Budget Bruiser: Maverick Scout Class 1 Scaler

[Mad Ax 9329]

Not got a huge amount to show for my work this weekend, so I thought I'd add a retrospective build thread for my Budget Bruiser, which has been a regular feature at local and national scale events for the past couple of years.

I acquired it back in 2015 as an RTR from a local hobby shop that no longer exists (or at least, no longer sell much in the way of RC cars).  I had no interest in the Scout (or any comp crawler / rock bouncer style car, if I'm honest, I disliked them then and I still dislike them now), but I needed something I could put under a hardbody for my wedding in April.  The plan was to build a hardbody pickup and have the rings driven down the aisle by a friend of mine.  I had originally planned to use a KBF-bodied CC01 (see other recent build thread) but was let down by two problems: a) I had lost the tailgate and couldn't complete the body in a tidy manner and 2) the future wife looked at the truck and said "that's ugly, that's not coming to my wedding."

I had an unpainted Super Clod body, and planned to use is over the Maverick Scout chassis.  I figured I could make a suitable runner in a single weekend.  Besides mounting the body, all I needed to do was make some shorter straight links, lower the shocks and fit some smaller wheels.  However I ended up abandoning that project, too - I used some TLT axles, an Axial transmission and a TCS X-trail chassis for that project, and although it ran down the aisle on the wedding day, it was far from finished - it was 2wd only, the suspension was rock solid and the rear prop was made from two UJs and a piece of allthread - it was way out balance and had no sliding mechanism, so there was no rear suspension at all.  It looked good but has languished in the box pending a complete rebuild (and having parts stolen from it) ever since.

For a short time the Scout got used as a light runner, using an old Parma El Camino body with the arches cut out, but I never liked it much.  After a while that body got repurposed onto a Traxxas E-Maxx, and the Scout rolling chassis was dumped in the spares pile.

It was early 2016 when I realised I had a good selection of bits that I could use to make something interesting.

[Mad Ax 9329]

Unfortunately that's about as far as I got.  Everything was canned and the truck didn't run in anger.  During that timeframe I built and ran an SCX10 G6 Edition rig, which became my one-and-only scale truck, and was all the truck I ever needed.  However as it grew bigger, with a heavy set of 1.9" alloy wheels and some chunky 120mm rubber, it became apparent that I needed a smaller, simpler rig for my more road-ready scaling fix.

In time for the 2018 UK G6 Recon, it got a fresh set of rubber and a new front bumper.

This shot shows how well the TCS X-Trail chassis fits with the Maverick Scout running gear.  The Scout is based on an AX10 and shares most of its dimensions.  The X-Trail was back from the days when to make a scaler you pretty much had to take an AX10 and add nicer chassis rails - these were a wallet-friendly way to achieve that aim without having to cut and drill 4mm aluminium sheet yourself.

[Mad Ax 9329]

A whole 2 months later and I had the body properly mounted and the links trimmed to size, more or less.  I'd also abandoned the super-long internal sprung shocks for some shorter cheapo alloy units with soft springs and no oil.

A little while later I decided to swap out the trimmed stock links (which were still a bit too long) for some M3 threaded rod.  Amazingly those 3mm links are still holding up after a lot of abuse!

[Mad Ax 9329]

A few days before my first visit to the UK G6 Recon, I took the rig to a good local crawling spot for a shakedown

 

[Mad Ax 9329]

Amazingly, I took no photos of the truck at the 2018 event, and it was a whole year before I'd give it an update.  For 2019's G6, it got a bigger set of tyres (taking it up to the class limit) and a cheap 3Racing winch (which was identical externally to the 3Racing winch on my SCX10 but had around half the pulling power and could be unwound by hand, which the other one couldn't).  I took these pics at a quick shakedown at a local beauty spot.

 

[Mad Ax 9329]

The latest update happened yesterday.

