PDA

View Full Version : Compass heli woes


Pages : [1] 2

leaverus
09-06-2011, 03:26 PM
Maybe i'm not meant to be flying the compass brand but i'm having problems with both my models. I'm the new owner of an old atom 500, just took her up for a maiden today and she just doesn't hold altitude in a hover, keeps drifting back to the ground - is it too heavy? I have it on a microbeast, mavrik g5 blades, mks servos, and kontronik 60lv esc with a zalman nb32k heatsink and i'm running 2600 - 3000mah 6s packs. Is this esc too heavy for the 500? The motor doesn't sound at all like it's bogging or losing headspeed. If it is the esc's weight, any suggestions - i'd like to stick with a quality brand with a good built-in bec? yge - they seem to be lighter and almost as good as the kontronik? And if it's not the esc, what else can i check?

2nd problem is my 6hv. She was flying fine one day, next day suddenly starts tilting right on spool up and hover. This heli is also on microbeast mounted with the stock tape. From what i've read, the problem is most likely from vibrations and switching to 3M 4010 tape seems to help some people, but then i don't want to just mask the problem of vibrations with a different tape. I've gone over the heli and there doesn't appear to be any obvious source of vibrations and i've also re-set the beastx from scratch. So what gives??

skunkworx
09-06-2011, 03:39 PM
That's honestly tough for me to answer because everything sounds perfectly normal on both machines.

I fly with 3300 6S packs and have even stuck 3500's in it at one point and it has never had a problem hefting the weight whatsoever. Sounds more like you're having a problem with your radio if both machines are in the tank all of a sudden. Are your batteries dead or fading out? What are your throttle curves like? What are your pitch curves like? It could be something up with your BeastX too, just tough to say without seeing it in person.

If the 6HV is drifting on you, you might have plugged it in and bumped it or didn't get it completely still while initializing which will cause a drift. Was it really windy when you tried to fly, or was it relatively calm? How hot/humid was it and how long after you got it out of the car did you hook it up to fly?

I can tell you, I've worked on tons of Compass machines and when they are setup even halfways decent, they'll just about out-fly anything else in the air, so hopefully we can get you sorted out and flying right. I know sometimes it can be tough to feel confident in your gear when you're having problems, but it's almost always explainable.

leaverus
09-06-2011, 03:48 PM
Thnx for the reply. BTW, the boom on the 6HV is grounded and has been since day 0 so it can't be that (i know i should do that on the 500 too). As for the radio - it's a year old DX7 and i actually have a new 2700mah nimh battery in it. Throttle curves on both helis are a 0-40-50-80-80 on normal and flat 90 on IU; pitch curves are linear as usual. Oh, the other thing that rules the radio out is that my 450s fly just fine.

donskills
09-06-2011, 05:39 PM
Check the pinion support bearing on the 6HV for looseness. If loose it will cause HF vibration.

Cullen Colapietro
09-06-2011, 05:43 PM
I know issues are frustrating, especially on 2 birds at once, but if you stick with it, you'll be better off for it. Both helis are very powerful.

Can you make it to lexington KY this weekend? Plenty there can help!

Andy.Kim
09-06-2011, 06:25 PM
I know issues are frustrating, especially on 2 birds at once, but if you stick with it, you'll be better off for it. Both helis are very powerful.

Can you make it to lexington KY this weekend? Plenty there can help!

Yea somethings not right with setup. The batteries on the helis could also be suspect. Having someone look over the heli is a good suggestion. The problems mentioned does not appear to be the heli related but more setup related.

Ah Clem
09-08-2011, 01:43 AM
I agree that something is wrong-hard to diagnose without seeing the machine.

The Atom should feel very powerful, not be struggling to hover. I have lugged a small camera around on mine and done aerobatics with it, so I cannot imagine the ESC being too heavy.

If the motor timing is not set right, the batteries are not performing, the throttle end points are not set right, or the radio is not set up right (as others have mentioned above) that might result in the poor performance you are experiencing.

Many people have had the experience of their FBL machines exhibiting strange behavior on take off (different brands of machines and different FBL units). You mentioned changing the tape-this does not necessarily mask the problem but can better isolate the BeastX unit as the different tape has different damping characteristics. Changing to the 3M tape would certainly be worth a try.

If you can get someone experienced, like Cullen or Tony Whiteside, to look over your machines at the Kentucky meet, it would be of great benefit to you.

flybar-les
09-08-2011, 03:03 AM
wich tx are you using ?

that 6HV problem sounds very suspicious as a faulty pot meter !

leaverus
09-08-2011, 12:41 PM
DX7 - other helis fly fine. OK, thnx for the help so far guys. What's frustrating about the 6HV is that it was fine one day and the next day it suddenly starts rolling right on spool up - so it's definitely not a setup issue. At this point, i guess i'll try the 4010 tape and see if that works.

As for the atom, i figured out the problem - it seems the links on my front cyclics were rubbing against the servo casings - not an uncommon issue? The dubro 670 arms still the solution? Will those fit OK on the MKS 9670A and still allow for proper setup on the microbeast (ie. that crazy 6 degrees thing on step J)? I could hook up the links on the outside of the existing arms but i'm afraid the links will pop off midflight because of the weird angle??

Ah Clem
09-08-2011, 01:35 PM
How are your servos mounted, sir?

I do not have a set of MKS servos to examine, but with the Futaba 9650's the best geometry was realized with the servos mounted from inside the frames. This provides a reasonably straight shot from the servo arms to the swashplate balls.

