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Old Oct 23, 2012, 06:30 PM
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Originally Posted by erh7771 View Post
Your thrust tubes are a little tight for my taste but that shouldn't overamp any thing...
After reading this I became concerned and started reading through all sorts of tube construction threads. I went out and measured the exhaust diameter at 54mm which is 80% of the 68mm FSA. I would prefer vertical thrust over top end so I could open this up a little bit. My tubes were made from a template for the raptor kit and is probably because of the exhaust ports are not round nozzles like other jets and the tubes sit kinda oval in shape due to the design.

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Old Oct 23, 2012, 07:03 PM
efflux RC's Avatar
United States, CA, Santa Clarita
Joined Aug 2009
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You have a lot going here Wally. I haven;t read the whole thread but here's a few other points.

I asked earlier about the motor your using. Is it a "Velocity-RC" motor?
The Velocity-RC motor (as mentioned by someone above) is 2900 kv. Not 2950. Perhaps some one is just calling there motor Velocity.

Your ESCs are getting hardly any airf flow. Remove the heat shrink from the leading and trailing ends of the ESC with a knive, for better air flow.

Did you build the fans or did someone esle do it?

Always wrap the front of your motor with (very thin) scotch tape or aluminum tape. This will help center the motor in the housing.

Motor screws possibly loose. Hmmm. not good for sure.

Fan rubbing?......Always make sure the rotor is not contacting the motor screws or the motor housing, by holding against your ear and turning the rotor slowly (by hand) while pushing rotor towards the housing. You should not hear any scraping, rubbing, or clicking.

Some folks make little fiber washers for use between the motors screw heads and the motor housing with plastic fans. But the Wemo fans have taken 2500+ watts without melting. or rotor problems of any kind. Yes, they may rub a bit during the initial break in. but not as bas as your photo shows.

Did you heat the shaft adaptor (per the Wemo dirs) before sliding it onto the motor? Or did you pound it on?

Genuine Velocity-RC motors are good motors. Although the wires are a few inches long, and you cannot cut the wires as short as you did to get the ESC behind the motor. They are only tinnned about one inch from the end. Were your motor wires that short? And tinned? Did you have to remove the enamel insulation to solder them?

Here's an example of the Velocity-RC motor on 6s in My Viperjet. The 9 blade Mach EDf is more heavily loaded than the wemo, and the motor is perfoming very well.
It now flies a 4:30 min routine at a top speed of 140.

Practice building and balancing the edf (using the "Clock" method) or have a reputable dealer build it for you.

Hope that helps, Gary

Viperjet Demo - Las Vegas 2012 (3 min 22 sec)


Ali Demos our Viperjet at Best in the West (5 min 37 sec)
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Old Oct 23, 2012, 07:49 PM
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Originally Posted by efflux RC View Post
You have a lot going here Wally. I haven;t read the whole thread but here's a few other points.

I asked earlier about the motor your using. Is it a "Velocity-RC" motor?
The Velocity-RC motor (as mentioned by someone above) is 2900 kv. Not 2950. Perhaps some one is just calling there motor Velocity.

Your ESCs are getting hardly any airf flow. Remove the heat shrink from the leading and trailing ends of the ESC with a knive, for better air flow.

Did you build the fans or did someone esle do it?

Always wrap the front of your motor with (very thin) scotch tape or aluminum tape. This will help center the motor in the housing.

Motor screws possibly loose. Hmmm. not good for sure.

Fan rubbing?......Always make sure the rotor is not contacting the motor screws or the motor housing, by holding against your ear and turning the rotor slowly (by hand) while pushing rotor towards the housing. You should not hear any scraping, rubbing, or clicking.

Some folks make little fiber washers for use between the motors screw heads and the motor housing with plastic fans. But the Wemo fans have taken 2500+ watts without melting. or rotor problems of any kind. Yes, they may rub a bit during the initial break in. but not as bas as your photo shows.

Did you heat the shaft adaptor (per the Wemo dirs) before sliding it onto the motor? Or did you pound it on?

