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I thought I already had a thread about this truck, but all I can find is something from back in 2016 when I first put it together, back before the Great Photobucket Treason of 2017 (may broken links rest in digital heaven). So here we go again, with a fresh thread and potentially only some rough ideas of what we had before. So - to recap - this started life as a Super Clod Buster delivered from an overseas hobby shop (either Tower or RCMart or something) back in the old days of the late 00s. I believe around summer 2007. My intention has been to build a scaler from the body and a stick-chassis crawler from the axles, but life got in the way, I didn't find the courage to paint the body and the comp crawling world moved away from sticks and into something else. The axles got fitted with 4-link mounts and axle-mounted servos and were used for a time on my TXT-1, before being consigned to a box on the top shelf for many years. In 2016 I refreshed the axles with new internals, converted from TXT wheels back to the original Super Clod, and built a budget racing clod up around a Reign K2-3S chassis. The end result was a bit of a pig to drive with 4S and Traxxas 550 motors, and again got consigned to the shelf while I tried to work out what to do with it. Last year, one of my first projects with my 3D printer was to make up some new servo mounts. These brace the servo against 3 parts of the axle instead of 2, so the transmission case screws aren't being strained and the servo doesn't flop around. With some 20Kg servos from Amazon, and some slightly revised geometry, it finally became driveable. However it was still a bit slow on 3S silvercans and a bit too hard to drive on 4S 550s. On its last outing it broke an RC4WD rod-end while bouncing over the grassy field at Robin Hood Raceway. For a while I couldn't work out why it broke, but then I took a look at the chassis and realised the geometry is all wrong for racing. You see, up until I started watching Trigger Kings videos a couple of months ago, I had no idea what a racing clod should actually look like. Now that I've been educated, I see I was still building my rigs like comp crawlers. Steep angle on the bottom link, horizontal top link, high middle for ground clearance and don't worry over much about the steering geometry. Now I understand a bottom link should be horizontal under static sag. For the best geometry, the top link should be parallel (when viewed from the side) and describe a marginally shorter arc than the bottom link (to maintain the correct caster angle under compression). I don't fully understand why the bottom link should be horizontal - maybe this is where the suspension is at its most neutral? - but I also wonder if the loading on the rod-ends is reduced with this geometry. When hitting a bump with a horizontal bottom link, the axle is free to move up and back. When hitting a bump with an angled bottom link, the axle must move forwards (towards the bump) as well as up. If my intuition is correct, this will increase the loading on the links and rod-ends. As you can tell, I'm kind of running on intuition here... Anyway - I can hardly make the rig worse than it is. So, with that in mind, and with my old metal-clad body looking a bit sorry for itself and a completely new JConcepts 1984 F250 body sitting around doing nothing, I figured a rebuild into a classic mid-80s monster truck style is on the cards. Righto - that is the talking done - now it's pics time! Here's a side-on view of the chassis as-is. K2-3S not really designed for Mod Clod builds but it's sturdy and tough. Geometry is more crawler than racer. Note tape around bottom links and endbells because of clearance with 550s. This view shows how much the bottom link wants to come down. I measured 47mm. Top links and wheelbase will be adjusted later.
Let's start with a back-story. It begins with a TXT-1. It begins in early 2007, when my love of Tamiya RC was kicking up a gear and I was buying pretty much everything I could get my hands on. A bit of spare cash came my way, and was rapidly swapped for an NIB TXT-1. Around about this time, I also found myself interested in the blossoming scale truck thing, as well as the interesting new sport of crawling. Figuring the TXT-1 was better as a hulking great impressive beast than a dedicated rock crawler, I put in an order to Stella for a Super Clod Buster and a TLT-1. The original plan was to use the Super Clod body on the TLT axles to make a cool-looking scale truck, and use the Clod axles on some UPVC cable trunking to make a super-twisty stick crawler. The clod body got parceled away from place to place and finally made it into Project Ringpull (on those TLT axles) almost exactly 8 years after they came into my possession, but the clod axles never made it onto the stick crawler. And so we must go back to that TXT, and its bizarre habit of lifting a wheel under power. I could never get into that, and I could never drive around it. I guess I just gave up enjoying the TXT. And I wanted more power. So the clod axles got assembled, along with my own special attempt to lock the diffs - two self-tapping screws pressed into the gears before the axle was assembled. Well, it seemed like a good idea at the time... Swivel hubs from the TXT axles were relocated to the Clod axles so I could run TXT wheels, HPI 550 motors were fitted, one re-timed for reverse rotation; a HPI GT speedo was stolen from my 12-cell Wild Dagger, the TXT gearbox was removed, a modded set of four-links was made and two NiMH battery packs were taped to the TXT chassis to power the whole thing. And what a heavy old beast it was. It soon became apparent that it was too short - the top-heavy chassis would wheel-stand and flip on command, but otherwise was impossible to drive. More money was spent on extended bottom links with integral shock mounts, the TXT cantilever shock system was junked in favour of conventional upright shocks. Original ball-ends were replaced with G-made ball-ends, on the basis that they were about as strong a ball-end as money could buy at the