BLADE TRACKING
 

Repaired my Titan SE after a crash. New blades, main shaft, feathering shaft, fly bar, one blade grip, (nylon). I can track it in on the ground at 1750 rpm. When I go in the air it is way out on tracking. This is a new one on me. Any ideas?

RE: BLADE TRACKING
 

Check the ball links. The ball side, where the small screw goes thru the ball. Sometimes the little screw gets bent and moves around under a load. Also check the plastic portion of the link. Sometimes the threads on this plastic portion strip and can move under a load.

Additionally, I recently saw a pair of medium priced carbon fiber blades that were warped and showed the same symptoms. On track at a certain RPM, but out of track at a higher RPM.

I just read your post again, what do you mean of tracking on the ground? There is only one way of tracking, and that is on a hover (in the air). Please provide further information about your tracking technique.

Rafael

RE: BLADE TRACKING
 

Or you might just grab the blade and the link and check for play.  There should be no play.  If there isn't then you need to make and adjustment ot the lenght of one of the links.  Have you ever done this?

RE: BLADE TRACKING
 

On the ground at 1750 rpm, 0 pitch.

I replaced some of the links because they were broken. I did a complete new setup. 10 -0- 10. I'll check for a bent screw, and try getting it to track just in the air. I have used the "on the ground method" many times without problems.

If that doesn't straighten things out, i'll tear the head down again and look for errors.

Thanks for the replies.

RE: BLADE TRACKING
 

OK, one more time. Simply check for play, check blade balance two ways. First weight. Next weight at the tips on a seesaw setup. Next use a sharpie and mark the tips. If one color is down you'll need to adjust that link longer than the other. You are way over analizing this.

RE: BLADE TRACKING
 

I balanced the blades for cg and as a pair. they are fine. I have built 4 heli's from Trex to to TT90, and a number of crash repairs, I have never had trouble adjusting the blade tracking into sync.

I went over the head again and found a little play in the fly bar. I adjusted this out, now i'll see what I can do tomorrow.

Thanks for the help.

RE: BLADE TRACKING
 

It's frustrating. One turn on the double link from the fly bar to blade grip makes the marked blade run high, one turn back makes it run low. Tried making the adjustment at the swashplate where a turn moves the blade less. Same problem, but I can get within 1/4 inch above or below with the marked blade.

Am I expecting too much? I have always been able to make them track perfectly.

RE: BLADE TRACKING
 

Sounds like your blade aren't balanced right. the seesaw balance needs to be perfect.

RE: BLADE TRACKING
 

The cg is equal and the seesaw balance is perfect on the Heli-Max ball bearing blade balancer. That's not the problem. I think i'll tear the head down and check the bearings, and make sure the thrust bearing are not backwards.

If I don't find a problem there, I'll pull the new main shaft and check to see if it's straight. Shoulda' done that before I installed it.

Thanks for the suggestions.

RE: BLADE TRACKING
 

Did you replace those 2 O ring on the Heads (some head have 4), Dampers they call it. That might be your problem if your damper are bad due to crash, it will give you hard time to track those blades. I do also have the heli max Ace 400 before and I encounter those, I thoght its the bearing but found that those damper are damage, or crack.

RE: BLADE TRACKING
 

O.K. I think I have found the problem, a slightly bent feathering shaft, (spindle). I put it on straight out of the package brand new. I just ordered a new one. If this doesn't fix it maybe i'll just fly it into a big tall heli-eating tree.

From now on, I check every shaft new out of the package. No more faith in NEW parts without checking them out.

Thanks to all who have responded with suggestions.

RE: BLADE TRACKING
 

I was sure the new spindle would fix it, but not so. Still can't track it in.

Another unpleasant symptom is it wants to slide to the left on spool up even at high rpm. I have to jump it right off as soon as it gets to hover rpm or it will slide 7 - 8 ft to the left. once I get it up the trim is okay, but it's very unstable in hover mode.

Does this ring any bells with anyone?

RE: BLADE TRACKING
 

Hi Flying Geezer

I'm sure you able to do a proper setup but have you looked and checked the following:
1 - Ensure swash plate is level
2 - Ensure trims are centre (sub-trim and trims or Tx face)
3 - Ensure fly bar is centred and paddles are aligned

It appears to me like you have either trims or a non level swash because of heli wanting to slide that much on spool up. Once in a hover, what does the heli do if you leave the cyclic stick? I would say that during your pitch setup you've compensated with your links for the skew swash. If it's not this, then the only other thing I can think of is for you to try a different set of main blades. They might be balanced and everything but maybe one flexes more at higher rpm than the other.

