Big 6 - Custom 6x6 Element Enduro Scale Builder's Kit

[Mad Ax 10847]

My original plan was to mount the body with velcro tape under the door sills.  They're already starting to flare, so it needed something to keep it in shape.  I figured I'd build some arch liners while I was at it, so I started with a panel cut to fit nicely over the floor pan.  I would later remake this as a slightly longer piece.

Glue on a diagonal to hold the arch liner

The perspective is odd in this photo, but this is a 3D piece

thus

[Mad Ax 10847]

I needed some inner panels to hide the air gap, too

Cut to fit around the shock tower.  Hand in 10:1 scale.

Two inner panels made, diagonals glued

Starting to look like some kind of crazy thing

For my next trick, I had to bend the arch liners over in a curvy curve and then clip them down with clamps and crocodile clips.  Roar.

[Mad Ax 10847]

Then I had my first disaster of the day.  I had lit the log burner, and decided to hold the panel close to said log burner to aid the drying of the glue.  And it all sort of went a bit melty.  But it's OK, I can still use it, it won't show when the body is on.

Here's the non-wobbly side in place.

Gluing both sides together with a square bit.

et voila

You totes can't even see the melty bit.

[Mad Ax 10847]

I think that works.  I can use some rubber stuff I got years ago to close off the gaps, if I really want to.

Made a spur cover out of a Core RC paint lid.

Fits nicely

In this shot, the body was fitted with long Velcro strips the full length of the door sills

[Mad Ax 10847]

However, there were several problems with this.

1) the body will flare behind the arches but not at the back, where it curves around to the rear panel, so it's very hard to splay it out to fit, and hard to get it off again

2) the front of the body wanted to flop around a lot as it wasn't supported

3) so much heavy duty 3M Velcro was putting a lot of twist into the arch liner structure every time I took the body off, worrying me that it would eventually break

So, this is another entry on the rather long List of Body Mount Options I've Tried Before Giving Up And Fitting Posts.

flash flash!

It had been snowing on-and-off all day, so I took the rig out into the garden for a test-drive.  Well, I would have taken it out for a test drive regardless, the snow was a bonus.  Or a drawback, depending on whether I was taking cool photos or having a wet workbench.

 

[Mad Ax 10847]

Then it was time for a real test - putting the rig on the 1:10 scale mountain!

This initial climb is tough, and challenges all my rigs.  There's really only one angle where it will effectively climb, and getting the front wheels in just the right place is tricky.  The extra axle puts more strain on the steering, so that extra 20-ish% overdrive on the front is really essential to get it around the tighter spots.  Perhaps a steerable rear axle would be of benefit if I modify the rig in the future (if I ever get an Element Gatekeeper I'll do an IFS front on it, which will give me a spare steering axle).

Despite this, and despite the cheap tyres, the 6x6 made it up the start better than any of my other rigs do.

There's loads of twist in those rear axles.  I can't decide if maybe the springs are too soft - at first they seemed too hard (hence the angled installation) which would make sense, as the weight is spread over more shocks than the stock truck, but there's so much flex, which might be costing me some bite.  Maybe I'll tune the shock angles, but it's got to be balanced with the max droop, because the middle driveshaft locks up if it over-extends.

[Mad Ax 10847]

The truck seems to be able to withstand some series side angle before it rolls.  In fact it didn't roll once during the test, despite getting off the ridge in places and leaving over real hard.  Those close rear wheels and short wheelbase definitely want to railroad the frontend.

This is a big flaw with the rig, though.  The axles seem wide compared to my other trucks, and that reduces the breakover angle on the pumpkin.  Once this gets hung up, there's no way out but backwards.  Maybe a skid plate will help.

This section was tricky, as the grippy broken concrete blocks will swallow a wheel and lock it up.  I've broken a few diffs here.  However the Axial transmission in this truck has a slipper, and it was set too loose - so I had to give it a helping hand in places.

It would definitely have made this climb, if the slipper wasn't slipping.  Or shredded a driveshaft.

 

[Mad Ax 10847]

fin.

[Badcrumble 4422]

Massive update! All that work resulted in a very cool truck .