As lockdown laws are being relaxed just a little here in the UK, it's now possible to go crawling again.  Actually that's been allowed here for a little while, but up to now I've been too busy doing my own thing and getting exercise in the little bit of time I get off each week that I haven't taken advantage of it.  But this week I'm going to meet a good friend of mine who is also into crawling, and we'll have a safe and socially-distant crawl around some local woods.  As my SCX10 is out of action waiting for a bracket to be printed to mount the 3D-printed front grille, I figured I'd take the Bruiser instead.

Well, would you know?  I made some mention way up in the To Do thread about having not touched my scalers since before lockdown, while fully expecting that crawling would be the one thing I could do solo under lockdown and socially-distant under later restrictions.  Here's why I should have been more prepared.

I think the last time the rig was run would have been at a Somerset Scalers meet at Ham Hill.  I remember it being a bit wet and muddy in places and although I mostly ran the SCX10, it looks like the Bruiser got a bit of a run too.  Maybe just around the car park before we packed up and went home.  Either way, I completely forgot that it saw action and, more importantly, mud.

That's how it came out of the box.  Actually, no, that's how it was after I'd taken it outside with a stiff brush and got the worse of the caked mud off.  I haven't thrown a battery at it yet so I have no idea if the electrics still work.  The servo and ESC are waterproof but the radio isn't - it's serviced a good few dunkings and is mounted nice and high so it avoids most of the splashes, but I usually make sure to dry it out as soon as I'm done so it doesn't corrode inside.  I might have neglected that important step here.

Also the axles were seized so hard I had to really rock them back and forth to free them up.  It looks like most of the stock bearings have corroded together.  I had hoped a bit of 3-in-1 oil worked in around the external bearings would free it up enough to run, but after turning it over by hand a few times mechanical sympathy took hold and I opened up an axle.  Good job I did, the mess inside was horrible.

Yes, that bearing was turning in the plastic housing.  I doubt it would do many runs before the plastic wore enough to cause a gear mesh problem.  This is supposed to be a budget rig and it's cheaper to buy a new bearing kit now than to have to source two whole new axles later.  I had a couple of new rubber shielded bearings to get started but this morning I placed an order for a full set to rebuild all the Scout axles and transmission.

The gears themselves are OK (at least in the front axle, I haven't opened the rear yet).  There's some surface rust on the gears but it brushed off easily and they turn smoothly.  The input gear seems to catch on the axle housing so I need to check what's up there and maybe install some shims.  I was warned that the Scout was supplied with no grease in the axles (and indeed, they have always been very noisy axles).  At the time I figured I didn't care because it was only a cheap rig.  Still, it's not a cheap rig if you have to replace parts because you didn't do some basic maintenance, so it's time to rebuild them with automotive axle grease.  As well as helping the gears turn smoothly, it might also prevent any incoming water getting into the bearings.  I've never been shy about running my rigs in deep or muddy water and I'll happily go crawling in all of Britain's many and varied weathers.

The centre transmission feels OK but I'll give it a quick strip once the axles are sorted to replace the bearings and give it a good greasing.  Hopefully it'll run quieter after this.

I'm not sure if I'll bother to replace the ball ends.  Most of them are quite stiff and working them with 3-in-1 oil hasn't helped much.  It might be better to pop the balls out and clean them properly.

The bearings won't be here until later in the week and I'm a bit pushed for spare time before the crawling trip on Friday, but hopefully I can get this old beast running before then - or I'll be running the SCX10 in the woods at night with no grille or lights...

[Mad Ax 9329]

Quick update on this one.

While I was posting the previous update, I went through some photos of the rig with the old Fastrax Kong tyres and, to be honest, I thought it looked a brazillion times better than with the Hyrax XLs.  These tyres were fitted before a national-level event and I wanted the truck to be as capable as possible, so I went with the biggest legal tyre size for class 1.  However that meant lifting the body and generally not looking as good.

So, as August's budget came into play and I decided not to buy a new class 2 rig, I figured I could spare some cash to change the tyres on the Budget Bruiser.  Enough cash, in the end, to have bought a whole new rig...  Be warned, this is no longer a true 'budget' build.

