White Lightning - Lunchbox-Bodied Solid Axle Truck

[Mad Ax]

What do you do when you've already got a million half-finished projects on the go, you've just pulled apart your only functional big-rig, and you've still got 3 race events in the next 2 months, all of which need different cars setting up for?  That's right - you start another project!

I actually go have a few good reasons for starting this one now: it's going to be part of the Globe Liner refresh that's had my attention recently, I'd like to have it ready for the winter trucking season, and it's going to need the same paint as the Globe Liner, so it can all be painted at the same time.

Also an NIB body came up on here a few weeks back, which was the trigger, plus the MST narrow axles were back in stock at Green's Models, and I've always been kinda nervous that they'll be discontinued, making it difficult to finish this rig if I don't dive right in and buy the parts now while they're there.  And I had the money spare from something else, so it make sense to make a few purchases.

So, what's the deal with this thing?  Well, it's going to be a solid-axle monster truck wearing a Lunchbox body.  I'm not intending for it to be a good performer - or even much of a runner, if I'm honest.  It'll mostly just be a demonstration piece that sits on the back of my Globe Liner's low loader trailer.  I'll be able to drive it on and off the trailer and park it on the layout, but it won't be used to wheelie or jump.  Motor and gearbox will probably be the 380-sized unit that came with my FTX Outback 2 last year - in fact the entire Outback 2 was supposed to be a donor for this very project, until I turned it into yet another scale rig.

Style-wise, it'll mostly be based on the original Rollin' Thunder, but design-wise it'll be a sort of Stage 2 / Stage 3 crossover - I'll be going with 4-links for cost and simplicity, but keeping the articulation relatively low, like a leaf-sprung truck.  I might even add in some faux-leafs if I can find a good donor material.  Axle-mounted shocks will keep the articulation low.  They'll be hard to tune, but as this won't be a fast runner I can add plenty of ballast, which might help with the slow-speed scale movement too.

Finally, the name - I wanted this truck to be Ford Diamond White, to match my Globe Liner, with similar blue details.  Around these parts, White Lightning was a clear cider with an alcohol content high enough to clean the oil off the driveway, famous for its appeal to underage and antisocial drinkers.  There was briefly a 1:1 monster truck called White Lightning, but this one will have no connections besides the name and a roughly similar livery.

So - where did it begin?

Well - I originally bought a set of MST MSA axles a while back, specifically for this project, but then I used them on my hillwalking rig instead.  So, before I bought another set, I figured I'd try them out for size.

Here's my hillwalking rig, upside down, so you can see the nice narrow rear axle.

Here's my unused Lunchie body sitting over a set of Fastrax crawler wheels and Proline tyres on my upturned hillwalking rig.  These axles would be too wide for a scaler build (unless it was a very jacked up and widened scaler build) but they should be OK for a monster truck build.  It'll be hard to find anything smaller unless I get someone to measure those PUDG pickup truck axles.

So I'm guessing these axles will be OK.  Next decision is - what wheels and tyres to use?

[Mad Ax]

Here's a set of Wild Willy 2 wheels and tyres mounted to the MST axles.  The track width is about as good as it'll get, but the tyres are too small for a scale MT build.  Eyeballing some photos of Rollin' Thunder, the tyres are about as tall as the body.

These are HPI monster tyres mounted on SMT-10 wheels.  The SMT-10 wheel is an oddball, being very wide, but these tyres can be made to fit by using the inner bead as they have such a deep sidewall.

I think these look about right.  I'd like them just a touch wider, but beggars can't be choosers, and maybe I can balloon them with some fatter foams.

This was around a week ago.  The SMT-10 wheels and HPI tyres are currently in use on my Clod-bodied Stage 2 monster truck, so I need to find new wheels and tyres in the same size.

[Mad Ax]

Once I was happy with dimensions, I ordered a new set of MST MSA axles, and then I managed to find some neat 2.2 monster truck wheels and tyres on Aliexpress for not much money at all.  I placed an order, assembled my axles, then sat by the front door, shivering with excitement, until the postman came.

