Originally Posted by itbvolks

Very interesting. Mine kind of does the same spiral drift around neutral where it requires constant attention....

Wonder if going to the 2622 would benefit me.....???

Noticed I didn't have the blade/grip looseness possibility in creating more vibrations so I went in the post and updated it for future readers. Do you have the MicroHeli CNC head and if so do you have the nylon washers installed between the grips and blades to take up the space you talked about having. The MicroHeli grips have a larger opening for the blades to allow a number of different blade possibilities so they included with the head, nylon washers or shims to use with blades that have a thinner grip end like the blades we fly. Both foam and plastic need these washers for a correct fit.
I do not have any trim of any kind set up in the TX, everything is set to zero. I agree with Tucson in trimming in that after many flights, if I constantly have to make a cyclic correction in one particular dirrection over and over to correct a hover, I will roll in 1/2 turn of the servo link rod end in the correct direction to cancel out the offending drift, eventually my constant corrections are not needed.
I will not tell you to run out and spend the money on a new reciever but the 2622 is a very good setup.

Originally Posted by itbvolks

Very interesting. Mine kind of does the same spiral drift around neutral where it requires constant attention....

Wonder if going to the 2622 would benefit me.....???

Imho the stock rx is only good for basic hovering. Swapping to the 2622 will make your M120D01 fly like a V120D02S. It is a little heavier but it flies very well. A recommended upgrade for me.

Originally Posted by A VIKING

Noticed I didn't have the blade/grip looseness possibility in creating more vibrations so I went in the post and updated it for future readers. Do you have the MicroHeli CNC head and if so do you have the nylon washers installed between the grips and blades to take up the space you talked about having. The MicroHeli grips have a larger opening for the blades to allow a number of different blade possibilities so they included with the head, nylon washers or shims to use with blades that have a thinner grip end like the blades we fly. Both foam and plastic need these washers for a correct fit.
I do not have any trim of any kind set up in the TX, everything is set to zero. I agree with Tucson in trimming in that after many flights, if I constantly have to make a cyclic correction in one particular dirrection over and over to correct a hover, I will roll in 1/2 turn of the servo link rod end in the correct direction to cancel out the offending drift, eventually my constant corrections are not needed.
I will not tell you to run out and spend the money on a new reciever but the 2622 is a very good setup.

Interesting.... I actually don't have any washers with my MicroHeli CNC Head. I wonder if this is some of the issues I'm seeing with blade tracking.... Any idea how thick the washers are? I could source here locally if I have an idea of what I'm looking for. This heli is second hand so trying to sort out any potential issues...

Sounds like I should certainly take another look at my setup. I always follow snemi00's method for setting up the swash using subtrims to level the arms best I can after physically adjusting the servo horns - then level the swash accordingly with the link rods. I haven't been making servo rod length adjustments for dealing with any drift issues though.... Seems like it might be a better way to deal with it.


Any issues using subtrims to align the cyclic horns perfectly level? I removed all of the horns originally and centered everything up best I could @ mid stick throttle location. Then used subtrim to dial them in (aileron/elevator subtrims). I do notice if the horns aren't all nearly perfectly level with the swash, the angle of pull/push changes the throw relative to the swash causing some cyclic variation throughout the travel (solely looking at pitch function). Not sure this is right but it's how I've been doing it....

snemi00 HF link for reference.

http://www.helifreak.com/showthread.php?t=305064

Originally Posted by itbvolks

Very interesting. Mine kind of does the same spiral drift around neutral where it requires constant attention....

Wonder if going to the 2622 would benefit me.....???

Going to the 2622 fixed the spiral drift issue for me without any mechanical changes. I quite literally flew it, it spiraled, I unplugged the 2616, plugged in the 2622, popped in a new battery and it hovered rock steady.

It's a pricy upgrade but I literally have cut my crashes by 3/4 because the heli is now utterly predictable. Now I only crash when I do something stupid rather than getting caught out when the RX decides it wants to be "quirky"

Originally Posted by TucsonFlyer

Going to the 2622 fixed the spiral drift issue for me without any mechanical changes. I quite literally flew it, it spiraled, I unplugged the 2616, plugged in the 2622, popped in a new battery and it hovered rock steady.

It's a pricy upgrade but I literally have cut my crashes by 3/4 because the heli is now utterly predictable. Now I only crash when I do something stupid rather than getting caught out when the RX decides it wants to be "quirky"

What's another $60... lol With all the spares I'm accumulating, what's one more?

Decisions decisions...

Originally Posted by itbvolks

What's another $60... lol With all the spares I'm accumulating, what's one more?

Decisions decisions...

If you get a 2622, just remember that you have to swap a pair of servo plugs vs the 2616 (PIT and AIL I think?). Otherwise you could wind up needing all those spares

Tucson,

Can you please describe what you mean by spiral? My M120 occasionally spins on me in the middle of a turn. I thought it was me but maybe not.
This never happens with my V120D02s.

What I experiance is in the middle of a turn the tail breaks loose, spins around and I have to quickly recover. Is this what you are talking about and reason for the RX swap?

Can I go right to the Devo RX 2622 D I think it is?
Thanks

Originally Posted by Travis MCH

Tucson,

Can you please describe what you mean by spiral? My M120 occasionally spins on me in the middle of a turn. I thought it was me but maybe not.
This never happens with my V120D02s.

What I experiance is in the middle of a turn the tail breaks loose, spins around and I have to quickly recover. Is this what you are talking about and reason for the RX swap?