Just a thought.

leaverus
09-08-2011, 01:44 PM
They are mounted from the inside of the frames.

Ah Clem
09-08-2011, 02:01 PM
Try mounting them from the inside. This will require the removal of the one tubular, aluminum cross-brace which joins the frames at the upper-most, forward corner.

I built mine before any instruction manuals were written, so I just tried different mountings until I got the best alignment. You can also use servo grommets and eyelets, if that helps position things better. They are unnecessary, from a vibration standpoint, but I have used them on several electric machines, specifically for alignment purposes.

Please keep us posted as to your progress, sir;

belcom
09-08-2011, 02:07 PM
How are your servos mounted, sir?

I do not have a set of MKS servos to examine, but with the Futaba 9650's the best geometry was realized with the servos mounted from inside the frames. This provides a reasonably straight shot from the servo arms to the swashplate balls.

Just a thought.

I had to mount my MKS DS9660A+ inside to get straight linkages but left Aileron servo arm does hit the auto-rotation gear at max travel. I'll have to figure out how to deal with this when it gets converted to fbl.

TheBum
09-08-2011, 03:37 PM
I had to mount my MKS DS9660A+ inside to get straight linkages but left Aileron servo arm does hit the auto-rotation gear at max travel. I'll have to figure out how to deal with this when it gets converted to fbl.

Remember that FBL will result in shorter arms, so it may not be a problem. If you go with a VBar, you may find that you need a *much* shorter arm. I ended up at 12.5mm and both cyclic and collective were within the recommended range. The left aileron servo arm clears the autorotation gear by a comfortable margin.

belcom
09-08-2011, 04:34 PM
Remember that FBL will result in shorter arms, so it may not be a problem. If you go with a VBar, you may find that you need a *much* shorter arm. I ended up at 12.5mm and both cyclic and collective were within the recommended range. The left aileron servo arm clears the autorotation gear by a comfortable margin.

Good to know. Thanks.

sarpilot
09-09-2011, 08:24 AM
Check the pinion support bearing on the 6HV for looseness. If loose it will cause HF vibration.
But DON'T locktite it! Just put it back in so it can fall out again......
:rotf

leaverus
09-11-2011, 10:15 AM
Well, oddly enough, i switched from the stock to the 4010 tape for the beastx and the 6HV is back ROCK SOLID and flying like a champ! So now i just need to fix the arms on the 500 to keep them from rubbing on the casings and i'm good to go. Thnx for all the help guys.

Ah Clem
09-11-2011, 10:34 AM
leaverus,

Glad that the 6HV issue is resolved, sir!

We are all here to help you.

All of us who fly Compass machines, and/or fly for Compass, want you to have the same positive experience that we are having.

Ask as many questions as you need to, we will help as much as possible.

Airworks
09-11-2011, 11:56 PM
man i had almost the start of your same issues , glad its resolved , the white beast tape i think degrades extremely fast, when i took mine off to change to 4010 , it didn't feel the same as the new pad of stock beast white tape i had (the other new piece).it was way softer feeling.

skunkworx
09-13-2011, 09:28 AM
I recently got to try some of the 4011 tape on an Atom 500FBL and man-O-man!!! That stuff is unreal!!! I was so impressed with it, I didn't want to hand the heli back. It's the stuff dreams are made of! :P

I'm scrambling to try and find some before I re-maiden my 6HV (BeastX V3 update).

TheBum
09-13-2011, 09:54 AM
I recently got to try some of the 4011 tape on an Atom 500FBL and man-O-man!!! That stuff is unreal!!! I was so impressed with it, I didn't want to hand the heli back. It's the stuff dreams are made of! :P

I'm scrambling to try and find some before I re-maiden my 6HV (BeastX V3 update).

I've tried it and it didn't work as well as the Futaba gyro tape on my 6HV.

leaverus
09-13-2011, 02:25 PM
That's a little odd; i wouldn't think the tape would make that much noticeable difference with a VBAR.

Anyway, new (minor) problem with the Atom today. I got the stock arms remounted on the servos with the tiniest of clearance on the casings - i'm still gonna try the dubros though. Well, i took the Atom up for a trial and a few minutes into the flight started spinning out of control; got lucky and sort of-autoed it down and fortunately only damage was broken skids. I thought at first maybe the beastx had gone bad, but it turns out the belt had come out of the guide and consequently tail must have stopped rotating. I guess i must have had the belt a little too loose but actually it was no looser than i have it on the 6HV. i'm gonna tighten it up now after i get some new skids on, but any of you guys have that happen to you before? when the belt is spinning that fast, i wouldnt think it would have enough slack to come out of the guide like that.

Ah Clem
09-13-2011, 02:31 PM
"That's a little odd; i wouldn't think the tape would make that much noticeable difference with a VBAR."

I have tried different tape and it does make a difference.

Cullen Colapietro
09-13-2011, 04:06 PM
I wouldn't run the belt that loose! If you hear it slapping inside the boom, it's time to tighten it a bit. Maybe your boom slipped in flight?

leaverus
09-13-2011, 05:02 PM
I wouldn't run the belt that loose! If you hear it slapping inside the boom, it's time to tighten it a bit. Maybe your boom slipped in flight?

Nope, the boom hasn't budged a micron. I didn't think i was running it loose enough for it to slip. You can see in the pictures below. The first picture is how it looked initially - that's a 2.5 hex driver for reference. The second depicts how the belt looked when the heli was on the ground.

http://img88.imageshack.us/img88/1152/belt1q.jpg

http://img69.imageshack.us/img69/1585/belt2b.jpg