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JennyMo

SRB Cage Racer - aka. Mjolnir (the heavy metal Hammer)

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1 hour ago, Percymon said:

Hmm, i hope she's not driving !

Ha ha - steering with her knees ;o)

I'm aware some further [arm] surgery will be required - I'm just debating which arm...

I do like the fist-bump out of the window, so I may mod her right arm to be holding the wheel... alternatively, her left arm could come inside and the right hand could be reaching for the radio (I'll also be using a Wild Willy 2 dash in this build) or as a deft one-finger on the gear lever perhaps?

I can also report that I've finally sussed the upper rear suspension mounting - just got a bit of alloy bending to do!

More soon!

Jenny x

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15 minutes ago, Country Mike said:

Awesome. 

Thank you!

I'm hoping for a whole lot more awesome too - got a few new tricks planned for this one ;o)

i-q9wMSdv-XL.jpg

photo. including a steering column/wheel that actually turns with the servo... complete with QR boss!

Jx

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1 hour ago, JennyMo said:

Ha ha - steering with her knees ;o)

Jenny x

Indeed, just need the vanity mirror and the make-up case ;)

 

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7 hours ago, Percymon said:

Indeed, just need the vanity mirror and the make-up case ;)

 

Funny you should say that... ;o)

i-MH7kFRP-XL.jpg

Jx

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Right, onto slightly more serious stuff!

More M2.5 screws arrived today, which meant I could finally fit the alloy side panels - it's starting to look a lot more like a real race-car now:

i-bnSkTgn-XL.jpg

You might also notice in the above photo that I have finally managed to mock up* a rear suspension mount:

i-qt2n56g-XL.jpg

photo. upper shock mount constructed from 35mm threaded rod and a series of Tamiya rod-ends, with alloy tube as bushing for the M3 set-screws and shock bolts.

*The shock 'bracket' was then mounted to a folded alloy plate (only 1.5mm thick, as it's all I had to work with at the moment), which sits in the cut-out of the SRB gearbox where it bolts to the chassis plate. Ultimately this design will work really well (I think), however at the moment there is quite a lot of flex, so I'll have to get this L shaped 'tombstone' CNC'd and make it around 5mm thick.

I will also take that opportunity to make it a little less slabby (while ideally retaining enough flat surface to mount the speed controller and receiver), and may even incorporate a pair of angle buttresses to add extra rigidity.

 

Cage and body mods.

With the side panels fitted, it was time to make a few cuts - first of all (with tin-snips) trimming the inner wings to match the flat floor of my chassis:

i-37f7gH4-XL.jpg

I also took the Dremel to the rear of the cage:

i-Wm7L5Lc-XL.jpg

...and the result is a much neater rear end I feel:

i-tCfC4rg-XL.jpg

Coupled with shortening the chassis/wheelbase by 10mm already (now 265mm axle to axle), I think this makes the car look a lot more squat and purposeful, and hopefully less like a Twin Hammers on little wheels?

i-3SFXTzP-XL.jpg

photo. I'll also mount a spare wheel horizontally above the engine*/gearbox, adding even more weight to the rear!

 

I then played around with a possible new rear light location:

i-KJH7V8m-XL.jpg

...but ultimately will leave this until I've fitted the *Knight Customs scale engine I ordered through Shapeways in plenty of time [I thought] before I left the USA, and which is now currently sitting in a box on Lisa's dining table... darn it!

 

So with that done, I had to see what it's going to look like with the wheels and tyres fitted (still got to drill the centres out, but that too is in hand now ;o)

i-dZNh8KP-XL.jpg

photo. Love this retro-combo look - Baja racing in the 80's!

 

i-BwhLFHM-XL.jpg

photo. Wanda thinks it looks pretty good with the headlights refitted too!

 

Battery location.

I know some of you suggested I drag myself into the 21st century with a Lipo or similar smaller sized battery with this build, but as I mentioned at the beginning of this thread, part of me would like to retain an old skool full-size 6-cell NiMh pack - at least when running - both as a homage to the donor (a Rough Rider) and SRBs in general, and to continue the 80's vibe I'm going for visually...

