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Old Jan 04, 2013, 10:59 PM
59 years of RC flying
Daedalus66's Avatar
Canada, ON, Ottawa
Joined Feb 2006
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Regarding the wires, I can say for sure that they work fine on 3s and I'll be trying soon on 4s. I'll be using a conservative prop like 8x4, so the current on 4s should be no greater than for 3s (though thé power obviously will be 33% greater). So I don't anticipate any problem.

Looks like we might get some flyable weather next week. I'll get the Eagletree recorder set up to measure current.
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Old Jan 05, 2013, 07:46 AM
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Northwest Ohio
Joined Jan 2002
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Quote:
Originally Posted by Daedalus66 View Post
Regarding the wires, I can say for sure that they work fine on 3s and I'll be trying soon on 4s. I'll be using a conservative prop like 8x4, so the current on 4s should be no greater than for 3s (though thé power obviously will be 33% greater). So I don't anticipate any problem.

Looks like we might get some flyable weather next week. I'll get the Eagletree recorder set up to measure current.
D66, you won't have any problems on 4S as long as you use the 8 x 4 prop. I ran two 4S packs through mine on the bench, including extended full throttle runs with no issues. If using the Maytech 40 ESC, set the timing to high for a 5% performance gain.

I recorded 29 amps and 440 watts on 4S on high timing.

Scott

www.ModelAero.com
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Old Jan 05, 2013, 11:09 AM
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Well I got mine all ready to go.
Didn't take too long at all. I love ARFS.

Even the elevator servo wasn't too bad and I put it off until the last
because I was dreading trying to squeeze all of that stuff
in such a small space. I opened up the nacelle for more wire space
using a hot wire. I just heat the end of an old control rod to cherry red and
melt foam away.

Actuall the only part of the design that I would change is that rubber band
hatch hold down. I think it is a pain trying to get a small rubber band
around both hooks while holding the hatch open enough to get to the
top hook. It could have been done similar to how the canopy fits on with the mechanical lock to the front and a simple magnet, or tape to the rear.

It would also be nice to have reference bumps or dimples at the CG on the top of the wing. Because of the mass of the motor above the plane it is easier to balance the plane upside down.

I am not criticizing this model. It is a great offering by Model Aero. I love it.

Going to try to maiden tomorrow.

Tim
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Old Jan 05, 2013, 01:46 PM
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Northwest Ohio
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Tim, I'm glad she went together easily for you. And I'll look forward to hearing the flight report as well!

It definitely makes life easier to remove some foam inside the nacelle area. In fact we recommend it in the instructions.

The rubber band hatch hold down works OK. I used a pair of forceps to maneuver the rubber band. Once in place it works fine but a magnet would be neater.

As with all of our kits we will review the feedback from customers and work to continually improve the products.

Scott

www.ModelAero.com
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Old Jan 05, 2013, 03:37 PM
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United States, TN, Arlington
Joined Jan 2005
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Elevator Servo Installation

I hoping those of you who have successfully made the elevator servo installation might offer some suggestions to help me out. Did you install the servo mount assembly, then connect the motor bullet connectors, or connect the bullets first, then epoxy the assembly to the inside of the nacalle? Do the bullet connectors come up from the floor of the nacalle below the servo and go directly up into the right side channel to the motor, or did you snake them around before taking them up into the right side channel. Where did you remove the foam to make more room in the nacalle? I have read and re-read the instructions, studied the photos, but am still struggling with this. Thanks!
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Old Jan 05, 2013, 04:52 PM
59 years of RC flying
Daedalus66's Avatar
Canada, ON, Ottawa
Joined Feb 2006
16,013 Posts
Installing servos and pushrods in the Ultra

Quote:
Originally Posted by gbman View Post
I hoping those of you who have successfully made the elevator servo installation might offer some suggestions to help me out. Did you install the servo mount assembly, then connect the motor bullet connectors, or connect the bullets first, then epoxy the assembly to the inside of the nacalle? Do the bullet connectors come up from the floor of the nacalle below the servo and go directly up into the right side channel to the motor, or did you snake them around before taking them up into the right side channel. Where did you remove the foam to make more room in the nacalle? I have read and re-read the instructions, studied the photos, but am still struggling with this. Thanks!
I installed the motor and fed the wires through. I removed a little foam to let the bullets sit a bit lower and further forward. Then I hooked up the bullets and tucked them well down and slightly forward.

