so are you happy with your x400/mx400?

[adam crosby]

well I like it but I have to admit it does have 3 problems
1. weak centre hub main rotor holder
2. weak skids and white plastic
3. cabin hard to fot over batteries

the first is overcomeable by upgrade to metal cnc


I really like it, how bout you?
adam

[a320jockey]

Hello,

I am really happy with my MX400 Pro even thought I am just hovering now, still a long way until being confident at flying around the park. I modified it in order to use the larger MX carbon blades by replacing the original ESC and motor with the corresponding parts for the TREX 450. This was mandatory since the larger and heavier blades draw more current which cannot be handled by the original motor and ESC. I also had to replace the short boom with that of the TREX, along with the blue CNC tail rotor and carbon blades. The result is a very stable machine which is helping me in learning to fly. I made these mods because the LHS ran out of crash kits for the MX (I bought the three they had) and dropped the MX in favor of the TRex which was more demanded by the local flyers.

I also had to replace the original canopy with a TREX because of lack of space for the batteries. In order to keep up with the MX look I transferred the stickers from the old to the new canopy and it looks good. In the end, mine is actually an MXREX, but still keeps a lot of the original MX. I did have a good introductory experience with the original configuration of my MXPRO (short blades and tail), but the need to modify after the usual learnin accidents resulted in a better machine which I fly at least once a week or whenever possible.

The bad part of the MX is lack of spares support, presently only Tower Hobbies seems to be the place where one can find M2 screws of different lenghts and some items which are unique to the MX like main rotor shafts, stabilizer bar paddles and drive gears. The rest is not a problem since many parts from the TRex work well. The other problem is that the MX replacement parts are more expensive, for example carbon paddle blades or main rotor blades cost more than twice compared to their TRex counterparts. Anyway I am still happy with my MX. I will need to see if I feel the same way when starting to fly the TRex which I presently have unassembled and stored.

Cheers,

Carlos A. Cordova
QUITO - ECUADOR

[equisol]

I love my MXs, I have three of them, they are great stable flyers and great for scale flying. I also have two T-rexes that I use to practice (one V.1 and a put together from parts one).
Overall the MX400 is more stable and more of a scale flyer than the T-Rex. Also most of the fuselages will fit the MX400 better than the T-Rex.
Mods I made on the MX400s:
- T-Rex canopy (fits better)
- Gorilla Gear
- Pro-gramable paddles
- K&B tail rotor blades
- 1 Copter-X head assembly (great price at 59.99), other 2 stock

Just my two cents.

P.S.: Original parts are all in stock at HeliDirect.

[istandalone]

overall, i'm happy. got the mx450xs and once all of the "issues" are sorted out it flies really good. parts are pretty cheap too. i've not had any main gear strip woes, but the skids are really easily broken. probly i'll switch to rex skids or gorillas. check out towerhobbies website. the price for the mx400/450 has come way down. you can get the mx540 arf for $150!! hell, at that price it's almost worth it to buy another arf just for parts.

[pam-mo]

Overall I liked my mx400 and would highly recommend one to someone who seriously wants to get started in R/C helicopters on the cheap ... $59.99 at www.towerhobbies.com (http://www.towerhobbies.com) ... it's a bargain for someone who is learning ... buy two and have parts on hand :-) and because it uses mechanical mixing with a lot more linkage than most of the popular eCCPM helicopters you'll probably be able to keep your servos after a bad crash :-)

I do think that a T-REX 450sa is overall a better helicopter but you should be able to bring some (maybe all) of your mx400 hardware over to a T-REX when you feel you need to get your dizzy on :-)

dislikes (strongest first)
1st - helimax speed control sucks (high internal resistance? cooks batt and motor. voltage cutoff way too low!)
2nd - short tail linkage (barely enough to setup w/ Futaba S3107 servos)
3rd - standard tail pitch slider seems to add a bit of stickiness (the hinged version is better)

