Tom Berg
Senior Member
Posts: 307
Loc: Clovis, California
Reg: 03-13-00
|
 07-05-02 04:40 PM - Post#8996
In response to jmkirsch
Some companies make a long shoulder bolt for the blade grips. They have a lot less play than the threaded bolts and do not bend as easy at high rpm. KSJ makes 3mm and 4mm long shank bolts and JR has the 4mm and 5mm (I think) long shank bolts. They are much nicer than standard threaded bolts.
|
jack01
New Member
Posts: 13
Reg: 08-22-02
|
08-22-02 02:01 AM - Post#9755
In response to Tom Berg
You need to make sure that your tail pitch slider cant move too far on your Raptor 30 because if it does, it can stick to one side, and that can make your flight VERY intresting and short.
|
Alan Gilmore
New Member
Posts: 11
Loc: Baltimore, Maryland
Reg: 01-23-03
|
01-30-03 04:25 PM - Post#15330
In response to Staff
Balancing main rotors can be much easier if you have a head button that you can apply a balancing target on. The attached file can be printed on a color printer and applied with double sided carpet tape. It must be precisely centered, and the red/green squares should be next to the main rotors, while the yellow/white squares should be next to the fly bars.
Do a static balance of the blades on your bench first.
Then spin up your main rotors slowly with the engine and watch the target carefully. When properly balanced the black dot will remain in the center. If imbalanced the black dot will form a circle or oval.
Notice the color in the center of the circle. Stop the rotor and look at the blade that is next to that color. That is the blade that you need to add weight to.
You will notice that the balancing target will indicate if there is any imbalance in the fly bars also!
I have used these for about a year now, and finally feel comfortable with the design. Yes, it took lots of work to come up with something so simple!!
The above instructions are the simple version, and I suggest that you experiment with it to see how it works.
Several other points I should make:
-Apply carpet tape to the back and clear packing tape to the top before you cut it out. The packing tape makes it water and fuel proof.
-The circles on the target are for helping you cut it out, pick the size that fits your head button.
-Be sure to spin up the rotor slowly. Often at higher speeds the circle changes to a dot and the imbalance is not visibly noticeable.
-If you see multiple circles/ovals, do not get discouraged. You are experiencing multiple oscillations in your rotor head. There are many reasons that this can happen, so look at all the possible causes...loose parts, sloppy linkages, tracking problems, etc.
-Mount it very carefully in the center!!! My latest method is to mark the center of the headbutton (if it doesn't already have a dimple). Then cut half way through to the center of the target with sissors. This allows you to fold back part of the target while aligning the center of the target with the head button.
Let me know how you like it!!!!
|
Alan Gilmore
New Member
Posts: 11
Loc: Baltimore, Maryland
Reg: 01-23-03
|
01-30-03 04:54 PM - Post#15332
In response to Alan Gilmore
Okay, I am not able to upload the .jpg, what am I doing wrong?
The .jpg is on my hard drive, and I used the "browse" button with Netscape 7 to find it, but it still did not upload to the server!@#$%^&*?????
|
Scott Owens
Member
Posts: 34
Loc: Dallas
Reg: 05-27-03
|
06-06-03 09:50 PM - Post#20854
In response to Staff
I use the Koll Rotor Pro Balancer and a GOOD gram scale to balance ALL my blades. So far the claims of perfectly matched blades right out of the box has not been true for me! The weight may be the same but the CG is always WAY off!
The instructions are confusing at best and I don't do it their way.
If your blades came finished than the weights should already be installed and visible through the cover. IF they have weights! Some don't!
Check the weight of each blade. One may be heavier. If it is note the difference in the weights and mount it on the rotor pro. This will be your master blade. Balance it on the rotor pro. Mark the CG through the hole in the bottom of the rotor pro. Now remove the master and mount the slave blade on the rotor pro. You will now just place a piece of tape (equal to the difference in the blade weights) on the slave blade in a spot that centers the bubble level. At this time just set the tape temporarily on the blade.
