Mad Ax

Happy Friday, everyone! Has anyone got anything exciting planned? My weekend is still "open" but I'm fairly sure I know what I'll do. Friday - work until 2pm, very busy and have lots to do but hopefully the time will fly past. This afternoon I'll try to get the hillwalking truck back to some form of runnable state, and then take it to my local walking ground. Although my local walking ground is actually the buffer land around a military training area, and last Friday they had some big exercise on there. It's around 7-8 miles away as the crow flies, but the shelling was making the floor shake and I could even hear the 50 cals. So, perhaps, if the floor starts shaking later, I'll go to a different place. I've been walking there when an exercise was on just over the hills and it's not a pleasant experience. Saturday - wife and child are out all day so I'll probably spend the day in the workshop, get the Mi-8 tidied up and on the setup deck, and try to finish some more structural work on the hillwalking truck - assuming it comes home intact from tonight's walk and doesn't need to much fixing. Sunday - quiet day at home with my daughter. Lots of little DIY jobs are stacking up, so I'll try to get some of those ticked off. Have a great weekend everyone

Got a couple of these in storage for a retirement fund - they just lost a heap of value. That said, the originals do have a numbered certificate inside - I expect their value will eventually recover. I don't usually buy kits that accumulate value for this very reason - you can never be sure that value won't be wiped by some market shift like this - but I'm not going to lose any sleep over it. In fact it would be great to see more of these being enjoyed. I expect some speculators might be a little upset

We forgot to brief the photographer, so he was late to bring his lens to bear. This is the only shot we have on the day. I was late getting it ready too - I'd planned to use a different truck but a week before my future-wife said "that's ugly!" - so I had to rapidly cobble this one together. It uses aftermarket chassis rails, a Traxxas Stampede transmission and TLT axles. On the day, the shocks had no oil in them, it was RWD only, and the propshaft was a piece of solid brass rod between two metal UJs, so the rear suspension was locked out. Also since none of the guests knew it was happening, it spent the entire morning switched on under a table behind the tablecloth at the back of the venue. The transmitter was hidden in a closet. I was terrified the battery would dump after being left on for so long, and the "top secret driver" (who was neither me nor best man) would have to crawl around under the table to dig the rings out and deliver them by hand.

Welcome to the forum I also had an RC ringbearer at my wedding

So, I've been using these FTX wheels and tyres on the truck since I first built it. I really like the tyres - the tread looks just right for this sort of rig, and they're just the right size. In fact all the arches were made speffically for this tyre. They're cheap, too - less than £10 a pair. However, there are some challenges. the wheels aren't quite right for the style of truck I need 2 more tyres for the spare carrier I need to add wheel weights, but the tyres are pre-glued I need to add stiffer foams, but the tyres are pre-glued My plan, since the start, has been to buy 4 new tyres and 4 new wheels, and install 1 pair of the old ones on the spare carrier. Then I was going to 3D print some portal style covers to go over the wheel centres for an authentic look. However - while floating around on Aliexpress today I found some portal-style 1.9 metal beadlock wheels that look just perfect. I placed the order, but I'm going to hold off ordering the tyres right away because there's a note on the shop's page about these wheels only fitting tyres with a 52mm bead, and the FTX website says these tyres fit a 54mm wheel. I'm not sure if that's just a difference in where the measurement is taken from, or if I'll have to get Chinese tyres for these wheels. There's quite an array of tyres on Aliexpress and some look like a really good match. And there we have it - there's still loads more work to do, but - fingers crossed - I won't get any more interrupted weekends for a while, so I can tick some of these things off the list and actually go drive the danged thing.

That pretty much took me up to close of play. I had to come in to put my childperson to bed, because my wife's plague was so bad that her runny nose precluded her from doing her turn at bedtime, and after that I just wanted to reheat my curry and watch a film and drink some alcohol-free beer. So, where are we now? Well, during Monday's lunchbreak I was too busy tidying the workshop for 20 minutes and then my wife came home sick from work and brought me pie so I went in to eat pie before my afternoon meeting that very inconsiderately started right after my lunchbreak ended, forcing me to actually eat my actual lunch during my actual lunchbreak. Yesterday I had an appointment to go to during lunch so I didn't have any time at all, and yesterday evening I decided against my better judgement to sit down and do my finances, which I really wish I hadn't done, because sometimes not knowing is better. Today my new red LEDs arrived, so I soldered up the rear loom, but my new RGB LEDs haven't arrived so I can't finish the front loom yet. I also started looking at fitting the rear light buckets. I've sort of got an idea how they'll go, but I'll need to make all-new backplates and also get the correct tyres installed on the rear. And here we have another problem opportunity...

