FMS F3A Olympus 1400mm (55") Wingspan - PNP

[Colorado_Scott]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

They are digital. The gear slop when touching the surfaces while power applied is not too good (the rudder for instance - the worst example - moved at least 1/4" each way with power applies to the servo). This is a combination of servo slop and servo arm hole fit with the pushrod. There is zero movement with the futaba and hi tech servos. (Better pushrod fit and much better gear mesh fit). The deadband with the servos on is close to zero. I think the deadband with the FMS servos was ok with the gear slop contributing to 95% of the movement (slop).

[Konrad]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

With the dead band at zero (or very close) as soon as the output shaft starts to move the amplifier should drive the motor to try to stop it. So the amount of gear slop should not be seen at the output shaft. Gear slop will drive up power consumption and might result in early failure of the output transistors. But with a digital servo powered and seeing a pulse width (code) from the Rx you shouldn't see any slop.

Now servo wheel to push rod to clevis to horn slop that is a real big problem with these foam models. I often fill in the servo wheel (arm) and control horn holes with CA. Once cured I re drill these holes for a proper fit with the push rod and clevis pin.
Now I haven't come up with a way to stabilize the hinges. Another source of control slop. But using seal tape seems to help.

Now I know the FMS ad says the servos are digital. But as we have learned from Volkswagen with their claim to have the cleanest diesel engines if false and a violation of the USA DOT and EPA regulation. What the OEM claims and what is true often are not the same. I'm not sure that servos are digital if you can move the surfaces with light pressure. Do you hear the classic high pitch whine from the digital amplifier?

All the best,
Konrad

[SwaggerJacker]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

Any of you still flying this bird? I've read several different comments on preferred CG. I'm assuming the differences in opinions is due to battery size. I'll be using a 6S 4500. To balance at 185mm has the battery pretty far back. Does anyone have anything new to share concerning 6S and placement?

Thanks

[Konrad]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

The placement of the CofG is not dependent on the size of the battery. But the placement of the battery IS dependent on the battery's mass. Most talk was on the fact that the manual originally had shown the CofG far to far forward. 185mm is a good starting point. Then move it aft as the plane's flight characteristics and your flying style dictate.

The static margin of stability is a personal choice. So other than going divergent in pitch (unstable) placement of the CofG is a trim variable for you to adjust during the test flight. I think I gave a trim chart earlier in this thread.

[SwaggerJacker]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

The placement of the CofG is not dependent on the size of the battery. But the placement of the battery IS dependent on the battery's mass.  Most talk was on the fact that the manual originally had shown the CofG far to far forward. 185mm is a good starting point. Then move it aft as the plane's flight characteristics and your flying style dictate.

The static margin of stability is a personal choice. So other than going divergent in pitch (unstable) placement of the CofG is a trim variable for you to adjust during the test flight. I think I gave a trim chart earlier in this thread.

I understand that the CG isn't dependent on the battery. I may have worded that incorrectly. I looked at some of pattern is fun's pics and his batts are placed about the same as mine. So, I'm sure I'm close.

Thanks much.

[Konrad]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

Looking at where someone has placed their components is NOT the same as measuring the balance point on your model. So please measure (verify) that the CofG is within the range stated in the manual 180mm to 190mm before you test fly your model.

All the best,
Konrad

[Alpha]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

I appreciate all the insights you provide in this thread, Konrad! It's all very valuable. I enjoy the Olympus for what it is in its stock configuration, and also enjoy reading about your comparisons with other components like Hitec/Futaba servos.

[SwaggerJacker]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

Looking at where someone has placed their components is NOT the same as measuring the balance point on your model. So please measure (verify) that the CofG is within the range stated in the manual 180mm to 190mm before you test fly your model.

All the best,
Konrad

I know that as well. I was simply stating that I felt better about my setup knowing that his was similar. The CG does not move. Equipment placement is done with the CG in mind.

I've flown trainers to IMAC. No jets...yet ;-) I was just worried about my setup. My plane came with the new hardware but the CG was still listed as the earlier models.

Having said that, I enjoy your posts. Very informative. Reading helps avoid some of the pitfalls of the hobby. I've fallen into a few pits!

Steve

[Konrad]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

I appreciate all the insights you provide in this thread, Konrad! It's all very valuable. I enjoy the Olympus for what it is in its stock configuration, and also enjoy reading about your comparisons with other components like Hitec/Futaba servos.

Alfa, Thank you Alfa.

I want to be clear on this, you (MotionRC) are fine with me making critiques "discussing" the range of products you carry against other brands or products you don't carry. While some, at times might take such comments as counter productive to MotionRC's sales of product.

I assure you, they are made to help all get the most out of their hobby dollar. You and I both know that in the end a satisfied customer who's expectations have been level set and matched, will be happier and come back, even if the product is not the "very best". I point to my satisfaction with Dynam were you, early on, had that disclaimer on the sales page. Without that disclaimer I'd have been real pissed. I really like truth in advertising!!!

All the best,
Konrad
[hr]

Looking at where someone has placed their components is NOT the same as measuring the balance point on your model. So please measure (verify) that the CofG is within the range stated in the manual 180mm to 190mm before you test fly your model.

All the best,
Konrad

I know that as well. I was simply stating that I felt better about my setup knowing that his was similar. The CG does not move. Equipment placement is done with the CG in mind.

