Mad Ax

I've got an addendum to this. I was going to mention it in my first reply, but I felt I'd gone on long enough already. So - I started making my own "series". The rationale is that I have more cars than I have shelves, but I don't like my shelves to be totally random, and I didn't want to have to make difficult decisions every month or, worse, just have the same cars on display month after month after year. So, when I made my car database, I added "collection" functionality. When I acquire a new car, I add it to the database and specify one or more collections. I can also tick a box to say the car is "displayable" (i.e. it has chassis, body and wheels). For example, there are: 2wd buggies 4wd buggies vintage buggies tracked vehicles street cars monster trucks black and silver gunmetal and yellow blue and silver motorsport liveries scale trucks M-chassis CC-01 Ford Toyota that's just a selection. There are over 40 collections in the database right now. Some collections just have 1 car, so they don't really count, but most have 3+ cars in them. Any time I fancy a change in my shelves, I can clear off my current displays, I can set the number of spaces I want to fill (min and max), and hit Get Display, and it will randomly select a collection of displayable cars. Since I have a lot of shelves, I can re-run this process as much as I need until all the shelves are filled. As a display is "created", it is stored in the database, so it won't tell me to display cars that are already displayed in another collection. Although it can be fun, for example, if I get a "Ford" display, and the last Ford is gunmetal-and-yellow, and then I get the Gunmetal and Yellow collection, so one display can kind of meld into another in a sort of natural progression. The downside is that a) I need to keep my database up to date with displayable cars and make sure they're in the right collection, and 2) I actually have to stop being lazy and shuffle my display once in a while. So far, since I built the feature 3 years ago, I've done it... Let me see... Once.

TBH, this is exactly what the vintage RC world was like before the re-releases came around. Collectors would spend years scouring ebay and collectors' sites trying to find that one last part they needed to finish a build. It may well be tricky, as the motor probably didn't sell in great numbers, but there will be some out there. Keep the faith, keep looking and keep asking.

It's Friday again! What's everyone up to this weekend? A reasonably quiet one for me. Friday - work until around 2pm, then probably go for a walk. With a lot of other commitments, it's been a while. I need to get some training in. Home for pizza and chill out in the studio. Saturday - spend the day with my daughter. Probably just chill at home playing games but maybe we'll go out somewhere. Probably watch a film in the evening. Sunday - workshop in the morning, then going for a meal with my family at lunchtime. My sister's family were supposed to be coming, but they are sick, so will just be us and my parents. My daughter will probably be upset as she doesn't see her cousins often, and it's supposed to be her birthday celebration. Daughter is going to stay with my parents after the meal, so I'll probably come home and chill out in the workshop until it's time for a light evening meal and bed. Workshop-wise, my Mi-8 rebuild is stalled waiting for parts, so I'll focus on the hillwalking truck. I forgot to order some high-power transistors yesterday so I might not be able to finish the distribution board, but I can work on a new servo mount for the steering. Probably get an early night, as I have a long drive to the office on Monday morning and I have to drive back again in the afternoon because I'm taking the wife out for a late Valentine's meal. Have a great one everybody, catch you on the flipside

That is a good point - it's definitely more awkward and "not scale" to have the entire cage roll forward with the cab, and if I have to turn it over or lie it on its side then those lets are likely to get caught in things. I really hope that I don't have to do too many cab off / turn over repairs, although I've had to do at least 2 so far. Both ended with me either carrying or pushing the truck home. I think we'll have to see how this goes. I could of course cut the legs off behind the rear crossbar (in that case I'd take the opportunity to replace that crossbar with a thicker and flatter one) and remake the rear part of the cage entirely. I hadn't originally planned to have a rear cage but it will work nicely with the roof cover.

