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Old Dec 22, 2014, 06:22 AM
RC4ME2 is offline
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FMS Olympus CG and Battery Tray Issue

I know this sounds crazy, but the FMS Olympus I just purchased seems to have the track for the battery tray mounted too far forward. When I watched the video by RC Informer (the 15 plus minute video on Youtube), I noticed the way he was able to put the battery tray in. On my Olympus I have to push the front end of the battery tray all the way up into the motor compartment and then get it started in the track. I could never install my battery tray the way the guy on the video did since the track is mounted so far forward.

When you look on the inside of the fuse where the track mounts, you can see where the fuse has cut outs that would accommodate the track being mounted further back in the fuse. It looks like if the tracks had been glued in as far back as the cut outs allow, then if would match up with what I saw on the video mentioned above.

The result of all of this is, when the battery tray is locked in place, to get the CG even close I have to mount the 6S 3300 35C battery several inches from the front edge of the battery tray which means that it ends up hanging off the back of the tray.

A buddy of mine purchased his Olympus some time ago and he said his plane balances with his battery mounted with 1/4" of battery hanging off the front edge of the tray (with tray locked in place). I tried that on my first flight and almost crashed.

So, it seems to me that the left and right tracks were simply mounted too far forward.

Has anyone else who purchased a Olympus recently noticed this issue?
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Last edited by RC4ME2; Dec 23, 2014 at 01:31 PM. Reason: mistake
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Old Dec 30, 2014, 02:23 PM
Anthonyr is offline
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My tray is almost all the way over the wing. With a 5 cell 4500 it works fine and the others in my club had no trouble. Maybe a picture?
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Old Feb 28, 2015, 09:07 PM
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RC4ME2: I just received my Olympus and have the exact same issue. Basically I cant/wont take the battery tray out (which defeats the purpose) and moved the straps all the way back. I also put a large strip of velcro on the bottom of the tray and have the corresponding velcro on my batteries (I also have this on my other planes). What CG did you find works for you?
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Old Sep 03, 2015, 03:04 AM
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My battery tray has to be pushed all the way to the motor with a a 6cell on it and it balances perfect the only thing i had to do was cut some fome away to allow the tray to drop into the runners.
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Old Dec 15, 2015, 01:44 PM
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Here is a link (below) that shows my battery location - the last post is a picture. I'm running my CG at 7.25" from the front of the wing (185mm). I run a 5 Cell 5000mah pack. While my battery hangs way over the back of the tray, I have some Styrofoam blocks to keep the battery from moving back and forth - see picture. Also, I do not remove my battery tray (actually I have a screw in place to make sure the tray does not slide forward (picture)) - the battery slides in and out thru the Velcro straps and works great. Clearly a late post but thought I'd respond for others that may read this.

http://www.rcuniverse.com/forum/elec...olympus-4.html

scott
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Old Dec 19, 2015, 06:46 PM
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Battery tray modification to push battery back farther

After thinking about this a bit I made a small modification which allows the battery tray to get pushed back about 2-3" and the battery now sits fine in the tray and very secure. I took a Dermal tool and cut out the back notch in the side slides - then did a bit of filing and the tray then slid back 2-3" in the track. I then mounted a small hardwood block (picture) in the Styrofoam which aligned with the screw hole I have in the battery tray. A 6x32 screw now holds the battery tray in place and is very secure. I like the solution and it's easy to do. I will be removing the Styrofoam rear battery supports you see in the picture.

Note the picture with the battery tray in position - you can see the mounting screw just to the right of the front Velcro strap. The red line is the original battery tray mounting position.
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Old Apr 07, 2016, 07:34 AM
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Batery Tray

Quote:
Originally Posted by RC4ME2 View Post
I know this sounds crazy, but the FMS Olympus I just purchased seems to have the track for the battery tray mounted too far forward. When I watched the video by RC Informer (the 15 plus minute video on Youtube), I noticed the way he was able to put the battery tray in. On my Olympus I have to push the front end of the battery tray all the way up into the motor compartment and then get it started in the track. I could never install my battery tray the way the guy on the video did since the track is mounted so far forward.

When you look on the inside of the fuse where the track mounts, you can see where the fuse has cut outs that would accommodate the track being mounted further back in the fuse. It looks like if the tracks had been glued in as far back as the cut outs allow, then if would match up with what I saw on the video mentioned above.

The result of all of this is, when the battery tray is locked in place, to get the CG even close I have to mount the 6S 3300 35C battery several inches from the front edge of the battery tray which means that it ends up hanging off the back of the tray.

A buddy of mine purchased his Olympus some time ago and he said his plane balances with his battery mounted with 1/4" of battery hanging off the front edge of the tray (with tray locked in place). I tried that on my first flight and almost crashed.

So, it seems to me that the left and right tracks were simply mounted too far forward.

Has anyone else who purchased a Olympus recently noticed this issue?
After a high recommendation from a friend, I received the FMS Olympus as a "Christmas Gift" suggestion to my wife. Assembled in no time at all and have been awaiting warm weather for the first flight.
Apparently there is a bit of difference in battery tray locations between the early and more recent models of the Olympus. I had the same problem as described above in that the tray was very difficult to remove. It had to be slid all the way to the firewall and then bent up to remove from the fuselage.
I more or less resolved to just change batteries with the tray in the plane..... no big deal. Decided to take one more look at it before the first flights. For some reason (maybe a CG issue?) they installed they battery tray rails approx. 2" forward. The tray rail moldings on the fuselage sides extend 2" further to the rear.
I removed the tray and attempted to pry the rail from the side of the fuselage. Surprisingly, it came out with a little bit of pressure and wedging. Cleaned the excess glue residue from the rails and reinstalled them 2" further toward the rear. Did a trial fit with the tray and there was still some interference from the fuselage side walls that prevented the tray from dropping in. Relieved the interfering foam with a razor knife and a heated putty knife.
Tray now drops right in and slides into the rails just like in the video. GG shouldn't be a problem... plenty of room on the tray to fine tune fore and aft.
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