Having repositioned the seats about 10mm forward (once I knew how long Kelly's legs were) I realised I could shorten the chassis/wheelbase by a corresponding 10mm too, and yet still have enough room to fit a battery pack flat behind the seats:

i-mN2Nzch-XL.jpg

 

However, I think ultimately I will have the battery angled as effectively a seat bulkhead - making it almost invisible when the car is running:

i-3GnZGJ9-XL.jpg

... and the lugs on the cage mean I can always fabricate a rear deck cover anyway for the space behind the seats - which would also be an easy way to hide the speed controller and other electronics/connectors too of course.

More soon - I can't wait to get the wheels on now!

Jenny x

 

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ps. Before any of you ask, yes, it's a heavy beast with all these metal parts - currently 560g - and that's with no battery, electronics or wheels & driver/dash/scale engine fitted...

So if I'm going to run this at all seriously, then that poor 540RS motor is probably going to need an upgrade too I feel!

Jx

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One step forward, four wheels back... or not, since I can't return them, only sell them now.

So I managed to get a pillar drill and a step-drill bit to drill out the RC4WD wheels to fit my SLW hubs:

i-FcCvBfb-XL.jpg

Great - everything nicely lined up and accurate... go to assemble the wheels (at long last!) and it turns out that the PCD OF THE SLW HUBS IS NOT THE SAME AS RC4WD'S 6-BOLT PATTERN.

As you might imagine, I immediately cursed the RCCrawler forum for the mis-information.

Turns out the SLW hubs have a PCD of 17mm (as far as I can tell with my reading glasses on and and my callipers), while the PCD of the RC4WD wheels is 16.5mm - doesn't sound much I know, but it's enough to mean the hubs will not line up with the wheel holes enlarged to 3mm - and even if you drilled out the bolt holes to 3.5mm, they will still not line up using the 4-40 bolts the SLW hubs require (and once you drill them out that far the scale acorn nuts will then go through the holes anyway)...

This massively disappointing on two fronts - mainly that I really like the idea of some scale Weller white 8-spokes on this build, and that all the other [alloy] 1.9 wheels that DO fit SLW hubs are either really chunky bead-locks that don't really suit this kind of car and/or stupidly expensive too ($100+ USD at least).

To make matters worse, so confident was I that these wheels would fit my SLW hubs, that I even bought a 5th wheel (at significantly higher cost here in the UK) as a matching spare for the back of the car...

It seems everything I do to try and get this car on four matching wheels is thwarted!

 

So, I've reassembled the original set of 4 wheels, now complete with Axial IFD 12mm hex hubs (all brand new parts) using the RC4WD M2.5 bolts, and am offering them here to anyone who wants some 1.9" internal bead-lock steel wheels that will bolt straight onto regular axle 12mm hexes.

i-kb93dbq-XL.jpg

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£40 for the set of four (including the original pin hubs and hardware) posted to the UK (International postage at cost) - unused and as new other than the centres have been drilled out to 12.5mm to fit the diameter of the IFD hubs. They'll even come in the original box.

My loss is your early Christmas present. Grrrrrrrr.

Jx

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Kelly saves the day! (and a lot of money! - well, for now anyway... ;o)

So while I spent half the night drowning my sorrows on eBay looking for some suitable wheels that will properly fit my SLW hubs, Kelly had a rummage in the spares box... and after a quick measure with the callipers, she reminded me that actually the F350 wheels have a slightly wider flange around the hub area - which means if you drill the centres out (to at least 10mm so the Tamiya spanner can fit in to do up the axle nut) they don't look butchered in the same way as the Pajero wheels did... hmmmmm.

While they might be a bit more 'flashy' than I envisaged for this build, they actually look pretty similar the Vanquish Method Roost wheels (which are the only non-beadlock alloy wheels that I've found, and that I like the look of) - albeit in plastic of course - and these Tamiya wheels even have some pretty scale looking acorn wheel-nuts moulded in!

