Axon vibration analyzer

[Fairview]

I had a vibration issue with the tail on an hd500 and I finally got that sorted, but now it is showing an orange to a red at motor speeds. I pulled the motor and the bearing that holds the pinion is fine. The motor only has about 15 flights on it. No play in the motor shaft. New bearings in the main gear. Checked belt tension from pinion to main gear and it has about 3mm of deflection which is what is called for in the manual. I am out of ideas of what can be checked and second how important it is to iron this out.

[im4711]

If its important or not depends a bit on yourself. As long as you are happy with the way the machine performs you maybe OK. Orange - red is not very cool for me.

What motor is it? If it has a 6 mm shaft I would try running it without the counter bearing and check vibration level that way. With 5mm shaft you run risk to break the shaft.

Also ... how tight is the main belt on the machine? If to loose the motor could try rocking and cause vibration on the counter bearing. My first guess is in that direction. Second is that the motor (regardless age and runtime) may not be balanced completely.

[Fairview]

I am running a pyro 650 78 with a 20t pinion. The pyro 650 has a 6 mm shaft. As far as belt tension goes. I get about 3mm of deflection of the belt when pushing on it half way from main gear to pinion. According to the manual that is what it should be although reality maybe different.

I don't really like running it with the motor vibes that high so would like to fix it. Is it ok to run it without the pinion counter bearing in it? Maybe try that first since it would be easy to do.

[DEMONjoe]

I cannot help with where the vib results from.
Just want to spend a word on the way the vib analysing display works:
If there is more than one vibration source on the heli, the Diagnosis will always show the hardest vibration first, marking the others as green. Not perfect, but the way it is. Once you got that vibration sorted out, at the next flight the "level 2" vibration is shown. That's why you did not see this before. Hope that at least explains the why.

[im4711]

Originally Posted by Fairview

I am running a pyro 650 78 with a 20t pinion. The pyro 650 has a 6 mm shaft. As far as belt tension goes. I get about 3mm of deflection of the belt when pushing on it half way from main gear to pinion. According to the manual that is what it should be although reality maybe different.

I don't really like running it with the motor vibes that high so would like to fix it. Is it ok to run it without the pinion counter bearing in it? Maybe try that first since it would be easy to do.

As stated - I cannot decide what vibration level is acceptable for you. I do agree that I would not run it with vibration in the red level.

Try running it without the counter bearing as one option (I did run one a few hundred flights without counter bearing as well since I had issues with the counter bearing). Also try swapping the belt. Something for sure seems wrong. E.a. if the counter bearing is not lined up correct and the shaft keeps hitting it it could cause vibration.

[Lowknifedge]

I back the motor off and use a piece of velcro on top. Run the motor up and feel the vibe. Keep moving velcro around until it smooths up. Works great on mine

[Fairview]

I finally got around to removing the counter bearing but that didn't change anything. I tried adjusting different settings in the esc. After I changed the timing to auto I never had it show red on the motor, but it is still in the yellow. I turned the governor off just to see if that would make a difference. Now instead of a yellow on the motor it is giving me a yellow on the tail. So I don't know if turning the governor off improved the motor vibration or the tail vibration just became stronger. Visually the tail seemed not to be as steady, but why would that change after turning the governor off just in a hover? The vibration analysis in the axon really doesn't give you enough information to do much.

[im4711]

very simple answer -> no governor means no automatic corrections. Its lows down under load and slowly picks up when you let go. I would check if the motor bearings are OK. Also check the motor pinion thats in the counter bearing. If you see a bit use then you know its shifting when the motor is trying to adjust for rpm.

Tail is unfortunate a bit of a pain on the HD500. Any small vibration can easy be kicked up due to the CF tail boom. If it is yellow you are most likely OK. Not perfect but at least flyable.

Also ... keep in mind on the Axon -. you see the highest source of vibration. So once motor vibration is gone and tail now is higher you get the tail showing.

[Fairview]

The end of the motor pinion looks good so I don't think that is the issue. To check the bearings on a pyro motor do you just take the screw out of the top of the motor and the can slips off? What kind of thread fastener (locktite) do you use on that screw where it goes in the motor? I have never pulled one apart.

[john2kx]

Originally Posted by Fairview

The end of the motor pinion looks good so I don't think that is the issue. To check the bearings on a pyro motor do you just take the screw out of the top of the motor and the can slips off? What kind of thread fastener (locktite) do you use on that screw where it goes in the motor? I have never pulled one apart.

https://www.helifreak.com/showthread...earing+removal

[KSHeli]

Originally Posted by Fairview

The end of the motor pinion looks good so I don't think that is the issue. To check the bearings on a pyro motor do you just take the screw out of the top of the motor and the can slips off? What kind of thread fastener (locktite) do you use on that screw where it goes in the motor? I have never pulled one apart.

Very easy to change out bearings, even Align didn't offer repair parts on the 800MX motor. I believe it's because of the strength of the magnets, when you pull it apart you'd findout. If when reassembling the and the stator and can slam together because they slipped you could damage the motor, plus since it voids the warranty it protects you sending in.