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Fifty-Fifty: WT-01 Pro-mod with F250 body

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I tidied up my wiring a little and relocated the receiver, then reassembled

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I stiffened the rear suspension by moving the bottom shock mount to the outer position and using a lower mount on the top.  I left the front where it was, but it needs to stiffen up as on tarmac it would happily lift a rear wheel in the corners.  I think if I set the front to the same position as the rear and then adjust the ride with the preload, I should have it about right.  Maybe it just wants a little more progressiveness on the front, but that will have to wait until I can get out to a bigger area.

It would be great to give this truck a proper run on a track, but the 3S soft pack is an issue.  Most tracks don't allow them, and on 2S it's just a bit lame.  I guess I'll have to see what 2021 brings.

I could probably have taken more weight off the plates, but I didn't want to pull off my sticky foam.  That might be a job for another rebuild sometime in the future, after I'd have time to play on the tracks and generally use the truck for the purpose it was built.  So, for now, I think it's pretty much done.  I don't even feel the need to tidy up the motor wires - it just is.  It's a neat rig, and until I can get to a track to prove it, I have to say - it probably works :) 

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Great thread, pictures used to load for me when I last checked few weeks ago. What did you use to upload them?
Love dagger threads

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42 minutes ago, Meobromon said:

Great thread, pictures used to load for me when I last checked few weeks ago. What did you use to upload them?
Love dagger threads

Pictures are hosted on tcphotos and they are still working for me.  Sometimes tcphotos goes down temporarily.

I've also noticed tcphotos isn't allowed at my office, so when I'm at work I can't even see my own photos :p 

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I was in between things to do this weekend, and my new projects database has been serving up quick tasks to stop me being idle in the workshop.  Next on the list was to sort out the shock setup on Fifty-Fifty.  In my last instalment, I moved the rear shocks to the outer position on the lower arm to stiffen up the spring rate, but I didn't have time to adjust the front to match.  As a result, the truck would lean hard over the front in corners and lift a back wheel off the ground.  On a full-size touring car that looks cool but on a wide-arm stadium truck it just looks a bit weird.

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While I was pulling off the front shocks, I noticed one of them was jammed in position.  The aluminium top hat that is supposed to act as a pivot had become seized.

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I drifted it out with a punch and a hammer and got it cleaned up OK

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Then I relocated the shocks to match the rear

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After that I went out for a drive in the garden.  It seems to be pretty much dialled now - no doubt it would need more adjustment if I went to a full-size track, but around the garden it will wheelie off the throttle, forward-flip under braking, spin the wheels like crazy on the patio and generally be a total hoot to drive.  I've enjoyed these chassis before but this one finally seems to be working for me.  It feels robust too, now that the shock position is more appropriate and the arms aren't being twisted.

It's just a shame my garden isn't bigger, I was constantly running out of space with all the kid toys littering the patio, and the grass is still covered with little stones from where we put buttons and eyes and mouths on the 3 snowmen we made back in January.  I need to clean it all up.  It will be fun once I have my proper monster truck course all laid out ready (although I'm falling behind on my monster truck projects now), but I'll have to keep the speed down or go back to 2S to avoid launching it right through the workshop window.

I'll do my best to get some action pics of the truck running, if I ever have a chance to run it anywhere but my own garden.

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I finally got to run the latest updates on a proper track during last week's epic Tamiya Junkies meet.  Power and gearing is about spot on - it's pretty fast in a straight line (I wouldn't want it any faster because it's pretty heavy and not that easy to stop), and goes right up on to its back wheels with a squeeze of the throttle.  However, while it's nice and compliant around my urban garden, it's still too soft for a big track.  In the corners it wants to roll a lot, goes up on two wheels, then the tyres dig in and twist around and it ends up going wherever it wants.  I've got the shock mounted in the lower holes on the towers, giving it more ground clearance, but I think that's making it too top-heavy on track.  I could (and should) have dropped the ride height by moving the shocks up to the higher position, but I had so many other cars to run that I didn't bother.  That was one of my bigger mistakes of the weekend.

Play was stopped when one of the front hinge pins came out and I lost yet another diff cup.  I had a few spares to replace it back home but I really need to swap out the screw pins for stainless pins with E-clips.

So - more work to do, including trying to make some sway bars.

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Wow - it's been 2 years since I ran this truck!  Interesting that this was the project that dragged me back into the workshop just before the pandemic hit, which kicked off this spate of custom builds and longwinded threads, but one of the first to get abandoned and boxed away when I was having trouble with hit.

Like my other big-wheel trucks, I don't really have space to run it at home (specially when I'm too lazy to mow the lawn) and it isn't eligible for racing anywhere, so it just sort of sits in the box and does nothing.  But, I'm off to Tamiya Junkies this weekend, so I decided a few weeks back that I should give it a quick test-run and make sure it's all OK.

Here's how it looked when it came out of the box (after putting the wheels back on, obviously:

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One of the big problems last time out (literally just go one post up and read) was that it had too much body roll and wanted to flip over all the time.  So, it really needed some sway bars.

I was sure I had some 3mm piano wire lying around, but I couldn't find it, so I used some 3mm brass rod instead.  Here I've added one bend to it, and positioned it against the stock sway bar mounts.

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Here's a sway bar.  It has some spring to it, so it should work OK.

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Finger not to scale.

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I trimmed off the ends - it was too long - then pressed on some RC4WD 3mm rod ends.  They went on pretty easily, tbh.  I was going to thread the rod, but brass is too hard for a conventional die.

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I had to grind out the lip at the front of the gearbox, as the mount for the standard sway bars is too small.

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Fitted using the stock mounting location on the back of the arm, using drop links made from RC4WD 3mm rod ends and some M3 threaded rod.  It all fits neatly and doesn't bind on anything.

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It works!

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There was a bit of a gap at the bottom of the front bumper mount that was causing the bar to twist, hence why it doesn't working 100% in the above pics.  I squoze in some strips of styrene to fill the gap.

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fin

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Well, that's all this time - I only had one rod of brass, so I couldn't make the bar for the back end.  That was a few weeks ago and I now have some more piano wire, but I don't have time now to make a rear sway bar.  I kind of hope the front end is enough, at least to control the crazy overactive front end on turn-in.

I also got the camber gauge you see in the pic above, and haven't had a chance to use it yet, so this was the first victim.  Let's see if it feels nicely planted and balanced on the big astro track at RHR this weekend :D

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It looks great! I misread the title and thought of it as a WR-02 build. :D But hey, trucks with big tyres always gets my attention anyways ... I guess I have to blame the Bigfoot I saw in the car magazines as a kid.

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Just now, CRC505 said:

Great, I think this WT-01 feels better than the new GF-02:lol:

I'm hoping the WT-01 comes with an unpainted body.  If it does, I'll build it stock and give it a test-run side-by-side with this.  TBH I think it will be better - Fifty-Fifty is real heavy.  Actually I've been thinking about a rebuild in FR4 to shave a little weight off, but we'll see...

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Great looking project, this chassis is massively under-rated. 

I made rails for a 6x6, if I told you I cut them with my teeth, you might believe me, it was rough but it worked.

I achieved the kick up angle by letting my boy jump it at the skatepark, but I think your way is much better.

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I'm surprised somebody more clever than me (everybody, lol) hasn't uploaded to fibrelyte, an adjustable set of plates for this chassis with middle spacers to change the wheelbase. Hint. Hint.

They are certainly better value than shapeways and stronger too with a choice of thickness and materials.

I even thought about joining 3 gearboxes together in a triangle fashion to build a go anywhere robot, but never got round to it.

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