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Lawsy

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About Lawsy

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  1. Well, more like a returning DB01 nut, since I started on this journey back in 2016. I simply proceeded to sulk about for several years and went MIA after the crash (truth be told, life just got hectic, busy work, busy being dad, had another baby... So a good busy). However, I forgot just how much I really, really like the DB01; it's been such a fantastic buggy and is very reliable—at least, when I'm not being a complete moron. I bet your car is a complete savage with the 18T pinion; those 4.5T motors do not mess about! I'd say that, with my Castle 5600kV, I would need to run the 20T pinion to keep up, at least, or maybe even the 21T (and I know just how spicy it gets with the 21T, it starts to really move with that gear ratio). But with the 3S, it's on a whole new level of stupid. I've not had the balls to stretch its legs on a long straight, or change the pinion to something bigger because I think the tyres might let go if I try. They are already turning into pizza cutters, so I can't imagine what another 20km/h will do to them. As for suspension, I used to run the thicker spring collars on the rear, but haven't this time around (simply because I had forgotten and you've reminded me; thanks). I'll need to throw them back on to quell the understeer. Off throttle (I don't run trail braking) she turns in like a monster already, so I'm not really sure what would help find that balance again. Most likely, I need to rebuild the shocks with thicker oil. I've just been lazy, and truth be told, I have absolutely no idea what oil viscosity is in there now. I should probably just use the thickest I have, given I'm running stock CVAs... So anyway, I might put the kit tyres on it—given they balloon a lot less than the Prolines, and therefore, should be more stable—throw the bigger pinion on and do a proper speed run with the 3S. I don't have a GPS tracker anymore, so I may need to measure between road markings, take some wider footage at 60FPS and calculate the speed manually. I don't think it will be less than 100km/h, assuming I have the gonads to hold it flat for long enough reach Vmax, but that will depend on the conditions...
  2. The 3S just finished charging so I felt obligated to take 5 minutes out of my day to quickly test and make sure it worked. Oh my... I was not prepared for that! After just three laps (going up and down a 50m section of street), I've had to bring it in because my hands started to feel like potatoes. We are going to have to make some tweaks and changes because this thing is entirely unsuitable for public consumption. That is completely mental! I recall my Durga was respectably fast before, all things considered, with a top speed of about 82km/h on a fresh battery with the 23T pinion installed. We just obliterated that, without a shadow of a doubt, running the 18T pinion. So what the heck do I do now? Should I lower it, soften it, square up the camber, throw the 16T pinion in (or the 23T, because you know... Science and all that)? I've just increased the punch control and adjusted the throttle map to what I believe will make it a bit more linear, but otherwise, I'm not sure what I need to do in order for this thing to really handle this sort of speed. Any suggestions?
  3. Ladies and Gents, after several years of moaning, I finally got around to fixing my DB01 over the weekend and I have to say, I really wish I had stopped being such a sook and did it years ago... I didn't admit my stupidity at the time, so I might as well do so now... I was street bashing with the 21T pinion (about 75-80km/h on a nice flat), and I was standing on the far corner of a relatively wide T intersection with the car coming towards me. I've briefly looked up the street I was turning into to be certain no cars were coming, something I've done many times before, however, I failed to appreciate that I don't normally run the 21T pinion (normally the 18 or 19). To make matters worse, I had only just stepped out the door, so I had a fresh battery on board. Needless to say, she was moving, to the point where the otherwise benign crest entering this particular side road made the car light enough that I had no brakes, and no steering, until 2m before the gutter... The steel reinforcement above the storm water drain proceeded to eat the car like the cookie monster, with springs, bits of lower control arms, shocks, bumpers and wheels all needing to be recovered from in and around the drain. Surprisingly, I had lost nothing; though, much of what was found was broken (or so I thought). So I went into mourning for the next 18 months with everything sitting in a box. My car was hurt, as was my pride and life just got too busy to really look at it. Then in a spur of enthusiasm a few weeks before my wife was pregnant with our daughter, I ordered a bunch of spare parts that I thought I would need, with lots of motivation and good intentions. Our daughter is nearly 18 months old and I've only just put it back together this past weekend. Quite frankly, I'm more impressed now than I've ever been with this chassis. Hardly anything, apart from the obvious, was severely damaged. The chassis; completely straight, with little signs of any impact. The arms and shocks on the non-impact side; completely fine, didn't even rebuild the shocks (because I'm lazy, they feel fine). The best part is, it drives just as I remember. Unreal! You would think, after years of lamenting my own idiocy, that I would now be more cautious, right? Well, you be the judge. Today I've just received my very first 3S Lipo and I'm wondering who else has shoehorned one into a DB01 and how they strapped it down, given it is quite a bit taller than a 2S (above the posts, so the kit brace cannot be used). Initially, I'll keep it off the bumpy stuff and use the firmly fitting body to hold the battery in place (and I mean firm, it does not even budge), but I don't particularly want to stress the body like this, long term. Any suggestions?
