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E-Flite Convergence...

Posted: Sun Feb 19, 2017 10:47 pm
by bdg
Just wanted to share my thoughts about this very interesting craft. As many know, I picked this up from MSC in early December. I was hopeful for a fun out-of-the-box experience. In many ways, my expectations have been met and/or exceeded but there are a few painful episodes as well.

The positives:
- Neat VTOL experience
- Decent flying characteristics
- Great in multi-rotor mode

The negatives:
- There are really only a few negatives that I have experienced but they are fairly significant:
(1) Plane --> Multi-Copter Mode: sometimes I find that the angle is not level and that the nose is pointed up. It does seem to settle to a more level position with time but initially it is really pointed upwards which can be unsettling.
(2) It does not glide particularly well without power. Nothing like my Skipper or Stryker F27Q.
(3) Perhaps the biggest issue that I have experienced lies in the LVC. The Convergence will switch to multi-copter mode as soon as the battery gets low. While this might sound like a good thing, it can be concerning depending upon when it happens. Don't get me wrong - with new batteries the LVC doesn't seem to be a problem BUT with older (and colder!) batteries the internal resistance is too high and the switch to multi-copter mode can happen without warning.
- once in the transition from multi-copter --> airplane the transition was happening but as I was making my first turn the LVC cut-in and the Convergence switched back to multi-copter mode in the middle of a turn. When the plane does not respond as you think, your reactions can be quite unexpected.
- today, after flying 2 great flights, I put it up again but on a battery from Nov 2015. 2.5 minutes in, and while in a banked turn approaching the ball diamond, the Convergence switched from airplane to multicopter. I was just barely able to get it over the fence and then it was hovering at the far corner of the ball diamond and orientation was a challenge... so I put it down. No real damage but lots of trudging through deep snow to try to locate it (thanks again, Chris, for directions!).

By using a variable voltage bench power supply, I've learned that the voltage for this switch is at 10.0V. That is close to the conventional 3.3V/cell when loaded. Once LVC is detected - even for a brief moment - the multi-copter mode is engaged and airplane mode cannot resume.

Tonight, I've installed a more permanent low voltage alarm. I'll set this to trigger at any cell <3.5V to start and will keep a closer eye on my battery age and flight timer to help make sure that the plane stays within expectations.

It is a neat aircraft, for sure. I like it but wish that the LVC would pulse the motors while in flight mode rather than immediately switching to multi-copter mode.

Just thought that I would share my experiences....


Re: E-Flite Convergence...

Posted: Mon Feb 20, 2017 10:33 am
by paulhughes
Good to know about this aircraft.I too was looking at it because of its take off and landing in small area.

Re: E-Flite Convergence...

Posted: Mon Feb 20, 2017 10:58 am
by bdg
Hey Paul!

It's not that it is a "bad" airplane.... I do like it... but the biggest limitation / surprise that I have found has to be the LVC happening without a warning and the unplanned switch from normal flight to multicopter mode, say in the middle of a turn at the far side of the field.....

Use newer batteries and the issues *should* be somewhat mitigated.


Re: E-Flite Convergence...

Posted: Mon Feb 20, 2017 10:59 am
by astroflyer
Any photos of the plane Brian, and can I use your review in the MAAC newsletter?

Re: E-Flite Convergence...

Posted: Sat Feb 25, 2017 12:34 pm
by bdg
Another two very successful flights with this plane (?) today in the fog. It performed perfectly. Just got to keep the newer batteries reserved for this plane!

And once LVC is detected, the plane will not exit multi-copter mode.

Would I buy it again? Yes. I really like both "sides" of the performance and the VTOL is pretty cool!

Just be aware of the potential issues with older batteries (I am sure that the programmers at HH don't use 1-2 yr old batteries!).