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Old Sep 04, 2012, 07:16 AM
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Originally Posted by slothy89 View Post
Ah yes I get a what you're saying a little better now. The part you highlighted is the Swash Anti-Rotation Pin. This stops the bottom half of the swash from wanting to spin around the main shaft with the rest of the head.

If you think one heli's swash has more movement, try swapping the swashes over? see if the restricted movement moves with the swash, or if it stays with the same Heli. That will confirm if the swash has a problem, or maybe your servos do.
Thanks a lot. As the stupid beginner that I am, I'm not sure if I understand the swash plate completely. The bottom half is supposed to be steady, right ? And the upper half is supposed to tilt depending on the control input, right ?

What I'm also considering right now: The main shaft has a hole for the main screw that fixes the shaft to the axis. Now, technically the shaft can be mounted in two different positions swapped by 180 degrees. Could this have any influence ... ?

Best regards
Frank
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Old Sep 04, 2012, 07:17 AM
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Originally Posted by slothy89 View Post
Someone a couple pages back did a stress test on a stock motor, and determined it was around 8 hours running time before a failure. I just calculated that at 12min/flight, 50 flights is about 10hrs running time. So really that's about to be expected. Brushed motors just can't last all that long, especially for what we pay for them.

I mean, you can see Brushless motors on sale anywhere between $15 and $200, and they're all around the same size/kV rating. I'm sure there'd be some $50 Brushed motor out there that would last 5x longer, but it's not really worth it.
Back in the day when I was a kid all we had was brushed motors. And motors had replaceable brushes. Lasted quite a long time. We would even clean and polish the commutator shaft, I still have those tools! Power tools still use brushes, and they work quite well.
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Old Sep 04, 2012, 07:26 AM
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Australia, VIC, Sebastopol
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Quote:
Originally Posted by Frank183 View Post
Thanks a lot. As the stupid beginner that I am, I'm not sure if I understand the swash plate completely. The bottom half is supposed to be steady, right ? And the upper half is supposed to tilt depending on the control input, right ?
Almost... Both halves will tilt when control inputs are given. The top half spins with the blades and flybar, while the bottom half does not. Think of these has two halves of a bearing.

Quote:
Originally Posted by Frank183 View Post
What I'm also considering right now: The main shaft has a hole for the main screw that fixes the shaft to the axis. Now, technically the shaft can be mounted in two different positions swapped by 180 degrees. Could this have any influence ... ?

Best regards
Frank
Maybe maybe not. I would be tipping not.

It is possible that one of the swash plates has a defect from the plastic moulding process, which restricts its movement.
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Old Sep 04, 2012, 07:40 AM
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Originally Posted by slothy89 View Post
Almost... Both halves will tilt when control inputs are given. The top half spins with the blades and flybar, while the bottom half does not. Think of these has two halves of a bearing.


Maybe maybe not. I would be tipping not.

It is possible that one of the swash plates has a defect from the plastic moulding process, which restricts its movement.
Thanks again so much !!!

Do you think this would lead to control problems as described ? I'll have to check tonight how they are moving.

BTW, has anybody ever controlled to helis with one tx ... ?

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Old Sep 04, 2012, 07:41 AM
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Originally Posted by Frank183 View Post
Thanks again so much !!!

Do you think this would lead to control problems as described ? I'll have to check tonight how they are moving.

BTW, has anybody ever controlled to helis with one tx ... ?

People have done it, but since they are not all exactly the same, you're bound to lose control of one pretty quickly
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Old Sep 04, 2012, 10:34 AM
Fly Fast, Fly Hard, Fly Fun
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Quote:
Originally Posted by slothy89 View Post
Someone a couple pages back did a stress test on a stock motor, and determined it was around 8 hours running time before a failure. I just calculated that at 12min/flight, 50 flights is about 10hrs running time. So really that's about to be expected. Brushed motors just can't last all that long, especially for what we pay for them.

I mean, you can see Brushless motors on sale anywhere between $15 and $200, and they're all around the same size/kV rating. I'm sure there'd be some $50 Brushed motor out there that would last 5x longer, but it's not really worth it.
Good call. Most of my flights were under 10 minutes so that number is scarily close to the bench test. I appreciate that at this price 8 hrs is decent, but to me having to pay $8 for 8 hours or say $50 for 40 hours - if there was no downside I'd go for the $50 just to feel more confident flying.

Quote:
Originally Posted by shahram72 View Post
Back in the day when I was a kid all we had was brushed motors. And motors had replaceable brushes. Lasted quite a long time. We would even clean and polish the commutator shaft, I still have those tools! Power tools still use brushes, and they work quite well.
Interesting! Were these used in planes and helicopters?
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Old Sep 04, 2012, 11:29 AM
when is the wind stopping??
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Malta, Marsaskala
Joined Apr 2011
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walkera #4 blades

Hello Guys I see a swashplate topic going around and some brushed motor brushes statements as well.....well I hope I will not interrupt your comments or thoughts on those subjects but just wanted to inform you that today I finally received the cheap >3USD walkera blades from Dealextreme. Now this is no news but for their ridiculously low price, I can already say that these blades are much stiffer than the stock blades and also stiffer than the Extreme carbon fibre re inforced blades I had tried previously(and broke on first outdoor flight) which are for upgrading the HBFP heli stock blades!! They have also less pitch but don't know if they are 10% but close as these also require more throttle to lift the F45 from the ground too! Below some pics of my F45 with the new blades.
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Old Sep 04, 2012, 12:05 PM
Fly Fast, Fly Hard, Fly Fun
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Those blades barely droop at all. I can't wait to see it fly.
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Old Sep 04, 2012, 12:09 PM
when is the wind stopping??
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Originally Posted by rexless View Post
Those blades barely droop at all. I can't wait to see it fly.
Me too I only hovered it a little inside coz it's quite windy today
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Old Sep 04, 2012, 02:34 PM
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Originally Posted by rexless View Post
Good call. Most of my flights were under 10 minutes so that number is scarily close to the bench test. I appreciate that at this price 8 hrs is decent, but to me having to pay $8 for 8 hours or say $50 for 40 hours - if there was no downside I'd go for the $50 just to feel more confident flying.



