Scalextric MG Metro Turbo makeover++

[Kevan]

Take a drab 35+ year old Scaley MG Metro and give it some oomph!

I'll keep the body and skirt mold and front wheels/tyres as nothing else is raceworthy.

First off that chassis, let's design something more akin to a Slot It product, removable pod with rear suspension. I wanted to limit the maximum width of everything under the bodyshell to 54mm for our club rules hence why the wheels sit inboard a bit. There are two lead ballast pockets either side of the pod that should be about 10g per side.

Next I modified a pod design slightly as I wanted it to be removable rather than printed as part of the chassis like most of my other 3D chassis. This is now a 3 part chassis/pod/suspension bar.

Club rules for these little cars are inline motor so my preferance is a 'C' can. There's an old SlotIt motor in at the moment but much better choices available, it won't be anything over a 22k as that's a pointless exercise and proven not to be quicker...slower in fact and a tyre shredder.

Front axle is sleeved in an 1/8" brass tube, adjustable height with grub screws then glued in place once the glue/trueds are in and front rideheight set to 1mm. I could use alloys here and have individually rotating wheels but that may come in the future.

Rear bearing blocks to suit NSR bronze bearings held in place with a two part pillow block then glued in place.

Next job was to make it look more like a 6R4, side air intakes were realively easy to draw up and 3 trial prints later I was happy with them. I didn't want to obscure the side door livery too much so these air intakes are a little short on length compared to the real car...what am I saying, this IS a real car...just smaller

The rear arches needed raising so used photos of a real real 6R4 to get the profile by importing the photo into Inkscape and saving as an SVG file to be imported into Fusion then a spline drawn along that profile to create a virtual pastry cutter...the rear was easy, the fronts however were a 3D head scratcher.

Rear arches printed...glued them onto the removable body skirt...looked great. Front arches needed the dremel to fit satisfactorily then glued in place.

Rear wing...I found a 3D mesh file of a 6R4 rally car and the wing was easily detached, opened in Meshmixer, made 0.8mm thick then saved as an .stl for Cura. Once glued in place the overall look with the other addons was racey!

Fit the body mounts to the chassis, sit the body in place then glue the mounts inside the body. These flexible body mounts are glued at the ends only so the body can move a little.

Fix body to chassis and now those arches needed grinding out. I tried a new idea for me, a long axle through the car, large diameter alloy wheels slid over the ends and pushed up to the body, draw a circle round the wheels with a sharpie then grind to the lines.

Some filler and a couple a coats of enamel paint and it's ready to wire up for track testing. I may fillet the joins to the body with UV glue then paint over to hide the gaps.

The front wheel arch mods were a pig to do but overall I love how this looks and can't wait to get it running.

...that guide is one I've printed also and deep enough for Scaley Sport.

Overall one of the longest builds I've ever done due to the body bits, it's not so easy when you're trying to learn how to do something new and having to look through Youtube videos on how to do what is basic stuff...like using a pulled spline to cut through a shape that is already shaped at an angle. Lots of learning going on here for the future and really enjoying this relatively new part of my hobby.

[-nimrod-]

Hiya Kevan,

Nice work on the body pieces but that chassis looks GREAT!!
How well does it run?
How easy is it to adapt to other small cars?

Cheers
NimROD

[Kevan]

Thanks.

I think that's a 23k slot it motor, far too much for one of these but when I turn the power down on my controller enough that it is still accelerating at the braking point at the end of the straight then it drives really nice.

Sadly that guide snapped right across the front, it was one I printed with the blade pointing vertically, a stronger one printed at 45° should be better but did break in my hand when I forced it. A new orientation of 45° from vertical and horizontal feels stronger again.

As far as modifying it is concerned, the first few chassis I printed were one file, what I've done now is save separate pod and chassis files then I can just import a pod into a chassis which saves a few hours.

I name all my chassis with the wheelbase included then start with one nearest what I need then shorten or lengthen the past between the front axle mounts and front of the pod.

The longest chassis was the Studebaker and the shortest so far is this Metro which was a slightly shortened (0.9mm) SCX Abarth 124 chassis. That has an orange Pioneer 19k motor which is a nice smooth motor for smaller cars. Not as good a performer as an 18k H&R though 😉👍

Here's the inside view of the Metro chassis:

[Kevan]

I just measured the chassis, the narrowest this design could go is 30.7mm but would require body mounts down the centre as per RTR cars.

...I do however plan to look at creating something for older pre-war GP cars as they're one of my favourites.

[Kevan]

Just for a bit of fun I wanted to stick a V6 in the back, sadly couldn't find a 3D file of the 6R4 so made do with a V6 powered Kart, deleted everything except the engine in Meshmixer. I don't know what I'm really doing in Meshmixer so exported an .stl file to open in Cura and scaled to fit inside the car. There's obviously some 'holes' in the mesh but it printed enough to make something resembling a V6 which will look better with paint. Meanwhile it's been ground to sit on the top of the pod and held with superglue...fun and games when the motor/gear needs changing!
I'll probably print another and mount it on a removable card.

[-nimrod-]

Great stuff, perfect fit, will you paint and detail the engine?
Icing on the Metro Cake

Cheers
NimROD

[Kevan]

I was thinking of yes, silver & red should be the majority.