So that's just saved me a consolatory purchase of $120 USD at least!

i-L5xxBj2-XL.jpg

photo. Ironically, this project has almost come full circle regarding the wheels - but then it helps to keep the 'Tamiya' vibe going too of course!

 

Once the front wheel centres were drilled out, my 3D printed hubs (see much earlier in this project) which I'd managed to prise out of the old Pajero wheels without damaging them a while ago were superglued in, and fitted with a pair of 1150 and 850 bearings.

The rear wheels simply fit directly onto the SRB hex adaptors already fitted to that axle (so that's all four expensive SLW hubs currently consigned to the shelf for now then); and finally, for the first time in what has been three and a half years [to the day!] since it's inception - the car now sits on four matching wheels, that spin correctly and are secured properly...

Good work Kelly!

 

Merry Christmas all - I hope to get a chance to get back on this some more over the holidays!

Jenny xx

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Seems to be real hassle. Shame you couldn't use the white wheels, they looked sick. Are those going to be painted?

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1 hour ago, _oliK said:

Seems to be real hassle. Shame you couldn't use the white wheels, they looked sick. Are those going to be painted?

Hi Oli - yes, it is a shame there are not more standard/traditional looking wheels that use the SLW hub pattern, and equally it's a shame that the various manufacturers can't all agree on the same six-bolt PCD too!

For the moment I'm going to leave the F350 wheels as they are - the look is growing on me, and they do match the bodywork (and ultimately the scale engine when it arrives too) pretty well - plus are recognisably Tamiya too of course.

But I may ultimately end up with some Vanquish alloy wheels at some point in the future - but that will most likely have to wait until I go back to the US again next year sometime. There are also some very nice looking scale disc rotors machined to fit the SLW hubs too - tempting!

For the time being, I'm going to concentrate on finishing the body mods - including a horizontal spare wheel carrier above the engine, and the dash and working steering column. The work out how best to hide the electrics once my billet rear suspension tower arrives! 

"More soon" as they say!

Jx

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Just a quickie: Kelly rolled into the workshop (well, it's almost a workshop - they just need some proper garage space for this increasing collection of accessories ;o) just in time for Christmas, so that Jack and Wanda could discuss what to do next...

i-PZ9td8W-XL.jpg

photo. rear cage modified (using off-cuts) to include a spare wheel cradle - wheel will be secured with scale ratchet straps.

 

The roof panel will most likely be formed from thin plasti-card covered with a carbon-fibre skin - certainly I think that panel will look good/better in black rather than bare metal - although I'm kind of tempted to get a Kellogg's All-Bran logo decal cut, if only because that was the cereal packet I used for the template ;o)

I will probably also look at filling in the rear wheel-arch quarters with some kind of panel-work, and similarly try to disguise the area around the steering rods too. I'm not a huge fan of carbon fibre in general, but I think on this build it might actually be appropriate on those panels that might otherwise be painted plain black?

I'm also toying with some overall graphics options - typically there would be a collection of sponsor stickers on a vehicle like this, plus race-number boards on each flank of course, but I'm also considering adding some stripes too - maybe a red/orange/yellow combo perhaps - to tie in with other Tamiya buggies such as the Super Champ and Hornet?

Hmmmmmm. I think I need to contemplate this over a glass of mulled wine...

More soon!

Jenny x

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OK, not much to report - just a little tweaking in between all the Christmas cooking and overeating!

I've been messing around with the rear shock mount geometry a little more - despite having twin shocks on each side, there doesn't seem to be a lot of rebound (although maybe that's an SRB trait anyway?) - and so the rear end was squatting as soon as you compressed the suspension once...

In that regard I've subsequently trimmed the rear of the plate chassis, and mounted it inside the recess in the gearbox assembly (rather than below), effectively giving me around 4-6mm more rear ride-height, which also results in a little more clearance between the spare wheel cage and the top of the engine* too.

