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Old May 12, 2011, 11:35 AM
agnotology
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Boiling water poured across the dings and dents in EPS will remove most of them like magic.

Kevin
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Old May 12, 2011, 12:15 PM
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silly question

i see several people posting about using counter rotating props. i assume you use 1 normal prop and i counter rotating?? I just connect 1 motor "backwards" to utalize the counter rotating prop?? Thanks.
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Old May 12, 2011, 02:29 PM
Dixie Normious
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Originally Posted by Turbobeaver View Post
Well after a little closer inspection of the kit last night,I can honestly say that a lot of the dings and dents on this model are occuring at the factory prior to foam wrapping.My fuselage which was sitting in the shipping box by itself (and was separated by card board from any other parts),was WELL wrapped in foam sheeting and then strapped with tape to the sides of the box to prevent movement.When I unwrapped all the foam sheeting from around the fuselage,it had all kinds of deep dings and gouge marks on it.There was not a single penetration mark anywhere on the foam sheeting that was used to wrap the foam fuselage section.This damage is obviously occuring in the assembling of these models at the factory and there is not enough attention to quality control to prevent this unecessary damage from occuring in the factory.There is no way that these type of damage marks are occuring in transit.Compression type damage from having the box dropped or slammed is what you should see and probably will see especially on some of the ends of certain parts.All parts that could possibly cause this type of damage are bagged and then put inside of a tight fitting internal shipping box so that most definitely rules out that as the cause.The other thing I seem to have a lot of on the varius model parts is what appears to be black smudge marks.Some will wipe off with a lot of effort and cleaner and others won't(black paint possibly?).There again,why is this happening in the factory and where is management to inforce tighter standards for quality control.This plane has great potential if the factory and management tighten up their act a bit.For the price point,I'm not getting too excited about it but I do want to bring it to the attention of others that maybe haven't received or ordered one yet so as to not get your hopes up too much and make them aware of the realities of this model.Much like the philosophy of RC Model Reviews Bruce Simpson,I believe in reviewing products like they really are and not buying into todays product hype.If it is a worthy product,it doesn't need my 2 cents worth of promotion.It should be able to stand on its own merits and that alone.

I will be bench testing the RC Timer 2830/7 1300kv motor for possible use on this model.The game plan is to use 3 bladed GWS prop with one counter rotating.I will be experimenting with both the 8x4 and the 9x5 version of these props and taking readings on the watt meter as we go.The engine nacelles will have to undergo quite a bit of modification to get the engine mounts back far enough so that the motor sits in the nacelles properly.My spinners arrived so badly warped that they are TOTALLY unusable.Again,obviously warped even before they were put inside the smaller internal shipping box.There was nothing inside that box that could have possibly have done this.They look like somebody put them in a vise and tried to squeeze them.They are not round but rather very oval.I hadn't planned on using them anyways but for all those people who might have planned on using them?Will post as we get further into the model.There are many areas of weakness on this model and I will be trying to address as many as possible with a very close eye on the weigh scale as we go.
Hopefully you get her worked out. Take a few pics?
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Old May 12, 2011, 05:25 PM
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left-hand, & right-hand, not counter-rotating, nor pusher & tractor.

Quote:
Originally Posted by ramw5p View Post
i see several people posting about using counter rotating props. i assume you use 1 normal prop and i counter rotating?? I just connect 1 motor "backwards" to utalize the counter rotating prop?? Thanks.
What those really are is right-hand, & left-hand props. Many European
airplanes, (the DeHavilland DH-82 Tiger Moth, for example), have engines built to turn left. To those people, left-turning propellers are quite "normal".
For this reason, the terms "counter-rotating", and "normal", could be applied to either kind of prop.
The reason for counter-rotating props, of course, is to cancel out propeller effects on a twin, or, in worst case, to minimize propeller effects in the event of one-engine-out situations.
On the P-38, the right engine turns right, and the left one turns left.
On the Bombardier CL-415, it happens that both turn right, as it is with most twins. Both aircraft operate quite well.
You are quite right, of course, about wiring the motors in order to turn the props the correct direction. In the Guan'Li model kit of the 415, both left & right-hand propellers are supplied.
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Old May 12, 2011, 05:44 PM
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Originally Posted by pulsery2k1 View Post
saucisse

thanks for the video , if you watch carfully you must
have lost the right motor, every time you gave throttle
it pulled to the right

then the final one the model must have dropped below
V2 ( safe single engine speed) and when you gave it
throttle it just rolled over and sprialed in.
about what would happen in a real twin on one motor.