Interesting! Were these used in planes and helicopters?
Yes, we had electric planes and I even saw one electric CP heli once. But not a lot because it was just starting and batteries were too heavy. Can you imagine a 7.2v nicad pack for a car in an airplane? (well, my twinjet is designed for this)
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Old Sep 04, 2012, 02:44 PM
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Those blades look like the fat ones I had on my Walkera V370D01. I replaced them with much smaller Big Lama blades to increase headspeed because the heli would shoot up and then have no control authority as you reduced the throttle.
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Old Sep 04, 2012, 03:45 PM
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Since it's lunch time I took a moment to post the video of the brush failure.
MJX F45 Main Motor Brush Failure During Flight (0 min 45 sec)

You can hear and see exactly when it fails. Up until that point I was flying around with no noticeable issues. Immediately after I had to throttle to 100% just to get back to where I wanted to land.
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Old Sep 04, 2012, 07:45 PM
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Questions for F45 brushless modders

I was looking up info about EH200 brushless motors and find there's three versions. There is a 3800kv, a 4100kv and a 5000kv.
I believe most folks are using the 4100kv version here - correct?
What is the main factor in choosing 4100kv over the 3800 or 5000kv versions?

Then I was thinking of the tail. Since increased rotation speeds reportedly have some effect on the tail motor's ability to keep up and/or survive flights - I was wondering what one might do with the length of the tail to help? If the tail is longer doesn't it also require less energy to affect the rotation (typical lever effect)? If so, anyone wanting to get a higher quality brushed or possibly a brushless tail that finds it's too strong or too weak - could maybe try different tail lengths to compensate? I was also thinking would the longer tail give you finer control over directional movements?

Last up - does anyone know what it would take to get the aluminium sides replaced with Carbon Fibre? I was looking into it and I have no idea what kind of sheet one would buy, if it makes more sense to cut on some sort of cnc machine, or even if the weight would be sufficiently reduced.

In for a penny, in for a pound?
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Old Sep 04, 2012, 11:06 PM
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Quote:
Originally Posted by rexless View Post
I was looking up info about EH200 brushless motors and find there's three versions. There is a 3800kv, a 4100kv and a 5000kv.
I believe most folks are using the 4100kv version here - correct?
What is the main factor in choosing 4100kv over the 3800 or 5000kv versions?

Then I was thinking of the tail. Since increased rotation speeds reportedly have some effect on the tail motor's ability to keep up and/or survive flights - I was wondering what one might do with the length of the tail to help? If the tail is longer doesn't it also require less energy to affect the rotation (typical lever effect)? If so, anyone wanting to get a higher quality brushed or possibly a brushless tail that finds it's too strong or too weak - could maybe try different tail lengths to compensate? I was also thinking would the longer tail give you finer control over directional movements?

Last up - does anyone know what it would take to get the aluminium sides replaced with Carbon Fibre? I was looking into it and I have no idea what kind of sheet one would buy, if it makes more sense to cut on some sort of cnc machine, or even if the weight would be sufficiently reduced.

In for a penny, in for a pound?

In for a penny stock here.. lol...

In my 2 1/2 cents opinion on the tail motor, normally a brushless main motor is designed for 11.1v atleast. Therefore, to suit this mod, you have to use an 11.1v tail motor as well, be it a brush or be it a brushless tail motor.

A guy named hadriez sent a video (on youtube) of him flying an f45 using a brush tail set of a walkera v400d02 if im not mistaken. I have posted the video here previously. I think this tail set is suitable to compensate an 11.1v system (as the tail motor is designed for 11.1v also) and the boom is longer than the stock too which may help to introduce a more stable flight.
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Old Sep 04, 2012, 11:31 PM
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Quote:
Originally Posted by rexless View Post
Then I was thinking of the tail. Since increased rotation speeds reportedly have some effect on the tail motor's ability to keep up and/or survive flights - I was wondering what one might do with the length of the tail to help? If the tail is longer doesn't it also require less energy to affect the rotation (typical lever effect)? If so, anyone wanting to get a higher quality brushed or possibly a brushless tail that finds it's too strong or too weak - could maybe try different tail lengths to compensate? I was also thinking would the longer tail give you finer control over directional movements?

Last up - does anyone know what it would take to get the aluminium sides replaced with Carbon Fibre? I was looking into it and I have no idea what kind of sheet one would buy, if it makes more sense to cut on some sort of cnc machine, or even if the weight would be sufficiently reduced.

In for a penny, in for a pound?
http://rtf-heli.com/ESKYHBFPV2_DD.html

http://www.addictive-hobby.com/popup_image.php?pID=1352
http://www.addictive-hobby.com/produ...oducts_id=1352
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