time. The result was a heavy, cumbersome, fragile truck that was almost impossible to drive and broke on every outing - usually a lower ball-end. I remember once carrying the whole heavy lump 15 minutes down the road to play at an abandoned BMX track and broke a bottom link after the very first jump, and had to carry it all the way home again. Also, quite predictably, my diff-locking technique royally failed and the screws came out of their homes and started rattling around inside the gearboxes, doing all manner of unseen damage. Not long after this would have been around the time when all my MiMH batteries started to have charging problems, and the 14.4v setup seemed to pull too much out of them. I took a 60 minute drive to a great bashing site to hook up with some other TC members, only to find all of my packs had peaked prematurely (oo-er) and only had a fraction of full charge. That must have been in 2009 or 2010, and was probably the last time it got used. It was shelved (with another broken ball end) and not touched since. I can't say I'd forgotten about the TXT/clod hybrid, because to be honest, even someone who hoards stuff like me can't forget owning an RC that big. I often found myself thinking about a rebuild, but memories of broken rod-ends and dumping packs and desoldering motors always put me off. Somewhere down the line, my project plans were all going wrong. I needed space, and time, to rethink. In mid-2015 I found myself placing an order for some new Traxxas 550 motors - especially since they do one which runs in reverse. And then a used lipo-safe Traxxas ESC came up for sale on here, so that was added to the collection. It appeared that there was a project in the works. February 2016 arrived, and the entry forms for the Iconic Revival were posted online. And I entered a Clod Buster into the monster truck race. So there's a deadline, there's a set of axles, and there's an idea. I've been looking for a good name, and Budget Buster has come to mind. I'm not sure I really like it since it doesn't suit the shell I have planned for this, but it probably fits. The general idea is that I already have most of what I need to make the truck run under its own power, so it'll be a low-budget build. On the other hand, I've been at this for just one day and have already spent a significant amount of cash. After promising myself that I wasn't going to buy any RC stuff in March. And we're only 17 hours into March. This could be interesting. So, here's the ultimate goal: Build a clod-axled racer using, where possible, parts I have in stock or can make myself. TVP chassis should be lightweight to reduce stress on ball-ends and should allow fitment of 4s lipo power for the Traxxas speedo. Batteries to be mounted low on bottom deck, radio and speed on top deck. Soft springs for landing big jumps, low-slung chassis for lower COG. 2 channel 2.4GHz receiver for front steering only. Shell will be something from my parts bin that hasn't had an outing for ages, but might get a bit of a makeover using a technique my wife found online and used for making something totally, totally unrelated - but oh, so cool!! And here's how we're planning to get there: Pull the axles off the TXT chassis Strip axles, remove stupid screws, clean and rebuild gearboxes Reassemble axles using Clod steering hubs and Clod wheels and tyres Fit Traxxas motors Lock out rear steering Repurpose a TVP chassis from parts bin, make custom upper and lower decks from delrin Make new 4-links for an aesthetically-pleasing length Remodel my monster shell and mount low and sleek over the chassis for an evil look Fit Traxxas ESC and radio, go find some wipe open space and have fun A new pair of tyres has already been ordered. I have the original (unused) Clod wheels and tyres, but one tyre was destroyed while I was experimenting with a crazy idea I had for getting traction on rocks. I considered going with the new Proline Destroyers, but since this is supposed to be a budget build and I only need one tyre, not four, buying a pair of Tamiya tyres was much cheaper. I also ordered a bunch more 2.4GHz receivers as I've run out, again! I seem to have far more runners than I ever actually run, but can't ever justify stealing a radio out of anything. How does that work, eh? So where does it begin? Well, today I nipped home from the office at lunchtime, pulled the old TXT/Clod hybrid off the shelf and started stripping off the axles. Here's what the old thing looked like after several years of being cannibalized for parts: Note TXT chassis, TXT wheels, abundance of dirt from last run Axles came off nice and easy Front gearbox disassembled. Those screws came back to haunt me - note one completely missing tooth. New front gears required - so that's one gearbox that won't be reassembled today. The rear had missing teeth on the bevel gears, and since I don't plan to lock this one out yet, there's nothing for it but to replace them too. I could have got away with just one gear set but, since both axles are apart and there's a bit of wear on all the gears from those stupid screws dancing about, and I want this truck to be reliable, I figured I might as well buy two new gear sets and rebuild both gearboxes fully. That's about all I have time for in a lunchbreak, especially as I knocked a pot of screws onto the floor and had to go find them, but the new gears should be with me in a couple of days and it won't take long to get the axles back together. Then I'll onto making that custom chassis. I suppose I need to decide what chassis to use - I have some AX10 plates which should work really well if I make some nice wide decks from Delrin, or I have a K2-3S chassis that's pretty much ready to fit and use right away. The K2-3S will be tougher and allow a more upright shock mounting position, but will be marginally heavier than my AX10 idea and will have a higher COG since I'll need to keep the chassis ends clear of the axles on full compression (or chop down the chassis a little). And that body needs sorting, too... And I have something special lined up for that which I just can't wait to share with y'all