*When I finally fit the Knight Customs scale VW engine back there.

I also mocked up a rear load bay cover, to help hide the battery and associated electronics:

i-55c3Jp4-XL.jpg

photo. The final dimensions will be decided once I have the [thicker] billet suspension tower bolting into place. Whether this becomes a fuel cell, or perhaps a stowage bin for a tow-rope etc. (or a combo of both of course) I'm not sure just yet...

Meanwhile I also messed around with some dash mounting ideas:

i-5cgSBdB-XL.jpg

photo. You might notice I've modified her left arm to keep it inside the car, and hopefully getting close enough to ultimately hold the steering wheel.

 

...and Kelly got a new outfit for Christmas:

i-7Ln6t2Z-XL.jpg

i-vTmpSfL-XL.jpg

To be honest, I'm not sure about those shades - but I'm liking the khakis and denim jacket a lot more than her previous garb!

 

Happy New Year all!

Jenny xx

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Ok, so it's not a very good video (I had to slow it down 50% and the little blighter is still too rapid on the kitchen floor!), but I just had to share this with you all:

Yes, finally the SRB Cage Racer moves under it's own power at last!

Chassis and build updates to follow soon!

Jenny x

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Go Jenny 

nice work as always looking forward to seeing the finished racer.

and you lady friend driving  Awesome 

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So what did it take to finally get it rolling you might ask?

Well, after I'd finished messing around with Kelly's new outfit over Christmas, I was able to work out the final seating postion so that her arm might also move with the steering wheel which I intend to animate (note. I'm still waiting for the postman to deliver a pukka 1:24th scale prop shaft to be used a steering column, after experimenting with and finally abandoning the idea of using Tamiya dog-bones and stub axles), and with those dimensions essentially set, I turned my attention once again to the chassis...

i-Qsh8Tnz-XL.jpg

While the original location for the servo posts was ok - using one Tamiya square mount on the bracket of the front suspension, and another with a 4mm cut spacer directly to the chassis - it did feel a bit of a compromise, although admittedly it was a pretty solid mounting...

However, the primary reason for raising the servo a few more millimetres (with some new mounts) was to allow a longer servo horn to be fitted - increasing the steering throw which was currently not sufficient to turn the wheels from full lock to lock with my existing 'shorty' horn.

So I cut the risers off a pair of servo mounts I had as spares for my crawler, and mounted them directly to the chassis plate between the front suspension brackets...

i-JqqJq97-XL.jpg

i-ZqB4zC3-XL.jpg

photo. Now that is 'proper'...

This also allowed me to use a deeper stepped servo horn - keeping the steering rods perpendicular to the chassis (to minimise/eliminate any bump-steer), and by mounting the servo slightly more centrally than before, meant the steering rods themselves were more balanced with equal amounts of thread showing on each end:

i-zF8T6PG-XL.jpg

photo. These are 3mm Tamiya steering rods with 4mm ball rod-ends - I forget from which Tamiya model, but the longer arm is 70mm and the shorter one 45mm. note. these particular lengths were required for the direct steering as I have widened the front track of the SRB suspension of course.

 

Chassis plate - evolution

Having yet another redundant hole in the chassis now (together with the four from where I'd repositioned the seats), I felt I'd ultimately need to cut a new plate anyway, so took the opportunity to experiment with some infill panels for the rear wheel-arches before the final redesign and cutting:

i-36nVHsd-XL.jpg

photo. Initially I considered making these triangular panels separate (from styrene, covered with carbon fibre sheet perhaps), and bolting them on...

Having mocked it up however, I realised that if I were cutting a new chassis plate anyway, then these inner arches could actually be part of the chassis and simply folded up to meet the cage...

i-hFqG4D9-XL.jpg

photo. together with the inner arches, I'd also mocked up a cover for the area behind the seats - simple and effective, and a great way to hide the battery and other electronics...

i-28sTVNK-XL.jpg

photo. roof panel back on too - gotta love those cereal packet templates! - plus messing with spare wheel mounting options (there is currently a Tamiya stub-axle through the RC4WD pin-drive hub)...

