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Old Jun 11, 2012, 07:41 PM
ancora imparo
jj604's Avatar
Melbourne, Australia
Joined Jul 2005
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Scooch, that's a GWS electric prop for small motors (indoor and little foamies). It is totally unsuitable for the Bixler.

What you need is a 6x4e APC prop or similar. Will be rigid and strong when you try and bend it.
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Old Jun 11, 2012, 08:00 PM
Better then Sliced Bread!
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United States, CA, Arcata
Joined Oct 2011
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Originally Posted by Scooch View Post
OK. After the canopy came off and took out the stock prop, I have had some issues. I figured that this was a good time to up to a 6x4e. The LHS did not have any so I did order some (just figured out that I ordered then from China. New order placed from US site with MUCH shorter delivery time). What I did get from LHS was some orange props. Markings say GWS ep-6030. Well, the center opening was not big enough. I drilled all 3 off them out to a sufficient diameter. Went to the field and put the plane up. At about 3/4 throttle the plane makes a gutt- wrenching sound that sounds like it is going to shake itself apart. I brought the plane down to investigate. When I ran the throttle up in my hand all was fine until about 3/4 throttle then WHAM! First the vibration then the prop self-destructed. Thinking that maybe I had somehow weakend the prop while drilling, I tried a second prop with the same results. The plane flies great at less than 3/4 throttle without any vibration. I did not balance the first 2 props. The third prop I did try to balance (I don,t have a balancer so I did the best I could) but still have the same results. I don't know the manufacturer of the props. I have posted a video of the issue. Any help would be appreciated.

http://www.youtube.com/watch?v=ofxWfU7Na5s
Drilling props is nearly impossible to do properly as it will never be dead center enough to be properly balanced.
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Old Jun 11, 2012, 08:05 PM
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United States, NJ, Jackson
Joined Nov 2011
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Originally Posted by NorCalMatCat View Post
Drilling props is nearly impossible to do properly as it will never be dead center enough to be properly balanced.
So you think the problem has to do with the drilling, or that it is the wrong prop for the application as jj604 said. I am not sure that the prob is with the drilling. I was leaning more towards the wrong prop for this plane/motor.
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Old Jun 11, 2012, 08:21 PM
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Enlarging the prop hole size - I'd recommend using a reamer, not a drill. It is too easy to drill off centre or for the drill to cut more to one side than the other (two cutting edges), especially with plastic. A reamer having a large number of cutting edges should produce a more central hole. Note that it will produce a tapered hole so "cut easy". Reamer - test fit, ream - test fit.... As the prop is clamped between metal flanges it should be on straight.
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Old Jun 11, 2012, 08:23 PM
Argue for your limitations
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Lincoln, CA
Joined Oct 2006
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Originally Posted by Scooch View Post
OK. After the canopy came off and took out the stock prop, I have had some issues. I figured that this was a good time to up to a 6x4e. The LHS did not have any so I did order some (just figured out that I ordered then from China. New order placed from US site with MUCH shorter delivery time). What I did get from LHS was some orange props. Markings say GWS ep-6030. Well, the center opening was not big enough. I drilled all 3 off them out to a sufficient diameter. Went to the field and put the plane up. At about 3/4 throttle the plane makes a gutt- wrenching sound that sounds like it is going to shake itself apart. I brought the plane down to investigate. When I ran the throttle up in my hand all was fine until about 3/4 throttle then WHAM! First the vibration then the prop self-destructed. Thinking that maybe I had somehow weakend the prop while drilling, I tried a second prop with the same results. The plane flies great at less than 3/4 throttle without any vibration. I did not balance the first 2 props. The third prop I did try to balance (I don,t have a balancer so I did the best I could) but still have the same results. I don't know the manufacturer of the props. I have posted a video of the issue. Any help would be appreciated.
The total problem you have experienced was caused by that GWS prop. It was not and WILL NOT run at those rpm's. Not a chance - never - nada. That prop was designed to run on brushed motors primarily and will self destruct EVERY time you put it on even a stock SkyS motor. Don't do it. Also, since you read that, there is no such thing as it being balanced right for the SkyS motor. It is immaterial. If you balanced it to perfection, it would still self destruct. That horrible noise you heard just before it flew apart is called "cavitation". It has made trash out of a lot of boat motors and MUST be avoided COMPLETELY in an airplane motor. Get an APC6x4E or Ep (or a TGS 6x4E) and you will be a happy camper. Also, PLEASE get a balancer. I own 5 different balancers and IMO, THIS one is hands down the best available (price is nice, too). Happy Flying.
I found out about GWS props years ago (no fault of theirs-well, not exactly). I blew out 5 - 6x4e (orange) props before I finally called GWS and they gave me the same info above. The only thing that "E" means is that it was built for an electric motor (less meat on the prop) - which is not a good thing, depending, of course, on the application.
Did yours sound like this - It is the last prop I blew out. You can hear it cavitate at :39 and blow out at :47. I hope this helps.
Wild Hawk ST Labs EDVR - Prop Breaks in Mid-Air (1 min 35 sec)

AJ
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Old Jun 11, 2012, 08:41 PM
AKA, Cheap Chiseler
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United States, FL, North Fort Myers
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Name: SS-Level-2.jpg
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Description: What I'm about to ask is out of step with the current conversation.