I've flown trainers to IMAC. No jets...yet ;-) I was just worried about my setup. My plane came with the new hardware but the CG was still listed as the earlier models.

Having said that, I enjoy your posts. Very informative. Reading helps avoid some of the pitfalls of the hobby. I've fallen into a few pits!

Steve

Steve,
I'm sure you were aware of the nuances as you were looking into this "advanced type" model. On the internet and with the typed word this can get lost. My post was aimed more to those that read the thread as much as it was to you. I wanted to make sure that the point was understood by all. I'd hate to see you or anybody crash because I didn't make it clear what we are dealing with. Some take offense thinking I'm talking down to them. That is not the case. I want to make sure that the concepts are well understood. Heck, with the way I type I'm sure I often make things worse. So I apologize, but the best way to get ideas across is to ask questions.

On the flip side, I ask a lot of questions as I want to understand the answers given or the questions asked. Again I'm not trying to put anybody on the spot.

Still digging my way out of some tar pits myself.

All the best,
Konrad

[Colorado_Scott]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

After flying the Olympus for about 15 flights over weeks of time due to weather related conditions (I would have liked to fly it every day for a week to get use to it!) I decided to build another plane to compare the two. It's the same size and using the same Motor, ESC and battery (5S, 5000mah) as the Olympus; it's an Angel Shadow. It actually has more wing area and is a bit larger, but the same "class" as the Olympus. This plane is a balsa built-up model covered with Monokote type iron-on material;, could be Coverite or similar? The model came covered and I had to add servos, ESC and Motor. I've made a few modifications to the elevator which I hope will improve tracking - but time will tell. I think the Olympus is a fine plane perhaps into Advanced - if no wind is present at contests. The rudder is very sensitive and as I use the rudder every 5 seconds during a flight, its taking me some getting use to so I prevent yaw on a continual basis.

I'll report back in a few weeks when I get a chance to fly the AS - but for now, snow moving in with 12-18" expected in the next days - so I sit and wait! Well, I can now clean up the garage after building this plane.

Scott

[Konrad]

RE: FMS F3A Olympus 1400mm (55") Wingspan - PNP

That Cantalizer does take a bit of getting use to. I've always liked the stiffer wood or glass ships over the foamies. That being said I love my Splendors (on 6 cells) for what they are.

Also let us know the weight differences. I just got back form doing some GA flying ahead of that storm.

All the best,
Konrad

[Colorado_Scott]

The AS came in at 96oz (6lb on the dot), using DS821 servos all around (1.5oz each - ouch). The Olympus comes in at 90oz (5lb 10oz). I'm using the Olympus motor and ESC (70A) and pull 56A at 1050W which should pull the AS around nicely. This is with the 5S, 5000mah Zippy compact battery. If I used the Hitech servos I put in the Olympus, I'd save 3oz as they are .75oz as I recall. The JR's center much better than the Hitech's for less money and have 70oz-in torque (again as I recall). No flying for a while as we have 12" of snow outside (came in last night) so I get some simulator practice for a few days.

[Alpha]

I'm eager to read your flight report on the Angel Shadow. Russian, right?

[Colorado_Scott]

I'm eager to read your flight report on the Angel Shadow. Russian, right?

My original 2M plane shown in my Avatar was made in Russia (a full composite model of amazing quality) by Vladimir and shipped into San Francisco where I picked it up. This smaller model is by Sebart and I got it thru the US distributor in Las Vegas, NV. I am quite anxious to fly it as many have reported it fly's very well. I will post after the first day of flying but it won't be for a few weeks I'm afraid as we still have a fair amount of snow on the roads and I'm sure the field is packed.

[Colorado_Scott]

A final note from me on the Olympus. I think I have my CG too far back as I see a fair amount of weather-veining when I fly and use rudder. I thought this was due to the Canalyzer but now think it's a CG issue. I will not be flying it much any more as the Angel is now in the air - and fly's very nicely. The Olympic got me in the air quickly and was a nice stepping stone back flying. Finally had a nice Colorado day - very little wind so took the Angel out. Slight pull to the canopy on a long down line and may change wing incidence just a bit to cure this but will try the CG back 1/4" more to see if that solves the problem. It was nice to fly this quality of plane again. I have aileron throws of 3/8" which will be about right for me in 'flying mode'. I did not notice any KE mix needed but did not do long sustained KE - but plan to look at this next time out. Happen it landed so nicely each time! I am using the FMS ESC and Motor and there is plenty of power for the Angel.

[Konrad]

Glad you got a good flying plane.

And to be fair you have said that your flights with the Olympus weren't in the best of weather condition. This can add complications to isolating trim issues.

I will be in Denver within the next 6 weeks. Maybe we can work something out:cool:

[Paul Blais]

I just ordered my F3a. I'm curious, can I cut the upper stab at the fuselage and only have the rear horizontal stab on the plane?

[OV10]

And why would ya wanna do that The larger F3A birds use forward fuse canards for a reason

[Paul Blais]

And that reason is?

[Habanero]

So my FMS F3A Olympus does a death spiral each time I add rudder input. I have my throws setup according to the book. The throws do look pretty extreme. Do I still have too much rudder? Any input beyond the slightest rudder turns the plane over, and I need to compensate with opposite aileron to keep the plane controllable. Other than that, it is a joy to fly. Maybe do one mode with very minimal rudder, then another one to pull off slow maneuvers like hammerheads?