MX400 PRO Tail ?

[Sam In Virginia]

Hi everyone, I need some help.
A friend at the field asked me to help him set up his new MX400 Pro. I have experence with Trex 450s and 600s and even got a HB 3D pro flying. So I thought it should be no problem. It came as an ARF and he installed the radio DX7 and gyro. After setting up the pitch and all controls,even the tail direction it apears their is not enough tail pitch to turn right and I dont see a way to adjust this condition. What an I doing wrong?
Thanks for any help
Sam
in Virginia

[jeff250]

I don't remember if that is the way mine wouldn't turn, been a while since I set it up and its been down. I read to flip the tail blade holders around so the ball links lead the direction of travel. You'll know that it is that way because the tail blades will thread in from the inside and it will seem awkward but that is fine . It made work great.

[Thrasymedes]

This may be something you already readily have noticed, but remember that the 400 tail blades turn in oposite direction from the Trex stuff. If you are looking at side of the chopper where the tial blade shaft comes toward you, the Trex spins counter-clockwise, and the 400 spins clockwise. The 10mm tip-to-tip offset when the tail blades are brought together still works, but backwards from the Trex 450.

I know this because a friend of mine help me set up my 400, having experience with Trex stuff, and setting the 10mm offest is opposite to that of a Trex. Took me a while to figure out what was going on.

After that, and after adusting the extent on the gyro, I configured my end points in the radio to get full mechanical throw in both directions, and that should provide enough right or left turn authority.

I would also recommend upgrading to the Helimax 450 aluminum tail slider, or the Trex 450 aluminum slider and drill the hole in the slider to match the Helimax tail shaft diameter. The 400 tail system has been known to blow, no pivot point for the slider link that attaches to the tail blade grips on the stock 400, and it is really asking the plastic to bend and take a lot of stress. The 450 and or Align pieces uses an actual linkage pivot point with a screw you can loctite into position. The Align slider pivot uses a bearing also, as opposed to a bushing.

A guy at a regional club had his 400 chase him down after the tail assembly blew...

While your at it, an Align servo tail boom mount, and Align carbon tail rod set-up will improve the tail action and ease adjustability, stuff you are probably already familiar with in your Trex experience.

A lot of the Align parts work on the 400, and some of them will substantially improve performance.

My two cents, good luck!

[Stan Williams]

Hello all i have a used mx400.The promblem im having is i rebuilt the head and now one blade moves up and down,the other blade does not move.Any ideas on how to fix this. thanks for the help Stan.

[z_man_95]

Stan - If you could post a close up picture it would help a whole lot.

Thrasymedes - your tail blades need to turn in the direction that makes them go up into the air coming down off of the main blades. In your pictures' case, that should be counter-clockwise.

[Thrasymedes]

Thanks, and you are absolutely correct z_man, been a while since I've checked this forum. I had somone else point his out also and I have since turned them around. It flew ok before, but the tail works better now. After so many Align parts, I started losing track of what was what... All the other points I noted remain true and have proven to work well, just had the idea of the blade direction incorrect.

By the look of the date of the original post I figure he must already have it fixed or moved on, and by the looks of the forum, not many people are trying to tune there 400's lately. Mine is only flying, and I use that term losely, long enough to build my next bird, at which point all the gear is coming out and going into a Trex 450. At that time I will have some sort of destructive fun with my mx400 frame assembly, possibly a large hammer, maybe thrown into a fire, dropped from a tall height, who knows....I may do all three and more, but it won't fly anymore.......and I will have expressed my frustration at this chopper fully...

Best of luck to all...