Many years back I bought an airbrush starter kit that came with a little tankless compressor. I didn't use it much until I got a nice dry loft room to paint in, only it would get warm in there, and over extended spray sessions the compressor would stall. In the end I had to rig up my industrial extractor fan to draw through the compressor body to keep it cool. Also having no air tank made it only useful in short bursts, so only for detail stuff, not for painting entire bodies. I haven't used it a lot recently but I've been powering it from a Clarke workshop compressor. That's not ideal as the Clarke can introduce moisture and oil, although I do have a wall-mounted moisture trap and pressure regulator. Last year my wife and I bought a new mini-compressor and airbrush at an event, but so far we haven't even unboxed it. In fact we only just cleared the spray bench 3 weeks ago.

There is a general consensus that rebuildable brushed motors are nowhere near as soon as they were, and this is probably broadly true, but it depends what you want them for. I've had good results with the Sport Tuned rebuildable range from ETronix. I've got a few of them in various states of tune in my vintage racers. I haven't noticed them being excessively slow and they have been reliable enough in the few races I've entered them in. At least, they haven't burned out or stopped on me. They have nowhere near the power of a Tamiya Super Stock and I wouldn't use one in a spec class, but if you want the rebuildable experience without a massive outlay then they're fine. It's also worth pointing out that I managed fine without a comm lathe for many, many years. Unless you are racing hard or abusing your car or using high-power low-turn motors, you aren't going to be burning your comm up too bad. I used to use some fine wet-or-dry paper to tidy up the comm when I did a brush change. Yes, now I have a comm lathe, that is mostly to recondition all the old motors that I was been cleaning up with wet-or-dry paper for 15 years. But it's a very old comm lathe and I think the bit may be damaged, as most of my comms don't look that good when I've finished. New brushes aren't expensive and as long as you get the correct type of brush, they don't have to be manufacturer-specific, especially if you're not competing at a high level. On the subject of brushless - it does make a huge different in terms of performance and battery consumption, but I have found it harder to buy good budget systems. The Gool RC stuff got recommended a lot but the one I tried has the most awful throttle profile, making it near impossible to drive predictable. An ETronix Photon system I bought a couple of years back was terrible too, for the same reason. I just want to drive my cars, I don't want to fight the ESC. For this reason, I no longer buy budget brushless - mostly it's Hobbywing or nothing these days. Hobbywing is good but not as cheap as it was and you have to be careful of knock-offs, Turnigy Trackstar used to be my go-to but last time I checked there was no stock anywhere so maybe they have disappeared. It's been a few years since I bought a Trackstar system so maybe they're all different now anyway.

I cut 3mm using a craft knife, but it takes a bit of effort and if you do the score-and-fold method it leaves a big edge that needs to be trimmed / filed / sanded down. It's also every hard to do curves using the score method - I generally cut straight and do the curves with a Dremel, then tidy up with a file and sandpaper. On the plus side it is very rigid, so if you're building something big, like a 1:10 trailer body or 1:14 truck trailer, it's perfect. 2mm cuts much, much easier. You can still get the raised edge on score-and-fold but it's easier to sand down. For smaller bodies it's plenty rigid enough, especially if you're building a box shape.

So, what now? Well, I need to work out what I'm doing about the canvas roof. If it will be laced on, I can braze on some more crossbars, but if it's going to be slid on then the crossbars will have to be clamped on somehow. So, next plan is to investigate that. Also my Arduino Embed should arrive this week so I can start wiring up the light distribution board. It's all coming together now...

Finally, I trimmed down the legs (at one point I thought I'd trimmed one to the wrong mark and made it too short, but it was just a trick of the perspective - it was fine!) There. Final photos for the day.

Then came the real scary bit - bending the cage to match the roof! It's hard to undo these bends (that's how I snapped the rod last time) so I have to get them in the right place first time. I drilled some 4mm holes into the bumper, and they're a perfect tolerance fit for the cage. I need to trim the roof a little.

Next, I decided to make a new rear bumper. I was never 100% happy with the previous one I'd made. I found a scrap of L-section that was the perfect size to make a bracket. New bumper cut and drilled Fitted. Ends of the bumper not filed and smoothed yet, I left myself some leeway in case anything was slightly off-centre.