I made up the ply mount using epoxy (next time I would reinforce the narrow front and back parts of the frame with some CF or very light fiberglass to make it more rugged while inserting the servo, though it's fine once everything is assembled).

I inserted the servo into the ply mount and glued it in with hot melt glue (so I can replace it if it goes wrong - just warm the glue with a hot air gun). Be sure to check that you have a good, smooth servo for this critical application.

I installed the connector in the servo arm (should be about 12mm /1/2" from center of shaft to center of connector. I plugged things in and made sure the elevator channel was neutral (no trim, subtrim, etc.). Then I installed the arm as close to right angles to the case as possible and fine tuned with subtrim.

Now I turned to the nacelle and inserted the push rod. I worked with a 1/8" rat tail file to get the hole properly aligned, using the slot in the side of the nacelle as my guide. It's absolutely essential that you get a straight run from elevator horn to servo arm connector or you will get binding and imprecise control.

There's a small rectangular piece of foam protruding into the compartment on the right side at the rear. Remove this so that the back of the compartment is flat.

I inserted the servo in its mount to check how everything lined up and found I had to remove a bit of material on the left side near the bottom of the compartment to give the arm some clearance.

Everything lined up perfectly with the servo mount against the right nacelle side and against the plywood spine at the back. I hooked up the pushrod and tested everything carefully. After a few more insertions and removals I was satisfied. Don't accept anything less than smooth control operation with no binding.

I marked the sidewall of the nacelle to show how far down the servo assembly should be.

The servo was already plugged in, so I was ready to glue. I used hot melt glue to give me a chance to replace the servo later if necessary. I put some glue on the back plate and then blasted it with the hot air gun to rewarm the glue and plywood, then added glue where the frame would touch the ply spine at the rear. Immediately I stuck the assembly into the nacelle and held it till set.

Then I slipped the plastic tube over the pushrod, inserted it through the hole and into the connector. I hooked up the clevis to the elevator horn and tighter the connector (1.5mm Allen wrench).

Now I tested the elevator action again and found very slight misalignment, so took out the push rod and used the rat tail file to open up the hole slightly. Put it back together and this time I was happy.

Now I mixed epoxy and Microballoons and used them to glue the plastic pushrod tube into the slot. Always do this with the linkage hooked up to make sure the tube is aligned. Note that the Microballoons not only add body and reduce weight of he epoxy but they prevent it turning yellow with age. I consider them a necessity on the workbench.

I tucked in the excess elevator cable and was done (except for a hatch, which I still have to make.

All this took about an hour, but everything went in easily and works perfectly smoothly.

The same principles apply to installing the ailerons servo and pushrods. Don't be satisfied until you have everything perfectly aligned and working smoothly without friction. Use that rat tail file to get the hole at the right angle for a perfectly straight run to the servo arm (which like the elevator should be 12mm).

The rudder is easy if the channel isn't blocked with glue. I see that Scott is checking this on all kits now. The rudder servo arm needs to be about 15-17mm to get plenty of throw on the control surface. Hook up the clevis to to outside hole on the rudder horn for maximum precision and use the longer servo arm. A short servo arm and moving the clevis in Is a poor way to get the necessary travel.

I'm very happy with the control set up on the Ultra. The only thing I have to do is to replace the aileron servo, as the one a used does not center as precisely as I'd like. The elevator servo must be the right size to fit the mount, but rudder and aileron could be slightly bigger.

I hope this is helpful. I would say the elevator servo installation takes a bit of patience but is not difficult and the result is very neat.

One point for those of you who have built a kit Polaris. The pushrod wires are much thinner, and this makes the installation fairly tolerant of misalignment. The pushrods on Ultra are fairly stiff, so the guides MUST be well aligned. It's easy and it's essential.

