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Jun 16, 2019, 11:48 PM
65 years of RC flying
Daedalus66's Avatar

Polaris Seaplane Parkflyer


Quote:
Originally Posted by Spencerw99
The thickness of the hull is more than enough. There is no need to reinforce this. I bounced my Polaris off of a flipped over boat as a bet and it never even dinged it. This mainly because I had a consistent layer of packing tape on the bottom that helps with ding resistance. As to the battery tray. It actually had a lot of strength when glued on all sides. Just make sure you use Velcro. Iím regards to the servos, one is plenty. Using more servos will add more weight and more spots for water to get into the fuse. Both not good things. The only spot on the airplane that needs actual hinges is the rudder. It is nice on the other surfaces but not necessary at all. All of the ones I have built have been done with 3M blenderm tape and they have held up for years and thousands of flights. If I were to build another I would use epoxy hinges (Robart medium I believe) and those would work fantastic on all surfaces if you were feeling the upgrade.

Plus one on nearly all of the above.
The exceptions? I like to add another bulkhead under the battery floor to add strength to both the floor and the fuselage bottom. Iíve never tried epoxy hinges.

The most important reinforcing is of the rear fuselage, which can break in a hard landing as the weight of the motor causes the tail assembly to swing forward, pivoting about the front of the plywood plate. What is needed is added tensile strength at the very bottom of the fuselage sides. The very simple, effective and light way to achieve this is with filament packaging tape. Split the usual 3/4Ē width down to 3/8Ē and run a continuous piece on each side from about 2Ē ahead of the step all the way back nearly to the rudder hinge line.

There are many ways to modify Polaris and many of them work well. But start from a recognition that thereís nothing wrong with the basic design. There are no essential modifications (an that includes the ones Iíve suggested). I flew my original Polaris absolutely stock for years. So these changes are a matter of preference, not necessity.

The key to a nice flying Polaris is to keep it light. I prefer to use a 3s 1800 battery rather than the 2200 often seen. With normal equipment, the model should weight 20-22oz.

By the way, donít skimp on the ESC. I always use a 35-40A ESC with switching BEC (SBEC) if possible. Use 50g motor, 2200kv, and APC 6x4 or 7x4 prop.
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Jun 16, 2019, 11:52 PM
Registered User
Spencerw99's Avatar
Quote:
Originally Posted by Daedalus66
Plus one on nearly all of the above.
The exceptions? I like to add another bulkhead under the battery floor to add strength to both the floor and the fuselage bottom. Iíve never tried epoxy hinges.

The most important reinforcing is of the rear fuselage, which can break in a hard landing as the weight of the motor causes the tail assembly to swing forward, pivoting about the front of the plywood plate. What is needed is added tensile strength at the very bottom of the fuselage sides. The very simple, effective and light way to achieve this is with filament packaging tape. Split the usual 3/4Ē width down to 3/8Ē and run a continuous piece on each side from about 2Ē ahead of the step all the way back nearly to the rudder hinge line.

There are many ways to modify Polaris and many of them work well. But start from a recognition that thereís nothing wrong with the basic design. There are no essential modifications (an that includes the ones Iíve suggested). I flew my original Polaris absolutely stock for years. So these changes are a matter of preference, not necessity.

The key to a nice flying Polaris is to keep it light. I prefer to use a 3s 1800 battery rather than the 2200 often seen. With normal equipment, the model should weight 20-22oz.

By the way, donít skimp on the ESC. I always use a 35-40A ESC with switching BEC (SBEC) if possible. Use 50g motor, 2200kv, and APC 6x4 or 7x4 prop.


6x4 is my all time favorite prop for the Polaris


Sent from my iPhone using Tapatalk
Jun 17, 2019, 02:55 AM
Youtube channel : solentlifeuk
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The pylon for elevator / fin and motor when it 'pulls forward' either by motor thrust or in a crash is stressing the wing literally where there is no upper fuselage. This is the reason I extend the ply plate forward. Once you reduce that bend that occurs there - all else falls into place.

Steve has taken a successful design and modified to create an easily built successful model that years after conception is still top line.

Each person will add their personal touch .. their idea of improvement. Some others agree ... some others do not.

My modifications centre around ease of replacing servos / motor and that pylon mount. I am rough on my models - expecting them to handle rough and reasonable flying areas. This means that replacing servos etc. can be as a result of the rough terrain ... and last thing I want is to have to carve into the model to get at it.
I have two hatches in top of fuselage ... one for the battery and another sits over top of Rx. The Rx one is cut beveled so with a touch of UHU Por - I can slot in virtually unmarked. But I have a cut line I can use to open up easily if needed.

With regard to fuselage bottom ... I have tried all types of exterior gutter tape .. packing tape .. etc. and nothing has survived more than one or two water flights. What I have used in the end is black poster paint to give decemnt contrast and then clear varnish over top to waterproof and make slick.
My latest Polaris (#6) is now getting a bit weak in the front half fuselage underside due to the number of flights of field grass - surprisingly abrasive. I will be considering whether to coat with laminating resin or add a 3mm skin ... Tape is not an option.
Jun 17, 2019, 02:58 AM
Youtube channel : solentlifeuk
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Prop ... I graduated to 6x4 3 blade props ... which I found to accelerate better.