once the aircraft drops below V2 the aircraft is no longer
controlable with full power on the good motor
so I don't think it was radio failure-
i have a grumann albatross and sometime (when i am down with battery)..
it happens. I gave throttle and roll over and sprialend in..
i want to know: in this case if i go on rudder.. CAN I SAVE the model ? going out the SPIRAL, roll up? thank you
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Old May 12, 2011, 09:15 PM
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I have both right and left hand props for my CL-415 but unfortunatly the kit only has spinners for one rotation. so I will not fit oposite handed propellers.

I did try right and left handed 3 bladed props on my GWS-38 but the pitch was too low so I went back to 2 blade propellers rotating in one direction. I could not notice any difference in handeling between either set up.

Ken
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Old May 12, 2011, 09:31 PM
6 months to finish a rtf
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upstate ny
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sozi81_ita

yes oppsite rudder is the way to recover from a spirial
if you have enough room , if your too low it will at least
you may hit easier.
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Old May 12, 2011, 09:46 PM
6 months to finish a rtf
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upstate ny
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NOTICE
design flaw


[COLOR="red"][COLOR="red"][COLOR="Black"]
I finally got to maiden my C-415 the first 2 flight when well
the model fly's very nice and slows very nice , on the second
takeoff I notice when I held it on the water the props dug in
it took off and landed fine ,I changed batterys and decided
to do a high speed taxi , if you hold it to long it does dig in .

then I thought I'd do a take off with flaps , it lifted off smoothly
started a slight climb and suddenly nosed up I gave it a little
down to correct and it flipped inverted and into the lake:

Cause and it was mentioned early in the tread about the elevator
servo outside on the tail , well from two takeoff's and landings
and all the spray from the high speed taxi the elevator servo
got water inside and shorted and jammed full down .

C:\Documents and Settings\PETER\My Documents\c-415\FATAL FLAW.wmv (1 min 44 sec)


But when its not crashing it does look and fly great
looked very impressive in the air.
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Old May 12, 2011, 10:04 PM
I'd rather be flying
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Quote:
Originally Posted by pulsery2k1 View Post
NOTICE
design flaw


[COLOR="red"][COLOR="red"][COLOR="Black"]
I finally got to maiden my C-415 the first 2 flight when well
the model fly's very nice and slows very nice , on the second
takeoff I notice when I held it on the water the props dug in
it took off and landed fine ,I changed batterys and decided
to do a high speed taxi , if you hold it to long it does dig in .

then I thought I'd do a take off with flaps , it lifted off smoothly
started a slight climb and suddenly nosed up I gave it a little
down to correct and it flipped inverted and into the lake:

Cause and it was mentioned early in the tread about the elevator
servo outside on the tail , well from two takeoff's and landings
and all the spray from the high speed taxi the elevator servo
got water inside and shorted and jammed full down .

http://www.youtube.com/watch?v=jSf5f6kO6P8

But when its not crashing it does look and fly great
looked very impressive in the air.
Man, that sucks, you can't catch a break!
I agree, the location of that servo is no good. I always put vaseline on my servo shafts and that hopefully helps to keep most of the water out, but it worries me.
Has anyone tried mounting the stab servo in the fuse?
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Old May 12, 2011, 10:23 PM
6 months to finish a rtf
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upstate ny
Joined Jun 2003
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baddb1

at least the water is softer then ground , damage is minor
and I can fix it easily ,

I had tryed sealing the servo , but thanks I had not
thought about filling the gear section with vaseline

I will try that , seal the case ,fill the upper gear section
with vaseline - then hook it to servo tester and run it for a while
in a glass of water. and see if it fails

thank's
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Old May 13, 2011, 12:07 AM
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Darwin Australia
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When I was installing the elevator servo on my Cl-415 I was concerned about the fact that I had a plug in the servo lead about falf way between the servo and the Rx.

