The Coast Guard Project (Mechanics Build up)
Once again I will be using the Century Scale 50 mechanics for this project. I will be using the CCPM conversion kit as I did with Santini Air. I am also using the electric motor/clutch setup. I will be using a four bladed rotor head from RC Aerodyne and the Helicommand Rigid for flybarless control. The mechanics build up the same as my
Santini Air project so I won't show as much detail with this section of the build.
Starting sometime early in 2013 I decided to try making my own belt drive transmission like the Goblin uses. At the bottom of this page you will see what I made. I really like how it works and it does seem to be a little less noisy than all gears. In May of 2013 the motor I was using failed catastrophically. I think it was due to the side loading being put on it from the tension put on the pulley from the belt drive. The belt needs to be very tight. I have redesigned the motor mount to include an upper bearing block motor shaft support. I am hoping this will take care og the side loading issue. I am now waiting for good weather so I can begin test flying again.
These photos show the scale mechanics as I removed them from the box. You can also see the Tow Defender pilot is trying to help me.
Here I caught Tim messing around with the motor. He was concerned it did not have enough power.
I told him to let me worry about that, ha-ha...
Here I have most of the mechanics assembled. I need a nut for the motor/clutch assy.
Here's a test fit into the fuselage to see how it looks. Might need some small wood shims and that's about it.
The RC Aerodyne rotor looks and feels very nice and smooth. The Helicommand Rigid is a nice small package.
Can't wait to try it out, but I'm afraid it will be mid winter before that happens. Then I will need a mild day for testing.
I have the Helicommand mounted and wired. I also did some preliminary setup on it. The next evening I finished
going through all the setup steps and rechecking everything I did. I think it's ready to go, although it is acting strange
when first powered up. I get an error led of three flashes meaning the heli was not stable during power on. It's sitting on my
workbench which is solid so I know it's not moving. After spending an entire evening on this I think I found the issue. It seems
the gains may have been to high. This is yet to be determined. I plan to start out in the FADER mode so I can use a slider to adjust
the gains. Then once happy with it I will switch to the FIX mode and see how it flys.
Here it is ready for it's maiden flight. I plan to test it using only two blades instead of the four. I believe it
should fly just fine and I only risk two blades, not all four. I say that because I have never used the Helicommand
system, and as of this writing I have been having some setup issues with it. I have now also been told the position
mode of the Helicommand is not that good. This is not what I heard before I bought it. I guess I will find out for myself.
The temp outside today was only 16*F and windy as heck. So no testing today, but maybe in a couple days.
After first maiden flight attempt. It was so windy I aborted after about 20 - 30 seconds in the air.
Winds were blowing around 15 mph, gusting to more. The heli was a major handful.
After above flight attempt I came home where the wind was a little less in my yard. I took off with the gain
slider in the center position. Again the heli was a handful. I landed and moved the slider up to the maximum
position. Took off and still was a handful but seemed a little better. I landed again and put in 30% expo on the
roll and pitch axis. Took off again and now it was much better. But by now the battery was getting low so I stopped.
Today there was no wind so I went out to try again. Same settings with the slider and expo. The heli is handling
pretty good, but it is badly out of trim. So I will be adjusting the mechanical setup to trim it out.
Turns out I have a faulty Helicommand system. This is why I have so much trouble getting it to power up correctly.
After many posting, searching the forum, and sending PM's to people I thought could help I finally was told to contact
Danny at eSprit Models. He will be taking care of my Helicommand unit for me even though I did not buy it from them.
Now that is GREAT customer service!!!
So remember that when you are wondering who to buy your next project or parts from. And no I don't work for them in any way.
** UPDATE Jan 2, 2012 **
I received my replacement Helicommand within a week. I installed it, loaded my saved setup, powered it up and it worked great.
The next day I went out to give a few test flights but was only able to do one as the temp outside was freezing and my fingers were also.
Good news is the Helicommand worked great. I did have to turn down the gain on the rudder gyro from my original settings. The mechanics
are very nose heavy in my current setup and I need to fix this before more testing can take place. It also just dipped to single digit temps
outside. Might be a while before I can test again, but then again who knows, this is Minnesota after all.
NEW BELT DRIVE TRANSMISSION SYSTEM for 2013
After seeing what Peter Wales was doing with the Goblin 700 mechanics I was cery interested in that myself. I contacted his biz partner to see if they had planned
on doing this for 500/600 sized helicopters. He said they were not going to. So I decided I would make my own setup just as they had. I figured I would start out
simple and just copy the motor to half shaft setup first. The pulleys and belt are from the Goblin 630. Below is what I have made so far.
This is the half shaft I need to replace. It has three diameters to it.
Here is my third attempt at this shaft. I am not a machinist so I make mistakes
that a real machinist probably would not.
I also had to make a new motor mount because the new system puts the motor more forward
than the original setup. So I made the motor mount and two side plates.
Here the motor and new mount are being test fit. Looks good so far.
After 18 to 20 flights with the above setup I had a major failure. The motor broke internally. I think there was too much side loading
from trying to keep the belt tight, or I did not have something in perfect alignment. Thinking the problem was side loading I have built
an upper load support bearing block. So far I only have a two minute hover test with the new design. Time will tell I guess.
Upper bearing block.
Hopefully this will work and I can put this issue behind me.