mimeauja

If you're going to buy the MX 400 helicopter, then here's a couple tips for you.

Buy the upgraded (metal) center hub right away. The 'plastic' center hub is so cheap, it breaks if you start the motor too fast. (see my rant at the end of post)

Point two, related to above. Buy an ESC with a governor mode to control the rotor spin up and 'under load' rotations. (Castle Creations Phoenix 35 for ex)

If you want a cheap solution for servos, but the EFlite S75 servos. No one even comes close to the torque and light weight for $15.00

The HeliMax 6 pole motor is a really powerfull motor. You could easily overpower your heli with it, so start with a lower tooth count pinion and step up from there.


About the MX400, problems

This is the age we live in, where manufacturers know there are huge problems with things and do nothing to straighten them out. There is no possible way that HeliMax (Hobbico) could NOT know that this center hub problem exists. Oh yeah, there is one way, they never tested any of their helis...but we all know that's impossible.

Ok, so I've had this heli for a month, never flown it, but have replaced the center hub already. Why? because I accidentally hit the throttle with my hand when setting up the mixing. Oh, no, the heli didn't hit anything! the torque snapped the center hub.

Now, I've flown the heli. I've crashed it, and it was a head crash (tail is fine), so I want to buy a head crash kit. Only problem is, 1/2 the parts in there I don't need. I don't need a main shaft, I don't need a feathering spindle. No, I need all new linkages, a new swashplate (yes, that's right, it ripped the balls right out of it), basically all the plastic parts. (oh this is about $90 US)

Why? because the center hub broke, and everything torqued off from there. Believe me, if that part had held together, I would have been able to use the standard crash kit, and been just fine.

My advice, either buy the metal center hub for the MX400, or buy a T-Rex, either way, you're paying about the same. Otherwise, I'd stay away from this heli, no matter how well it flies, eventually you WILL crash it, and you know what happens after that.

bdavison

My Feedback: (1)

Id venture to say the same thing is quite possible with the stock plastic hub on a T-rex too.
Both the T-rex and the MX400 have a lot of power under the hood. If you dump all that power in an instant....stuff is going to break.
If your head didnt shear, you probably would have at the least taken teeth off the main gear. Even the little E-flite Blade CP will eat teeth off the main gear if you jam the throttle stick to full throttle really fast.

Dont be so quick to blame the heli, when it was your mistake.

jh4db536

My Feedback: (2)

youre suppposed to use "soft start" to prevent the head from snapping and also from stripping the maingear

the x400 head is designed to be weak on purpose for crash reasons, that's why it's so cheap

helimax/towerhobbies does not make the MX400, ARK does which sells updated versions under the x400 name.

why wouldnt you buy an esc with gov mode??? that's how CP heli are supposed to be run. no gov mode means, no softstart also.

if you think a helimax motor is powerful wait till you try a 450TH or Astro803T. IMO, the helimax motor is crap.

i dont like tower's recommendations on equipment for the MX400. they recommend only items that they sell and a lot of it is sub par not only in quality, but it's inadequate for use in a heli like the MX400. ie the 1250mAH lipos when x400 supposed to have at least 1800mAH. you should be using the same motors etc used in Trex.

mimeauja

Heli-Max is hobbico, see here [link]http://www.hobbico.com/[/link]

um, I didn't hit full throttle, more like 1/4 throttle, and I do have the ESC in governor mode (ultra soft start). The part is junk.

How many people have broken this part already? Respond to this message, thanks.

jh4db536

My Feedback: (2)

a video of my soft start (6megs): this is how it should be :

http://media.putfile.com/soft-start-idle-up

im using approximately the same ESC, phoenix45

kevntri

My Feedback: (15)

Broke one on a landing...
Brought it down to about 4 inches and set it down and SNAP....

bdavison

My Feedback: (1)

jh4db536....

That was georgeous.

EZ Money

Mine broke last week when I was setting the pitch. same way, I bumped the stick and it hit my arm (it smarted too!). I have since replaced it with a metal head from ARC (Grand RC) and metal blade grips.

What a job that was. The ball links on the collective are very hard to get to to unsnap and re-snap.

Tell me more about soft start. My ESC does it but I thought something was broke so I put the setting back on number 1 for airplane.

Ron

rwthomas1

I have yet to fly my X400 however I have had no problems with the head yet despite numerous spooling up and down of the assembly during setup. ESC is Phoenix 35 and soft start is on. Will report when I actually put it in service. Regarding getting more parts than you need in a crash kit that just seems to be the way it is with all heli makers. You can get all the parts individually from grandrc and others. So the X400 head is weak, so what? Upgrade it and enjoy the heli. Any heli you crash will need repair. RT

credence

My Feedback: (2)

Heli-max is a Great Planes brand. As stated, they only re-brand and re-distribute the helicopter. It's actually made by ARK Taiwan. It's more expensive than the X-400 kit because you pay for the name and, to an extent, support. I'd imagine replacement parts for the x-400 would be cheaper in comparison aswell compared to buying them under the MX400 name.

