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The light in the workshop was getting a bit difficult to photograph in (too much light and shadow) so I came out onto the bins to get some complete chassis shots.

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I had a quick drive up and down the lane.  The truck tracks straight and true and bounces a lot over the a raised kerb.  On 3S with silvercans it's quite driveable although not blisteringly fast.  Probably fast enough for me in this area, but it will feel really slow on a big track.

Anyway, then it was time for the final touch to the body - the name!

Now, there have already been some hints in the right direction, but no spoilers.  I have already mentioned I have two '79 bodies and that they will be sister trucks.  In a previous photo there was a shot of a new-build standard Super Clod chassis.  So we've got two Clods - one standard, one custom.  Once my ideas-jamming session took me down the avenue of twins with a myths-and-legends theme, I found myself buried in ancient Greek mythology and reading through the names of hundreds of twins.  After some time, the answer jumped out of the page at me.

Phobos and Deimos.  Twins in Greek mythology, the gods of fear and terror.  Apt names for monster trucks and fit squarely in my swords-and-sorcery theme.  Phobos and Deimos are also the names of the moons of Mars, and while they aren't famed for having much in the way of colour, Mars is.  The Red Planet.  Well, technically it's more orange, hence the orange livery.  The white was really there to break it up a bit - an entirely orange truck wouldn't have looked right.

After that, I had to decide how to decorate the trucks.  The names didn't seem to want much in the way of graphics, just some name decals, so that made life easier.  Now, I was a big player of the original Doom back in the 90s (and I still regularly play modern ports of Doom even now - IMO it is still the original and best single player first-person shooter).  Doom Episode 1 was set on the moon of Phobos, and episode 2 was set on Deimos.  So it felt natural to borrow some Doom imagery for the truck names.

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Well - that's got to be about the quickest monster truck rebuild I've ever done.  It would have been a driveable chassis last week if I hadn't had to give up some time for DIY.  So basically 2 weeks to build from the pile of parts I had to start with.  Actually I'm kinda disappointed because I expected it to take so much longer.

What's next?  Not much, really.  If I feel like cash it a bit spare I might swap in some different servos - the Alturn 780s work well enough but the rear will get a bit of a shimmy on under full throttle.

I could consider hotter motors.  The ESC is a Traxxas EVX-2 so it can handle 4S and/or hotter motors.  I was running it on Titan 550s on 4S but the motors are a bit too big for the space, and they draw so much current the ESC constantly goes into cutoff mode.  I might look into what the Sport Mod trucks run in the states and go down that road.

The shocks are a bit too stiff.  They're using a medium spring.  I disassembled them and fitted the softer spring but even with 4-hole pistons and the lightest oil I could find (Losi 25) they were pretty slow to extend even in my hand.  I might go back and try them again with some Axial 30wt.  For now, when dropped, the truck just bounces off the tyres - the shocks don't seem to do much at all.

Beyond stuff like that, I think I'm done.  Now fingers crossed I can find some place to run it over the next few weeks.

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I like the Doom reference. They are also very cool moons. Can the next cars be Titan and Enceladus? 

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L-ove it!

Love orange -the first RC I painted was orange.

Love a bit of Greek myth (part of my uni course).

Love Doom (spent far too much of my time at uni designing levels for my housemates to duel on)!

Oh, I like Ford's too.

I think you made that truck for me :D

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This was another truck that had a chance to run at the Tamiya Junkies meet.  I didn't put it on track much as it felt a bit lost out there, but it had plenty of racing around on the grass with @Ministrone's yellow Clod.  The big tyres are right at home on grass.

The last time this truck got run in anger was at the Junkies meet last Feb, when it was still wearing its Full Metal Jacket body.  Back then it still had the K2-3S chassis with its high centre and steeply-angled lower links, and it lasted about 3 minutes on the grass before it snapped a rod end.  This time (admittedly running silvercans instead of Titan 550s) it fared much better and came home in just the same state it went out in.

If there is a complaint, it's a bit, well, slow.  I might have to do some experimentation to find a better motor combo.  I'm using twin silvercans on 3S in Fifty-Fifty and that is fast enough, but I guess the Clod has lower gearing as standard (even with those big wheels) because it just doesn't have the same feeling of pace across open ground.  It's not exactly slow, it just doesn't feel that fast.  On the track it's hard to drive because it's hard to get enough speed to clear the jumps, and landing short means a hard impact.  I could try to find an adjustable motor mount to run taller gearing (it's probably got enough torque) or look for some lower turn options.  I have a few Etronix Sport Tuned motors which are quite cheap and have adjustable timing, so when I have a moment I'll see if they can be set to 0 degrees or even reverse timed so I can run them on the rear of the Clod.

Once I've got more speed I'll probably come up against all kinds of handling and reliability issues and maybe have to spend more on servos to keep it all in line, but that a problem for future ax.

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Haven't been around much lately but just saw this thread and love what you did with this.  Definitely a much more race-oriented stance than you previously had it set up.  Lower links parallel with the ground is what you want for racing and it definitely has the "racing" stance as it sits.  Body looks great as well.