But while I was working on that, I had to strip a lot of the truck down and take off the wheels, and that makes it hard to put in a place where it's safe, won't fall over, but still lets me access all the important bits. So I changed my direction and started building a professional truck stand, instead. All using reclaimed material, some from my wife's recent custom fitted shelf installation and some from when I took my airing cupboard apart a few years ago. If anyone wants a custom car stand, message me. I will be selling these for £100 plus postage. For an extra £20 I can even scribble signwrite the slogan of your choice onto the scrap of plywood base in Sharpie. How cool is that?

So, what next? Well, I've been worried about the front crossmember for a long, long time. Since I made the front skid plate, really. If you cast yourself back 10 or so pages, you'll see that I bent the stock bumper/cab mounting plate back on itself and then bent some sheet aluminium to make a skid plate / sump guard. It looks cool and provides protection for whatever is behind it. The problem is, that skid plate, and the bumper mount, and the front bumper, and the entire cab, and by extension the entire brass roll cage, are all attached to the truck but just 2 screws. These self-tap into the plastic crossmember that sits just in front of the steering servo. One heavy descent into a badly-placed rock or tree root, and either the screws will bend, or the plastic crossmember will crack. And then I've got to carry the cab, bumper and all associated lamps back with me while also trying to drive a cabless truck. My plan had been to braze up something from brass to reinforce the back of the skid plate and provide a triangulated mount against the body, but the front end of the truck is starting to get obscenely heavy, so it needs something simpler. Also the stock screw holes in the front bumper mount are in kinda the wrong place, making it really awkward. However, it doesn't really need to be screwed in - just having something behind the bumper mount to stop it from twisting under in a crash would be enough. This is the genesis of that part.

I wanted to make a proper box to go over the electrical stuff, but it was a bit too much work for a shortened Sunday, so I just made this quick panel instead. I got my measurements wrong for the switch so it's a bit distorted - later I'd change the design. I kind of want to tidy up the plugs for all the servos. If I built this again I'd put them at the other end so they're not in the way of the battery packs. Some kind of block connector to move everything out of the way would be nice, but I don't have anything in stock that will fit. Oh yeah - about that switch! What's that for, I hear you ask? Well, this was something I'd planned right from the early days of the code. I figured, with all the complex stuff I've added like cruise control, reverse mode, inertia-based steering and all the rest, there was the potential that I'd stumble on a rare and awkward bug that would render the truck completely undrivable half-way round a challenging route. Since it's a huge weight to have to carry back, I installed the switch as an override. If I flip the switch, it goes into pass-thru mode - that means the incoming channels in the receiver are passed directly out to the relevant servos. Or more specifically, the ESC and steering servo - all the others are set to the centre position. That means it can still be driven like a normal truck, if anything should go seriously wrong. Although I think I need to relocate it, because it's going to get in the way there and probably get knocked all the time.

Here is how the electrical box is mounted. Tilt it into the space, align the holes. When the panel is tilted up against the side of the truck, the screws automatically go through the holes. They don't need nuts on the end to hold it. Eventually I'll put some hook-and-loop fasteners on the back of the panel to keep it in place. Old hook-and-loop still there from where I tried and failed to mount the full-size Arduino. Headlamps working. This is a modern truck, so I went with modern pure white LEDs instead of the vintage natural off-white LEDs I use on the older trucks.

It was at this point - around 11:30am, to be precise - when my wife dragged herself into the workshop to tell me she felt too ill to stay up and was going back to bed. My daughter didn't want to spend the day alone, so I shut down the vents on the log burner and went back inside for what I expected to be the rest of the day. However, around 2pm, my daughter decided she wanted to practice her ill DJing skillz on my Numark digi decks, which are in the studio, which is in the workshop. After a quick refresher course, she decided she wanted to be left on her own to mix some sick beatz, so I shut the door and went back to my other project. I discovered that a) I don't have any more 5mm red LEDs, so I couldn't wire up the rear lighting loom, and 2) I had ordered common cathode RGB LEDs for the dash indicator light, and my new electrical breakout box requires a common anode RGB LED, so I couldn't wire up the front loom either. With that in mind, I decided to throw on a sacrificial plug just so I could test the headlights. I've deliberately put these little JST connectors on either end of my LED looms so individual parts of the truck can be taken off without having to pull all the loom out with it. Here is the LED multiplug connected. Also tidied up the front wiring a bit. I also had to make up some extension cables for the servos and ESC so as to not have the wires stretched across the battery tray.