This sky surfer is my first plane. Bought it 2/12. Crashed 11 times, flown 26 times. I'm gaining on it.

1. I'm trying to take-off and land from runway to qualify for license to fly.
To this end I installed a 'belly wheel' And tail skid. Tried 4 times to take-off and did not. Tail skid got ground down to the return stub. Is the 'angle of attack' to flat? I can cut down the bottom of the tail for more upangle. I've seen vids of the SS taking off from grass but mine seems to push down hard, won't move.

Please tell me what you think,
DJ
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Old Jun 11, 2012, 09:02 PM
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United States, WI, Fond du Lac
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Originally Posted by Sculptor View Post
Attachment 4931232What I'm about to ask is out of step with the current conversation.

This sky surfer is my first plane. Bought it 2/12. Crashed 11 times, flown 26 times. I'm gaining on it.

1. I'm trying to take-off and land from runway to qualify for license to fly.
To this end I installed a 'belly wheel' And tail skid. Tried 4 times to take-off and did not. Tail skid got ground down to the return stub. Is the 'angle of attack' to flat? I can cut down the bottom of the tail for more upangle. I've seen vids of the SS taking off from grass but mine seems to push down hard, won't move.

Please tell me what you think,
DJ
More AOA would help but the wheel also looks too far forward. If you can, remount the wheel closer to the CG and lower the wheel (have more wheel protruding).

If you are flying off grass, raising the fuselage will allow it to gain speed quicker as it won't be plowing through the grass. Ideally you'd like enough ground clearance that the tail could lift off the ground and allow the elevator to rotate the plane into the correct AOA to lift smoothly off. I suspect in the current configuration it would eventually leap into the air if it was going fast enough.
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Old Jun 11, 2012, 09:42 PM
AKA, Cheap Chiseler
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United States, FL, North Fort Myers
Joined Mar 2012
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Originally Posted by pmullen503 View Post
More AOA would help but the wheel also looks too far forward. If you can, remount the wheel closer to the CG and lower the wheel (have more wheel protruding).



If you are flying off grass, raising the fuselage will allow it to gain speed quicker as it won't be plowing through the grass. Ideally you'd like enough ground clearance that the tail could lift off the ground and allow the elevator to rotate the plane into the correct AOA to lift smoothly off. I suspect in the current configuration it would eventually leap into the air if it was going fast enough.
Flying off hard deck. I can put this wheel anywhere you think. 2" forward of CG maybe?

I'm installing a rate only E-Sky 704 gyro on the rudder tomorrow. Before it got up to take-off speed (what ever that would be) It 'ground looped' big time.

I know I'm drifting here, but yesterday I flew as usual in a 10 to 12 mph wind. I parked the plane in front of me into the wind, it was amazing. A plane going nowhere and I watched for the first time the two gyros at work WOW! My interest is 'Scale flying' not hard core, no contest, but this amazing little plane is teaching me what I need to know about wind, control and air born beauty.

Thanks for looking at the photo and giving you considered opinion,

DJ
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Old Jun 11, 2012, 09:59 PM
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Canton, Michigan USA
Joined Jul 2007
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Quote:
Originally Posted by Sculptor View Post
Attachment 4931232What I'm about to ask is out of step with the current conversation.

This sky surfer is my first plane. Bought it 2/12. Crashed 11 times, flown 26 times. I'm gaining on it.

1. I'm trying to take-off and land from runway to qualify for license to fly.
To this end I installed a 'belly wheel' And tail skid. Tried 4 times to take-off and did not. Tail skid got ground down to the return stub. Is the 'angle of attack' to flat? I can cut down the bottom of the tail for more upangle. I've seen vids of the SS taking off from grass but mine seems to push down hard, won't move.

Please tell me what you think,
DJ
DJ,

Great idea. I have wanted to dabble with a single wheel as well for tarmac takeoffs and landings. Stryker Q has a wheel that looks like it would work just fine.

It will take off just fine. I skid mine on 3M Extreme tape and it pops right off the ground.

Bil
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Old Jun 11, 2012, 10:33 PM
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United States, WI, Fond du Lac
Joined Sep 2008
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Originally Posted by Sculptor View Post
Flying off hard deck. I can put this wheel anywhere you think. 2" forward of CG maybe?
Hmmm....