I hope this helps. Don't hesitate to ask questions. Good luck and enjoy the Ultra.
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Old Jan 05, 2013, 05:49 PM
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United States, TN, Arlington
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Thanks Daedalus. I'll try to get the bullets up toward the motor. I'll work with the rat tail file as well to align the pushrod with the servo connector. Lots of good information in your post. Thank you!
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Old Jan 05, 2013, 06:24 PM
59 years of RC flying
Daedalus66's Avatar
Canada, ON, Ottawa
Joined Feb 2006
16,013 Posts
Quote:
Originally Posted by gbman View Post
Thanks Daedalus. I'll try to get the bullets up toward the motor. I'll work with the rat tail file as well to align the pushrod with the servo connector. Lots of good information in your post. Thank you!
You don't have to move them ahead and down much as long as the servo is mounted right to the back. It will become obvious when you try it.
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Old Jan 05, 2013, 08:31 PM
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United States, FL, Gulf Breeze
Joined Apr 2008
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Made a little progress on my Salty-Ultra

got some stainless hardware in for horn mounting
selected some CF for pushrods
ordered stainless piano wire & HS-65HB's.....
installed servo trays
slowly but shurely......
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Old Jan 05, 2013, 08:58 PM
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and............just for grins............a mach up of an idea on how to pass some of the proposed 600 watts through the firewall and out the upper hatch
having fun now!
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Old Jan 06, 2013, 09:57 AM
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ggtronic's Avatar
Montreal
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subscribed...

thanks for this new release Scott... Nice bird...built time
was a big bummer... you will catch lots of new pilots i think

i'm surprise you didnt push the FPV purpose on your
ultra website ? this plane become more & more good
for FPV ! more robust & easy to built...

FPV market grow really fast

fpv gear add 50 to 75g... should be ok but what if we need to move
the battery for CG purpose ? i would have made the top fuselage half empty
on top all the way to the propeller ...

i dont see much picture about ESC area & battery area ?
its often the worst problem with molded EPO... lack of room...

if there is enough room for battery shift... i may jump in
(i also have GOPRO task in mind )
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Old Jan 06, 2013, 10:19 AM
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there is tons of room inside this plane!
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Old Jan 06, 2013, 10:34 AM
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Montreal
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Quote:
Originally Posted by gatorb8 View Post
there is tons of room inside this plane!
thanks for the quick reply... NICE

more room also mean lighter with EPO models... = good

in addition , we often use cokpit/pilot area for camera & video TX
component... so we just need room for battery to shift back...

VrFlyer might like this kit 485 000 viewers enjoy VrFlyer builts yet !

F16 Full operational.wmv (4 min 50 sec)
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Old Jan 06, 2013, 05:42 PM
59 years of RC flying
Daedalus66's Avatar
Canada, ON, Ottawa
Joined Feb 2006
16,013 Posts
Quote:
Originally Posted by ggtronic View Post
in addition , we often use cockpit/pilot area for camera & video TX
component... so we just need room for battery to shift back..
Using a battery of around 200g, it needs to be at or near the rear of the battery compartment as currently configured. However, the space behind that, all the way back to to wing spar in the radio compartment, is unobstructed. All you would have to do is remove the foam at the back and extend the channel. Then you'd be able to slide the battery as far back as you want (or at least its own length) leaving the cockpit area unobstructed. Actually, given the weights involved, I doubt you'd want the battery that far back.

The Ultra is a very nice, easy to fly model. I now have five flights on mine.
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Old Jan 06, 2013, 05:45 PM
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Thanks for the hint Deadalus good news...

about 3 phase motor lead ...as told before, donot compare
battery pack amp to motor amp ... motor awg 20 is not so small...
but might be silicon to withstand the heat if max Watt scenario occur...

smaller wire size reduce/spread the amount of peak energy if a short circuit
occur or when using very long battery lead to ESC (inducting pulse effect)....
so smaller wire size often reduce failure dammage
since we dont use protective fuse in our RC model....

max power setup for this plane might use 500w

while providing 500w... the lipo should drop to approx. 11.5v :

500/11.5 = 43 battery pack amp WOT

3 phase motor amp with ESC+motor loss :
http://www.cerusind.com/catalog/docu...ngFormulas.pdf

500w divided by ( 1.73 x 11.5v x 0.8PowerFactor) = 31 amp max. (motor amp scenario)

31A per phase is only while doing WOT take off & stunt
... maybe few seconds at a time...

i guess that most of the flying will need only half of this = 15 motor Amp
wich require #14 for full performance...on the ground

In the Air, we can afford to loose few watts while saving lots of weight...
so #16... or 18 or even 20 will do the job...that's why quality RC plane use
silicone wire insulant : to support 200deg. C
http://www.belden.com/products/catal...k-03-28_32.pdf
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