 

So once again it was out with the pens and the ruler, and to sketch out the revised chassis plan:

i-W6Dff24-XL.jpg

photo. A new piece of 2mm thick aluminium sheet (300 x 150mm was the perfect size), and a template cut before the final scribing on the metal itself.

 

i-SWhVrWd-XL.jpg

photo. the new chassis follows the same dimensions at the front as before (with the revised holes for the new servo mount), plus the two inner 'wings' are folded up to follow the line of the rear of the cage...

 

i-8cs36dV-XL.jpg

photo. pretty cool eh?!

 

i-TcrprKq-XL.jpg

photo. Inside: the chassis is now bolted on top of the rear subframe (in the recess) - lowering the rear end and levelling the chassis when the weight is on the axles. note the rear shock tower is still a temporary piece (folded from 1.5mm plate), I've not been able to get a dedicated piece CNC'd yet. Now that the chassis is above the subframe, I may well extend the lower face of the L bracket to add more support and stiffness.

 

i-zZgCGnQ-XL.jpg

photo. And this is what it looks like all bolted together!

cont.

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cont. 

More Power!!!

Fortunately all this chassis work coincided with my ESC and an alternative battery pack arriving this afternoon, which meant it was now feasible to get the car rolling and actually running at last!

i-47hdT3m-XL.jpg

photo. Mtroniks ESC compact enough to fit between suspension tower and gearbox - nice!

Based on a suggestion way back towards the beginning of this thread, I went with a Modelsport/Mtroniks ESC - being very compact, particularly for the price; and while the original [programmable] suggestion - the Sniper RV-12 - was out of stock, I took a punt on their RV-20 'auto' version instead, which seems to work just fine, and ought to be perfect in this application.

 

i-gWwtKWB-XL.jpg

photo. 6-cell (7.2v) NimH battery pack in square format - more easy to disguise as a scale fuel cell perhaps?

While I was confident my new folded chassis design would still allow a regular 6-cell stick-pack battery to sit below any rear deck cover I fabricated (and I can confirm it does), since I'd been able to incorporate proper inner wings as part of the chassis, and that the ESC can be effectively hidden between the suspension tower and the SRB gearbox, then it's feasible that I could now leave much more of the interior exposed (like a real cage buggy) behind the seat themselves, and simply fabricate a scale fuel cell to cover the square battery instead?

So this is the next thing I'm going to play with, while I wait for my animated steering components to arrive so that I can finally get the dash-board fitted properly and Kelly finally fixed in her seat!

 

More soon!

Jenny x

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I can vouch for those MTroniks ESCs; all my cars use them without issue.

The cage racer looks fantastic! Nice work on the floor pan :)

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I know you’ve still got a bit to do still but you have to video this one down the beach. :)

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9 hours ago, SRB Bloke said:

I know you’ve still got a bit to do still but you have to video this one down the beach. :)

Hee hee - by the time it is actually finished, hopefully it will be warm enough here in north Wales to brave going onto the beach! ;o)

Jx

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2 hours ago, _oliK said:

Amazing!!!

Thank you! - and you're gonna really like this next bit too I think... ;o)

 

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Up on the roof!

So I thought I'd break-out the styrene and make a start on some more of the body details - first up, turning that cereal packet template into a proper roof panel:

i-XdXksvx-XL.jpg

Once cut, scored and heated/folded to the correct angle to follow the cage profile, I decided to try something new - using sticky-backed 'carbon fibre' sheet to cover the plain plastic:

i-VGPRp2q-XL.jpg

I have to say, I think the result is quite effective and realistic?

i-QqX4zR8-XL.jpg

I elected to use some spare black M2.5 button heads (that originally came with my Vaterra rear cage used on Desmond) to secure it, very stealth ;o)

i-9D77kLV-XL.jpg

 

More soon!

Jenny x

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