Regards,
Gavin

RE: BLADE TRACKING
 

that's might be right

RE: BLADE TRACKING
 

You Might be right Gavin. This is a new set of Maverick wide blades. I have never used them before. That could explain the whole problem.

I'll check it out. Thanks.

RE: BLADE TRACKING
 

An addition to what Gavin suggested, if everything in the head is correct, then your only option remains the blades. I could not believe it until I saw it right in front of me. Brand new carbon fiber blades, just out of the package the night before.

Rafael

RE: BLADE TRACKING
 

I can set each blade at zero deg.. Then move the guage from the end of the blade to very close to the hub and it stays at zero deg.. I believe the blades are o.k.. Is there a better test.

I only replaced one blade grip. Today I noticed that the octagonal indent for the blade bolt is at the top instead of the bottom. That's upside down from normal. Is there a difference, or are they symetrical?

The grip I did NOT replace looks fine. Should I replace it too?

Today I got it much closer to tracking, but still not spot on.

RE: BLADE TRACKING
 

Did you check your dampers? How are your bearings in your blade grip? On a bad crash, the bearing could be shot.

RE: BLADE TRACKING
 

The dampers are undamaged and very stiff in the Titan SE. Maybe i'll just replace everything involved with the head except the metal head itself, it shows no distortion.

Thanks

RE: BLADE TRACKING
 

Good point. I forgot to mention the yoke (head). Looks good to the eye but spin test it on a balancer to be sure. Take off all moving parts to test.

RE: BLADE TRACKING
 

Thanks B.T.D.T. i'll tear it all down and go over everything.

RE: BLADE TRACKING
 

I guess that is a good test. Your blades could be good. We took the baldes off the heli and looked at the leading edge and the trailing edge. There was a very slight bend on the trailing edge of one of them. Barely noticeable.

I thought the grips for the 50 were symetrical. not only that, there ISN"T a left and a right grip, they are both the same, since they rotate in the same direction. Could it be that you inadvertendly installed a blade/grip assembly backwards? It would not be the first time that I've seen it done.


If one grip was upside-down, then both grips should be upside-down. If you did this on-purpose is another story, but then I would be looking at other assemblies that could be installed upside-down if you did not do it on purpose.

Rafael

RE: BLADE TRACKING
 

Blade grips on the new Titan 50 SE have the hex shape on both sides of the grips. This is because on the older Raptors, you had negative delta inputs (link on trailing edge of blade) but positive delta (link on leading edge of blade) on the new one. You would notice that if you had installed the blade grip wrong, then one blade would be positive pitch while the other would be negative. I had a brand new set of CY 600 carbon blades that balanced perfect but still had tracking problems. Put one blade parallel to the tail boom while 0 deg pitch, push blade tip towards tail boom and measure deflection. Do the same with the other. Check that both "flex" the same. Otherwise, pick the heli up by the blade tips and see if one blade bends more. Another thing maybe is to see if the "old" blade grip rotor bolt hole is not elongated (oval), this will also cause tracking problems.

Regards,
Gavin

RE: BLADE TRACKING
 

Thanks for the correction. I did not know the newer Raptors had the hex cut on both sides.

How can you install ONE grip wrong if both grips are the same? There isn't a left and a right grip. You either install both of them wrong or install both of them right (depending on what you call right or wrong, trailing edge control or leading edge control) So the posibility of installing ONE of them wrong is NULL. UNLESS you install other parts wrong to fit your wrongly intalled grips.

The comment on my post above, was more of an insinuation that a blade could have been installed backwards. I've seen it happen, several times. Other than that, you would have to intall both grips a certain way and then make the rest of the head "fit" the way you installed the grips. I've also seen it happen.

RE: BLADE TRACKING
 

The new blade grip I put on was an old style grip with one a round hole on top and a hex hole on the bottom, but it's on upside down. I had these grips in stock for an older Titan. Perhaps there is a little difference. I'll change out the other grip and arrange them so both have the hex hole down, then i'll know I have a match.

I just came from the shop where I did a little more inspection. I'm finding a very slight play between the bottom and top of the swash plate. With the bottom held in place firmlly, I can rock the top ever so slightly. Play this out over the length of a blade and it could be substantial. This afternoon I will tear down the entire head assembly, check all the things you guys have suggested, change the other blade grip, and replace the swash. I really think the swask is the booger now.

Thanks guys