Project Ringbearer: TLT-based leaf sprung monster

[Mad Ax]

So, what do you do when you're 95% complete on a bunch of fun little projects and the workbench if overflowing with parts that you don't want to put away until you've completely 100% finished those projects?

Drag a load of parts out of storage and start a new project!  Right?

...right..?

Here's one I've had on my to-do-list for an absolute age.  I found all the parts for this while I was looking for something else around 8-10 months ago, and I made sure to put everything nearby so I could get at it when I wanted to start it properly.  Which of course meant that when I wanted to start it properly yesterday morning, I had to shift around 2 dozen huge boxes in a terribly confined space to find the axles, which were right at the back of the storage area, in the most inaccessible place, right at the bottom of a stack of boxes, and still attached to another unfinished project.

Anyway, enough waffle, let's start at the beginning.  This is the box that I dragged down from the more accessible location:

And this is the joy contained within.  A Super Clod body (actually that wasn't in the box, it was in a Super Clod box, along with my other Super Clod body), some HPI Mud Thrasher tyres, some Axial SMT10 wheels, a TCS X-Trail chassis and a set of 4 leaf springs and shackles that I randomly bought online around a decade ago (supplier unknown).

To find the axles, I had to dig even further back.  I'd originally thought I had a set that weren't attached to anything, but of course I used those already - one the front of the Grand Hauler tipper truck, and one on the front of the 6x6 tow truck.  But, right at the back of the storage area is this old thing:

[Mad Ax]

The old Wildcat isn't really that bad of a rig, it was just never properly finished and was quite badly flawed under the body.  Not fatally so, but I lost enthusiasm to finish it half a decade ago.  Maybe I'll give it another go some day with a proper chassis - the Reign K2-3S-based custom rig here has some flawed geometry and the suspension is hard as rock, so it always handled terrible.

On the plus side, I found a D-99X low-profile servo in it - bonus!

This is what I was after - a set of TLT axles.  Lockouts fitted to the rear.

Before I got too heavily in to the build, I pulled the rear axle apart to check why the diff was locked.  Back when I built the chassis originally, I had a habit of locking everything up solid - not ideal for a car designed more for rally-raid than for crawling.  Fortunately I hadn't filled it with epoxy - I'd just inverted one of the pinions.  I unlocked the diff and stuffed it full of Blu-tac to stiffen it up.

I had drilled the topside of both axles to have inline screw holes, for mounting the shocks, but I hadn't drilled them well and I figured I wanted a perfect mount for my leaf springs if the axles were to be square.  The underside of the TLT axle has perfectly-level screw holes that are conveniently just the right spacing for my springs.

[Badcrumble]

Aw, the Bowler loses its axles . A Kamtec Bowler was the first shell I ever painted, mine sits on a TL-01! So not that capable either .

Looking forward to seeing the progress on this one - and you already have a name for it!

[Mad Ax]

OK - here's what it might look like when done, although with some arch gap:

such was my hurry to take these photos that I didn't notice until later that I'd put the wheels on backwards, and had to shoot with the axles the wrong way round

I quite like the stance and width here.  I was trying to go for an early monster truck look, before they went all big wheels and tubular chassis - around Bigfoot 2 era.  So I didn't want to go excessively wide.  I think this look is pretty good, although I will have to fit wheel spacers if I want to increase the steering angle - as it stands the wheels can hit full lock without touching the leafs, but standard TLT steering is limited and I might have to do 3point turns to get around my lawn.  Unless I buy new cases for the rear axle and go 4ws, like Bigfoot 2 had (IIRC).

This is roughly where the springs need to go, although the chassis is too wide at the moment, so will need new crossmembers.

[Mad Ax]

The chassis rails, for those who care, are TCS X-Trail.  These were a conversion available to turn the original AX10 rock crawler into proper scale rig, back before the SCX-10 was a thing.  I bought a couple of sets BITD, and these have been lying around mostly unused for an age.  They're perfect for this conversion, as they're cut from 3mm aluminium, unlike mass-produced chassis rails which are pressed C-channel and therefore harder to make things fit into them.

