Mark@ny

Gary all stock running gear, 6s 5000mah pack 16x10 prop thats how I bought it at a swap meet. I bought it kind of by chance, wasn't in the market for something like that it just looked good and I got a great deal on it. It also belonged to someone that I know and I trusted his opinion. That stinks yours was lost it really is a very good flyer.

Pattern freak

My Feedback: (1)

Hi all, hope everyone is doing ok. It has been a while since anyone has posted on this thread, it was a nice read and seems that everyone likes this little foamy and it's surprisingly capable and a good trainer model. I'm about to start flying competitions again after 16 years and I need a plane to practice (F-21) I know this plane is not the latest 2 meter design but I'm really eyeing the Olympus. I'm a glow guy and this is going to be my first go to epower.

Regarding batteries and weight I'm thinking on using a 5S 4300mah -35C from roaringtop https://www.roaringtopusa.com/35c-43...is-35c-4300-5s props APC 15X10/16X8. Will this setup get me through the F pattern? I will upgrade to carbon linkages and will try to safe weight where it's possible. Will use power of the batt for everything.

Thanks for any help and stay safe!
Blessings
Greg

Thenightstalker

Hi,

I still have my Olympos in the Hangar but not flying it lately.
I'm far away from beeing a pro pilot, I'm mostly flying my CFK Glider.

However, there are some things I know from my few flights with the FMS ...
First, if it flies it flies well and keeps direction in all situations but it doesn't like wind that much because of it's profile - what makes it a stable plane in calm conditions, makes it a little nervouse in the wind.
I was using a 6s lipo that's something I'd not recommend, the Olympus gets quite heavy with 6s and with the original prop and motor you end up needing much more speed than you may like.
Also it's hard to get the CG right, at least with the 6s battery. So gettign a 5s bat will make the thin lighter and with the right prop you'll get more thrust but a lower stall speed. That will help a lot.

Another problem I encountered was the ESC, sometimes it couldn't catch the motor, this gets worse over time and it sometimes caused motor shutdowns from time to time. That means you had to pull back the throttle and push forward again to get the motor running again. So my recommendation, replace (at least) the ESC with one you trust. Even better, replace the whole drive combo but usually a good ESC should be able to drive almost every motor.

All this leaded to some more or less hard landings, nothing too bad but it was enough to crack the landing gear mount so the gear isn't alligned correct now and I wasn't able to fix that. I should replace the gear with a more stable construction, that would hurt the look of the model but I think that's better then a cracked gear. However my battery died after 2 seasons and because I had only one, the Olympus ended up parking in the Hangar ...

Maybe I will do some maintainance works this year and bring her back in the air if I can finde a replacement gear that fits. Or maybe I try building one from CFK ...

I hope I could help you a bit, would be nice to hear from you!

Regards

Pattern freak

My Feedback: (1)

Hi thanks for all the feedback much appreciated, its good to know that a 5s is the way to go. What connectors did yours come with? Are they all the same?.
I'm a little confused as it looks like they differ, horizon is listing it with a wood prop.

Thanks.

Thenightstalker

Hi, tbh I can't remember which connectors it came with, I think it was XT90 ... at least that's what I have built in atm. Only thing I remember is that I changed them to XT90-S (anti spark) because with the 6s bat the sparking was quite annoying.
Mine came with a regular APC prop in gray nylon. Maybe there are different models out now but a wood prop doesn't make sense to me but maybe ...

For 5s you'll need a diferent prop anyway. But again, if you have something suitable in spare then you's change the whole drive set just in case. I almost s... my pants when the motor shuts down the first time, I was barely at a save height and reacted quieck enough but if that happens in a critical situation ... you know. I've seen such problems befor and some ended with a good ammount of "work" while others ended with a not so good ammount of cash for a new model :-)

And before you ask, I DID ground tests with servos and the drive but these things usually NEVER happen on ground.

Regards

Pattern freak

My Feedback: (1)

Thanks so much for your feedback I have decided to order some deans yes the one they sell at horizon comes with a wood prop doesn’t say the size but I will try the 15X10 will try a 16X8 also with the 5s lipo how many minutes you got on your batt?

Regards
Greg

Thenightstalker

Yes try different props, you will find the one that fits best.
I had a 6s 4000 mAh batt. I'd say I got about 6-8 mins. but again I can't remember exactly. I must have exaggregated sometimes because the battery died quite soon ;-)

Pattern freak

My Feedback: (1)

Cool, thanks I’m contemplating between a 5s 4000/5000 the weight difference isn’t that big and I could use the 5000 for a 2M setup we’ll see. 7min would be enough for a training flight of FAI P-21. I have seen some videos this little plane looks like a lot of fun and it can be used also for 3D.

