Volantex Ranger 1600 under powered

[Brian Dorricott 1]

Just got a new Volantex Ranger 1600 powered glider and find the supplied 2212 1400kv motor rather gutless with its 8x4 prop. The prop diameter im stuck with if I want the tail to stay on ( clearance) but can up the pitch at bit but I would like to up the motor . I have calibrated the 30amp ESC so its not that but it flies rather sluggish and I don't want a camera on it until I trust it , the extra weight wouldn't help . There are plenty of 2230 1200/1300kv motors around that I could try but was wondering if anyone had tried an upgrade and what they found . Would a 3 blade help do think as 8x4 only gives a few millimeters clearance to the fuselage . Any ideas ? 

[Dickw]

You have a 1400kv motor fitted so changing to a 1200/1300kv would give you less power not more.

A physically bigger motor means it can handle more power - not that it will produce more power.

 

The best option would be to fit an 8x5 or 8x6 prop to you present motor. That will give you more thust/speed, and it looks like a 30A ESC should handle the extra power OK.

 

Dick

[EarlyBird]

Looking at HK reviews for this model it looks like 4S is used for more power and to carry the extra weight of a camera.

 

 

[Shaun Walsh]

Four options
Fit an 8x6 2 blade prop

Fit a 3 blade prop, 8x4 or 8x6

Fit a 2212 1800Kv motor with an 8x4 prop.

Use a 4s battery.

You will need an ammeter to make sure you don't exceed the ESC rating.

A set of luggage scales is useful too, attach to the tail and measure the available thrust.

[Brian Dorricott 1]

DOH ! Try the prop on right way round dummy . Not flown with it corrected yet but suspect that's the problem , whenever its a pusher I get confused with which way it should face ,  tractor prop no problem . Thanks for replies everyone , when flown just might up the pitch a little if needed. 

[Martin Harris - Moderator]

Just remember that the prop doesn't care if the motor is behind or in front of it!

[Philip Charlesworth]

I maidened my 1600 this week and also found it gutless (the prop was the right way around).  It really struggled to climb.  I changed it out for an 8x6 prop and it managed to climb slowly with the motor running flat out and needed about 80% for level flight.  I'm accustomed to aircraft which will climb on 70& throttle and cruise on 50% so this was a bit of a shock.

Back on the bench I weighed it and put the power meter on the motor.  It's about 50Watts/pound, which I think is very low for an aircraft intended for FPV.

It seems to need some extra thrust so I'm currently working on a 3D printed motor adapter to raise the motor and allow a 9/10 inch prop.  There is an adapter on Thingiverse but it changes the direction of thrust and I suspect that it's not aligned with the thrust line so I'll make my own adapter.

 

I'm interested to get other people's views on this.
 

[EarlyBird]

There is something wrong, is my view. They do fly out of the box with no problems on 3S for FPV 4S for the extra weight. There should be no need for a larger prop.

 

What can the problem be?

 

There is definitely a lack of power.

 

Throttle calibration?

ESC setup?

 

Just thinking aloud. 

[Philip Charlesworth]

31 minutes ago, EarlyBird said:

There is something wrong, is my view. They do fly out of the box with no problems on 3S for FPV 4S for the extra weight. There should be no need for a larger prop.

 

What can the problem be?

 

There is definitely a lack of power.

 

Throttle calibration?

ESC setup?

 

Just thinking aloud. 

I think the root problem is lack of thrust.  The cause is unclear. 

I've seen videos of the PNP aircraft flying acceptably on 2200 batteries & 8x4 props, which was my setup.  Mine flew nothing like theirs.  It improved with the 8x6 but still didn't match the videos.

 

My thought process so far:

The ESC is running at 12A to 13A from a 3S  2200mAh lipo, which is well within spec.  Looking at spec sheets for generic 2212 motors they seem to have a max power of around 150W, so 50W/lb is probably as good as it gets for this aircraft.  I'd have thought that 70W/lb  to 100W/lb would be better as it gives some 'get out of trouble' power and avoids running flat out all the time.  This suggests that the aircraft needs about a 250W motor.    Delivering that power to an 8 inch prop would require higher RPM and probably a steeper pitch, and I haven't yet found a motor/prop combination which will work.  The obvious choice is to increase the prop diameter and motor power/KV to gain extra thrust.
 

[EarlyBird]

Yours is not PNP then?

[Don Fry]

Have you checked the things Early Bird mentioned earlier? They are logical answers.

[Philip Charlesworth]

14 minutes ago, EarlyBird said:

Yours is not PNP then?

Mine is PNP, with 2200mAh lipo and Spektrum Rx.  Battery was fully charged, and a fresh battery was used for each flight.

 

[Philip Charlesworth]

13 minutes ago, Don Fry said:

Have you checked the things Early Bird mentioned earlier? They are logical answers.

It can be run up to full power (145/150W) so throttle cal and ESC setup should not be a problem.

Looking at Shaun's suggestions I haven't tried a 3-blade prop as I don't have one handy. 

I have a 1900kv 2212 from my recently-deceased Bixler which I might try.  The problem with the 2212 sized motor is that they can't handle any more power as it's already running at max power.  I suspect that increasing RPM with the 8x4 or 8x6 prop will just overload the motor.

 

[EarlyBird]

Hmmm ?

 

How is the prop fitted? 

 

They are normally CCW so looking from the front the prop turns CCW.

 

BTW I am running out of ideas and grasping at straws.

 

My thinking is that you have all stock equipment and it should work without modification as thousands/millions of others have done.

 

 

[Philip Charlesworth]

42 minutes ago, EarlyBird said:

Hmmm ?

 

How is the prop fitted? 

 

They are normally CCW so looking from the front the prop turns CCW.