Next I wanted to mount the electricals box in a manner that made is secure, but was easy to remove for maintenance and to upload new code. Although I can probably fit a USB cable permanently to make it easier to plug into the laptop. This is a bracket I made. It goes here, bolted to the rear bed using the same holes as the side panel mounting bracket. Electrical box will sort of go sort of here Like this. The screws are permanently screwed into the plasticard sheet, and they just sort of pivot into the mounting holes.

OK... Right... Where was I..? Sunday dawned bright and unexpectedly cold, but that's OK since I still had one box of fresh firewood left. It was around 3 degrees in the workshop, so I got the fire lit and started planning out my day. Since the weather was so good, and I'd missed my Friday walk because I had some family things to sort out, I figured I'd go for a walk on Sunday afternoon. That limited my workshop time, and also focussed it, if I was to have any chance of getting the truck ready to go with me. Since I had all my electronic stuff out and in the way, I figured I'd start by making up some lights. These are the headlamps. I still need to find some way of properly protecting these - one unfortunately-placed branch and these parts will snap. I've no idea how hard they'll be to replace. They're not fitted in the conventional way, and the standard backplate also holds the LEDs for the lights in the lower bumper, which I don't have, so I had to hot-glue these bulbs in. I'll have to 3D print a backing plate eventually. It should fit neatly sort of like this. I left plenty of space above the bumper because the bracket that the cab hangs on goes here.

The TL01 should be a great base for this project. Despite the incorrect drivetrain, the long box centre looks much like the central chassis on a big rig, and gives you plenty of space to hang fuel tanks and tool boxes either side for more scale looks. I look forward to seeing how this turns out

This thread seems in keeping with the Club 380 phenomenon that seems to be gaining traction all over. Perhaps this is another in a line of backlashes against the cost and complexity of racing - people got fed up with racing modern buggies so we started racing vintage, now the vintage scene is full of top-class racers running heavily modified cars, plus high-cost re-res have taken over from simpler vintage cars, and once again it's a series where you have to have the latest and most expensive kit to be competitive. So now we're fitting 380 motors to our old buggies and changing the rules of engagement. Yeah, I love the idea, but I've just put a 380 in my Fox so I can do some Club 380 races this year, if I get some spare time and money. I haven't owned a Grasshopper in years and I'd like an excuse to buy another, but one more car = one less race meet. This kind of strict limitation is going to keep more people out of races. That said, the new Club 380 races taking place here in the UK have got different classes within the regs, so if you enter a Hornet you'll be racing against other solid-axle cars.

I'm a software developer, so I had a head-start in writing the code for the Arduino, although I'm not a C++ developer and there are a lot of gotchas that us .Net coders never have to worry about. I was able to get started easily but once I started trying to do advanced things, I got myself into heaps of trouble (or maybe stacks?) and had to do a lot of learning and troubleshooting. Electronics-wise, I covered the very basics at college but mostly we only did theory, I don't think we ever touched a breadboard or a diode. I still remember the basics from school (V = IR and P = VI) but all the other stuff I've had to read up on. The internet is full of advice but again, once you go beyond the basics it can be hard to work out what question to ask to get the answer you need. Hence why I spent a long time getting confused about my transistors and wiring them wrong twice before I finally found the info I needed. I'm pleased that all the electronics work the way I intended now, but still can't be 100% happy with the cable routing or the tidiness or the amount of space it takes up. I suppose I could get a PCB made, but that requires a lot of screen time and I get way too much of that already.

