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Old Oct 21, 2009, 11:36 AM
Gone Flying.
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Western NY
Joined Nov 2006
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Autozone happened to carry the CRC Di-Electric silicone-based grease for about $9 per 3.3 oz. bottle, enough to lube thousands of thrust bearings, no other well-known stores had silicone-based grease, was glad that Autozone had this stuff so I bought a can of it. It has its own applicator (not needle-precise, but precise enough for thrust bearings), and is 100% petroleum-free. It's approved for use on o-rings, rubber parts, flashlights, batteries, motors, electrical contacts, etc.

Do you heli fanatics use grease on other areas of your heli other than the thrust bearings? For example, main rotor bearings, tail bushings, swash, etc...
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Old Oct 21, 2009, 11:47 AM
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My heli has shipped, now i just have to wait for the motor, and servos to come in stock.
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Old Oct 21, 2009, 08:25 PM
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Think these would work good or no

http://www.hobbypartz.com/4ptopromgmeg.html
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Old Oct 21, 2009, 08:49 PM
Gone Flying.
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Western NY
Joined Nov 2006
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If the torque rating is accurate, that is 84 lbs./inch of torque at 6V, which is definitely high torque for a servo. The price is great on them. The only drawback is that they are a little slow, 0.13 sec/60 at 6V, and 0.17 sec/60 at 4.8V, though that should be sufficient for sport flying. I would consider a faster servo for the tail, otherwise, they should do the job.
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Old Oct 22, 2009, 09:19 AM
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United States, NJ, Manville
Joined May 2006
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Those servos are a little too long...I tried to install hitech HS225bb servos and the servos were too long and the backs of the servos were touching and even with spacers they were too long....http://www.bphobbies.com/view.asp?id...83&pid=S505368
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Old Oct 22, 2009, 09:36 AM
Gone Flying.
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Western NY
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skizziks -

Good catch on that one, I overlooked the dimensions of the servo. The TowerPro MG930 Digitals work well in a 500 frame, they fit into the frame without the need for spacers. They don't have quite as much torque as some of the more expensive brands, but they are fast and strong enough for both tail and cyclic control for basic 3D and sport flying.

To get an idea of dimensions for servos that will fit comfortably without modification within the HK-500GT frame, here are the measurements on the TowerPro MG930 digital servo, use this as a baseline then try to visualize the size difference when using a larger servo. The MG930's fit into the 500GT frame with about 1mm to spare around the entire outer perimeter of the servo, and there is a ~4mm gap between the 2 front cyclic servos without the use of spacers...

36.2mm x 15.2mm x 28.7mm
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Old Oct 22, 2009, 10:45 AM
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Thanks for the info guys. I think ill get the 930s when hc has them again
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Old Oct 22, 2009, 11:24 PM
Team Wack-a-Mole
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Maryland
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Quote:
Originally Posted by rcnewb
st200 -

I noticed the same thing with my HK-500GT. Had a test flight today, the tail is virtually unmovable when the head speed comes up to where it should. .
All helis do that to some extent unless you put the Chinese weight mod on the tail blades.

That's why tail servos that perform well not only need to be fast but also stronger than people realize.


I did the chinese weight mod on my EXI 500 CF version so my Futaba 9257 can perform better. Although the HK500 is more like the EXI 500 plastic version, They share pretty much the same charactoristics in the tail.

I've got Chinese weight mods in my 450's my 500 and my TT e550. They so make s difference in the force of the tail and thus helps to speed the servos up quite a bit.
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Old Oct 23, 2009, 01:18 AM
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So.I'm a new guy.

What is this mod?
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Old Oct 23, 2009, 02:52 AM
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Joined Mar 2009
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Quote:
Originally Posted by wrugen
So.I'm a new guy.

What is this mod?
http://www.mycoolheli.com/chineseweightmod.html
Here` a link to one way of doing it. Do a search for chinese weight mod an you`ll find more.
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Old Oct 23, 2009, 03:15 AM
Team Mulikow 3D
Oxfordshire, UK
Joined Jan 2007
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Quote:
Originally Posted by Melnic
All helis do that to some extent unless you put the Chinese weight mod on the tail blades.

That's why tail servos that perform well not only need to be fast but also stronger than people realize.


I did the chinese weight mod on my EXI 500 CF version so my Futaba 9257 can perform better. Although the HK500 is more like the EXI 500 plastic version, They share pretty much the same charactoristics in the tail.

I've got Chinese weight mods in my 450's my 500 and my TT e550. They so make s difference in the force of the tail and thus helps to speed the servos up quite a bit.
Mel,

if it is like the tail on my (non-thrust washered tail clone) then the is different - this was the tail binding because the centrifugal/centripedal force is over-powering the bearings at high speeds, not due to tennis-racket affect.

