HK450 does this sound right? (motor sounds strange) - Page 5 - RC Groups
Thread Tools
Jul 09, 2009, 12:30 PM
Registered User
flypaper 2's Avatar
Hey, it's all part of the learning process, just have fun. As the old saying goes, the only guy that never made a mistake never done nothin.

Sign up now
to remove ads between posts
Jul 09, 2009, 12:59 PM
Registered User
Glasswalker's Avatar
Originally Posted by jasmine2501
Is it possible you don't have the pinion pushed all the way down and it's contacting the "curved bottom edge"???
These pinion gears have a wierd design. they are like:

Where X represents the main teeth, H is also toothed, but smaller, and S is the set screw. (the set screw noticably sticks out past farther than the main teeth do, but it is lower down on the gear). The O and space shows where the shaft is in the pinion. G Represents the main gear.

I know that's pretty crude, but it illustrates how it looks. So I don't think it's possible the main gear is hitting the bottom of the pinion. It is possible I guess that it's hitting the set screw, but in walking it through several rotations it had clearance from set screw all the way around. But if it's wobbling more under power than when I move it by hand, then it might be hitting it (but in that case it would be striking the tail gear, and possibly the airframe in places too). But I don't see why it would wobble more under power than when I turn it by hand (when I turn by hand I'm using the motor body to turn it. so the "force" is still being applied by the pinion gear)

Does that make sense?

The shaft
Jul 09, 2009, 01:58 PM
Rocket Programmer
jasmine2501's Avatar
A lot of crazy stuff can happen when you apply power to these things. It is hard to say what might be going on, but you have to eliminate that horrible noise before you fly it.
Jul 09, 2009, 02:58 PM
Registered User
Glasswalker's Avatar
Yeah I'm going to drag it down to the LHS tonight. I called them and they said they can take a few minutes to take a look at it and see if they have any suggestions. And they have the 3 packs of the V2 Blue Align branded gears in stock for $15, so I'll grab a pack of those too just to have on hand.

One way or another we'll get rid of that damned noise weather's supposed to be really nice tomorrow and I want to get it in the air dammit!

Thanks! I'll let you know how it goes after I visit the LHS.
Jul 09, 2009, 03:14 PM
How does it work? How did it?
mareklew's Avatar
Originally Posted by Glasswalker
And they have the 3 packs of the V2 Blue Align branded gears in stock for $15

They cost €6.5 in Germany, 19% VAT included, german salary and german rent included as well...
But I understand your frustration...

Jul 09, 2009, 03:45 PM
Registered User
Glasswalker's Avatar
According to my calculations 6.5 Euro is like $11 CAD. I would pay tax on top of the $15, and it's $15.95 to be exact, so $18.02 CAD is my actual final price. But I figured that wasn't bad since it's a 3 pack. one main gear from HobbyCity for the HK450 is $6 USD plus shipping. So when you look at it that way, it's not a bad price. (considering it's align brand, and superior in quality to the HK one) or am I missing something? lol
Jul 09, 2009, 04:40 PM
Registered User
I can't help but to jump in this conversation, I went through hk450 settup recently.

I don't know if Align gears are better than hobbycity, my stock gear runs fine. I had problem with tail gear slipping on the shaft, you might want to glue that one with CA, its a very common problem with HK450. here's someone else's explanation.

I'm also using 11T pinion bought from hobbycity, I'm sure 13t would be fine too.

Like yours, on my HK450 the blades seem to form a V-shape. It flew but I had problem tracking the blades. After checking the feather shaft (fine), I replaced the blade holders with ALIGN which solved it. Now I'm using CopterX head/tail, newer version with larger feathering shaft and thrust bearings.

Remember-SAFETY first! especially during testing of unproven setup.

Now, if I had to redo it, I'll go for this one

Although my HK450 now flies as smooth as my upgraded mini-titan.
Last edited by belier; Jul 09, 2009 at 04:48 PM.
Jul 09, 2009, 05:16 PM
How does it work? How did it?
mareklew's Avatar
Originally Posted by Glasswalker
But I figured that wasn't bad since it's a 3 pack. one main gear from HobbyCity for the HK450 is $6 USD plus shipping. So when you look at it that way, it's not a bad price. (considering it's align brand, and superior in quality to the HK one) or am I missing something? lol
Yes, you are missing that the $6 at HC is main gear, main gear hub, one-way bearing, one-way hub and tail drive main gear assy, while the three pack you are buying now is just 3x the plastic part of the top (main) gear.

Don't get me wrong: I went through 6 main gears and never broke the other parts, so I needed only the Align spares, but these are not the same sets.