As for your problem, well, gunning the throttle breaks things. It's not an MX400 specific problem. Most helicopters will sustain damage if you jump the gears when the main blades aren't atleast rotating. Learn from your mistake and engage throttle lock from now on when adjusting things on your helicopter or transmitter. I won't do anything on my heli unless throttle lock is engaged.

t--bone

the plastic blade grips are worthless if u grab them they will twist out of center . i put the alumium ones on they are great . now i guss i got 2 get the metal main head

danlee1

Has anyone had issues with the rudder servo linkage not being long enough? I bought the recommended servos and the tail responds very slowly and not too smooth throughout the range. I thing a longer linkage would help but I'm curious if anyone else has had the issue. Thanks,

Dan

jaless

Dan,

See Trex build thread at http://www.trextuning.com/.

Look at build step 21. The links on the MX400 tail may be backwards. I have read that the grips should be in front of the leading edge of the tail blade. I happened to stumble on this last week and this change made quite a difference to the rudder control. Be sure to reverse the Gyro and servo if you make this change.

Joe

jaless

Dan,

After making this change I was able to shorten up the rudder linkage but there seems to be many opinions as to which way the blade grip should be. The trex build thread said it should be leading the tail rotor but on the x400 build thread it shows the grips trailing. Does anyone else have an opinion as to which way they should be? I have them leading and I did have to change the gyro and servo direction and also shorten up the servo linkage but my tail control seems to be better and more even in both directions. Lets see if anyone else has an idea. I am new to RC helicopters and I would hate to tell you wrong but this does appear to be an important issue that needs to be cleared up.

Joe

danlee1

Thanks Joe, I'll give it a shot and let you know.

Dan

spicy

Dan,
I had the same problem with the push rod. I made a servo mount for the boom out of thin plywood, some double sided foam tape, and a couple of plastic ties. I also made a new push rod and used a ball link on the servo. Its nice and tight and I now have a nice straight run for the push rod.

spicy

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tlrascal

My Feedback: (56)

eVERYBODY THAT DEFENDS hELIMAX ON THE plastic hub must not be aware of the problem. It will snap under the lightest load, it is pure junk and is going to hurt somebody soon. You can touch down lightly or spool up slowly and it is going to snap. I challenge anyone to fly one of these repeatadly with the plastic hub, it can't be done.

Shadrack

Could someone post a picture of the change they made to the tail rotor to give more play with the stock setup. I don't understand the trailing/leading aspect that you guys are talking about.

rwthomas1

I have the X400, the ARK version and have wasted three sets of blades crashing into bushes, grass and a tree. I am still using the stock plastic HUB! Soft start on the PX35 and no issues. I have probably 8hrs of hovering and some repeated hard landings. No issues other than blades, feathering shaft and a flybar. There is your challenge. RT

spicy

Shadrack, these are for you. Leading simply means that the ball link that controls the pitch of the blade is in front of the blade, Trailing would mean the ball link would be towards the trailing edge of the blade. My setup is leading the blades.

TITANFLYER

I have flown heli for ten years and flown just about all of them if you want an electric micro heli get the trex a little more money but it goes a long way. Im tired of the helimax problems and poor support.

spicy

Titan, do you have a MX400? Your advice really doesn't help those of us that do already own them. It would be helpful if you would share your experience on setups, etc, instead of implying that we should throw all our heli's in the trash and buy a Trex. So far I have had very good luck with my MX400.

TITANFLYER

NO not a mx 400 but my experience with the tech support from helimax has been the poorest iv ever delt with. They tell me they will send a pick-up ups and 2 weeks later nothing. so i call and they tell me that they mailed it but it could not be delivered because the mail man could not find my address. BULL SH_T we are the largest auto repair facility in the region and receive and ship mail daily. They said they sent it but my mail man did not deliver because they could not find that adress. THat is a straight faced lie from the manager at hobbico. hE SAID HE WOULD E-MAIL A PHOTO OF the returned letter never got that believe it or not the people at tower/hobbico are dishonest and sell in my 25 years of modeling experience the lowest grade of RC products available. Sorry to tell you got the junkyest rc micro on the market read all the other posts. Im just trying to save any others that have not spent the money. One bad purchase for a newbee rc r can devastate their modeling experience. Sorry to ofend you and your heli

spicy

The MX 400 is a re-branded version of the ARK X400. In my humble opinion it is a fairly good quality helicopter. Yes, I have had a few minor problems, but overall it has been a good heli. This heli is not comparable to the Helimax Rotofly.

Titan,
Sorry you have had such a bad experience with Helimax customer service.