I wanted some tyres that were similar to the Kongs - around 90mm in diameter.  I spent half a day floating around various UK-based scaler parts suppliers and finding practically nothing in the 1.9s category that would work.  A shame, as going down to 1.7s would mean new wheels, and as there's not a lot of 1.7 wheels out there, that would likely mean steel or alloy, pushing the price higher.

In the end, this cost me over £200.  Quite how I justified that on a rig that probably owes me less than that all-in (excluding current tyres) is anyone's guess, especially as I would have been most way to an MST CFX or upgrading my DAW software to the latest version and getting a ton of new synths, FX and features to play with.  But hey-ho.

These are RC4WD Stocker wheels with BFG mud terrain tyres.  Nice and heavy with super-sticky rubber, they should be great in the mud and on the rocks.

I got the tyres assembled during a long work meeting (WFH has its advantages) and attached them to the truck as soon as I was off-duty

[Mad Ax 9329]

Of course, this gave me mountains of work to do.  The body now sits too high, so I had to lower it.

At the front end, the body is mounted with velcro on top of a tower made from Delrin blocks.  It's easy to lower the front by removing a block.

At the back, the body is secured by posts glued into the shell that poke down through a Delrin plate attached to the rear crossmember.  The simplest solution here was to remove the plate from the top, and re-attach it underneath.

Overall this gave a 10mm drop at the front and a 20mm drop at the rear.  I actually experimented with a 20mm drop at the front but it didn't look even - I guess the truck has always been a bit too high at the rear.

[Mad Ax 9329]

To get the back to sit level, I had to cut a section out of the bed.  Those who don't like to see butchery of vintage Tamiya parts, look away now.

Chassis

[Mad Ax 9329]

I didn't need to reduce articulation - the new tyres are small enough to allow plenty of twist without catching the arches.

Out in proper daylight, the truck looks cool

[Mad Ax 9329]

Now there are some drawbacks to this expensive new setup.

1) the new wheels are very wide.  I wanted a scale look, but they just sit too far out.  Having spent all that money, I considered going all-in and buying some RC4WD axles to bring everything closer in, but that's yet more cash on what was supposed to be a cost-effective build.  I found some narrow Axial hexes which have helped a little and I've ordered some rubber arch extensions from China - they probably won't be as good as the RC4WD ones, but at less than a quarter of the cost, who's complaining?

2) I broke an axle.  Well, one of the axles is slipping.  I got a rear wheel stuck in my scale mountain and kept trying to drive it out before I noticed one wheel wasn't turning.  Actually under trail conditions it's OK, but I guess the spool must have plastic parts and the torque has worn it out.  I'll take a closer look at the axles and see if a metal locker from something else will fit.  Maybe I can even repair it with epoxy.  Alternatively, I could just buy some new axles - RCBitz have some ARB axles for a good price which would narrow the track a bit too.

3) it's now more of a trail rig than a crawler.  A combination of smaller tyre diameter and lower body means the front bumper hits the rocks before the rubber does, and it gets stuck more easily.  That's pretty much to be expected, and I knew there were going to be performance trade-offs when going to a more scale appearance.  On the plus side, the majority of local events are more about trails than rock crawling - often the SCX10 feels like overkill.  This should be a really good rig to run when it's a bit too bumpy for a CC01 but not rocky enough for the SCX10.

I'm having a little break with the family next week.  My wife is taking me caving, so I said as a bit of a hobby exchange, I'll take her crawling.  There are loads of good trails where we're going, and it will be a good chance to run the Budget Bruiser in its favourite environment.  Hopefully it won't break a servo horn 2 minutes into the run like it did last time I took it there.

I'll run the Bruiser because it should offer a little bit of a challenge, the wife can run my SCX10 because it should go over just about anything that trail can throw at us, so should be ideal for a beginner.