Jul 10, 2009, 12:07 AM
Registered User
Glasswalker's Avatar
Yeah I realize that now that I got them lol...

Either way when I brought it down to LHS he told me two things right away after poking at it a bit:
- Gear mesh is too damn tight
- Gear is out of round

lol so exactly what you guys were saying. He said get the align gear, and said to mesh it with a double piece of paper (a piece folded in half) and once meshed, and motor locked in place, I should have about a half mm of play rotating the main gear left to right with the motor held still...

I did that when I got home, installed align gear, re-meshed with his instructions (and taking into account what I learned so far in this thread) and now...

No wobble at all
Way less noise. (still noisy as hell but it's much better, and not as "grindy" lol)
So I think the pinion is not 100% perfect so that's why the noise now... or it might still be just a little too tight. I will tinker with it. But it's way better than it was.

tomorrow if weather is nice I'll go give it a test spin-up in the park (and maybe get it in the air finally!)

At the very worst, at this point if I chew up a main gear, I have some spares

Anyway thanks for all your help everyone!
Jul 10, 2009, 12:17 AM
Cranky old fart
Balr14's Avatar
Get another video with sound to see if you still have any kind of gear problem.
Jul 10, 2009, 08:24 AM
Registered User
Glasswalker's Avatar
Yeah I planned on it, Just waiting till I can do it more safely this time. Either that or if I can't get out to the field I'll spin it up with blades off and record that. It's still loud, but not nearly as bad sounding as it was.
Jul 10, 2009, 08:38 AM
Registered User
flypaper 2's Avatar
Can you hang on to the big gear and feel a bit of play when you move the motor casing back and forth. Should have a tiny bit of slack between the gears. Should have a whine like a gas turbine when you wind it up. With the blades on, it should take a while to wind down with the motor shut off.

Jul 13, 2009, 02:29 AM
Registered User
any update on your noise problem?
Jul 13, 2009, 07:49 AM
Registered User
Glasswalker's Avatar
Was busy this weekend, didn't get a chance to spin it up one more time without the blades, to post a video, and the weather has been completely uncooperative.

I don't think we've seen a day without rain in 2 weeks. Save for Friday, but I was too busy on friday to get out to fly lol... Yesterday wasn't bad, it was sunny, but very windy so didn't think that was a good idea either.

As I said above, it's still a bit noisier than some I have heard online, but not nearly as "raw" sounding as it was. I think it might still be slightly too tight, I'm fiddling with it trying to get it just right.

Also there were some white plastic shavings stuck in the pinion that I couldn't get out. When it spun up to full speed for 30seconds or so (by mistake) it appears to have worked all that loose (and now there are bits of flakes on the main gear, but they look white, not blue, so I believe it's the flakes from in the pinion working off onto the main gear).

I think the noise might improve once a little more of that works it's way out.

Anyway, I'm hoping tonight to get at least a spinup video to post up to confirm that it sounds right. Then on the first cooperative day, I will get out for maiden flight.

Thanks for all of your help so far everyone!

Will be back shortly with more videos.

Jul 13, 2009, 07:19 PM
Registered User
Glasswalker's Avatar
Ok weather still not cooperating *grumble* *grumble*

Anyway, I did another bladeless spinup test on my bench to hear the difference.

I have adjusted the mesh so I have about 1mm of play in either direction if I hold the motor still and rotate the main gear by hand. Now when I rotate the main gear the motor rotates freely (with some good resistance, but it still rotates fairly well) Before when I rotated the main gear, the motor wouldn't turn at all (no matter how much strength I put into the main gear). As you can hear it's smoother. Still a bit rough but much much smoother. I think any additional noise is just from the gear not meshing 100% perfectly (as I have heard other say, sometimes pinions are just noisy lol)

But I'm looking for your opinions. If you can confirm this sounds right, and looks good, then I'm ready to jump on the next patch of good weather to get it spun up in the park blades on, and hopefully get my first ever hover underway

Video is attached.


Spinup with new main gear (Align) (0 min 23 sec)

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Does this sound right? (Blade CP Pro motor) rgoodwin Micro Helis 1 Oct 10, 2007 04:00 PM
Does this sound right? Beeping ESC, rumbling motor QuazBotch Power Systems 6 Aug 05, 2005 02:03 PM
Does this sound right? irate 850 iflych52 Batteries and Chargers 3 Mar 19, 2004 03:27 AM
GWS Spitfire - does this sound right? mattski Parkflyers 10 Sep 07, 2003 08:17 PM
Does This Sound Right? Scomis Parkflyers 4 Mar 01, 2002 11:46 AM