Normally, I'd say somewhere between the LE and halfway to the CG depending on how high the center of mass is above the wheels. The Bix/SS CoM is pretty low but the high mounted motor will tend to nose it over if applied too quickly before there's enough speed for the elevator to be effective. Elevator's not in the prop wash either.....

What I would do is glue in a pair of plywood plates parallel to the center line, wide enough apart to fit the wheel, with a series of holes for the axle. Use a removable axle so you could try the wheel in different positions. I'd move the wheel back as far as I could without nosing over too much.

You get better looking touch and goes if the wheels aren't too far forward.

I haven't searched the thread, but someone has probably already figured out the best position.
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Old Jun 11, 2012, 10:43 PM
AKA, Cheap Chiseler
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United States, FL, North Fort Myers
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Originally Posted by pmullen503 View Post
Hmmm....

Normally, I'd say somewhere between the LE and halfway to the CG depending on how high the center of mass is above the wheels. The Bix/SS CoM is pretty low but the high mounted motor will tend to nose it over if applied too quickly before there's enough speed for the elevator to be effective. Elevator's not in the prop wash either.....

What I would do is glue in a pair of plywood plates parallel to the center line, wide enough apart to fit the wheel, with a series of holes for the axle. Use a removable axle so you could try the wheel in different positions. I'd move the wheel back as far as I could without nosing over too much.

You get better looking touch and goes if the wheels aren't too far forward.

I haven't searched the thread, but someone has probably already figured out the best position.
I haven't ck'ed the thread either it's so big. It's only one wheel in the belly.
Thank you for responding,

DJ
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Old Jun 11, 2012, 11:29 PM
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Originally Posted by Sculptor View Post
Attachment 4931232
1. I'm trying to take-off and land from runway to qualify for license to fly.
Why? If it were a REAL(TM) aircraft it would be towed and you'd have nothing to do but follow the towing plane. So, why do they require you to ground launch with that plane? Logically you would hand launch. Isn't it your ability to fly that is in question?

Another question with that licensing - if you have gained one from flying a plane that could just about fly itself and then move on to something totally overpowered and unstable; it doesn't sound like you'd have any chance of successfully flying it but you'd still have a license - doesn't make sense.

Quote:
To this end I installed a 'belly wheel'
If you look at my blog you will see a picture of where I put my wheel, about level with the leading edge. Yes, I can take off on a hard surface OK. Forget grass, it adds drag - unless it is covered with snow as it was the other day.
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Old Jun 12, 2012, 02:53 AM
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Hey Everyone,

I'm wanting to modify my bixler a little bit but before I do wanted to get some feedback from you guy's in case there's something I'm missing or overlooking. Basically, I want to install 2 motors (1 on each wing) and convert my bixler from a pusher prop to a multi-motor.... kinda like the twinstar. I know rcpowers did something like this with his HawkSky but can't seem to find the video to get more details on it. I was thinking that if I have 2 motors (Turnigy 2826-2200kv), than I can also have 2 battery's in there.... one to supply each motor.
Anyways, what do you guy's think?

Thanks fellas!
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Old Jun 12, 2012, 05:50 AM
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Originally Posted by Mac50L View Post
Why? If it were a REAL(TM) aircraft it would be towed and you'd have nothing to do but follow the towing plane. So, why do they require you to ground launch with that plane? Logically you would hand launch. Isn't it your ability to fly that is in question?

Another question with that licensing - if you have gained one from flying a plane that could just about fly itself and then move on to something totally overpowered and unstable; it doesn't sound like you'd have any chance of successfully flying it but you'd still have a license - doesn't make sense.

My thoughts exactly. Pointless rules like this are why a lot of people refuse to join a club to fly.
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Old Jun 12, 2012, 08:13 AM
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United States, WI, Fond du Lac
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Originally Posted by AVIATION_RULZ View Post
Hey Everyone,

I'm wanting to modify my bixler a little bit but before I do wanted to get some feedback from you guy's in case there's something I'm missing or overlooking. Basically, I want to install 2 motors (1 on each wing) and convert my bixler from a pusher prop to a multi-motor.... kinda like the twinstar. I know rcpowers did something like this with his HawkSky but can't seem to find the video to get more details on it. I was thinking that if I have 2 motors (Turnigy 2826-2200kv), than I can also have 2 battery's in there.... one to supply each motor.
Anyways, what do you guy's think?

Thanks fellas!
Twins are cool!

A couple suggestions: a pair of 2826's is way more power (and weight when you consider the extra battery) than you need. A pair of Turnigy 2209/28 1050kv with 9x6 or 10x5 props is what I've used in 3 twins I've built. It's a nice set up. Draws only 25A, over 50 oz combined thrust and runs well on a single 2200mAh battery. Quiet too.

Use a single battery, or a Y connector for two batteries. No reason to separate the batteries and if you do, they'll have to be perfectly matched.

I'd make the wing one piece and bolt it to the fuselage. You'll also need landing gear or prop savers.

Should be a neat project.
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