[Mad Ax 9329]

I found some cheap rubber arches on Wish, which I figured would be a good way to cover the wide wheels without spending a fortune on narrow axles.  Delivery was pretty fast and they look the same as the RC4WD arches, only much cheaper.  I expect the quality is lower than RC4WD, but having not spent that kind of money, I don't know for sure.

Supplied with some very small mounting hardware - the nuts are smaller even than the smallest hole in a Tamiya box wrench, I have no idea what I'm supposed to tighten them up with.

I actually used my own hardware in some places as it was more convenient.

Here is a previously-damaged arch.  I tried to cover it up by melting it with a lighter to make it look like it was trail damage, but it never looked quite right.

The rubber arch hides it nicely.

Fitting involved lining up the arch, marking holes and drilling them, then screwing the arch on.

[Mad Ax 9329]

While they are held on OK for now, I think the screw heads are too small.  Already the rubber is deforming over the heads, and when I tightened one up too much it went right through.  On the trail it's likely the arches will catch on a rock and rip right off.  I plan to re-fit later with larger screws and also some impact adhesive to hold them in place.  The impact adhesive will probably do a better job of holding them on than the screws.

For subsequent arches I didn't bother adding nuts to the screws - just the tension of the screw in the body is holding this in place.  There is less deformation around the screw head.

Leading edge of front arches come with a supplied countersunk screw in black, but I preferred this stainless hex head

Deformation clear to see here

[Mad Ax 9329]

I found some more trail damage at the front

Finished installation (glue and bigger screws still needed)

[Mad Ax 9329]

This latest update highlights a slight suspension alignment issue.  This rig still uses unsleeved 3mm threaded rod for suspension links - I need to make a new jig and remake the links in 4mm and add sleeves.  That's a job for a lazy Sunday, and with a slight change in our life plans I might not get many of those for a while  

[Mad Ax 9329]

It's been a long time since I updated this thread, mostly because I haven't really touched the Budget Bruiser in a while.  Last time I ran it on my 1:10 scale mountain, a rear wheel got stuck in an axle-breaker and broke the rear spool.  It was still semi-driveable but a quick run in the woods a few weeks later with only 3 wheel drive convinced me to consign it to storage until I had time to work out what to do with it.

The problem was the locker in the rear spool.  It's made of plastic in the Maverick axle, and after a time it strips out.  Once it's slipped once it just makes itself worse and worse, so it was only a matter if time before this happened.  A replacement spool is £30 - not a bank-breaker but quite a lot for a budget axle and a spool which is only going to fail again.

Well, I'd wanted to fit some narrower axles anyway as the new wheels are so wide, so at the beginning of Jan I ordered some RC4WD ARB axles from RCBitz.com

These are a fair bit narrower than the Scout axles.

[Mad Ax 9329]

I figured I might have a bit of work to do getting these fitted, but I hadn't realised just how much work there was.  Cutting new links is all well and good because the 3mm threaded rod is a bit weak and has bent in places, I don't mind re-fabricating the links in 4mm rod.  However I hadn't realised before hitting the Buy button that these axles are designed for leaf mounts, so they don't have 4-link mounts on top of the pumpkin.  So - I'll have to come up with a new plan.  I do have some leaf springs somewhere, but I was saving those for something else, and I'm not really sure I want this to be a leaf-sprung rig.  Although I've lowered it a little since fitting the new wheels, I still want to retain its capability - it's always been a pretty good performer considering it's a parts-bin special and does well in the Class 1 category at the G6 and the Nationals.  So it looks like I'll have to build an axle bridge for the rear and maybe a 3-link with a panhard rod on the front.

Also there's no front servo mount, so the servo will have to go onto the chassis.  That pretty much dictates a re-working of the front end where the winch and electrics currently sit, so that's a bigger job.

And finally, the axles rotate in the opposite direction to the Scout ones.  I could flip the axles over, but the ARB logo would be upside down (literally this would matter on any other axle I could have bought : faceplam: ) or I could mount the transmission backwards, but I'm pretty sure the spur will interfere with the interior (right now the body only just fits over the transmission).  So probably I'll end up relocating the transmission to the front and using a transfer box to reverse the rotation - as luck would have it, I have one.