This chassis needs a lift, so I mounted the spring mount down under the chassis rail.  The shackles that came with this kit are quite long, so I didn't need to drop the front of the chassis.

At the back end, I started by mounting the rear shackle on the stock chassis holes and cut a new plate to make the leaf mount from, but then I realised the front and back of the chassis are not actually level, and if I made it like this, the rails would be pointing upwards.

To get around this, I cut a new bracket plate, and carefully measured out a line to match the rear leaf mount with the front leaf mount

It took me a while to figure out how best to do that, before I came up with this idea - some aluminium L-section and a steel rule

It's hard to measure the wheelbase exactly, and some final judgement is always needed, so I gave myself various options.  The big mounting plate and the rear drop bracket can shuffle forward on the pre-drilled chassis holes, and each have 3 different options for mounting the leafs.

[Mad Ax]

Leafage screwed onto the axles for test-fitment

well, something like that...

With the concept proven, I tidied up the plates and made copies for the other side

the bench polisher got a quick workout

heck yeah!

[Mad Ax]

Starting to look something like a chassis now

The existing crossmembers were made from Delrin, and I have a suspicion they were made (badly) by me last time I used this chassis for something.  I tried using a cheap plastic mitre block to cut the rear crossmember down to size, but it wasn't precise enough and the Delrin block came out with an angle on it, which isn't really good for a crossmember.  It'll do for holding it together for now but for the finished model I'll make something else.

Up front, I used some alu L-section to cut some crossmember brackets.

And some 3mm FR4 to make the crossmember itself.

Wow, check out that crazy articulation!  This is with the primary leaf and two secondaries installed.

[ad456]

Shaping up nicely!

[Mad Ax]

Wooden blocks to lift the body - if I don't trim the arches, this is roughly where it will sit

And that was all I had time for yesterday!  But, all-in, that's a pretty good start to the project.

Still loads to do - it would be nice if this rig had a transmission up front and a transfer case in the middle, like a stage 1 monster truck, but I'll have to see what I can get hold of.

As for the project name - that's a story for another day...

[ThunderDragonCy]

This is ace! Top work making all those brackets

[Badcrumble]

Great work, your fabrication work just gets better and better!

You weren't wrong about Bigfoot 2 and 4WS...

[bRIBEGuy]

This looks good so far... fun project for sure!

It's been ages since I've seen one of those Reign K2-3S chassis!  I still have one or two of the K2-3L variants kicking around...

[87lc2]

Fantastic stance on this rig, nice work!  I much prefer about 1/4-1/2 of the tire tucked in the fender wells like the old school trucks had.  Square body GMs will always sit higher than the Ford due to the squared arches, I think it looks great where it is.  2.2 monster trucks are awesome, but every time I build one I end up selling it due to them being generally useless in real life.  They look cool, but don't crawl, certainly don't race so it leaves them in a weird no mans land as far as actual using them goes.  Guess they would make good mud trucks, but after putting that kind of time in no way I'm getting it muddy!

Awesome truck, can't wait to see more.  

[Mad Ax]

10 hours ago, 87lc2 said:

2.2 monster trucks are awesome, but every time I build one I end up selling it due to them being generally useless in real life.

This is the problem with all my monsters, to be honest.  Nobody here races them.  In fact I don't even know anyone local who has a proper solid axle monster truck, unless it's a broken vintage Clod that's sat at the back of the workshop for years gathering dust.

So they pretty much get run around my garden, or sometimes I'll take them to the hills where I walk, if it's been dry and the grass is short enough.  There's lots of space there for the bigger trucks to really stretch their legs, although it gets boring as it's mostly flat and there isn't much to do unless I take the ramps also, which makes it much more of a mission.  The only other time they get run is at rare bash events, where they're being run alongside Traxxas and Arrma type vehicles, so I'm always the slow guy who won't do the big ramps over burnt-out 1:1 cars.

2.2s with slower motors are perfect around my garden, although the lack of steering lock can be a problem, hence why I'm considering 4WS on this one, as the leafs will prevent me from increasing the lock on the TLT axles.