Greg

Ken Cz

Excellent thread with just the info I was looking for!

nosram

I recently acquired an Olympus in a trade. After several trim flights I arrived at a C of G of about 185mm from the leading edge, which is in agreement with many of the readers in this forum. This was confirmed mainly with an inverted 45° upward incline at 2/3rds throttle and zero elevator. I noted that the plane drew an almost straight line with a small downward tendency. With this setting I also noted that here is very little rudder to aileron or elevator coupling. Brilliant!

Fine but the battery was half hanging off the tray and there was no way I was going to try anything violent like a snap!

With the cantelizer removed this gave an excellent inspection hole. I removed the stop at the end of the tray slide and carefully cut slots in the foam so that the tray could extend rearwards. Now the tray was in the desired position, but with very little support at the end of the tray, apart from the foam that I had slotted. Fortunately the end of the tray lined up with the hard plastic support for the rear wing screws. I printed a plastic retainer that grabs both the top and bottom of the tray. The retainer was then attached with two 3mm screws to the wing support.

Next job was to stop the tray moving when in position, for this I printed a secondary tray to use as a spacer while retaining the original clip function.

The only additional mod was to remove about 1/8” from the rear wing mount screws just to ensure they don’t disrupt the now extended rearward tray slots. All my supplied screws are the same length. I wouldn’t remove anymore than 1/8” because this may make screw removal difficult.
I hope this is of interest....
Nick Marson

ronron1

My Feedback: (1)

hi can you give the stl thanks,

I found that there is two manuals for the olympus one with a cg at 185 mm and another one with a cg at 150-160mm.
185mm is really way back i touch the back wall in the fuselage

nosram

185mm is the correct one.
Nick Marson

nosram

Has anyone considered mounting the receiver behind the wing ? This would do two things:
1) Move the CG back a bit
2) More importantly it would move the receiver away from all of the electrical wiring and possible reduction in range.

Thanks in advance
Nick Marson

GarySS

My Feedback: (13)

Nick,
Well, the two aileron servos are out in the wing and the rudder and elevator servos are way back in the tail. There shouldn't be any interference from the servo motors. The receiver's antennas are not anywhere near the servos. In addition, there is adequate distance from the motor on my model. I just made sure the receiver and antennas (I run one satellite) are well out of the way of the battery in cases of a crash causing the battery to slide forward. I didn't have a problem setting the CG with this arrangement.
GarySS

nosram

Gary I was more concerned about getting the receiver away from the high currents and voltages in the motor and ESC. Granted both positions are a long way away from the servos. I am also planning on using a satellite...
Thanks Nick Marson

GarySS

My Feedback: (13)

Nick, Have you had previous problems with other electric powered aircraft in this area?

nosram

Gary we fly in a very noisy area so I try and minimize the number of fades I get with my Spektrum. Futaba owners suffer with failsafe lockouts. I try to not get any frame losses. I normally fly 2 meter pattern planes with the maximum number of satelites possible....
thank you for your interest
Nick Marson

F-4

Folks, recently received an Olympus from FMS. Am doing the assembly and have questions. Before I post them, would like to know if this thread is active?
John

GarySS

My Feedback: (13)

Hello John, I got email notification of your inquiry. As you can tell this isn't active nor is the one in rcgroups, but if you post questions these threads would "wake up".

crash1ace

Hello,
So I am now building a FMS Olympus I had recently purchased from FMS. I understand everyone has been talking about the CG needing to be between 180-190mm back. The instruction manual that came with mine, does in fact state the cg should be between 180-190. I did
mine for about 185mm back. Also have the battery tray snapped backwards into the fuse as the instructions also state. Am using a 6S 5000ma battery. But I still found the plane to be "super" nose heavy. Im kinda afraid to even fly the plane now. Just seems like FMS engineering really screwed this design up IMO.
But any suggestions and recent good ideas would really be helpful. I will not fly it until im better sure the battery wont move and absolute that the CG is correct.

Thanks

mrbiga

what is the weight of your bat ?and if possible send a photo of its installation

F-4

First flights on Olympus yesterday. CG at 180mm first flight. Very nose heavy. Lots of elevator trim for level flight. Lots of down elevator for level flight inverted. Second flight with CG at 185mm and 1/2 elevator trim removed. Much better. Will move cg back a little, but this was flyable for me. However, still took more up elevator trim than I thought should be required.
Thought the gear was a little soft. Need to work on landings. ESC failed after 3 flights!
John