250 250 Wabble

[jwcole1968]

I bought a Erazor 250, Replace the rx with a Spektrum so I could use my Dx6i. I setup the helicopter and Tx using the setting Tony used in his Erazor 450 setup video. Everything was fine. It worked perfect (inside) it hovered and responded correctly. As I set the 250 down so I could go outside, dumb thumbs occurred, and I touch the concrete floor with one of my main blades and broke the feathering shaft. I replaced the Feathering shaft Main blades and the flybar, for good measure. Now there is a bad wabble when I try to hover, the whole heli wabbles. I even pulled the main shaft out to see if it was warped, but it was good. Blades are balanced... Does anyone have any ideas what might be going on?

 

[Tony]

Are you sure your flybar is centered? Also, are you sure you put the correct shims in the blade grips? If they are off center by just a little bit it could cause this. Also make sure your blades are not too tight.

 

[jwcole1968]

I have checked the flybar several times with and without the weights and paddles, it is centered. The shims, if you mean the brass washers on the feathering shaft, I lost the one when the shaft broke... I bought a set of washers and bolts when I bought the 250, and I used a pair of the washers in the bag, they were the same size.

 

[Tony]

Is there any way you can get some closeup pics of the head without the blades or a video? Video would be better with a spool up to show us what is going on. I know you said the blades were balanced, but did you double check each one? I never trust them from the supplier. They have been known to mix them up. Another thing, and this is going to take some work, is to take the blade grips apart and make sure you have the exact parts in each side. But, if you can get a video first, I would do that.

 

[crashbash]

Also check the little plastic linkages, one might be split, one of mine split and I didn't notice, luckily I stopped on spool up as it did not seem right.

 

[jwcole1968]

Ok let me take it apart and try again. taking pics of it it look s like one of the bearings could be out of place. My pic will not load

 

[Tony]

Pic wont' load? Download Photoscape and reduce the size to 800x600. Should be less than 100kb when done. the file may be too big. Or, you can upload them to photobucket and then upload them here with the img code from their site.

 

[jwcole1968]

The pic I took is a close up of the head and it looks like one of the bearing might either be out of place or a little wider than the original, let me pull it back apart and check all of the bearings in the head and the linkages and try it again. I'll see if I can make a vid if this does not work. BTW after showing my wife your vid of the Mcpx and how tough it is, She told me to get one... And I am a fan. Thank You

If you can get to it the pic is now in my album

 

[zenmetsu]

I noticed an issue with pics also. I resized to the point that the pic was only 10k in size and the forum still complained. I have to post all my pics to picasa or some other site, then link via URL. >.>

Regarding the wobble, try removing your blades and spinning up the motor (don't go more than half throttle though, you don't want to overspeed the head/motor). Does the wobble still occur? Does the head button appear to be centered, or does it wobble? I have had a few issues with the main rotor housing not sitting squarely on the main shaft, and this may be your issue.

If the wobble does not occur with the blades removed, try putting them back on and trying again. If the wobble persists, switch blades with respect to the blade grips. I have an issue with mine where tracking is off if I don't put the blades back in the correct grip.

Lastly, check your main bearing block to make sure that all the screws securing it are tight.

 

[Tony]

She just said to get one? Wow, wanna trade? hahaha. I'm trying to talk mine into getting a Tarot 450 but not having much luck.

I did get into the pic and everything looks pretty good. I dont think that little bit will matter much but it could with the head speed. I think a spool up video will be best if you can't find the issue after taking it back apart. I did notice one thing they need to quit saying though, that 250 is not for beginners lmao. Can't wait to see some videos of your mcpx when you get it. Most LHS have them ready to go BNF.

 

[jwcole1968]

It does wabble a little without the blades but as i spin up it feels like it smoothes out. Could the head button have been knocked off center when i broke the feathering shaft, I'll check it anyway.
I believe I am learning more from the crashes, than running down the batteries in fligt...
Thank You

I already got the Mcpx and it is as tough as you said it was, the only thing is the bearing inside the swash plate pops out when I, uh have thumb control issues.

 

[jwcole1968]

oops.

 

[Tony]

Your main gear will also slip down in a crash as well. This is all normal. it's either something is going to move, or something is going to break. I would rather have to push something back in than spend money adn replace something.

The head button will do nothing. You can take it off if you want. My other idea was the head block got bent. if you spool it up with or without the blades, and you see the bolt in the head button moving, then something is bent. I would take the bolt out of it (the head block), disconnect all linkages to teh swash, and pull the head off. Leave the main shaft sitting there in the frame. Then, spool it up and see if the shaft is straight. If you don't notice anything there, then you may want to order another head block.

 

[jwcole1968]

When I finally got to play with my heli I took the head apart, one of the bearings on the blade clamp was not full in pressed it a little and it fully seated. It doesn't wobble now, but it still doesn't hover very well either. I think I will play with my other heli for a while, to keep from getting too frustrated. I think next weekend I will break it completely down and reassemble it completely. Another chance to learn a little more.
Thank You

I will have to look up the Tarot 450, I've got my Erazor 450 flying great, by your setup. and thanx for that too

 

[Tony]

It's my pleasure, I'm glad I could help out. And you are doing the right thing by walking away from it for a day or so. When you go back, you will more than likely see what is wrong. More than likely, it's a blade link or something that is out of adjustment. If you have a pitch gauge for the 250, check it.

 

[zenmetsu]

Glad you got the wobble solved. These little things are highly sensitive to blade tracking issues too, so take Tony's advice and pitch-gauge the thing if you can.

I found two things about the 250s:

1) They are more stable at higher head speeds. Mine does well at 80% and up.
2) The controls are MUCH more responsive at higher head speeds. (Translation, not newb friendly)

It is kinda hard to find the perfect balance on the 250 as a newb (like myself). On one hand you can smooth things out by upping the throttle curve, but at the same time you increase your chances of dumb-thumbing the thing into the ground. Instead of playing with Expo settings, I am limiting the travel adjustment in the transmitter so that I still have linear cyclic response, but the response is gentle enough that I am able to get a handle on the thing.

 

[Tony]

You can also use expo to achieve the same response but still keep your full travel.

 

[zenmetsu]

Yeah, you can. New pilots will never need more than 4-5° of cyclic. If you ever command the cyclic to full left/right, the heli will roll over and die faster than a newcomer can rectify the situation. Expo is great if you can avoid large stick inputs; something that newcomers tend to do in a panic situation.

I think it is all preference, but I prefer linear response. My bigger crash (where I put the thing nose first into the pavement) was due to full forward cyclic due to mixup while doing nose-in hover. I am trying to prevent a repeat of that situation by limiting cyclic travel and slowly work it back up as needed.

 

[jwcole1968]

Update: The main rotor shaft is slightly bowed on the bottom right in the area of the main gear... Shssh Without the head assembly and buckles in the way there was still a wobble to the shaft so I pulled it all apart and rechecked the shaft and it has a slight bow, I guess that made it wobble on the top. Now I just have to wait till I can order some more parts. Thanks