And here they are.  White wheels (perfect), BKT-logo tyres (not entirely correct for an 80s truck but works well enough), plus the wheels also have screw-on planetaries moulded in black, which look awesome.

However, just like the HPI tyres, they have this humungously deep widewall, which just doesn't look right at all to me.  Also the wheels had a very narrow offset, so they were tucked a long way in under the body on the narrow MST axles.  I was very excited to get these tyres and see what the truck might look like, but IMO this just looks like a cheap toy.

[JimBear]

Great stuff! Right up my alley - I am trying to figure out what to do with some CR-01 axles ... so this provides inspiration.

[Mad Ax]

There's more to follow on this - I started posting updates yesterday and then parenthood happened, I'll finish the thread over the next couple of days and hopefully get to work on the chassis this weekend.

[markbt73]

I like where this is headed! I think those tires on some wider/deeper-offset wheels might just be the ticket.

Also, this inspires me to get back to work on the CEN-based 4x4 Wild Willy that I started a year ago. What's that you say about too many projects going at once?

[Mad Ax]

OK...  Where did I get to?

Aah yes, that's right!  The wheels were too inboard for my liking, so I had to find something else.

I had 2 options: 1 was to use the wheels and tyres from the MTX-1 (or more specifically buy a new set, as I don't want to take the set of my MTX-1).  I'd already decided these would probably be too wide, but it was worth a try.

The second was to use my new BKT-branded tyres on some Axial SMT-10 wheels.  In fact my original plan had been to use SMT-10 wheels and tyres, but the tyres are like gold dust over here.  I'm annoyed that I don't have a set since the SMT-10 builders kit includes the wheels but not the danged tyres and they're literally the only tyres that fit properly on those wheels and you can't get the tyres for love nor money in the UK!!  Somewhere, somewhen, some board member said "hey, I've got a great idea...  how about we don't include the tyres..?"

Anyway, rant aside, I started by pulling 2 wheels off the MTX-1, and 2 wheels off the leaf-sprung Clod-bod monster that's been sitting 95%-finished on the log burner since the winter ended.  That would be enough to give me a rough idea.

Here they be.  One tyre is backwards because I only had one end of the leaf-sprung truck available, but that's fine.  Also I left the HPI tyres on because they're roughly the same size and profile as the BKT ones, so they'd be fine for a proof of concept.

On the other side, I put the MTX-1 wheels.  They have literally a flat rear face, so they stick out a long way even on these tiny axles.

By comparison, the Axial wheels have some offset.  In fact a little too much - the inside of the wheel rubs on the drag link on full lock.  I'll worry about that later...

Here's roughly how it might sit.  TBH it still looks a bit lame - this might be one of those projects that doesn't look right until it's finished, or, maybe, just never looks right due to the dimensions being slightly wrong.

Even the SMT-10 wheels sit in a little too far, but that can be fixed with some extended hexes, if needs be.  The MTX-1 wheels are too far out for my liking, although looking at a 1:1 comparison of the Rollin' Thunder truck, they're not far off true scale.  However they are really expensive to buy, so I'll stick with what I've got, and use extended hexes.

Here's a final shot with a BKT tyre installed.  Hopefully with some careful gluing they will look nicely scale.  Also I might have to wear down those huge chevrons - real trucks of the time didn't have big heavy treads like that.

Axial wheels are now on order - pending delivery...

[Mad Ax]

I was super-excited to get an early start in the workshop on Sunday morning, although my first plan of action was to finish the wiring on the Globe Liner (updates to follow on that later, when I find the time).  After that was done I threw what was left of Friday night's freezer pizza deluxe into the microwave, and the sweet potato fries that my daughter didn't finish during our trip out on Saturday into the air fryer, and piemunched the lot down while watching videos on YouTube.

After that, it was time to get started on the White Lightning project.