Still, I managed to bend it mostly back into shape so it doesn't actually look too bad.

Legs. In theory the brace sits on top of the transmission and the legs go on the chassis rail. Something was stopping it from fully seating here. I left the legs deliberately too long so I could cut them to the perfect size. In retrospect I shouldn't have brazed the crossbar to the cage first, I should have brazed it to the legs. But we live and learn. The problem was that I had to turn the cage upside down, and use a block of wood to support the legs. But once I got it hot enough to flow the solder, the crossbar went soft and sagged. This will be fully visible on the finished cage so it's not ideal.

Updates! I figured I'd at least start with today's updates before I head in to make my dinner, although I doubt I'll have time to finish. I got a surprising amount of work done today, despite taking a few hours out for my daughter's birthday party. I started out by trying to work out what to do behind the cab. I figured a pair of sturdy legs with a brace would give something to support the cage on. The legs will go either side of the transmission and sit on the chassis rails. I want to screw the cage to the back of the cab, and there are two convenient screw holes where the stock body post is supposed to be. I made a brace plate to go here. Here's the legs with brace fitted. I had to make this twice, as I accidentally brazed it upside down the first time around

I now have the dilemma working out what to do about the back part of the cage. It seems to be I have 2 options. 1) bend the rods down behind the body and find some way of bracing them against the chassis. This keep the cage to cab-only which will be lighter and more rigid, but working out how to brace and secure it will be challenging. 2) bend the rods to match the box and mounting them onto the rear bumper. There must be a good way of doing this, and it will be much easier to pop this off and lift the cab. I can add another crossbar behind the cab and run a couple of verticals down to brace against the chassis (maybe I can even make some receivers for them). Right now I'm leaning towards option 2, because that also gives me something I can use to fit my sliding fabric roof canopy too - which might bring forward my colour choice and livery designs, so I can get it ordered sooner. I've got a couple of hours before my daughter's birthday party kicks off tomorrow, so maybe I'll get a little more work done...

Anyway... Just before the wife and child returned, I had time to cut some standoffs from brass tube and properly fix the cage. And here it be!

If the resistor is going inside the body, it will need to be insulated. The outer part of the resistor is non-conductive, but if the heatshrink doesn't cover the body it's likely to peel back and expose a live contact. It could short out and blow the LED or damage something further up the chain. Of course this insulation will reduce heat radiation too... However, after running for a few minutes the insulation was still intact, so it must be less than 125 C. For my final experiment, I bundled it all up inside the body and taped up the holes. I then left it running for 30 minutes. Thing to consider: ambient temperature was around 6 C this afternoon. It will be warmer than that if I'm out at night in the summer, although (for obvious reasons) most of my night walks are in the winter torch was sat on a well-insulated worktop. In the real world, it'll be mounted on a brass bar (with a plastic insulating strip, admittedly) on top of the truck air in the workshop was still. Outside, there is likely to be some breeze, and the truck will mostly be moving at around 2.5mph torch was upside down, with the screw holes exposed. When mounted, those holes will be all but sealed After 5 minutes I could feel the warmth in my fingertips, but they were intensely cold. It felt cold in my lips. I dunno about anyone else but I always use my lips to test how hot something is, although not without testing it on my fingers first, at least not since that incident with the treacle tart in 1994. After 10 minutes the warmth was barely noticeable on my lips. After 30 minutes it was very obviously warm, but not so warm as to be concerning. Easily cool enough to touch, nothing like, say, a hot coffee mug. I don't really think it's a problem. I'm considering mounting the resistors under the roof mount, so they'll be exposed, and if I can tie them against the brass then it will help dissipate the heat. The alternative is to buy some 5W resistors which have aluminium bodies, although they don't have screw holes so I'm not 100% sure how I'll attach them to the brass. Glue kind of voids the point of it being a heatsink.