Genuine Velocity-RC motors are good motors. Although the wires are a few inches long, and you cannot cut the wires as short as you did to get the ESC behind the motor. They are only tinnned about one inch from the end. Were your motor wires that short? And tinned? Did you have to remove the enamel insulation to solder them?

Here's an example of the Velocity-RC motor on 6s in My Viperjet. The 9 blade Mach EDf is more heavily loaded than the wemo, and the motor is perfoming very well.
It now flies a 4:30 min routine at a top speed of 140.

Practice building and balancing the edf (using the "Clock" method) or have a reputable dealer build it for you.

Hope that helps, Gary

http://www.youtube.com/watch?v=vNVGeDjK4zQ

http://www.youtube.com/watch?v=Tt7KPFIa2_M
Hello Gary,
The motors im using in my twin setup are:

http://edfhobbies.com/index.php?rout...product_id=176

Which I believe to be the real deal and is what this thread is based upon. Correct me if I am using cheap chinese knock offs.
I will remove more of the shrink to allow more air flow. I was also wondering about doing this.
I had paid extra for this fan and motor to be mounted and balanced for me. I did the other one myself and it hasn't failed yet.
On the fan I made I used electrical tape to wrap the motor until it fit snug and centered in the housing. Is scotch tape better? Idk what edfhobbies used to wrap the one that failed.

When I removed the motor screws they were snug tight with loctite material visible on the threads.

When I recieved the assembled unit I had checked the rotor to see if it was making contact with the heads. It didn't make any scratching noise and appeared to be good.

Idk if edfhobbies heat there adaptors when assembling but with my fan I was able to slip it on by hand and tighten the grubs. It was a very tight fit. Should I use heat only when it doesn't press onto the shaft?
My motor wires ARE that short (only a couple inches). They were pre-tinned and I could pull back the insulation a bit to reveal more of it. I did not use strippers or cutters on the motor leads. I did cut the esc leads to about 2" and soldered directly to the motor. This was to reduce wiring and weight. Steve @ CC said this is common and will not void the warranty.
When I get the new esc I will remount the rotor and use the clock method to balance.
The shroud I used to replace the worn WeMo has more gap between rotor blades and shroud. I suppose I should reduce this gap by replacing it with a WeMo shroud.
I really appreciate your feedback and I am trying to get this right. This particular project is my first build so I have been researching things until my eyes bleed. I am having to learn how to do everything through these RCG threads. Nobody to ask questions to in person. Do you see anything wrong here with what I am doing? Thanks again for your feedback.
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Old Oct 23, 2012, 09:52 PM
efflux RC's Avatar
United States, CA, Santa Clarita
Joined Aug 2009
8,912 Posts
Quote:
Originally Posted by WhalleyB0Y View Post
Hello Gary,
The motors im using in my twin setup are:

http://edfhobbies.com/index.php?rout...product_id=176

Which I believe to be the real deal and is what this thread is based upon. Correct me if I am using cheap chinese knock offs.
I will remove more of the shrink to allow more air flow. I was also wondering about doing this.
I had paid extra for this fan and motor to be mounted and balanced for me. I did the other one myself and it hasn't failed yet.
On the fan I made I used electrical tape to wrap the motor until it fit snug and centered in the housing. Is scotch tape better? Idk what edfhobbies used to wrap the one that failed.

When I removed the motor screws they were snug tight with loctite material visible on the threads.

When I recieved the assembled unit I had checked the rotor to see if it was making contact with the heads. It didn't make any scratching noise and appeared to be good.