For power, Sport mod trucks run 17t brushed motors (Reedy Radon, JConcepts) and 2S power so with stock gearing it makes for a slow truck, but you are allowed to modify gearing in Sport Mod so that's where it gets fun.  I've never set up a Clod for that class, mostly use SMT-based trucks, but going with the largest pinions you can fit in there would really be all you can do.  Most guys in that class run the largest pinion they can fit because of the relatively short heats.  If you just want to have fun with the truck then why not throw dual brushless in it?  Twin 4000-4600kv setups would get that thing moving in a hurry.

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It's been a long time since I've done any more than use this truck for putting body pins on when I'm checking under the shells of other cars on my rack.  It got a run out in the garden last summer, when I did a one-person MT race/tournament, but otherwise it's been like all my other monsters, and just sat there gathering dust.

I never really got it set up properly after all the mods, I just threw on some shocks, gave it a quick test-drive, then left it.

I've been working on a 2.2 leaf-sprung monster truck and I wanted a matching set of 8 shocks.  I've got 4 NIB Desert Lizard shocks that have never come out the box, plus 4 installed on this truck.  Since the Desert Lizards aren't really the right sort of shock for this kind of truck, I figured I should probably put something more appropriate on.  As luck would have it, I got given a much-abused SWB Traxxas E-maxx a few months ago, with a set of 8 original shocks.  The springs have gone rusty and they're long overdue for a rebuild, but under all the dirt they're not a bad shock, and can probably be configured to work well under this rig if I can get the right springs on them.

Here's how it sits right now.  The G-string Clod.

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It's pretty gosh-darned dusty.

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First spot of bother - the shock tops are quite big, and I don't have any free-fitting ball ends to hand.  I'll have to go through my stash and see if I've got enough spares.  The standard E-Maxx mounts use step screws, which are OK on an E-Maxx because the shock top only needs to rotate on one axis, but it's no good on a Clod where the shock needs to move around as the axle articulates.  I'll solve this problem properly later, for now I've just used some old Tamiya bushes, which are too small and allow the shock to wobble around.

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Installed.  The shocks are slightly shorter than the Desert Lizards, plus they're way too stiff for this truck.  This is on full extension - ideally there should be a little more travel here, and the lower links will be level under static sag.  Unfortunately there's no sag in these shocks at all - no bother, lighter springs will come later.

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Ready for a test-run.

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I took the rig out in the garden to see how it drove.  TBH it was just as bad as it was before - pretty bouncy, with minimal suspension movement.

I then decided I would try to do a back-flip against the garage wall, landed heavily on the nose, bend a lower link and snapped the Kimbro servo saver.  Meh, worse things have happened, it can be fixed.

I think I'll make some extensions to drop the top mount, this will also help to space the shock away from the chassis (I used two nuts on the mounting screws as I didn't have time to make spacers for the test-run.  This should reinforce the chassis at what looks like a weak point, and also give me some more positioning options so I can tune the shocks.  This might be a quick job I can do at the weekend if I'm stuck waiting for parts for the 2.2 build.

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TRX8361 is what I put on top of my sets to give me a ball end to connect to. I’ve tried fuel tubing too but it was a bit restrictive still. 
 

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10 hours ago, ad456 said:

TRX8361 is what I put on top of my sets to give me a ball end to connect to

Sweet!  I had started writing a thread asking if there was a recommended ball for these shocks, I never realised there was a whole proper shock cap!

Thanks :)

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No worries, I was doing exactly the same thing a couple of years back and found that Traxxas Ultra and GTR bits are somewhat interchangeable. 
There’s a progressive T-Maxx shock spring too, TRX4957R. 

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thanks, I was about to start investigating spring options :) 

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So this truck has been sitting neglected since the end of January, after doing my last round of mods, when a link got bent and the servo saver broke.  It's actually been in the way, sitting on the workbench in the shop, instead of in its special display place in my office, but I've been busy with other stuff and haven't spared a few moments to look at it.

I had to place an order with Wheelspin last week, so I ordered some new shock tops and springs (thanks @ad456 for the part numbers), and they arrived on Saturday while I was finishing off some other little jobs in the workshop.

Here's the dusty old beast, partly covered in bedroom dust and partly covered in shop dust.

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And here's the bent link, albeit slightly out of focus.

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It's made of 4mm threaded rod, so should be fairly strong, and able to withstand being bent back into shape.  I pulled off the link and bent it back in the bench vice until it was 95% straight.  After that, I figured I'd cut some sleeve out of 4mm ID alu tube, which I normally get from B&Q.  I've recently run out of this stuff, and had enough to cover just two links.  I figured I'd do the front lower links as these take the brunt of any impacts.

Unfortunately something went wrong somewhere in the measuring area and this happened.

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As I've already mentioned, I had just enough tube left to do two links, and having cut one of them too short, I now had enough to do just one link.  Faceplam.

One link done

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And installed

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While I had the wheels off, I figured I could swap over the shock tops.  Ideally the shocks need a full rebuild, I don't know what pistons or oil is in them, and they've probably never been opened since they left the factory.  They are from an old SWB brushed E-Maxx, so they're quite old.  That said, all 4 were full to the brim when I pulled off the shock tops, although they all have a slight squeak as if there's a bit of air in there somewhere.