That was about all I had time for last night - it took me around 4 hours to do all that, and I was pretty exhausted when I came in, not to mention heat-burned, frozen to the core, and smoke poisoned. Today I should have been looking after my daughter, but my wife took her to town this afternoon for a haircut. So I naturally did what any married man does the second the house is guaranteed to be empty for a couple of hours - I went straight into the workshop and turned on the soldering iron! My new resistors arrived today, so I was able to do a test-run on the torches. Here I'm running a 3ohm resistor, which as you can see pulls around 650mA. What's over 3W for just one torch - I'm glad I ordered that 20W buck now! A cheap 5W voltage regulator was going to fry with this much power going through it. This is a little over half the current drawn by the complete torch, albeit at 4V and without an inline resistor. It's really hard to get a feel, but the torch on the left in this photo is running off its own 18650 battery, and the one on the right is powered by the power supply via the 3ohm resistor. The one on the left is brighter, but they're both beyond what this camera can process to they both appear to be brighter than the sun. Both are impossible to look directly into. That should be bright enough for a dark night on the trails. This is the resistor. It's rated to 2W. However, after a couple of minutes it was too hot to touch. A little splash of water on the surface bubbled away very quickly, although it wasn't hot enough to fizz when touched against this wet sponge, so it's less than 100 C. That *should* be OK, but it really depends how much heat can be dissipated. My plan was to bundle the resistor inside the torch head, which is aluminium and has cooling fins moulded in, but there's no way to securely fix the resistor to the body, so it will have to bake the air inside the torch head before it can be radiated away through the aluminium body.

Cage trimmed and holes drilled. Mounted with too-short screws so it's too close to the cab right now, but the concept is proved. This gives us plenty of height to allow for the torch wiring under the roof mount And also allows the cab to tip!

et voila Cool! To work out how to mount the cage, I screwed the front panel on. This gives us some lines to work with and makes sure I don't mount the cage too close to the cab. Here are two convenient screws. How can I get to those from outside..? Like this! I bent the bars to match the lines of the body, added a crossbar, then cut some gussets to give me something to drill into.

Other side done. The point of hanging the rods over the edge is that gravity should keep them perfectly vertical. However, to get the rod hot enough for the solder to flow, I had to get it cherry red - and at that temperature it starts to sag under its own weight. This seems to be a recurring problem with my brazing attempts - I have to get everything seriously hot. According to our future overlords, this is around 900 C, so perhaps I'm not properly fluxing my joints. It seems to me that my flux wants to bubble up and run away instead of staying around the joint to help the solder flow. Anyhoo - I did get a slight sag in the right hand rod, but it was nothing I couldn't bend out before it had fully cooled. This is roughly sort of maybe how it's possibly going to go. But not quite. I decided it made sense to add some more horizontals - both to protect the body on the trails, and to support the cage while I continue to modify it. Here is a bar below the winscreen. Adding the bar above the screen was harder. I had to support it up off the ground. In the end I did this. Nailed crossbar to a piece of wood. Nailed cage to another piece of wood. See this has been used for brazing duty already.

OK - the learning is done, now for the fun stuff now! I finished work at 3pm yesterday. Normally I go out for a walk, but the weather was looking changeable and it was going to be dark early with the clouds coming in, so I decided to light the log burner and do some work in the workshop instead. I've been putting off doing the rollcage for this truck since I snapped my last remaining brass rod a few weeks ago, but with the log burner lit, it seemed like a good time to give it a try. Ambient temperature was 4.7 degrees C before I put the fire on, which is too cold really to try bending brass rod, but if I lay the rod over the top of the stove, it soon gets warm enough to be bent - albeit with some effort! While the burner was getting up to temperature and my brass rod was slowly cooking, I made a strip of plasticard to act as a spacer betwix'd lamphead and rack mount. This is necessary because the movable part on the end of the torch is a slightly larger diameter than the flat base that I want to screw to the rack. I drilled an extra hole for the wiring, and enlarged the hole in the torch body. I'll use the slotted hole for mounting the torch, so I have some adjustment once it's all in place. With that done, I trimmed the legs on the roof mount, bent two pieces of 4mm rod to match, then used the hot stove as a workbench to braze on the roof mount. The stove top makes for a safe brazing bench, but it leeches too much heat out of the joint - however when it's up around 200 degrees C the differential is significantly less, so it doesn't leech the heat so fast. 455 solder has a melting point of around 630-660 C, so it's still going to leech. Here is my workspace for the evening. The flue gauge was reading around 200 degrees at this point and yes, my thighs were pretty gosh-darned warm.