Mike.
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Old Oct 23, 2009, 07:03 AM
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USA, NC, Matthews
Joined Aug 2008
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I started my build last night and everything is going well. I was surprised to find that there wasn't one piece of paper or parts labeled. No bid deal really, I just downloaded the TRex manual and it is close enough. I was a bit disappointed that there were no washers provided for places that obviously needed them, like the landing gear brackets. I also found a couple missing screws, like one of the set screws for the flybar paddles etc. The tail seems ok but I won't know until I spin it up. Where are you guys mounting your electrics? For now I am putting the esc on one side, the RX on the other and the gyro on top behind the main shaft. Once I get it dialed in and working my plan is to install my KDS Flymentor. Fortunately there seems to be plenty of room for it.

I ended up using these servos for the cyclic,

http://www.rcdude.com/servlet/the-11...l-Servo/Detail

They fit but just barely, The 2 side servos actually touch in the middle but still mount securely. I went with the actual Align tail servo as I couldn't find anything close to the size in Hyperion. After seeing how it mounts, I now realize I could have gone with a larger one with no problem.
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Last edited by techspy; Oct 23, 2009 at 08:15 AM.
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Old Oct 23, 2009, 07:04 AM
Gone Flying.
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Western NY
Joined Nov 2006
2,401 Posts
Quote:
Originally Posted by Melnic
All helis do that to some extent unless you put the Chinese weight mod on the tail blades.

That's why tail servos that perform well not only need to be fast but also stronger than people realize.


I did the chinese weight mod on my EXI 500 CF version so my Futaba 9257 can perform better. Although the HK500 is more like the EXI 500 plastic version, They share pretty much the same charactoristics in the tail.

I've got Chinese weight mods in my 450's my 500 and my TT e550. They so make s difference in the force of the tail and thus helps to speed the servos up quite a bit.
Melnic - I'm aware of the Chinese weight mod and definitely considered it as a secondary fix for my 500GT if the Align part doesn't completely resolve the issue. I am in agreement with MikeHRC on the bearings causing the binding at a certain threshold of centrifugal/centripetal force, even the strongest of servos would have a major issue moving the tail rotor at high RPMs, or it would draw so many amps that my 7-Amp BEC might fry as a result. I do like the Chinese weight mod, it makes sense, and I may use it on this heli depending on the servo amp draw characteristics in flight.
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Old Oct 23, 2009, 07:13 AM
Gone Flying.
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Western NY
Joined Nov 2006
2,401 Posts
Quote:
Originally Posted by techspy
I started my build last night and everything is going well. I was surprised to find that there wasn't one piece of paper or parts labeled. No bid deal really, I just downloaded the TRex manual and it is close enough. I was a bit disappointed that there were no washers provided for places that obviously needed them, like the landing gear brackets. I also found a couple missing screws, like one of the set screws for the flybar paddles etc. The tail seems ok but I won't know until I spin it up. Where are you guys mounting your electrics? For now I am putting the esc on one side, the RX on the other and the gyro on top behind the main shaft. Once I get it dialed in and working my plan is to install my KDS Flymentor. Fortunately there seems to be plenty of room for it.
Techspy -

Yes, if you're looking at the T-Rex 500 manual, they do recommend washers on the stabilizer and tail fin, etc., but a little CA will do the job also. I nabbed some washers from a salvaged HK-450 that I demolished last year and used them where needed.

As for mounting the electronics, check the T-Rex 500 manual and some of my photos. I mounted the ESC and BEC on the left side of the heli, and the Rx on the rear, which was one of the recommended mountings within the T-Rex manual. My Gyro is mounted on the top of the boom housing, many others will recommend against this but I'm not too concerned about a $20 Gyro getting shredded in a crash. Most of my wires are routed through the inside the frame to the back where the Rx is located. Number of servo extensions used: 0.
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Old Oct 23, 2009, 09:22 AM
Team Wack-a-Mole
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Maryland
Joined Oct 2008
8,436 Posts
Quote:
Originally Posted by rcnewb
Melnic - I'm aware of the Chinese weight mod and definitely considered it as a secondary fix for my 500GT if the Align part doesn't completely resolve the issue. I am in agreement with MikeHRC on the bearings causing the binding at a certain threshold of centrifugal/centripetal force, even the strongest of servos would have a major issue moving the tail rotor at high RPMs, or it would draw so many amps that my 7-Amp BEC might fry as a result. I do like the Chinese weight mod, it makes sense, and I may use it on this heli depending on the servo amp draw characteristics in flight.
OK, now I gotcha. If the bearings are the cause then I can see how it can affect it. Maybe lighter tail blades will help? Seems the chinese weight mod will help some but the tennis raquet affect is LESS around center and more as you push out. You might want to try the mod to see how much it helps. I did mine up w/ washers on the 500. I'll try to post what I used.
There is that Hiem Joint (spelling) guy who sells something better but it's like $20.
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