Idk if edfhobbies heat there adaptors when assembling but with my fan I was able to slip it on by hand and tighten the grubs. It was a very tight fit. Should I use heat only when it doesn't press onto the shaft?
My motor wires ARE that short (only a couple inches). They were pre-tinned and I could pull back the insulation a bit to reveal more of it. I did not use strippers or cutters on the motor leads. I did cut the esc leads to about 2" and soldered directly to the motor. This was to reduce wiring and weight. Steve @ CC said this is common and will not void the warranty.
When I get the new esc I will remount the rotor and use the clock method to balance.
The shroud I used to replace the worn WeMo has more gap between rotor blades and shroud. I suppose I should reduce this gap by replacing it with a WeMo shroud.
I really appreciate your feedback and I am trying to get this right. This particular project is my first build so I have been researching things until my eyes bleed. I am having to learn how to do everything through these RCG threads. Nobody to ask questions to in person. Do you see anything wrong here with what I am doing? Thanks again for your feedback.
I like the thinner tape as I feel it centers the motor better.
If the shaft adaptor just slipped on. Your OK.
It looks like you getting on the right track.
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Old Oct 26, 2012, 05:59 PM
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Ok so I decided to try this twin setup again with a 5s instead. This will reduce rpm/ load and cooling requirements etc. and should still be able to get excellent power and thrust to weight ratio. (Target 8lbs x 300W = 2400W total)

I would have to guess my new continuous current draw with the 2950kv in the WeMo fan can be roughly 50-60 amps per side at WOT. Burst at 80 amps at best. Currently I have 4 pieces of 2' long wire feeding both these power-plants. In an attempt to reduce overall weight I would like to remove one pair of 10 awg wiring and share the other pair between the two speed controllers. I think I would only need 2 sets of capacitors to take care of the ripple voltage? I could possibly use a single 5s 5000mAh 30c pack and still be within margins. I am concerned about the possibility of over loading the wire or connectors. What is the rating for stranded aluminum with silicone insulation? A lot of conflicting charts out there.

Once I get all the parts together I intend to do some more bench testing but do you guys think this will work?
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Old Nov 01, 2012, 11:03 PM
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Has anyone tried putting this motor in a Funjet with 5s/6s packs? Im very tempted to try it.
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Old Nov 02, 2012, 07:07 AM
it wasn't me flying that plane
Hover or die's Avatar
United States, NC, Wilmington
Joined Mar 2011
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Whalley,
Putting props on the edf motor does work but the motor is loaded more with a prop that a fan and will draw more amps..I know it seems like it would be the opposite but the prop loads more than the fan..i use the eflite bl15 motor with the 6x4 horizon stryker prop(old model)on 3 and 4s and the performance will blow your mind..125 on 3s and 160+ on 4s and insane power...give it a go...
Take care..................Chris
It will throw the occasional bearing on 4s...
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Old Nov 02, 2012, 10:49 AM
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Originally Posted by Hover or die View Post
Whalley,
Putting props on the edf motor does work but the motor is loaded more with a prop that a fan and will draw more amps..I know it seems like it would be the opposite but the prop loads more than the fan..i use the eflite bl15 motor with the 6x4 horizon stryker prop(old model)on 3 and 4s and the performance will blow your mind..125 on 3s and 160+ on 4s and insane power...give it a go...
Take care..................Chris
It will throw the occasional bearing on 4s...
Yes Chris, at those speeds it will blow my mind. It just so happens that I have BL15 sitting here too. But that would leave my 2950kv out of work... A buddy flies his FJ with the Delta V-32 2150kv motor on 5s and it is pretty darn quick. I must ensure that I am quicker... muwahahah!
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Old Nov 03, 2012, 11:28 PM
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Guys,

I'm experimenting with a BL15 (the 3600kv version) on 4-cell, using an APC 4.75 x 4.75 pusher prop. I watt-metered the setup and am peaking almost 80 amps and 1300 watts at WOT on the bench. I tried a 5.5 x 5.5P and briefly saw 90-ish amps at around 80% throttle before shutting in down (only running an 85A ESC).

I'm wondering...if I should step down to 3-cell, and use a 6 x 4P instead. I'm attempting to (safely!) push this motor to the edge...looking for max performance without burning it up.