[BuggyDad 6380]

8 hours ago, Mad Ax said:

Then I had my first disaster of the day.  I had lit the log burner, and decided to hold the panel close to said log burner to aid the drying of the glue.  And it all sort of went a bit melty.  But it's OK, I can still use it, it won't show when the body is on.

Here's the non-wobbly side in place.

Gluing both sides together with a square bit.

et voila

You totes can't even see the melty bit.

Very tidy. Did you heat the sheet to create the bend (the one you wanted, not the accidental one) or just glue it in its bent position? 

Love these 6 wheel proper crawlers and how much performance you get scratch building. 

I can feel a mini mountain coming on. I've got a 45° bank in the garden, wonder what I can do with that and some rocks. 

[Mad Ax 10847]

12 hours ago, BuggyDad said:

Very tidy. Did you heat the sheet to create the bend (the one you wanted, not the accidental one) or just glue it in its bent position?

It's just glued, hence why I was using clips and clamps.  That sheet is 0.5mm, so it bends easily.  The rest is 1mm for more rigitidy.

12 hours ago, BuggyDad said:

I can feel a mini mountain coming on. I've got a 45° bank in the garden, wonder what I can do with that and some rocks. 

We originally had a big mound of rocks and broken concrete at the top of the garden, but the rocks were too big for crawling over - gaps pretty much big enough to totally swallow a 1:18 scale crawler, so there was no way a 1.9 rig was going to get over it.  Even clod sized wheels struggled.  However the rocks and concrete were really attractive (just had the perfect scale rocky outcrop look) so I planned to keep them and fill in the gaps with cement to make it crawlable.

However we ran out of space, so we had all those rocks carted away.  We had another path and an old pond structure made of concrete, and I figured that would be perfect.  Unfortunately when it was broken up, it had been laid direct over dirt, so the rough underside had taken on a dark stain.  Also the concrete came apart in more blocky chunks, less natural-looking faces, so it never looked half as good as the old mountain.

It's a nice feature as a place to test my rigs (actually it's the most challenging climb I know if within an hour's drive of home) but there's really only one possible route, so it's not something I come back to every day to play at.  I would consider rebuilding it in the summer, but we've got plans to build a lean-to in this area so it doesn't seem worth the effort.

[Mad Ax 10847]

Bit of a late update on this one, as the pre-Christmas week was kinda crazy at home and I didn't have that much time to do this sort of thing.  This batch of work took place on the 18th December.

So I started with the rear end, using a light boss I had printed in resin to hold the rear LEDs.  This print probably wanted more work, as you'll see, but for now it works just fine, even if it's a bit ugly underneath.

Here's the rear metal bracket with the tow hooks and holes for LEDs, with the new resin boss I printed.

The boss was sized to fit neatly into the recess at the back, but I knew I would have to drill out some space for various bolts under there.  That's where the problem started.

The lower face of the boss was grown directly off the print foot, to reduce the need for tidying up all the support fixings.  The bottom 5 layers are exposed for round 5 times longer than regular layers, so they adhere to the print foot and don't come off mid-print (this has happened before and is somewhat annoying).  This means those layers shrink more than normal, and are more brittle.  The shrinkage wasn't an issue here as this is the bottom of the boss, where sizing isn't a big deal, but the brittleness will be an issue later.

I printed the recess in the back for the LED lip.  I have to go oversize on this as there will be some shrinkage during print and it's not possible to widen it without a milling bit.

My measurements weren't spot on but it fits well enough

[Mad Ax 10847]

I put the boss into place and drilled through where the mounting bolts will go.  I didn't want to design these in as the holes were originally drilled on an "it looks right" basis so I had no precision measurements to go from.

As you can see, left and right are slightly different in terms of hole position.

I then had to drill-and-mill in the other axis to make space for the nuts that mount the metal sections together.  However, as resin is kinda brittle, slow-drilling to mill it out often ends up shattering it.  This is OK as it won't be visible, but in retrospect it might have been better if I'd just allowed space for this in the print.