NOTE: my personal feeling on the center hub is that a beginner is better off with the plastic one ... however I can see it being a problem if the user moves the pitch too quick (3D flight) or lands and throttles down into a high amount of negative pitch (I have done that a couple times and I could hear the stress on the head)

recommend
-phoenix 35 or 45 brushless esc
(get the programming cable and configure your castle ESC properly)
(I like setting my voltage cutoff on the high side @ 10 volts just in case)
-Align 430l 3550kv brushless "out-runner in a can" motor (pinion size?)
-check all the head linkage (mine had a couple screws that weren't tightened)
-tail-boom servo mount if your tail linkage seems a bit short
-stock pinion seems ideal if using stock blades with the pheonix 45 esc and helimax 2580motor


good luck to all and have fun :-) ...



BTW I crashed my mx400 good on Friday 2007-12-07
I was trying to hover stable against a cloudy darkened gray sky about 150' up and 100' out... taking some video with my CVS "disposable" camcorder... before I knew it all I could see was the tail boom -panic- before I could figure out the orientation I was about 25 feet up in a fast dive ... the battery and mx 400 need to be replaced ... but the rest of my gear is perfect ... if I were to buy all the parts it would probably cost around $50 ... but for $59.99 I can just buy a new one :-)
this has been my favorite helicopter to date ... I have put in around 5 hours of flight on it and only replaced the tail pitch slidder and added the boom mount for the rudder servo

not sure if I will do another mx400 or get a T-REX 450sa

pam-mo
Concept 30DX -R.I.P.
Nexus 30 -sold

[a320jockey]

Hello all,

just some hours ago while doing my usual hovering practice 30 ft up with the MX something happened, a bang and immediately a strange and sudden change in the blades' noise, like a flapping sound and it went into the ground, not at full speed however a hard hit into the pavement. After disconnecting the batt I went on to check the wreckage: a broken left landing gear, stripped top dome screw and a broken main MX carbon blade, the other one was also damaged. A more detailed inspection showed a missing pitch control linkage in the rotor head, the one which goes from the swash plate to the main blade control lever. Everything else was in place however both blade control arms were apart from their links as well, however it must have been a consequence of the crash. It seems the missing linkage went off the rotor head in flight causing the corresponding blade to flip, hence the change in noise and later flapping sound -the top dome was found displaced upwards on that blade's side, maybe hit by the blade's control arm suddenly going upwards- and control was lost. The rotor did not stop turning because of its rotational moment, which may explain the lower speed during the fall but the heli was no longer controlable.

Later I noticed that the ball link on the swash plate had its sides flat instead of round when compared to the other ones which were visible so it seems like that was the one which failed. I never found the complete linkage. Going back into my maintenance procedures I remember to have been working on these linkages, specifically on the swash plate links in order to adjust blade tracking which is the normal procedure, however I never took a more detailed glance into the ball links' condition. Lesson learned the hard way: always do a regular check of the ball links specially on the rotating segment of the rotor head, a flattened ball link can an will cause trouble.

The MX seems repairable as far as I can see: replace the landing gear, a new linkage set, new set of main and tail blades, however being so difficult to get spare parts for the MX at a decent price here in Ecuador, I may be declaring my poor MX a total loss and leave it as a spares source if I can get my hands on one of those cheap MX helis which pam-mo mentions. Anyway I had a really good experience learning to fly this small heli and would have continued to do so if this accident did not happen.

Cheers and happy flying to all,

Carlos A. Cordova
QUITO - ECUADOR
(Now-considering-to-build-that-stored-Trex-ha!)

[istandalone]

two things i strongly suggest doing to a mx series heli. one, remove the tail rotor shaft (the part the slider slides on) and polish it to a shine. that black oxide coating sucks hard. also, get some carbon rod for tail linkage and a dubro ball end kit. all told less then $10 for the rod and the ball ends, and i shit you not when i say it made such a huge difference that it could have passed for a new and better gyro and servo combo. very good authority.