Gauging interest: Greyscale Racing MR-CG chassis

[color01]

Latest update 11/04/07

Introducing the MRCG: A pan chassis aimed at open-class racers who need a lower CG, more responsive handling, and more tuning options than a standard Mini-Z.

(RM prototype pictured, final car will have bespoke MM motor mount)





This Mini-Z MR02-based chassis has the following design features:
- MM configuration for agile handling
- Narrowest battery configuration possible to increase responsiveness
- Long flex-plate suspension similar to Mini-Z F1
- Compatability with many rear suspension configurations: side springs, tri-shock system, disk damper, oil damper, or any combination of those
- Battery pack placed far more rearward than in Mini-Z MR02
- Adjustable weight bias by shifting battery pack fore and aft
- Electronics plate cinches down on any AAA or lithium-polymer pack that fits
- Front end allows ride height to be adjusted fully independently of spring preload and front end maintenance without kingpin removal
- Thin fiberglass tierod and electronics plate, minimal hardware used in order to keep chassis weight low
- Compatability with many servos and electronics packages
- 98mm wheelbase

Parts included:
- G10 fiberglass chassis pieces: Main chassis, Front lower bulkhead, 0°, -1° and 1° tierods, Electronics plate, Rear body/damper mount, Body mount clips (2), Flex plates (2), Rear pod bottom plate, Rear pod top plate (for disk damper), Rear pod top plate (no disk damper)
- Delrin pieces: Differential height adjusters (for rear pod; 4 settings)
- Aluminum pieces: Rear pod left and right side plates
- Hardware: Stainless steel screws and nuts

Additional parts required:
- Mini-Z MR015/02 front knuckles, kingpins, springs, spring perches, c-clips, rear ball differential
- Mini-Z MR01/015/02 wheels, tires, bearings
- Micro servo (no wider than 23mm), servo saver
- Receiver and ESC (or combo), compatible transmitter
- Mounting tape for electronics
- 130-size motor, 48dp 2mm shaft pinion
- Battery pack
- Body

Optional parts:
- Extra MR02 front springs and spring perches (for rear end tuning)
- Atomic RM DPSII spare parts set (includes the 3 plastic shock assemblies and 4mm ball nuts)
- Atomic RM DPSII spare spring set
- Atomic AR-071 4.1mm ball nut (for the 3 plastic shocks)
- Disk damper post, friction disks, springs (Atomic, PN Racing, etc.)
- Small 2mm washer (for disk damper)
- Kyosho MR015/02 oil damper or equivalent

Rear end options:
- Side springs (adjustable preload via threaded nuts)
- Side plastic shocks
- Center plastic shock
- Disk damper
- Oil damper
- Any combination of the above


The MRCG was intended from the start to be a versatile, durable chassis, which explains the KISS design and the preference for using adjustable rather than fixed standoffs and mounts. The rear suspension was designed to give the user full tuning freedom; with no other chassis are mounting points for extra springs, shocks, and dampers so readily provided. The front suspension employs two stacked fiberglass pieces to hold the kingpin, but these pieces are stacked underneath the knuckle to allow easy maintenance without extra disassembly. Part functions are doubled by design -- the servo strap is the tierod mount, the battery strap is the electronics plate, etc. -- to keep construction simple. All this amounts to an lightweight, stiff, easy-to-maintain chassis that you'll appreciate every time you visit the track.

[pchan0]

I'm in for one!

Wow! that looks really cool. I like it even more thyan the pro-z chasis.

[color01]

Thanks guys; I also should mention that if there is a lot of interest I will do an MR015-width front end and caster option parts for both widths. I will, if I can find time, CAD up an approximation of the tri-shock system to give a better idea of how the final product will look.

(Off topic note to pchan: check your email please. Thanks!)

[byebye]

I'm interested. Put me down on the pre-order list.

-Byebye

[color01]

Noted, thanks byebye.



An approximated and highlighted damper system (obviously the real stuff is black). Shims will be provided, and can be used to alter the behavior of the springs.

[color01]

Yeah yeah, more teasers... getting ready to buy a 4-axis CNC mill, so why not take advantage of its capabilities?




Rear end options:

Here's the basic rear end:


With side springs:


Side springs + oil damper:


Side springs + disk damper:


Disk damper + tri-shock system:


etc.





Mini-Z, is there anything special I need to consider (besides cutting costs) regarding selling this chassis through you? We haven't talked in a while.

[Draconious]

That tie rod final or temporary in the colored render?

Does the tie rod flex? If so that is going to act like an unbalanced spring from left to right...

If not.. its going to prevent the knuckles from moving up and down with the suspension.. unless there is another seperation between parts from that screw to the knuckle...

[arch2b]

it looks like the servo horn shoe has depth to it to account for that movement?

[Draconious]

Cannot see enough of the tie rod to tell, but it just looks like it has enough room for the arch effect in the servo horn...

[color01]

Drac: The tierod is raised above the knuckle level, just like the standard 02. It won't bend under suspension compression, because the chassis will bottom out before the knuckle forces the tierod upwards. No worries.

Arch: The servo horn shoe does have a lot of depth to allow for different servos and the height of the horn when installed in the chassis. Since it's open-bottomed, you can also take out the tierod without messing with the servo.