Drilling the back end out for the tow shackle nuts was a pain.  The drill was just shattering it, so I had to use a grinding stone in a dremel, which made lots of dust and took a while.

 

[Mad Ax 10847]

From underneath, the finished product isn't pretty

But is isn't a structural part, and it can't be seen from above

The next thing I printed were my updated hub nut covers.  A nice big locking ring for the front, and some smaller caps for the rear, roughly modelled after an early 80s F150 hub design.

I made a slight mistake in my last update on these designs and made the internal recess just slightly too short, so I had to drill them out from inside a little (about 0.5mm) to allow for the threads on the end of the Element axles.

One for the spare - fewer screws fitted here, you wouldn't normally fit all 8 bolts on a spare wheel.

Fitted on one side.  I didn't have space on the printer for a full pack of these alongside the LED boss, so I need to do another run before Friday.

[Mad Ax 10847]

After the main parts of the build were over, it was time to focus on the graphics.  I'd been planning on this name and livery for a while - I could possibly have gone a bit more adventurous here, maybe even incorporating some wheel graphics overlaying the lettering, but that's a job for another day.  This was something fun to do one evening.  I cut and fitted the graphics one night last week, while watching Death Race 2000 (the original one) on Prime.

[Mad Ax 10847]

This rig has its maiden run on Friday - assuming this sore throat and muscle ache doesn't get any worse (judging by reports from the local area, it will get worse, a lot worse, before it gets better  ) - fingers crossed I make it to the quarry, and the truck comes back in one piece  

[bavee 1195]

Fingers crossed for you @Mad Ax! Great truck and a great read!

[Re-Bugged 11654]

With all the prep for this fantastic truck I really hope you get to give it a proper run. Best get on the Nurofen’s 👍🏻

[Mad Ax 10847]

Heavy rain was forecast for the entire of Friday 30th December, which would make for a cold and soggy day at the disused quarry where the Southern Scale Trail Pay & Play day was to take place.  Bedridden with a crippling sore throat, muscle cramps, headache and tiredness all week, I didn't fancy a day huddling in my waterproofs trying to stay warm, but as luck would have it, the rain dried out and my sore throat healed up just enough to allow me a few hours away from home.  As I'd pretty much been trapped there since Christmas Eve, it was nice to get out.

The Big 6 got its first proper run, and performed well.  The weakest link was the cheap rubber, with a general lack of traction all round, and a lot of squeaking from the cheap rear propshaft, which will probably have to be replaced with a high quality item at some point (along with all the other propshafts, which are either cheap Aliexpress items or cut-down Element plastic parts).  It isn't a lightweight rig, by any measure, but its weight is spread across 6 wheels instead of 4, so there's less mass forcing each individual tyre into the ground.  That might be having an effect.  I'm still tempted to replace the Chirax tyres with GMades, as they're cheap and grippy and have a cool-looking shape that will suit the vintage look of this truck.

It had a couple of big rolls, one down a very high bank (almost a cliff) that I'd half-ascended before getting too sideways, but nothing was damaged.  The roll bar remained intact, didn't bend, and didn't become detached where I'd (sort of) soldered it to the aluminium crossbar.  Even the dodgy cuts-out-when-it-wants-to servo didn't give me too much trouble.

If there is a problem with the rig, it's the spring rate.  Initially I designed the rear to have the same geometry as the stock truck (I'd even planned to use the stock shock hoops).  But after doing a sag test, the rear end seemed to stiff - of course, the rear of the chassis (at least before I'd built the cage and spare wheel holder) wasn't much heavier than stock, but was spread over twice as many springs.  So it seemed there was too much spring in the back.  Laying the rear shocks down has the effect of increasing the leverage on the spring, thereby softening the back end.  However, out on the trails, it felt too soft.  Of course, when it's running over uneven ground (especially big ruts and climbing rocks), much of the time the majority of the weight is just on one axle.  Softening the rear meant that axle just articulated away from the obstacle, and didn't actually push the tyre down into it.  So, added to the project list: increase the stiffness of the rear, to find a compromise between static sag on even ground and useful spring force when climbing.

