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I love it.

Last structural bits of the main cab now in; rear body mounts extended by cutting off the regular pip, drilling out & using the shorter vertical body mounts; also started on the front arches - used some artistic licence to give them more strength, and a lot of fettling/trimming will be required to get the body to sit level again ...

More progress: a lot of the front arches needed trimming away to get the body to sit flat again, that & putting in a couple of pieces to act as reference points was about as must as I got done yesterday ... today was the rest of the hood/bumper structure.

Still a lot of filling/sanding/bracing before I can move on - but I'm already thinking about plumbing: the water tank will have to go at the highest point of the chassis at the rear - even if I make it rectangular to use as much space as possible it'll only hold about 1,100 cc - not much in terms of duration (30 seconds?) - but a lot in terms of weight (1.1kg, obvs, or nearly 2 1/2 lbs) for a 1:10 car, especially high up...

I'm thinking a more asthetic looking oval will only hold half as much, but also weigh half as much - and I can keep the duration up by going down to a single cannon (which makes more sense for application on a small truck like this anyway).

I had hoped I could use a windscreen washer jet (no point reinventing the wheel & all that) but they all seem to be very ugly & plastic - so it looks like I have to machine something from brass. as long as it's got some sort of convergence (taper) & the business end of the nozzle is very small, I'd hope it would work ok ...

Your windscreen jet is a good idea. More pressure less debit. And you can put it into the body and go with a small pipe to the canon wich I am sure you will build perfectly.

Used Milliput to fillet ahound the hood panels, filler on the other joint lines & sanded back again...

Also quickly machined a water jet from 1/4" (6.35mm) brass hex, internal "taper" is in steps from 2mm to 1.5mm to 0.9mm, initially I tried 0.7mm but that seemed to be putting too much strain on the motor. I'll add bits to it to make it look a bit more the part, but it's performing well enough that I'm not inclined to try anything else - a very temporary test rig showed a range on 7.2v NiMH of about 13' (4m) maximum in a fairly coherent stream, water consumption (measured from 100ml) is a bit less than 1L per minute, so my target tank size will give about 30 seconds total duration.

I'm thinking vertical adjustment will have to be by hand - but having a second servo matching the steering input should be quite straightforward

I've been working on the tank the last couple of days ... an oval might not be the most space efficient shape, but I want it to look nice even if it's not on show.

Starting with four formers (middle two with some cutouts to allow water to flow, but not too much) + a bunch of stringers ....




... to make the basic shape:




Skinned with two layer of 0.5mm sheet, + capped the end & started on filler cap/tube & breather ... also working on sump + 4BA brass fastener prior to being machined into an output spigot:




A little bit of detailing, plus fixings to hold it in place - currently just held on with Blue Tac ... filler & breather can to be reduced in height to clear roof...




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Maximum capacity is a smidge over 400ml - a bit less than my target, but good enough

It is tooooo nice Jonny.

Really cool project, Jonny! Looking forward to a video of it hosing down the cat

Seems to have been an awful lot of faffing about to get to this point on the water cannon ...