So - given the time of way when I started, and how much work there was to do, and how cold it was now that the fire had gone out, I figured I was better off packing everything away and cleaning myself up for a night of music-making ready to come back fresh on this project next Sunday.

Watch this space!

[Mad Ax 9329]

Belated updates!  I've been busy in the workshop recently but haven't had a lot of time for updating my build threads.  So here I am trying to catch up in between putting the child to bed and putting the finishing touches on today's build, which is a new-built Tesco's Tikka Masala with some hop-ups and a few custom parts.

Saturday 24th dawned with heavy snow (something of a rarity here in the South West), so after helping wife and child to build 3 snowmen while I waited for the log fire to warm up, I dug out the Budget Bruiser project and took a closer look at what I'd have to do to fit these axles to the chassis.

Here's what I started with:

I like to start a custom project with a jig.  For a long time I've been using a wooden one that gets rehashed for everything, but it's seen better days and no longer entirely square.  So here's a new one made from alu right-angle section.

Chassis plonked over the top

And resting on the body for wheelbase check

This position should be around full compression, so I'd want the links about horizontal here.

[Mad Ax 9329]

With everything positioned in place I can measure the first link.

drawings "not to scale"

And repeat for the front

[Mad Ax 9329]

These axles have no inboard link mounts, so they can't be 4-linked unless I make new bracketry, and that's likely to interfere with the transmission, which will go above the front axle.

So, I would have to use a 3-link front-end with a panhard rod.  The top mount on the axle wasn't making for nice geometry with the available holes on the chassis, so I decided to make an extension bracket for the axle.

However, this position turned out to be too limiting for upward travel - the new bracket hits the chassis under compression.  Time for a re-think...

[Mad Ax 9329]

OK - new plan!  A more scale-correct panhard setup with shorter link arms.  This required some re-drilling of the chassis.

Top link mounts to the same position as the bottom link.

I spent a long time deliberating over how to mount the panhard rod before I had the somewhat out-of-the-box idea that I'd mount it through the chassis using a rubber bush, just like a real car.  OK, a real Toyota isn't like this, but lots of cars have torsion arms connected with only a rubber bush for hinging action.

Replaced the top kingpin screw with a ball screw.

And this was where I had to finish.  Lots more work still to do, but the concept basically proven.

I did wake up early the next morning in a panic that the new kingpin screw arrangement would interfere with the wheels, however the wheels fit quite nicely, which was a relief.  However, that in itself would turn out to be a problem that came back to bite me later...

[Mad Ax 9329]

I had a few days off work this week, although I spent one of them buried under a blanket with some kind of mysterious virus (who would have thought you can catch anything other than Covid right now..?) and another buried under DIY and workshop tidying that I've been putting off since before the pandemic started.  The last of them, however, was Thursday 28th, and it was almost 10 degrees C in the workshop when I got started.  Last week it took about 4 hours of wood burning to get the gauge that high.

So - I figured I'd try to sort the rear linkage first.  I'm not so pushed for space at the back, so I could do a conventional 4-link.

[Nobbi1977 1793]

Funny I just sat my Bruiser body on my SCX10 with Maverick axles today and started to play. I will have a good read through all your posts later

[Mad Ax 9329]

I mounted the shocks from the top of the axles, although I may relocate them later as the back end is quite high when unloaded.  I either need to soften the springs or lower the mounting points.

There is still some gap under compression, meaning the shock mount could go lower, but under articulation the wheels touch the arch so it's probably not far off perfect if I keep this much articulation in the rear

[Mad Ax 9329]

Turning my attention back to the front end, I had to file away part of the chassis to allow full compression on the front axle

I went with a more upright position on the front shock for better scale appearance, but I had to make a bracket to bring the shock mount rearwards.  I will probably re-make these brackets in a more scale shock hoop appearance once I'm happy with the front end and possibly cut off the stock shock hoops or hide them behind bracketry.