I was worried that if water got ino this plug the elevator servo would fail. The plug is in aposition that makes this possible. So I removed the pins from the plug and threw away the plastic pieces. I then pluged each wire in individually and covered each join with 1.5 mm heat shrink tube. After shrinking this made for a watwertight join in the elevator servo lead.

Ken
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Old May 13, 2011, 12:43 AM
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Darwin Australia
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After reading the warning by pulsery2k1 I decided to test the water resistance of a Hextronik HXT900 the same as I am using for my elevator servo.

I have a lot of these servos so I decided to go for the most extreme test. The HXT900 was connected to a servo tester and then fully immersed in a bowl of tap water. A battery was connected to the servo tester and the tester set to cycle the servo. The test was run for five minutes and there was no malfunction of the servo.

The battery was then disconnected and the servo removed from the water and I will allow it to stand for one hour before testing again. After this test the servo will be stripped for inspection.

Twenty minutes after imersion the servo still functions.

Fourty minutes after imersion the servo still functions.

One hour after imersion the servo still functions.

The Servo has been stripped and examined under a magnifying glass. There was no sign of any water inside the case. Both of the case joins showed signs that some sort of grease had been used to seal the join and the servo output gear was greased so this is probably why no problems were encountered with this water resistance test.

Ken
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Old May 13, 2011, 07:54 AM
I'd rather be flying
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United States, NY, Saratoga Springs
Joined Jan 2009
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Quote:
Originally Posted by kensp View Post
After reading the warning by pulsery2k1 I decided to test the water resistance of a Hextronik HXT900 the same as I am using for my elevator servo.

I have a lot of these servos so I decided to go for the most extreme test. The HXT900 was connected to a servo tester and then fully immersed in a bowl of tap water. A battery was connected to the servo tester and the tester set to cycle the servo. The test was run for five minutes and there was no malfunction of the servo.

The battery was then disconnected and the servo removed from the water and I will allow it to stand for one hour before testing again. After this test the servo will be stripped for inspection.

Twenty minutes after imersion the servo still functions.

Fourty minutes after imersion the servo still functions.

One hour after imersion the servo still functions.

The Servo has been stripped and examined under a magnifying glass. There was no sign of any water inside the case. Both of the case joins showed signs that some sort of grease had been used to seal the join and the servo output gear was greased so this is probably why no problems were encountered with this water resistance test.

Ken
Interesting test. I wonder how a hitec 55 servo would survive?
The only additional thing I would like to see you do is to splash or forcefully spray water on the servo as would happen while taxiing for take-off...? This may change the outcome of your test?
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Old May 13, 2011, 08:23 AM
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servo test

Ken- Did you do anything to waterproof the servo before you tested it under water?

This thread has lots on waterproofing servos:

http://www.rcgroups.com/forums/showthread.php?t=922465

Here are details on mineral oil and also stainless steel rods:

http://www.rcgroups.com/forums/showt...o#post17508974
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Old May 13, 2011, 08:25 PM
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Darwin Australia
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Quote:
Originally Posted by BloomingtonFPV View Post
Ken- Did you do anything to waterproof the servo before you tested it under water?

This thread has lots on waterproofing servos:

http://www.rcgroups.com/forums/showthread.php?t=922465

Here are details on mineral oil and also stainless steel rods:

http://www.rcgroups.com/forums/showt...o#post17508974
The HXT900 was taken out of its plastic bag and imersed in the water without any special preperation to make it water resistant.

As for spray, previos experiance with my Islander seaplane conversion shows that it does make waterproofing dificult but the problems normaly are at the front of the aircraft. I had to change to smaller diameter propellers because the spray was sometime striking the propellers.

The other thing is that the spray is greatest at the time just before the model comes up onto the plane. Once the model is on the plane there is very little spray. So at slow taxi and take of speeds spray was not a problem.

My Islander used HXT900 servos and although I had problems with water getting into the fuselage I did not have problems with any of the three servos fitted.

Ken
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