Can I go right to the Devo RX 2622 D I think it is?
Thanks

I think it depends on what your using for Tx. If your running the earlier Walkera stuff (eg: 2801) you'll need to source the non-"D" version of the 2622. If your already on the Devo train, that's the right rx....

Originally Posted by Travis MCH

Tucson,

Can you please describe what you mean by spiral? My M120 occasionally spins on me in the middle of a turn. I thought it was me but maybe not.
This never happens with my V120D02s.

What I experiance is in the middle of a turn the tail breaks loose, spins around and I have to quickly recover. Is this what you are talking about and reason for the RX swap?

Can I go right to the Devo RX 2622 D I think it is?
Thanks

The spiral I'm thinking of is a little different from what you're describing. What I exprienced did not involve the tail at all. Rather it was more like a phasing issue. Essentially forward cyclic would result in forward and left. Of course I tried adjusting the phase and that corrected my inputs but the gyro's inputs were then even more out of phase. All in all the problem seemed like the gyro was correcting out of phase with the heli. If left hands off it would try to circle (cyclic only) with about half a meter diameter and gradually get wider and faster.

I did have the same issue with the 2616 that you're describing where the tail would blow out. Mine was due to the rudder ext pot being defective so I could only have the min rudder travel. That was enough to hover but any time I needed more tail holding power the tail could not get enough pitch and the heli would spin (and I'd crash). If you haven't checked the Rudder Ext pot, I'd give it a try. Turning the Ext pot you ought to see the servo endpoint change.

The RX2622 comes in WK and Devo versions. Just pick the TX type and plug in the servos and you'll be good to go. I think I've mentioned before that a pair of servo plugs need swapping to get it working correctly, a channel might need to be reversed too so test it with the motor unplugged first

OK, great Tucson, I'm going to give it a go.

Travis

Originally Posted by Travis MCH

OK, great Tucson, I'm going to give it a go.

Travis

Assuming you don't fall afoul of walkera QC this will be the best thing you could do for your M120.

Just a couple more photos for those interrrested showing the battery installation in my modified M120. The 600mAh battery being short will push up against the long battery hold down with the battery connection passing aft as shown. Make sure the charge plug is looped back forward to prevent it from fouling the main gear. A rubber band is needed to hold in place.
The long 850mAh battery slides in under and is pinched down as it always had been by the hold down bulkhead.
No matter what battery you use, with the installation as shown in the photos the c.g. is the same and correct for both which works out nice.
Side note:
I was able to mount the DO2S mast, swashplate and rotor head into my M120 as an experiment and I am happy to tell you it made absolutly no difference in weight. The mast in the DO2S is so heavy that the plastic head pieces didn't create any weight savings over the aluminum parts of the M120. I could have saved myself a lot of time by just weighing each assembly on the scale...oh well. So the weight stays at a very light 102g's AUW!

Originally Posted by itbvolks

Interesting.... I actually don't have any washers with my MicroHeli CNC Head. I wonder if this is some of the issues I'm seeing with blade tracking.... Any idea how thick the washers are? I could source here locally if I have an idea of what I'm looking for. This heli is second hand so trying to sort out any potential issues...

Sounds like I should certainly take another look at my setup. I always follow snemi00's method for setting up the swash using subtrims to level the arms best I can after physically adjusting the servo horns - then level the swash accordingly with the link rods. I haven't been making servo rod length adjustments for dealing with any drift issues though.... Seems like it might be a better way to deal with it.


Any issues using subtrims to align the cyclic horns perfectly level? I removed all of the horns originally and centered everything up best I could @ mid stick throttle location. Then used subtrim to dial them in (aileron/elevator subtrims). I do notice if the horns aren't all nearly perfectly level with the swash, the angle of pull/push changes the throw relative to the swash causing some cyclic variation throughout the travel (solely looking at pitch function). Not sure this is right but it's how I've been doing it....

snemi00 HF link for reference.

http://www.helifreak.com/showthread.php?t=305064

The washers or shims for the CNC head blade grips are about as thin as paper and there are two per grip, one above and below of each blade when installed to take up the gap that exsists. You should be able to find a substitute locally.
I don't believe there are any issues with using sub trim but I have zero adjustments there in my setup.
The travel variations you see when moving the trottle up and down when looking at the servo horns is normal, in flight they will track properly. My DO2S has some slant to the servo horns at mid throttle which can not be corrected but again in flight they will track properly so I don't worry about sub trim which is my preferance, as long as the horns are as close as possible to horizontal it's all good.
Found something iterresting on my new CNC head while replacing the bent feathering rod because of a nasty crash
When it was built the person who assembled it put an uneven stack of washers between the hub and grip which effectivly made one blade longer and heavy during operation. Originally I had to balance it out with tape which is rare with the plastic blades but it balanced ok. During the re-assembly of the head I placed two washers in between the grip and hub so grip spacing was equal and guess what, I had to take all the balance tape off, the blades are in perfect balance.

Debating if V2622rx (D02s) is worth the upgrade?

Originally Posted by Torch8

Debating if V2622rx (D02s) is worth the upgrade?

If you have the 60 bucks burning a hole in your pocket you will enjoy the new flight experiance the V2622rx will bring you, it's a solid feel you don't get with the other rx's. I am getting one for my old D05 if that is any indicator for you.
If your thinking of purchasing another helicopter soon, you might keep the 60 bucks for that, but make sure it has the V2622rx installed!