That said, I doubt this one will get run very much - I don't want to trash a Clod hardbody too badly, even if it is a later Super Clod type.  I just hope it'll give some nice scale action on the lawn, some low jumps and some car crushing, like it was back in the 80s.  I doubt those leafs will be up to heavy jumps.

[Busdriver]

Great looking truck. Much more my style than the super jacked spaceframes. Maybe I’m showing my age but this is what I mean by a monster truck!!!

[87lc2]

4 hours ago, Mad Ax said:

This is the problem with all my monsters, to be honest.  Nobody here races them.  In fact I don't even know anyone local who has a proper solid axle monster truck, unless it's a broken vintage Clod that's sat at the back of the workshop for years gathering dust.

So they pretty much get run around my garden, or sometimes I'll take them to the hills where I walk, if it's been dry and the grass is short enough.  There's lots of space there for the bigger trucks to really stretch their legs, although it gets boring as it's mostly flat and there isn't much to do unless I take the ramps also, which makes it much more of a mission.  The only other time they get run is at rare bash events, where they're being run alongside Traxxas and Arrma type vehicles, so I'm always the slow guy who won't do the big ramps over burnt-out 1:1 cars.

2.2s with slower motors are perfect around my garden, although the lack of steering lock can be a problem, hence why I'm considering 4WS on this one, as the leafs will prevent me from increasing the lock on the TLT axles.

That said, I doubt this one will get run very much - I don't want to trash a Clod hardbody too badly, even if it is a later Super Clod type.  I just hope it'll give some nice scale action on the lawn, some low jumps and some car crushing, like it was back in the 80s.  I doubt those leafs will be up to heavy jumps.

The 4WS will definitely help get around the garden without too much backing up.  I feel the same way about the RC monsters.  If I didn't race them I probably wouldn't be as into them or have so many.  I rarely take them out at home unless I'm testing a new chassis since it's not much fun to just run them around on flat ground.  When I'm home its a lot more fun to drag a crawler or buggy out.  

Either way I'm really looking forward to your progress on this, its off to a fantastic start.  The stance & width of the axles are just perfect.  

[OldSchoolRC1]

Love to see some TLT's get some use. The axles that started the crawler craze! Looking great with the leafs installed. 

I kinda agree on the monsters...I never really thought about it, but both of my 2.2 monsters are pretty dusty. Can't tell you the last time I dug out the SMT. 

[RustyHunter]

That looks really great, and I'll be curious to see how the leaf springs do. The build looks really good, and that's half the fun, right? Probably not the end of the world if this doesn't get run that hard.

[Mad Ax]

I usually go out for a walk after I've finished work on Fridays, but this week my wife was going out so I needed to be home to do the evening school run.  What better way to pass the time than to get up in the workshop with some warm clothes on and start wrenching on a project?

Here's where things started:

This is the Delrin crossmember on the back of the chassis.  I'd originally made this when the chassis was wider, and tried to cut it down with a mitre block, but (you can't really tell from the photo) the mitre block wasn't really fine enough for a junior hacksaw and the cut wasn't straight.  Add to that, the original screw holes drilled in the ends weren't straight either, so having cut the Delrin down by 10+mm, they no longer lined up with the holes.

I figured I'd get around this by making a new crossmember from 3mm FR4 sheet.  For that, I'd need some more brackets.  I used the chassis as a template to drill the holes, giving me plenty of options for adjusting the back end later if I need to.

Brackets cut, tops and sides drilled

And fitted.  Finally the chassis is starting to feel rigid.  The suspension is very bouncy - the leafs (with 2 supporting leafs under the main leaf) are quite stiff and don't really compress much when dropped (admittedly the chassis it still very underweight) and it seems a lot of bounce comes from the tyres.  They have no foams installed and are quite rigid.  But that's a problem for another day.

[Mad Ax]

Today was Workshop Sunday, and as it's been a long week with its share of hardships, I was quite keen to get in there as early as possible, light the fire to ward off the winter chill, and start doing something to help me unwind.  That something being: making a monster truck.