Previously I was using 6x5 and 6x6 ... the 6x6 was incredibly loud !! 6 x4 2 blader was good but lacked 'punch'.
Jun 17, 2019, 08:28 AM
I'm a pilot, 100 yrs too late
Thermalin's Avatar
I'm about ready to install the 2212-6 motor which will use the 6" diam prop. I didn't see any reference to where the motor should sit on the firewall in terms of higher or lower. Besides ensuring the prop clears the wing\fuse, is this critical as to how high or low on the firewall it should be? I realized we're only talking a small amount here but didn't want to have level flight or trim issues etc if the thrust line is not close to where it should be.

Solent….
I'm not an electric guy really and with the motor used, would moving to a 6x4 3 blade overload the motor? I;ll have a bit larger than required esc in use. I think the 3 blade would go nice with the unusual design. I prefer to fly a bit slower so there won't be much it any wot throttle flying... Hand \ eye is slowing down just a bit..

Thanks
Mike
Jun 17, 2019, 08:40 AM
Youtube channel : solentlifeuk
solentlife's Avatar
Placement of motor ... with a 6x4 - central is fine. With 7" - its wise to move it UP ...

3 blader ? I have loads of them from other models and as you say it looks 'cool'. I was surprised how well the Gemfan 6x4 3 blader ran even though its more flexible than the 2 blader. I've used MAS (stiff and very good) ... unknown Hobby King stiff (very good and cheaper) .... GWS (bit flexi but ran well) .... Gemfan (flexi but good).

Given that setup can handle a 7" prop ... the 6" 3 blader is fine.
Jun 17, 2019, 02:47 PM
65 years of RC flying
Daedalus66's Avatar

Polaris Seaplane Parkflyer


For the fuselage bottom I use Scotch Tough Transparent Duct Tape, wrapped up the sides by 1/4Ē or so. It has excellent adhesion even in water, and is tough enough for landings on asphalt. I replace it about once a year, when it gets badly scuffed.

Extending the ply plate forward is a good idea if building from scratch but doesnít help once the plane is built. Also, it still leaves the lower fuselage susceptible to cracking, though obviously much less so.

Reinforcing the lower fuselage with filament tape can be done at any time and adds almost no weight. It is very effective in protecting against moderately hard landings.

Best of course is both an extended ply plate (so it rests on the spar) and tape from ahead of the step to the base of the fin at the very bottom of the fuselage sides. To be effective, the tape must be non-stretchable (I have also used Kevlar thread glued on with epoxy).
Jun 18, 2019, 09:17 PM
I'm a pilot, 100 yrs too late
Thermalin's Avatar
Thanks... very much appreciated.
I'll be doing a number of the above mentioned items.
I taking tomorrow off but have quite a few honey-do items to handle but we'll see how much progress I can make.
Jun 20, 2019, 08:06 PM
I'm a pilot, 100 yrs too late
Thermalin's Avatar
Was hoping to bring her on vacation but not working out . A bit to much to do and I don't want to rush things so I'll pick this back up week after next. Appreciate the help and I'll post some pics of the end result.
Mike
Jun 29, 2019, 02:33 PM
jhi
jhi
Registered User
jhi's Avatar

Polaris high alpha


Hello Polaris friends!

I just wanted to say hello and pay tribute to "jetset44" and his great RC models. Polaris was my first depron build and one of my first planes ever. Still following this thread, I enjoy reading about Polaris and watching videos.
Descriptions on YouTube.
Here is a flight I did yesterday with my Polaris #2.
Regards
-Jan

Polaris high alpha PD (2 min 4 sec)
Last edited by jhi; Jul 15, 2019 at 05:24 PM. Reason: Typos
Jun 29, 2019, 03:23 PM
Registered User
Squall's Avatar
Pretty cool! I never even thought of attempting that with a Polaris. Maybe net time I'm out with mine.
Jun 29, 2019, 10:57 PM
Park Jet Guru
jetset44's Avatar
Thread OP
Quote:
Originally Posted by jhi
Hello Polaris friends!

I just wanted to say hello and pay tribute to "jetset44" and his great RC models. Polaris was my first depron build and one of my first planes ever. Still following this tread, I enjoy reading about Polaris and watching videos.
Descriptions in YouTube.
Here is a flight I did yesterday with my Polaris #2.
Regards
-Jan

https://youtu.be/2xETLCpLbX0
What a beautiful flying site, Jan! Glad to hear your enjoying the Polaris.

Steve
Jul 06, 2019, 05:10 PM
Registered User
Whatís up with modelaero?

I went to order a Polaris kit and the website is gone. Shows up on google but doesnít work.
Jul 06, 2019, 06:20 PM
65 years of RC flying
Daedalus66's Avatar
ModelAero closed down a month or so ago. Sad.
Jul 06, 2019, 10:23 PM
Registered User
Oh man. That sucks.


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