Anthony's MST FXX-D

It's finally here! MST's FXX-D RWD chassis kit. Unlike the Wrap-Up Next FR-D that is a conversion, this is an ARTR kit. First thing I noticed is that there is no motor plate to bolt. The FXX-D features a clamp style motor mount. Pro of this will be easy install for the motor, but a possible con is impacts may cause motor to shift and worst case, chew gears.


Unlike MST's regular ball joint suspension, the FXX-D features pin/hinge style suspension. Same parts that were used for the XXX-D HT suspension.


The FXX-D comes with Plastic uprights to keep the cost down, but have the same dimensions as the new MST KPI Uprights.


The steering design is quite standard. It does feature an offset mount, so by switching it around, you alter the position of the entire steering assembly. Unfortunately the center bridge is not length adjustable for altering Ackerman independently. May I add though that It does come with a second "Ackerman" option hole setting... However this option hole is not useable out of the box. I will get into detail about this when I dissemble the FXX-D.


MST has made specific front axles for the FXX-D, it certainly looks a lot cleaner. The additional rotational mass may be a bonus as well.


Both the upper and lower suspension arms are pin/hinge style, which is great. It helps maintain proper tolerances longer.


Given out of the box is a 30g ballast weight, and you can see the rear-front suspension block is -.5, with the rear-rear block +2.5, giving an effective 3* toe in.


Extra diffuser hole set for optional diffuser. You can also see the 2.5 rear-rear suspension block, with the rear-front being -.5, giving an effective 3* toe in.


The rear diff is a standard ball diff, composed of plastic housings. This may be a shock for some people, but the theory in this design is to act more like a Limited Slip Differential (LSD).
Luckily the plastic diff was given aluminum diff out drive covers to pro-long life and help endure stress.


And finally the transfer case. The transfer case is also composed of carbon gears (the larger two), mating against steel gears (motor pinion, and the smaller gear). Pro of this design? It's a lot more spacious so maintenance would be easier, however, the gears are not standard "Pinion" gears. they are MST FXX-D specific gears, which as of now, has no cross referenced part with any other chassis.

Ugh!!!! I want one so bad. It's so nice looking!

Are you planning to do any upgrades?

[Chiefy707]

Great pics. The quality of the mouldings, machining, and anodizing look even better than on my XXX. How about a 50/50 4wd conversion lol?

There was a cs kit leaked with pictures on facebook


Sent from my iPhone using Tapatalk

superb

The front suspension blocks come with +0.5 blocks on front-front, and front-rear.


9 screws and the top half is off, which makes maintenance a breeze.


Shots on how spacious the transfer case is.



Caster can be adjusted by multiple ways: Typically the lower arm can be shifted forward or backward by changing the spacers around. Then there is the upper arm. On this design, the pin actually stays put. The arm is 2-piece, thus you are able to space it to adjust castor.

You may either flip them from right and left, and/or add spacers.




2 screws on the bottom
4 screws on the top
and the transfer case is out!
Honestly I think this is the highlight for me, with past experience with the FR-D, I have to maintain the transfer gears regularly. It was a pain before, but i have gotten used to it and found the easiest ways to go about it. For someone who find that irritable, this would be a big Pro factory for you.


Back side of the transfer case.


Here is the steering assembly pulled out. Also very easy to remove.
As mentioned earlier about the offset mounts (Visible at the top, unit is upside down). This helps a lot when trying to adjust your Ackerman and steering throw. It's unfortunate that you can't adjust Ackerman independendly via the center bridge... Anyways, the center bridge does have two choices in placement which would affect Ackerman, however there is a male and female side to this connection between the center bridge and the steering arm, and only one hole has it... Even if you were to space it correctly, the center bridge cut outs that wrap around the post would no longer wrap around. My only assumption is that MST will release an optional center bridge.


The FXX-D is able to run batteries across the chassis. This was achieved by elevating the main drive shaft above the battery. In order for them to connect it to the final drive without distorting the CVD's, they angled the diff pinion gear and utilized an universal joint. Thankfully they used C-clips rather than grub screws!

The photos you've taken is quite nice. And the chassis itself is better with silver than red (IMO). Have you tried driving it?

Such an awesome write-up. I always learn so much from just reading through your threads Ant.

Thanks guys! Let's move on to building it back up!

MST suspension arms uses 2.5mm suspension pins.
Side by side with WUN Intel Y arm



Profile shot of MST and WUN Intel Y Arm, as you can see, the suspension axis is inline with the King pin for the WUN, but for the MST, the axis is more inline with the damper mounts.


The WUN Intel Y arm is narrower by 2mm


WUN Intel Y arms installed.


WUN VX rear arms installed.


Back up with WUN Intel Y & VX arms, Yokomo Dampers, Vertex RC Adjustable post, MST diffuser, and stainless steel screws as always.



Took out the plastic KPI uprights and added MST short uprights (I prefer these)


Mark II almost done!

Awesome build and great job cataloging the build up