a nice laser cut balsa one on eBay.


Took the Xtream to the field this morning prepared for a maiden but a storm was brewing and the winds came up so the first flight had to wait.  I took some pictures, fueled up to check for leaks and tuned the new engine.  Surface throws are set to the recommended settings.



1/29/2017 – Finally got the chance for the maiden flight and it went well. Trim was perfect, balance feels right and the power ratio with the DLE55 is very nice.  The recommend throw settings  are very conservative so I’m changing the high rates to the low rates and increasing high rates all the way around.

The landings are very stiff.  Not much give with the carbon fiber gear and firm rubber tires.  Could just be me, so I’ll work on the landings some more and if I can’t smooth them out I’ll look for softer tires.

11/17/2017 – I now have nearly a year of flights and really enjoy flying this plane.  Takes a bit of getting used to as it has very aerobatic characteristics by design which require a higher level of concentration to fly well.   A few issues cropped up that required some repair/modification.

The side door blew off after a few flights but luckily no damage to the airframe and 99% of the door pieces were retrieved.  Door was repaired and reattached.  Cause was determined to be air pressure build up in the fuselage.  I did not modify the firewall and left the exhaust pipe cutout in place so not sure why this happened. Solved the issue by cutting out some covering near the tail of the bottom of the fuse which relieved the pressure.

After a few months one of the metal wing strut retaining clips broke.  I needed a quick fix to fly the same day I noticed the break so I used what I had in the shop. A 1/4 zip tie. Used a heat gun to form the tie around the strut and drilled a mounting hole. Has held up for several months just fine.