I started by making these brackets for the centre floor.  This is where the transmission and/or transfer case will be mounted, depending on which drivetrain solution I go for.

Various holes drilled, mostly to allow the side plates for the rear suspension to move forward, in case I need to shorten the wheelbase later.

I found this removable ziptie in the box of parts from whence came the axles.  Not sure if this might be a standard TLT part?  It was useful for holding the chassis rails at the right distance so I could drill the hole for the floor pan.  I went with a long floor, but possibly I'll have to change it depending on what transfer case I use.

Having real trouble getting my countersink to work smoothly.  I read that going fast and hard was the best way to avoid chattering, but I found that going super slow and waiting for it to take off any edges its created worked better.

Lightly polished and fitted.

It really feels like a proper truck chassis now!

[Mad Ax]

Next - shocks!  The leaf springs are more than enough spring for the truck, so I just wanted something for damping.  It needed to be scale-looking, and fit between the big wheels and the chassis without rubbing.  I first went for a set of white internally-sprung shocks that I've used on scalers before, but I know them to have poor damping, and the pistons were drilled ages ago for another project.  Then I found these in the parts stash:

They are original TLT shocks.  I've not been able to use them for an age, as I foolishly lost the springs and spring cups a decade or more ago, but I don't need springs for this project, so they're perfect.  They look awesome and are the right length and scale width.

Using the stock TLT shock mounts, the hoops are too far forward on this chassis - but that's a problem for later.  Watch this space...

Rears look better, as the axle is better aligned with the stock hoops.

There...

[Mad Ax]

OK - how do we fix those front shocks?  If I pull the top mount back, the shock fouls the wheel on full lock - so I need to move the shock inboard a little.  Using a longer bolt, I can position the shock over the spring.  It all just about fits without fouling.  I'll put a spacer between the shock mount later to stop it collapsing.

I cut this extension to move the shock top mount backwards.  It's a bit ugly, but functionally it's fine.

Making a mirror of the bracket for the other side

Finished and polished

et, voila

[Mad Ax]

With all that done, it was time to go back over the suspension again.  So far it has all just been dry-assembled with no spacers or bushes just to prove the geometry.  Oddly, the leaf spring kit didn't come with any spacers at all, so everything had to be made.  This week I took delivery of some brass tube with a 4mm OD and 3mm ID.

This isn't it, by the way.  This is a standard Tamiya shock mount tophat part, perfect for preventing the shock mount from collapsing.

This is the front spring shackle.  The back end is mounted using plates made from 2mm alloy, but the front end mounts direct to the chassis, so it doesn't line up quite right.  Here I was going to have to do some more fabrication...

I had some offcuts of 2mm alloy left over from making the rear brackets.  These were perfect for remaking the front spring hangers in the correct thickness.

I had an almost overwhelming temptation to draw a smile on the left one and a sad mouth on the right.

[Mad Ax]

OK - now to bush up the front end!  Here's my 4mm brass tube, cut with a pipe cutter and tidied up with some drill bits.  I find a large (8mm) drill bit is perfect held in the fingers to cut off the nastiness left by the pipe cutter (I can hold the bush in my Tamiya shock  shaft pliers), then use a 3mm drill bit in a small electric screwdriver to open out the internal hole again so a screw will pass unheeded.

Push-fit in my new hanger

Mounting on the chassis

Perfect!

[Mad Ax]

At the other end, I cut another bush to go in the end of the spring

And at the top of the shackle, a wider bush to allow the shackle to sit 2mm away from the chassis, where it naturally wants to be.  Now the entire front end is torqued up properly and everything moves freely with little play.

The rear end was a similar story, except I didn't need the additional 2mm on the shackle top bush as there's a piece of 2mm alu plate between the shackle and the chassis.

There!  Suspension-wise, the point is pretty much proven.  I have considered adding some torque links, as the original monster trucks has these, but I'm not sure if they'll hinder the suspension movement.

Also replaced a lot of the assembly cap screws with button-head screws, as these are much neater.  Definitely looking proper now!