But the good news is, it works! Everything re-fitted, battery in, and the lights come on and are controllable from the transmitter. Superb! I think I need to adjust the settings a little - I have two brightnesses for the roof lamps, and the lower one is still a little bright. I might even add 3 settings - that shouldn't be hard. I even managed a very brief test-drive outside, although I took it steady because it's on tarmac. This thing is now seriously heavy - the standard FTX tyres and foams are almost flat when it's resting with batteries in. It's going to need some much stiffer foams, and it could get very tippy if I'm not careful. TBH I'm sort of worried for the axles now - how much weight will they take before they snap? It'll be OK rolling on the smooth sections but bumpy terrain could kill it. I don't know what options there are for strengthening those axles - I guess their narrowness works in their favour. There's still so much to do here, I'm not even sure where to start. I guess getting the electrical box properly and securely fitted is the next step, so I can actually drive it again. Fitting the rear tubs will be essential to keep the water off the Arduino. I want to build some more reinforcement around the front end to protect the standard headlamp buckets. I was going to make something from brass but I can't afford to add any more weight - I think this truck needs to go on a diet, especially at the front. It would be nice to get more light buckets fitted and LEDs wired in, so I can actually test all the light functions at the same time, plus that front winch needs to be hooked up somehow. I need to work out where to begin on Sunday!

Now here's where it gets seriously challening. I can't get the torches onto the rack while it's mounted, so it needs to come off. Getting them on is fiddly because I have to pass 2 wires, 1 with a fat resistor on, through the holes before I screw them down. Getting it back on isn't exactly easy either, there's a lot of faf and fiddle here. And getting all those plugs connected with the cab on is impossible. The finished truck will have a windscreen as well, so all this needs to be re-thought. In the end I had to take the hinge mount off the front crossmember. That's not easy because it's behind the sump guard, so that's got to come off first. And will be even harder soon because I need to build more reinforcement under the front end.

I finished work a bit later than planned today, and had to fetch my daughter from school at 5pm, but I still had a little over 2 hours to play around with the rig. My main aim was to make the wiring loom for the roof lights and get them installed. It's a challenge, because I decided to keep the 30hm resistors outside the torch bodies for cooling - they get seriously hot, hot enough to make the torch body warm on a very cold day. But that means they come out underneath the lamp, so I need a hole drilled in the mounting plate, and another in the cab, for each lamp, and it needs to be big enough for the resistor to go through. Plus a connector plug so I can remove the lamps without having to desolder anything. Anyway, here's me testing the loom. Bright enough to hurt the eyes. Because of the resistors I've chosen, each torch actually draws less current than they would when powered by an 18650, but there are 4 of them, which should make up for it. I used silicon wire for the loom. It's overkill really, but it's much more flexible than the cheap automotive wire that I've got left over from my 1:1 car days. I decided not to drill out the MFU trailer connector in the back of the cab, which means I've had to use many smaller plugs on the loom instead of one big one.

Here's some photos from Weds, when I remade the LED board. The small thermonuclear reaction you see on the breadboard is an LED having 16 volts forced across it. Here's a tidied up electricals mounting board. It'll sort of go here Power distribution board refitted And power connected

After the events of the last couple of days, I have a feeling you'll be waiting for a very long time!

Good morning, people of Tamiyaclub! I hope you've all had a good week. It's Friday again, what is everyone up to this weekend? I think it'll be a quiet one for me. Nothing concrete is planned yet, so I can play it by ear. Friday - work until around 2pm. I've been waiting 3 weeks for my new pit hauler to arrive, my LHS owner called me earlier this week to say he's had problems with the delivery company and he'll deliver by hand today. But he hasn't called, so I don't know if he'll be here or not. I feel the need to give the workshop a quick panic-tidy in case he wants to check over my latest projects. This afternoon I'll be taking the wife's car to the bodyshop on the other side of town, and having a lazy walk back. Might treat myself to a takeaway lunch on the way back. The budget has been so badly blown this month that another few quid on a sausage roll won't make the tiniest dent. Hopefully I'll have time for some messing around in the workshop before I have to get the child from school, then the evening is my oyster. Pizza and zero beers are planned, but I don't know if I'll do more workshop stuff, or get creative in the studio, or watch TV or play games. Saturday - day with my daughter. No solid plans. Maybe take her to see some elderly family if her snotty nose has finally dried up, it's been almost a month now. I'll have to make time to do the finances to see how March is going to look, after such a heavy February. Curry-from-a-jar in the evening, and probably watch a film. Sunday - Workshop Sunday, probably. I've put untold hours of lunchbreaks and evenings into the hillwalking truck this week, I'm so close to having all the electrics done now. The weather is looking good, so if I can get it all done in time, I'll take it for an evening shakedown and see how well the torch lights work once the sun goes down. Alternatively, I could take a break and ride the motorcycle to the coast for the day, if the finances work out OK. Have a great weekend everyone, and I'll catch you on the flipside

A couple of years back I was watching some documentary on BBC where they were excavating some old burial chambers or something. There was a long, low earth tunnel that was too narrow and unstable for a person to go in safely, so they had planned to send in an RC car chassis with a camera on the back. What chassis did they choose? An SRB! I'm pretty sure they chose that because it gave someone on the team an excuse to go buy a childhood dream and build it. I was literally shouting at the TV saying "that won't work, it'll get stuck 2 feet in!" It got stuck. Something like an E-maxx would probably have been perfect, especially if modified for 4WS and low-speed smoothness.