OK, I'm building up for some kind of proper update here, but first I need to catch up on the theoretical stuff that's taken place this week. In a post above, I dismantled a cheap Amazon torch that I want to use for the roof rack. The plan is to have 4 of these torches casting a good, solid beam out the front so I can see where I'm going without having to wear my head torch. It's worked well enough having a head torch strapped to the roof of the truck, but it looks ugly and there's no way to control it from the truck, so if I find myself driving towards a Member of the Public then I have to turn the truck so it isn't blinding them. Dismantling the torch turned out to the the easy bit. I thought working out the resistor values for the LED would be trivial, but it's turned out to be far from it. When I took the torch apart and powered it from the adjustable power supply, I noticed it was pulling over 1 amp just to run one bulb. That's a lot of power for an LED. I'm used to those little plastic dome LEDs that have a maximum current of around 40milliamps before they go pop. But then again, modern torches are very powerful, and I noticed when I took a head torch apart last year that the LEDs get extremely hot - too hot to touch, too hot even to put some electrical tape over to stop them blinding me. That is the price to pay for all that light, I suppose. I noticed on the specs for SMD LEDs that they need to be mounted to an aluminium plate for heat dissipation. So - the next thing was to work out exactly how much amperage my LED needed. I had measured a voltage drop of 3.2V, but that's fairly normal even for a low-power ultrabright LED like I use in my scalers and tractor trucks. It was hard to imagine that the driver circuit was drawing more than a few milliamps, but could the LED really take 1 amp? I couldn't get the LED out of the torch body as it's all been bonded together, but I eventually found on the instruction leaflet a note that says LIGHT SOURCE : CREE XML-T6. I've heard of Cree LEDs. So, it's got one of those, then? Turns out the XML-T6 is a fairly old bulb now and there are much better ones out there, but that's probably why the torches are so cheap. There's no guarantees its even an genuine Cree bulb in there. They're available for peanuts in Aliexpress and come pre-mounted to a 16mm or 20mm aluminium disc, for heat sinking. Unfortunately, they come in various different power outputs and there's no way to tell what mine is, so I can only go from what I've measured, and try to stay below that. I tried mounting my multimeter in series with the bulb so I could measure the actual current through the bulb, but couldn't get a sensible reading. Instead I had to rely on the output from the power supply. After a bit of maths, I decided I must have a 10W bulb, but it's not being driven that hard. The 10W bulb operates at between 3.2 and 3.7V and can take a whopping 2.5 amps. OK... That's... uh, a leeetle bit more than I'd allowed for... My plan had been to drive the Arduino off the 7.4V BEC from the ESC, and also to switch the 7.4V output to the LEDs via transistors, as the Arduino can only supply around 200mA max, and that's not enough even to run all the regular LEDs. However, if we're pulling over 1 amp for the torch LEDs, and there's 4 of them, that actually puts us dangerously close to the 4A max output from the BEC. Once I started throwing values into the LED calculator to reduce the power from 7.4V to 3.2V, I realised I had a problem. I was going to be drawing way too much current for the BEC. So the next thing I'd need would be a 5V buck convertor, which could power the 5V in on the Arduino (much more reliable than using the Vin at 7.4V) and also all the LEDs. Most of them are only rated to a few watts, so I had to hunt around on Aliexpress to find something that would do the trick. After all that, I needed to order some more resistors, as they'd need to be able to handle more than the 1/4 watt max of the little components I keep in stock. According to the LED calculator, I needed 2W resistors. I then went back to the workbench and wired up the torch LED directly to the power supply, using Constant Amperage mode so as not to explode it, and turned up the dial until I had a sensible amount of light coming out of it. 500mA seemed about right. It's not as bright as running the torch off the battery, but should give longer battery life, longer LED life, lower heat in the torch, and lower current draw on the buck. To make up for there being less light, there are 4 of the danged things, so it's not like I'm going to have trouble seeing where I'm going. I ordered 2 different values of resistor so I could play with brighter lights later, if I want to.

