MX400 Thread

[Sev Fontaine]

By demand... here is my MX400 Thread

Quote:
Originally Posted by Sev Fontaine
Hello Luc,
I think you made a good choice as a first heli. I learned to fly helis on a Blade CP with no simulator experience. Note that I also fly rc planes of all kinds so that helps a bit.
I recently purchased an MX400 and finished building it last night. I hovered around in my basement to try and get things dialed in.

This is such a great hobby!
Welcome

Quote:
Originally Posted by Warren
Hey Sev,
Maybe something for a new thread - which 400 did you build - can you post any pics, with, maybe some specs for what you put in it !?!?!

[Sev Fontaine]

I recently purchased an original MX400 for 119$ (not the pro). I like the idea of being able to purchase my own motor and speed controller and the pro already comes with these. They would have been a waste for me.
After doing some research online and talking with some local previous owners I made a list of things that are highly recommended if not necessary.

First of all... the main hub on the head is plastic and has been known to break in flight. This has even happened in the past on the first flight so I instantly upgraded to an aluminum main hub. (about 25$)

It may be an ARF but I suggest you go over all of the screws to make sure they are tight. Any metal screws going into metal parts should be removed and reinstalled with some blue loctite (semi permanent). This is especially important for the bolts holding the tail blade grips.

For the gyro installation do not and I mean (DO NOT) follow instructions which call for mounting it below the main gear right next to the motor. This will cause problems in most cases... (interference, glitches, drifting, etc...)
I bought the aluminum tail gyro mount (about 8$) and mounted the gyro on top of the tail boom on the back of the main frame.

For some reason I was supplied with a tail pushrod which was too short for the conventionnal installation of the tail servo. So I also bought the aluminum tail boom servo mount (about 10$). This worked out perfectly for me since I can now adjust the belt tension without having to readjust the servo pushrod. I also just shortened the supplied pushrod and it worked perfectly.

[Sev Fontaine]

Here is a list of the hardware I used on my MX400

4x Futaba 3107 servos
G90 Eflite Heading Lock Gyro (using my transmitter to switch from rate to heading lock mode)
Hitec Electron 6 receiver
Align 420 LF brushless motor (3200KV, 26 amps) (designed for Trex)
Castle Creations Phoenix 35 brushless controller
Thunder Power 3S1P 2100mah LiPo

Upgrades:
Aluminum Gyro Mount
Aluminum Main Hub
Aluminum Tail Boom Servo Mount

The MX400 kit comes with a 14T pinion for the motor but this will only work with motors in the 2500KV range. I purchased the Align Pinion set (9T, 10T and 11T) and used the 10T pinion. It should be noted that I had to enlarge the hole in the pinion to 3.17 mm. I used a Lathe for this but a drill press could also work.

I was hovering around in my basement last night and am very impressed with how stable this heli is. Almost hands off hovering. Definitely better than my Blade CP (now sold).

[Sev Fontaine]

I don't have any pics at the moment so I'll post some tonight when I get home from work.

[Warren]

Thanks for all that good info ( I'm drooling at the thought - this is what I have in mind for the new year )...

I think that a couple of other previous "blade-ers" went this route, but they have dissappeared from the board..

looking forward to the pics !!

ps: you must have a good sized basement :)

[Sev Fontaine]

Here are the pics... as promised.
572573574

For the canopy I thought i'd experiment with paint.
I gave it a base coat in pearl green. Once that was dry... I sprayed water on it to form water drops. Then I lightly misted some gold paint from a distance. I waited about 5 minutes then very gently dabbed the surface with a paper towel (no rubbing) to remove the water dropplets. I let that dry for a few hours... applied the decals and then gave it 3 coats of clear.
I really like how it came out.

[cgroves]

Niiiiiice, that is a sweet canopy.

[Warren]

Thanks again Sev - veerryy nice paint work !

[Sev Fontaine]

I was recently flying at the RA center when a friend noticed that the bearing in my swashplate was coming out. I could have just glued it with CA, bought a replacement or even upgraded to an aluminum swash but for the price it made sense to upgrade to eCCPM (about 60$). The upgrade kit comes with a completely new upper frame, CCPM aluminum swashplate, new linkages including ball links for the servo horns and an aluminum top hat.
I picked up the kit at dynamic hobbies immediately after the RA center indoor event and performed the upgrade in a few hours. It was ready the same night for some more indoor flying at Carleton University. The upgrade does require a computer radio which supports CCPM 120° swash settings but that was not a problem for me since my Hitec Eclipse 7 transmitter works for airplanes, gliders and helis.
Overall i'm very happy with the results. In flight... it seems much more responsive and definitely locks in place in a hover.
587
One problem I recently encountered (unrelated to the CCPM upgrade) was glitching. Even though I use a Hitec Electron 6 receiver (dual conversion) I would get some fairly severe glitching when flying indoors. I tried repositionning the speed controller, rerouting the servo leads away from the speed controller and rerouting the antenna wire. All of these changes did improve the glitching situation but still didn't fully cure it. This weekend I added a ferrite ring to the speed controller lead and so far this has proven to work well. (see yellow arrow in picture for ferrite ring location) We'll see next weekend if the problem is cured or not.

[Warren]

Hey Sev,

Where did you manage to get the "ring" from ? I have been strip searching every electronics store in town for one, nobody carries them - tried an online order, but they never responded to my emails :(

( I have heard many good results from using them )

thanks,

W

[Sev Fontaine]

The Ring of Power was given to me by a fellow heli flyer. I believe you can buy them at dynamic hobbies but they were out of stock at the time. Just give them a call (I spoke to Neil... their heli specialist) and I'm sure they can order some or point you in the right direction.

[Warren]

Hi Sev,

are you still satisfied with your decision on the MX ? - any second thoughts or things that you would change now or have done differently............

just curious -

regards

[Sev Fontaine]

Not at all...
I really like the mx400 and am flying it at least twice a week. I did have a crash which broke the tail assembly and so I replaced it with a Trex 450 unit as it has an extra fork on top to take out some slop.
I haven't really had a chance to get it fully dialed in yet but my first impressions are that it really liven's up the tail. The yaw rate is definitely faster than before.
On a separate note... I never got the hitec electron 6 to run reliably in the MX. Even with the ring... I was still getting the odd glitch. Since I had a Sombra Lepton 5 receiver sitting around I threw it in there and it's been 100% glitch free since. Now I'd just like an extra channel for remote gain.

Another excellent upgrade is to change blades. The stock ones have quite a bit of flex and end up giving the helicopter a sort of "laggy" feeling. Great for a beginner but no good for a sport or more experienced pilot. Of course carbon blades are ideal but I went with trex stock wood blades as they are stiffer than the MX stockers.

[Warren]

thanks Sev - good to hear it :)