Sadly play was cut short when I lost a drive pin from the middle axle's propshaft.  I'm still not 100% sure how this could come out, since it's a chunky thread into plastic, but it must have been present before I set out otherwise it would only have been 4 wheel drive, and I'm sure I'd have noticed.  I decided not to risk running it in 4wd mode and losing more parts from the prop (it's one of those designs that self-disassembles if the cover isn't held in place by the drive pin), so I packed it away and got out the BOM instead.

Anyway, it was great to give is a proper run over the sort of terrain it will be thriving on in 2023, and I got some nice photos too.  Recent heavy rain has turned part of the usually-dry quarry into a lake, which is a sort of reversal of how things were 6 months ago when many of our local lakes were returning to their former shape as disused quarries.

[Mad Ax 10847]

[Mad Ax 10847]

[Mad Ax 10847]

I managed to get some workshop time on New Year's Day, so I turned my attention first to replacing the propshaft pin, then sorting out the rear shocks.  My first instinct was to rebuild a set of cheap alloy faux-reservoir shocks that came attached to a used Manta Ray I got from ebay, but it took me a while to notice they weren't even lengths, and after a lot of messing around I finally realised they would never look right, and I aborted.  Instead I found some stiffer springs (I think they are Yeah Racing, but very old) that fitted nicely on the standard Element shocks.  Despite the black-and-gold theme of the truck, the blue shocks looked OK out back, so I kept it that way, with the stiffer blue Yeah Racing springs, and moved the bronze shocks from the Kit 2 up front.  It would be nice to have matching shocks all round but unless an older set of blue shocks comes up cheap I won't bother.  There again, I've still got to buy an all-new set of bronze shocks to make a matching set for the spare Element Enduro kit that I'll be finishing at some point.

I didn't take many photos of this process, but here's the ones I have:

I gave it a quick test-run over the 1:10 scale mounted, and it completely blitzed it.  Most of my rigs will struggle, especially at the start section, but with a bit more spring in the back the 6x6 did a pretty good job.  Some more expensive (or, at least, better) rubber and this rig should be unbeatable.

[BuggyDad 6380]

@Mad Ax a question if I may. Possibly a stupid one...

My bronze Kit 2 shock top mounts are very loose on their white plastic kit pivot balls. To my mind it's like they're made to fit a much larger pivot ball. Do you have the same on the front, how do your blue vs bronze ones compare and if yours are similarly loose, do you care and would you fit a bigger pivot ball to solve it? 

[Mad Ax 10847]

32 minutes ago, BuggyDad said:

My bronze Kit 2 shock top mounts are very loose on their white plastic kit pivot balls. To my mind it's like they're made to fit a much larger pivot ball. Do you have the same on the front, how do your blue vs bronze ones compare and if yours are similarly loose, do you care and would you fit a bigger pivot ball to solve it? 

Not a stupid question at all, and one I've asked myself multiple times recently.  The Kit 1 and Kit 2 shock tops and pivot balls are different, I think the Kit 2 holes are larger, as when I came to fit the Kit 2 shocks to the front of the 6x6 (where the blue shocks had been) they were more floppy than before, and I had to find the Kit 2 pivot balls.

This however does seem to be a thing with modern crawlers - the pivot balls are there because somebody on the design team saw them on another model and figured they were necessary, but had no idea how they actually worked.  That's my take on it, anyway.  At least, with Tamiya pivot balls, they press-fit into the shock tops - but obviously over time they wear out and pop off.  I totally understand that other manufacturers want to come up with a new way of doing this.  But they don't seem to have fully understood what they're trying to achieve.

Yes, the shocks flop around on the pivot balls.  It's odd.  Apart from mix-n-matching pivot balls and spacers to stop the shocks moving around, I'm not really sure what the solution is.  But I've decided not to care about it, as this isn't the only crawler in my fleet that has this problem.

Of course, it's entirely possible (in fact quite likely) that I am the most stupid link in the chain and I've overlooked something terribly obvious, and that nobody else has these problems.

[Busdriver 6551]

11 hours ago, Mad Ax said:

I love the way this truck hugs the ground. There’s something fascinating watching a multi axle truck a bit like tank tracks!!