I began by cutting two pieces of L-section to make the chassis rails.  I figured I'd probably need to put a drop on them to hang the axles and transmission from, but this was a good start.

Next trick was to go find the transmission so I could work out how much drop I needed.  The transmission is in a big box marked "misc axles, chassis and transmission" - and in there I found a super-bonus!  These are Reign K2-3S chassis rails, which I bought many, many, many years ago for a TLT/Pede project that never got finished.  The last time these were used, they were on my Clod Buster - but they've been in the box for quite some time, completely forgotten about.

Here is the transmission.  This is from an FTX Outback 2, it's a dinky little motor so it won't be up to much speed, but that's OK since this is primarily for show.

I drilled into the Reign chassis so I could mount the transmission night and low.

[Mad Ax]

I had some trouble getting the RC4WD M3/M4 rod ends into the lower brackets on the chassis...

A few cuts with a craft knife solved that:

And now I can start mounting my axles!

It's not easy to see here but I mounted the front lower links inboard on the axle, using a spacer made from alu tube in the lower link mounts.  This gives a bit more clearance on the front wheels, although it's still not perfect - another reason why I'll need to space those wheels out a little.  Also the upper links are so short the RC4WD rod ends are stretched beyond their normal range (actually it's more like they catch on the axle mount - a set of cranked rod ends would be better) but it does fit, albeit slightly stretched.

And here we are - a rolling chassis already!  OK, there's still loads more work to do, but this isn't bad for 2 hours work.

[Mad Ax]

Note, however, that I had to take the transmission off.  There isn't enough clearance to get some of the screws for the links in, so I'll have to stand the transmission up to get more clearance.  I started work on a bracket on Sunday, but it was getting late and I was tired, having been on RC projects since 9am with only a short break to eat reheated junk from the fridge and stare at reheated junk on YouTube, to I decided I'd call it a day.

Here's some photos of the body resting over the chassis at what is probably the final position, or thereabouts.  I think it looks a lot better now, although the angle isn't great.  It's got that 80's sky-high look about it that was lost as trucks got more custom-built and more racy.

I still think it looks slightly narrow from the side.  In fact there's something about it that's just...  not quite...  right..?  I can't put my finger on what it is...

With the body lifted a little, the wheels no longer look quite so tucked under.  They'll need to come out a bit though, otherwise they won't clear the shocks.  I don't like using hex extender but needs must - I might be able to 3D print some to my own exacting specs, like I did with the F150 tow truck last year.

I had a note today to say my new wheels had been despatched, so I'll get the tyres mounted properly and have both sets fitted for another shoot, so I can work out how wide they need to go.

Watch this space!

[Grumpy pants]

Looks great already 👏

I wonder if the LB would look less narrow visually with the arch widening kit you can buy? 
 

[Mad Ax]

Updates!  New wheels arrived yesterday, another set of SMT-10 wheels so I don't have to cannibalise my leaf-sprung truck.

With the new BKT tyres pulled over, they look OK - I think the beads will need some work, but I'll work that out later - that's a problem for another day.  It looks a bit happier like this, though.

[Mad Ax]

This lunchtime I popped up to take a quick look at the rig.  I'd taken off the bottom plate so I could try to make a standup bracket for the transmission, but while it was off I realised I no longer need this to be a full-width chassis, if the transmission is going to stand up.

So I set myself the mission of making a narrower bottom plate in my lunchbreak.  I started with some tough 3mm FR4 sheet.

Then cut some L-section.

I had to call it after 45 minutes and go make some lunch, but I had some quiet time this evening so I was able to finish it.

[Mad Ax]

Here's a little look at how the transmission may or may not fit.  I also remembered I had a transfer case lying around, but alas it is a 6x6 transfer case, so potentially a bit much for this.  Still, it might be nice to have the motor and transmission up front where they would be on the real truck.  OTOH that's a lot of extra work for a rig that's mostly going to sit on a trailer with transport wheels on.

The body should sit roughly around here maybe

Now that I've got matching wheels, the width doesn't look so bad.