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And while the shocks were off, I put on the new progressive springs too.  Actually I can't really feel any difference between them by hand, so it's not like there's a huge difference in spring rate, but hopefully the progressive rate will compensate for the steep angle of these shocks.  Once I've got time to run it properly, maybe I can stand them up a little.

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At the business end, I needed to replace the broken servo horn.  This was a genuine Kimbrough heavy duty saver, but I had to file into it to clear the link and drill it out to accept the ball stud, so that weakened it somewhat.  I'm using a heavy duty servo (although admittedly I have broken these servos before), so I went with a solid horn this time.

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I actually went into the radio and zeroed the trim and subtrims before I fitted this horn.  Believe it or not, this is with zero trim - this is perhaps the most centralised servo horn I've ever seen.

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done

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All back in one piece and itching to get out in the garden

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Which leads us on to the next problem: the ESC.  I have something of a bad history of ESCs in the various builds of this clod over the years.  A long time back I was using an old Hot Bodies dual motor ESC, but it wasn't LiPo safe, so I had to use LiPo alarms.  Except, for some reason, when the LiPo alarms got triggered (which happened quite a lot, as the ESC and pair of HPI GT550 motors were able to temporarily pull both my 2S LiPo packs down below the cutoff voltage), the radio would go haywire.  I guess the alarms somehow interfere with the radio.  Problem is, the haywireness would cause the motors to go full throttle / full brake / full throttle, which would cause the alarms to trigger, causing the radio to go haywire, which would generally throw the truck upside down and have it twitch and twist its way down the road until I dropped everything and ran after it.

I replaced that ESC with a Traxxas EVX unit, because of course those are LiPo safe.

Except the one I got wasn't.  Apparently only some of them are LiPo safe.  So, with money well wasted, I went out and spent it again on another EVX, this one with LiPo Safe clearly written on the ESC.

Except for some reason, it has the most sensitive cutoff I've ever known on any ESC.  This rig only has silvercans right now, and whether I'm running on 2S or 3S, a good boot of throttle and it'll go into safety mode.  Yeah, apparently this is a thing with Traxxas ESCs.

So, yeah, I strapped in a 3S pack that was at storage voltage, and went outside for a quick blast, and promptly came back in again when it went safety on me.  But apparently the HW 880 can handle 3S or even 4S power, so I'll put one of those on the next-time-I-place-an-order list, and get that Traxxas junk out of there in favour of something that will actually do the job.  I hope.

I doubt I'll do any more on this until I can afford a new ESC, because it's no fun modding a truck that can't be run without electrical gremlins, but it's going to be fun making those shock extensions to level it up a little, and it'll be nice to find out if it handles any better when those Traxxas shocks are working as intended.  For now, the rig is back in its proper display place on my carpet, adding to its thickening coat of dust.

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If you ever want a stronger saver than the Kimbrough there are some GPM alloy ones for about 12 quid on eBay, I’ve got 5 of them on various builds and they can be tuned by taking off the circle spring things. 
Glad the part nums were a help, I couldn’t tell the difference in the springs either but found my truck settled better with them than the reds. A 6ft straight drop and the truck would bounce with the reds, it just plants with the whites.

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Quick update on this truck.  I haven't done a lot with it this year, with no events where I can properly run an MT and a lawn that hasn't been mowed all year.  So, it's kinda sat around doing nothing for ages.

Part of the problem was the Traxxas ESC.  I've had several of these dual motor ESCs from Traxxas, the last one was a genuine LiPo safe model, but it had the world's most sensitive cutoff, and would go into low voltage protection with the merest whiff of full throttle.  This seems to be a common complaint with these.  I decided in the end not to persevere with it, and instead I bought another Hobbywing 880 with some spare cash at the end of August.

Fitting it gave me a chance to tidy up the wiring by tucking it all under the plasticard radio tray.

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I got the truck out for a quick test-run a couple of weeks back, as I want to take it to the Tamiya Junkies meet this weekend, and needed to give it a test-run.  I noticed that the springs don't compress at all under its own weight, it literally has no sag at all.  These are the progressive springs for the Traxxas shocks.  I guess this is the problem with using axle-mounted shocks - there's not enough leverage to really work the spring.

I experimented with a much more laid down position, using the top link mounts:

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Although that did give a little bit of static sag, it made the truck way to soft from side-to-side, so there would be tonnes of body roll and flapping of wheels over bumps.  What it really needed was a softer spring.

I went digging through the box and found some big bore shocks that I got from Aliexpress a few years back.  Can't remember why now, the shocks themselves are quite rubbish but the springs were soft.  By unthreading the spring collar from the cheap shock, and using the bigger spring cup, I was able to make them fit on the Traxxas shocks.

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That's more like it - now there's a little bit of sag, at least.  I don't know if maybe this truck wants a bit more ballast low down - I'm going to test run on a big track this weekend so maybe I'll get some ideas on how to improve it...

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