Happy Friday, everybody! What's going on where you are? Anybody up to anything exciting? It's an unusual one for me, a bit different to the norm but hopefully it will work out well. Friday - working until 3pm, then I'd normally go for a walk, but the forecast is unclear and there'll be less than an hour of daylight by the time I get to the hills. So maybe I'll go in to the workshop and do some more work on the hillwalking truck instead. I still have to make the roll cage, and start designing the layout for the circuit board. Saturday - chilling with my daughter in the morning, then wife is taking her into town in the afternoon for a haircut, so I might get a bit of time to myself. Probably tidy the workshop a little. Sunday - a certain well-known right-wing British "politician" is coming to do a talk in the centre of my local nowhere town, and judging by the comments on the Book of Face things are likely to be a bit stressed. Fortunately it's my daughter's 8th birthday party, so we're heading to the next town over for a couple of hours of bouncing at the trampoline place. Hopefully there will still be some town left when we get back. Sunday evening I shall relax with some dinner and a beer on the roof while I watch a small and localised apocalypse take place.

Interesting question, and one I've asked myself on several occasions. When I first got into RC in the mid-00s, it was about having the fun I wanted to have when I was younger. I got the DF-03 because I'd never had a 4wd buggy, and it seemed to have a very good spec out the box. Then I got a Midnight Pumpkin because I'd always wanted one when I was younger. Then I got a Blackfoot Extreme because people here said they were a good mix of robust and fun. Then I noticed my collection was growing at random, so I thought I might try to streamline it. At the time I was into Nissan road cars, so I listed out all the Nissan cars Tamiya had made, to see if I could collect them all. That idea lasted for about a week. Then I started working on a film project, and we wanted to use RC cars for all the vehicle action scenes, so I started collecting cars that we could use in the film. Then I realised most of my fun was in bashing with mates, so I started collecting 1 of every "class" - vintage 2wd buggy, vintage 4wd buggy, modern 2wd buggy, modern 4wd buggy, classic monster truck, modern monster truck, stadium truck, touring car, fwd m-chassis, rwd m-chassis, big-wheel monster truck... Then the vintage racing scene kicked off, and in order to get a race entry I needed to have a buggy for every class, and then having a spare buggy for each class was a good idea too. Then I got into big rigs, and I decided I wanted both a US and a Euro tractor, with a trailer each, but then I wanted smaller, more basic versions of each which were easier to drive, plus multiple trailers, plus driveable vehicles that could go on said trailers. Then the crawling scene kicked off, so I wanted a class 1 and a class 2 crawler. Then I started inviting non-RC friends to crawler meets, so I needed more crawlers that they could borrow. Then lockdown hit, and it became about what I could run at home - Blitzer Beetle, G6-01, MTX-1, XV-01T, and then when we were allowed to socialise outdoors I needed multiples of all my cars so a bunch of us could meet and play together. But during lockdown I really got into custom builds, so now I'm always looking at what the next crazy custom project might be, and also trying to improve my racing, and make my scale crawlers more scale, and expand to more race series, and build something that I can take on long walks anywhere in the country.