[Mad Ax]

I think the next challenge is the shocks.  I've got some 95mm crawler shocks that are about as old as the K2-3S chassis rails, they're terrible shocks but should be OK for this build, if I can find them.  So far I can only find 2, which is bizarre, I can't recall if I installed a pair of them somewhere else.  95mm is probably too long but I don't want a lot of travel on this truck, so I can space them internally to reduce the travel, or maybe even chop the springs in half to give them a droop setting without adding preload.

I've just looked at buying a set of 90mm Injora shocks but that's more money I didn't want to spend on shocks that will probably still be too long.

[JimBear]

@Mad Ax - yep, it does look much better with the new rim/tyre combo and the body sitting further back, especially if you want to catch a bit of the Rollin' Thunder vibe.

[Mad Ax]

UPDATES!  - and an Advance Warning - I'm on my lunchbreak and have to be at my desk in 25 minutes for a meeting, so I might have to abort this update mid-way through a sentence and run off to attend.

Anyhoo, was in the workshop bright and early on Sunday as I was keen to make some real progress on this rig before I had to call it a day, and, well, a month, since we've got family holidays, race meets, and my wife going away for a bit, so there won't be a lot of workshop time in August.

My first plan was to get some shocks on, as it's hard to really get a sense of what the truck looks and feels like when I'm just balancing the body on plastic blocks or holding it with my stiff and calloused fingers.  I had planned to use some 95mm internally sprung shocks that I've had for an age, but after spending an hour throwing the workshop upside down, I couldn't find them.  They'll turn up somewhere, but I wasn't prepared to abort the job, so I grabbed these 100mm Xtraspeeds instead.  I bought these a few years back as possible shocks for a Mod Clod project, although they weren't quite right for that rig.  They do look kinda cool tho, plus they're narrow enough to fit behind the fat tyres, and they'll look the part on a rig that's supposed to be leaf-sprung.

They are too long, for sure, but I figured I could put some travel limiters or change the springs to help with that.   With that in mind, I rooted around in my spares box and found all the spare springs for my 100mm Yeah Racing Desert Lizard shocks - these are a similar (but arguable better made) internally-sprung shock, which come with 3 different spring stiffnesses, in both regular and droop-sprung configuration.  Droop-sprung means the main spring is about 2/3 the length of a standard spring, with an extra 1/3 length spring which goes under the piston, to limit the extension but still allow some extra extension if the geometry demands (like a solid axle rig at full articulation will pull on the opposite shock).

Here's all the parts.

The MST axle kit also comes with moulded shock hoops, which were dead easy to fit to the K2-3S chassis.  I just had to drill 4 new holes.

Here's the shocks fitted.  Note I also made some closing panels for the chassis side.  Blue is the protective film, will be removed for the final version.  Geometry is a bit out as the links need adjusting, and the shocks are at full extension.

This is way too high, but there's loads of scope to bring it down.

This should be about right.

[Mad Ax]

Mega-bonus - the Desert Lizard springs fit perfectly in the Xtraspeeds, and with some green slime and soft MST oil, they work smoothly enough for a rig like this.

That looks better

While I had the shocks fitted, I thought I'd try something else - fitting the transport wheels.  Part of the point of doing this is so the rig can sit on a low loader behind my Globe Liner, but monster trucks aren't usually transported with the big wheels on.  For transport and moving them around the shop, they're either fitted with small tractor wheels or big rig wheels, depending on the axle.  Finding tractor tyres in the right scale was proving impossible, but these big rig rear wheels with some screws poking through the holes like studs look about right.

However there is a problem - the smaller big rig wheels don't clear the steering assembly.  So, it looks like we will definitely need extended hexes.  That's a problem for later...

[Mad Ax]

Next step was to finalise the body mounting position, and work out the mounting solution.  I started my making these brackets.

They screw up behind the side step and exhaust parts to give me something to mount the floor on.

I used 2mm FR4 sheet for the floor, as it's light, stiff, and easy to work with (although the sanding dust is toxic).