According to E-flite's website, this motor is rated for 46A continuous, 55A burst (15 seconds). I've read in another thread that some are using a 6 x 4 prop (though apparently not a pusher prop) on 4-cell....can't quite figure out how they're doing that without torching the motor! ??? I'm certain amperage would be well into 100A, how is the motor able to handle it?
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Old Nov 04, 2012, 01:54 AM
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United States, NC, Wilmington
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That motor runs absolutely best with the 6x4 prop from horizon..the prop from the old stryker,not the stryker (z),but the f27c stryker..you will get around 20% more thrust over the apc 6x4..anything bigger just loads the motor and will not allow it to "cut loose"....on 3 cells its incredible but on 4.........well,it sounds like the wings are going to come offf....just make sure your servos are up to the task as the cheap ones will not hold...i also had to go to balsa elevons as the foam ones give up and yell "mercy"!
Start with 3 cells, i use the 2200mah with this setup..at least 45c on the batteries..in the air i only run wot for burst on 4 cells as it is screaming...good luck...
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Old Nov 04, 2012, 02:26 AM
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Originally Posted by Hover or die View Post
That motor runs absolutely best with the 6x4 prop from horizon..the prop from the old stryker,not the stryker (z),but the f27c stryker..you will get around 20% more thrust over the apc 6x4..anything bigger just loads the motor and will not allow it to "cut loose"....on 3 cells its incredible but on 4.........well,it sounds like the wings are going to come offf....just make sure your servos are up to the task as the cheap ones will not hold...i also had to go to balsa elevons as the foam ones give up and yell "mercy"!
Start with 3 cells, i use the 2200mah with this setup..at least 45c on the batteries..in the air i only run wot for burst on 4 cells as it is screaming...good luck...
How many watt/amps are you getting with that prop?
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Old Nov 04, 2012, 06:22 AM
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Whalley,
I have never checked but i can today..its only 6 in the morning here but give me a couple hours and i will throw the watt meter on there and run it up..going flying today so will not be a problem to check...
I have always run this setup on my strykers,pusherprop viperjets and also used it on profile F22s but its not too fastt on the 22 because the airframe will tourquebefore you could every use the availible power...but i use it for raw power on that airframe...do passes at high alpha and 5 mph and hit the throttle and go straight up as long as you like lol...
Im testing another viper-like pusher today and will see about getting some video...
Take care and ill check back through after flying today....
Also wanted to mention that i have tried many other props looking for a better "sweet spot" and they just seem to drown the motor..the prop from the new stryker is a 6x6 and it will not even turn up,static or in flight,i have tried both,,,but the 6x4 will scream..what really took me by surprize was the difference in the horizon an the apc prop..if you look at the prop side by side you can see why one is better..the apc is not a smooth prop in comparison,lots of flat areas whereas the horizon transitions smoothly through its pitch....
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Old Nov 04, 2012, 09:39 AM
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Quote:
Originally Posted by Hover or die View Post
That motor runs absolutely best with the 6x4 prop from horizon..the prop from the old stryker,not the stryker (z),but the f27c stryker..you will get around 20% more thrust over the apc 6x4..anything bigger just loads the motor and will not allow it to "cut loose"....on 3 cells its incredible but on 4.........well,it sounds like the wings are going to come offf....just make sure your servos are up to the task as the cheap ones will not hold...i also had to go to balsa elevons as the foam ones give up and yell "mercy"!
Start with 3 cells, i use the 2200mah with this setup..at least 45c on the batteries..in the air i only run wot for burst on 4 cells as it is screaming...good luck...
Ok, but are you using that prop in a puller or pusher application? Silly question, but just want to be sure we're on the same page before I order one.
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Old Nov 04, 2012, 12:01 PM
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Ive been told its a puller prop but it is the stock prop for a stryker and mounted at the back of the plane...mounted 2/3s back on the profile 22s...
Theyconly cost 2 or 3 bucks so certainly worth getting a few to experiment with........

We are going to try an afternoon session as the wind is blowing pretty good and trying to maiden a micro today....
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Old Nov 04, 2012, 12:09 PM
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I have found this video illustrating the setup Hover is suggesting (except for the 6x4). Clearly it isn't too much for the 60A eflite esc which was my concern.

FUNJET (1 min 44 sec)


Funny how I had just yanked the guts of my H2 and how it makes for a far better setup in the FJU. I can't wait to get this airframe and try it out. I am currently bench testing this setup on my watt meter too.
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