Now both blades should be the same weight and balance span wise.
Mark a spot on the span wise CG on both blades. Now turn the rotor pro sideways and slide in the master blade centering it on the spot you just made. Level to get the chord wise CG. Mark the chord wise CG from below. Slide your span wise CG mark to match the chord wise position thereby combining the two marks into one. This will be your master blade CG point. Remove the master and check the slave. If you're lucky they will match. Most likely they wont! Try and position the your piece of tape toward the lite side of the blade to get the chord wise CG to match. If it does you're done. If it doesn't you will have to add more tape to the lite side until it does. Of coarse this extra piece of tape will make the slave blade heavier than the master and you will have to add a equal weight of tape to the CG of the master blade to get them back in balance. This is easy to do, just center it on your span wise/chord wise CG mark on the master blade. This will increase the weight but not change the CG so both blades should still match. Check one against the other to be sure.
Now although I told you the points are the blades CG the truth is there not. Why? Because the rotor pro is also being balanced with the blade. But it doesn't matter because what you're doing is getting the blades to match in weight/span wise CG/chord wise CG and they are. Its just that the actual CG although they are the same they will not be on your marks. Don't let this confuse you. Both blades are now exactly the same!
You can use any kind of tape. Tracking tape, clear tape just as long as it wont come off. Sometimes I just use Scotch Brand tape and so far its not come off.
If your blades are much different in weight you may not be able to do this with tape. That's when it gets tough! Drilling holes to glue in brass dust and all that! I don't mess with all that. I don't find the new built blades to be that out of balance as far as the weights are concernered. But if you build your own it can happen. And for that reason I don't bother building blades anymore. It doesn't hurt to take your rotor pro and gram scale to the hobby shop and check the blades before you buy if you can! You might get lucky and find that so called perfect set!
I think most people just check the weight difference, bolt them on and fly. But if you've already got the rotor pro you might as well do it right. At least you wont be wondering if that vibration is coming from your blades.
Scott
The Sun's up. Go Fly! 
|
|
WildMisterT
Member
Posts: 97
Loc: Canada
Reg: 06-17-03
|
 07-21-03 04:32 PM - Post#23314
In response to Staff
To balance my Main Rotor Head+Flybar+Paddles, I remove the Head and Shaft from the Heli and put it into a PowerDrill, secure the shaft as a drill bit, then select the proper direction, hold the drill vertical over my head and spin the rotor.
That way I was able to troubbleshoot a vibration problem I had. Now be shure to tight the shaft properly, you don't want the rotor to fly off the drill...be carefull.You will see and feel the vibration if any, then ajust paddles, flybar, etc...
| Don't Drink and Fly... ;) |
|
velocyraptor
Member
Posts: 47
Loc: Jakarta, Indonesia
Reg: 08-28-03
|
10-17-03 01:30 PM - Post#28296
In response to WildMisterT
For anyone who looking for cheap tail boom replacement, go to aluminium store (they made alu display, etc). I get tailboom replacement for my Raptor with only $4 for 10 unit tailboom. So it only 40 cent each. It's slightly heavier but worked perfectly. The raptor diameter is 7/8 inch.
Albertus Herinanto
|
Duffy
New Member
Posts: 3
Loc: Virginia
Reg: 03-03-04
|
12-29-04 11:13 PM - Post#55824
In response to Alan Gilmore
I like the idea about the color wheel. I can't seem to download the att.??
Happy flying.. 
|
casio
Professional User
Posts: 68
Loc: -n-load
Reg: 04-03-07
|
04-27-07 06:41 AM - Post#83739
In response to volare
I am getting ready to run new wood blades, I did what you suggested. I am curious why they even have a coating on the blade. Is it ok if the plastic is not sealed near the grips? the leading edge of the blade's plastic is loose.
| DUCK!!! HEAR IT COMES!!!!!!!! |
|