OK - hex wideners!  This is a Tamiya 10mm hex, with a barrel nut that came from an aftermarket extender (which was plainly never going to fit on these axles).

I drilled it out from behind using the drill press.  This didn't go entirely well, it's a bit off-centre - I drilled the others from the front and they are more centralised.

Fitted using the barrel nut and washer from the extender kit.

[Mad Ax]

OK - the body is now sitting way lower, it's probably too low like this.  It looks cool but the tyres will rub on lock or partial compression.

However it definitely looks a lot better with that wider stance.

Next trick was to mount the transmission.  I had opted at this point to buy another transfer case to mount in the middle, and put the FTX transmission up front.  However there were clearance issues with the body, and it was going to take up space where an interior might go, so instead I opted to fit it out back.  Certainly not standard, but it won't be visible on the finished truck and I can always put the battery out front to counter the weight.

I started by drilling some holes in some 2mm alloy plate.

Then filed it into a nice shape

Transmission now mounted in the rear

[Mad Ax]

More to follow - my meeting awaits!

[Mad Ax]

I had to take a chunk out of the floor to clear the motor, I'll probably have to take a little more before my work is done.

Next plan was to try to work out how to mount the body.  The design philosophy here is almost the same as that on my leaf-sprung Clod monster, the problem with that truck is I could never work out how to mount the body.  I'm pretty sure that's why it's been in the same place since October last year, unfinished.  So it was imperative that I got over this hump so as not to get similarly blocked on this project.

Since the end of the K2-3S chassis runs nicely to the end of the body, it made sense to tie the body to the chassis there, at least for a starting point.  So I added another bracket behind the bumper.

While I was at it, I cut a spacer to go on the front of the floor, like a lifting block, to get a bit of extra space between body and chassis.

So the finished bod should fit around here.  I think that's just about perfect.  You can even see the convenient holes in the end of the chassis rails.

[Mad Ax]

Two more pieces of aluminium cut and filed.

And fitted.  It was around 17:30 hundred hours pm in the afternoon at this point, and I had planned to finish at 5 so I could get cleaned up and ready to have the dinner on the table at 6.  I don't usually cook on Sundays but we'd run out of rice the previous day, so I had to cook the rice to go with our reheated curry.  However I was so close to finishing that I kept at it, getting more and more frustrated and desperate to finish.  As you can see, in my haste I made something of an error and drilled the holes of the brackets on the wrong side.  It doesn't matter, it'll never be visible when it's fitted.  Anyway, it's weight saving.  Practically Colin Chapman stuff, this.  Might have to add that missing 4th hole or the truck will lean over to one side.

Here it be.  Rear-mounted transmission looks crazy but it works (well, I hope it does, my transfer case is still in transit).

et, voila!

Perfect!

[Mad Ax]

So, there we are - I got finished just in time to throw some rice in the saucepan.  Also, as I came to take my very last photo of the day, my camera battery died.  I think that told me everything I needed to know.

What a day!

So, no more progress on this one until August - I'm away on a works trip tomorrow night and will be in a mad rush getting packed on Thurs.

When I get back, I've got to fit my transfer case and sort out some driveshafts - I think I've run out again - and work out a way of securing the body at the front.  Then it's a battery tray and electrics, and then it's all the fiddly stuff like final details, paint, scale accessories, and all the rest.

I'll see you all in August.  Please have some after-sun lotion ready.

[Mad Ax]

OK!  Here we are - today's updates, earlier than usual because I can't be bothered to do anything else right now.

First thing on the list was getting the transfer case in place.  Here it is - an Inajora unit, from Aliexpress, and a cute little thing it is too.  Not a lot of play in the shafts, a little bit of noise but not too much, and a lovely casting that looks like a real transfer case.

It has two threads on the bottom for mounting.

Inside it has nice chunky gears and full bearings, and a smidge of grease.  Probably just the right amount, tbh - the gears were all coated with a very fine film.