 

BTW I am running out of ideas and grasping at straws.

 

My thinking is that you have all stock equipment and it should work without modification as thousands/millions of others have done.

 

 

Prop's the right way round on the 3mm shaft and turning the right way.  I agree that it should work.  I've come across a few other comments and videos which suggest that its underpowered so I don't think I'm alone here.

I'm running out of straws to clutch!

 

[EarlyBird]

One last question then I give up.

 

How do you know that the prop is fitted the right way?

 

On pushers fitting the prop the wrong way is quite common.

[Shaun Walsh]

4 hours ago, Philip Charlesworth said:

It can be run up to full power (145/150W) so throttle cal and ESC setup should not be a problem.

Looking at Shaun's suggestions I haven't tried a 3-blade prop as I don't have one handy. 

I have a 1900kv 2212 from my recently-deceased Bixler which I might try.  The problem with the 2212 sized motor is that they can't handle any more power as it's already running at max power.  I suspect that increasing RPM with the 8x4 or 8x6 prop will just overload the motor.

 

Putting some numbers into eCalc indicates that the 8x6 3 blade would probably draw too much current for the motor/esc combination.

Using a 4s battery would considerably increase thrust and draw just under 30 amps.

A 1900kv motor would give the same unloaded rpm as as 1400kv motor on 4s battery. so Philip's Bixler motor is a reasonable suggestion provided the motor and esc will handle the current, otherwise a smaller prop would be needed. I have a Graupner Cumulus 2800 which flies on a Turnigy SK3 2836 1500kv motor with an 8x4 prop and performance is adequate, pretty much in line with what would have been expected with the original glow motor but by no means spectacular

 

[Brian Dorricott 1]

Just to remind you I flew mine with the prop the wrong way round on standard setup and it was under powered but flyable and was brilliant when swopped correctly . Anchor it down and open throttle full the direction with the most blow backwards is the right one and make sure the motor turns anticlockwise and Bob's your mothers brother . Mine on standard setup with 2200 3S climbs very well and quickly to height so if its anything else something must be wrong .

[andyh]

On 06/08/2021 at 09:24, Philip Charlesworth said:

My thought process so far:

The ESC is running at 12A to 13A from a 3S  2200mAh lipo, which is well within spec.  Looking at spec sheets for generic 2212 motors they seem to have a max power of around 150W, so 50W/lb is probably as good as it gets for this aircraft.  I'd have thought that 70W/lb  to 100W/lb would be better as it gives some 'get out of trouble' power and avoids running flat out all the time.  This suggests that the aircraft needs about a 250W motor.    Delivering that power to an 8 inch prop would require higher RPM and probably a steeper pitch, and I haven't yet found a motor/prop combination which will work.  The obvious choice is to increase the prop diameter and motor power/KV to gain extra thrust.
 

 

I have the PnP version of this which came with a no-name 1400Kv 2212 & an 8x4.  it's by no means a pylon racer, but it performs pretty acceptably & pulls about 15A on 3S.

 

I'm currently rebuilding it to put install a FC & am going to put a Sunnkysky 2212 1250Kv motor in it at the same time.  I have these in other models & they'll spin an 8x6 quite happily on 3S & pull ~22A (or probably rather more if I fresher LiPos).  what is notable is that it's a substantially chunkier motor than the no-name 2212, for the same stator size.  they also do a 1400Kv version, so there are motors in this size range that will handle a bit more than 150W.

 

if you want to go nuts, they'll turn an 8x6 on 4S too.  ?

[Philip Charlesworth]

Thanks Andy.  I'm still trying to understand why some people, like me, have problems getting this aircraft to fly while others don't.  I wonder if there's a lot of variability in the unbranded 1400KV motors.

Today I fitted a 1680KV motor with a 40A ESC.  The higher revs should give it more thrust with the 8x4, and I can consider an 8x6 later.  Flat out it was pulling 22A on the 8x4.  I'll give it a test flight on Sunday to see how it performs.

 

[Frank Skilbeck]

This might not be the problem, but I had a similar problem on a flying wing pusher, ended up that the rotating can wasn't locked to the drive shaft, so at full power the can was slipping on the prop shaft. Properly secured the power was much improved.

[Philip Charlesworth]

Took it to the field today with the new setup.  Apart from the usual launch dip that Pushers have, it flew much better than on the stock motor.  On its first flight it was struggling to climb on full throttle, and needed 80% throttle for level flight.  Today it was a totally different aircraft.

It cruised comfortably on 50% throttle and climbed steadily on 80%.  The only time I ran it up to full throttle was to pull up when I decided to go around again.

 

Takeoffs needed a bit of care because the pusher dip is quite noticeable.  Launching on full throttle resulted in it dipping enough to hit the ground.  A colleague hand launched it.  I set the throttle to 50% and slowly opened up to about 80% after takeoff and had no problem.

 

The bigger motor required a larger battery to move the CG forward, so I put a 4000mAh 3S right in the nose.  That seemed to be a good combination as it landed after 8.5 minutes with 73% battery remaining.

All things considered it was a much more positive experience that the first flight.  

[Brian Dorricott 1]

Glad you got it sorted , they are so nice to fly better than my Bixler which I thought was the perfect lazy easy to fly plane .

[Philip Charlesworth]

23 hours ago, Brian Dorricott 1 said:

Glad you got it sorted , they are so nice to fly better than my Bixler which I thought was the perfect lazy easy to fly plane .

I rather enjoyed my Bixler 1 before its sad demise.  It was a handy little trainer, passable glider and not bad at slope soaring.  A versatile little plane for under £100.  I confess that on full throttle the whine from that 6x4 prop was a bit irritating, but I hardly ever needed to ramp it up that high.