More quick updates while I have a few minutes between jobs. Pics to follow in a day or 3 when I have time to upload them. I finished making the new LED board last night and hooked it up to the Arduino board. I've done so much soldering over the last week that I'm getting faster at it, but it's still a challenge, it's still fiddly awkward work, and I still make some untidy joints sometimes. That was all hooked up and tested, and it all seemed to work very well, although the LEDs were incredibly bright. Like, ultra-bright. Like, burning my eyes bright. And these weren't the big ones on the torches, no, these were the little 5mm ones that go in the headlight buckets. After double-checking I had the right resistor, I broke out the multimeter to test the voltage across it. It measured over 16 volts So it turns out the "5V voltage regulator buck" that I ordered from Aliexpress does not come pre-calibrated. There's a teeny tiny little screw on one of the components that needs to be turned to set the voltage. I was asking myself how on Earth I'd managed to not completely blow the Arduino by pushing 16v through it, but I just checked this morning, and I made a happy mistake / lucky decision that I'd forgotten about. You can power an Arduino either by the +5V pin, or the Vin pin. +5V is for use if you have a clean, steady 5V power supply, such as a voltage regulator, USB or wall-wart. Vin is for unclean power sources, and will reduce the voltage down from (theoretically) +30V to +5V. In practice, dropping from much above +10V isn't recommended because there are no heatsinks on the voltage regulator chips, so if you're getting close to the Arduino's current limit of 200mA they can get somewhat toasty. I actually let the magic smoke out of one of these chips on another board a few weeks ago when I accidentally connected the +7.4V BEC to the ground pin and the BEC's ground to the +5V pin, and now that board can only be used with a clean +5V source. The full-size version of the Mega 2560 has 2 voltage regulator chips on board, but most of the Embed models only have a single chip. Fortunately, I'd paid the extra (about 50p extra) and bought the Embed Pro version that has 2 voltage regulator chips, so presumably they shared the load, plus I had ignored my original plan when soldering everything together, and I'd used the Vin instead of +5V. So - saved by my own mistake / last-minute decision (I don't remember which because I don't remember doing that part of the board at all). This also means that I have the option of turning up the voltage a little if my LEDs aren't bright enough - I've deliberately set somewhat conservative resistor values, so I have some headroom to play with.

OK - so those of you who were trying not to laugh at me when I started this update yesterday are probably laughing at me even harder now. I went to the workshop this lunchtime to do a little more work and realised my "quick fix" of the LED transistor board wasn't going to work. The transistors are backwards, so everything is always on all the time now. The board is so tightly packed that it isn't really practical to desolder and flip the transistors, so I started again with an all-new transistor board. I have literally just enough transistors left to make a new board. The bizarre thing is I am absolutely sure I tested this last night, and it was working fine. But there you go. I know I tested the transistors on the bread board before I started, but I distinctly remember plugging in all the patch leads last night and I saw the LEDs changing intensity etc as I was moving through the settings. But today, all the LEDs are on all the time, which is exactly what happens when I hook up a transistor the "wrong way round" on the breadboard, as a proof of concept. So obviously I didn't test it after all. Still, I might have a couple of spare hours tonight. My Deans connectors arrived today so I have soldered the connections between Arduino board and 5V power supply - so today was the first time I was able to power the entire rig off a LiPo battery since I switched from full-size Mega2560 to the embed format. Although technically it wasn't fully powered because the ESC wasn't connected to the motor and none of the servos were connected. Testing this thing with such limited space and short servo leads if becoming a serious challenge, and I'm tempted to wire up some extension blocks to make it easier to run the truck on the bench with everything exposed for diagnosis. I also need to make a proper stand for the rig, because the driveshafts rub on a regular car stand and make it fall off.