  4. Sorry for an almost insulting suggestion, but it happened to me while trying to fix my nephews old RC car. It was unreasonably slow and I was ripping my hair out as to why... Have you checked the radio endpoints?
  5. Well, yes I guess we do, don't we... The thing our cars lack is any amount of front aerodynamic aids, and to be honest, I don't know how we could properly implement something without adding massive drag and remove the effect of the rear ring (which would make this pointless). I believe ensuring there is positive rake would be one thing to try, but you would need to be quite careful to stiffen the front I think. A lot of internal limiters, and an additional collar to preload the springs (front and rear) would probably do the trick... I haven't bothered with this yet as I don't think my DB01 is fast enough, but maybe if I end up getting a 3S I could test this. My DT01 consistently hit 63km/h with the 3930kV motor, 17T pinion... If it didn't have two bent axels, I could drop the 5700kV and 19T pinion in that thing and aim for 90. I can't imagine stopping the DT01 from these speeds... From 80km/h, even the DB01 feels like trying to brake on ice in an emergency (doesn't everything?), however, in reality, it stops like it was driven into a brick wall. The DT01 never stopped well, though. It felt like stopping on ice from walking pace, let alone 65! I'd need another 100 metres to stop it from 90. In other related news; I'm a moron. I was chasing cars with the DB01 yesterday... It's a quiet street so this means only 1 or 2 cars per minute when it's busy (if that). This doesn't make chasing cars any less idiotic, though. This is a momentously stupid thing to do, especially if you forget that you've tightened the slipper clutch and reduced torque reduction to better control acceleration during speed runs... Up until this point, I could gently roll onto the power and catch cars within a few seconds with ease without stressing the driveline at all. But for whatever reason, I was truly ham-fisted on the power on the next run. Maybe I was talking and got distracted, but it was certainly not intended. Through a purely accidental, yet perfect balance between initial clutch chirp, longer gearing, torque and available grip, this thing accelerated with such brutal ferocity that I nearly ran under the rear tyre of the last car I chased down, missing by 200mm or less. It was like they were joined by an elastic tow rope. I've launched this thing hard before, but this was something else entirely; the perfect fluke resulting in the perfect launch. Although it was awesome, it nearly ended my DB01. I stopped chasing cars at this point...
  6. We could work out roughly what three parasitic losses will be and estimate what might be possible. Speculation based on estimates and guesswork is fun. We call it engineering
  7. Are you going to run 4S or 2s2p? My apologies if this was outlined somewhere, I'm a bit late to the thread and haven't read the whole thing yet...
  8. I just realised I gave the mph conversion for 84.1, something I was working out for a completely different reason. 82km/h should be 50.95mph... EDIT: I didn't refresh the page before posting, and you'd already picked up on it.
  9. 82km/h = 52.25mph my man... I'm not sure my DB01, in its current form, has anything left at this point. It's getting slower and slower as the rear tyres wear, and boy do tyres wear out quickly from speed runs in the dry. Three degrees of static rear toe-in, on tyres that become pizza-cutters at speed, shreds them very quickly. The inside-centre of the tyre has a full millimetre less tread than the outside, most of that wear was from the last couple of days (it's been hot and dry - when it was slightly damp, tyre scrubbing was reduced and it was easier to get 82km/h on Saturday - if my phone wasn't playing up, I'd have two much better videos for you). But with worn tyres, both the static and rolling diameter has been reducing quicker than my ability to keep it straight has improved... So I might call it a day at this point. I tell you what, though - send me some cash to fix my phone, a decent Lipo, a tripod, a nice light GPS unit that fits under the body and some new tyres, and I reckon I could top the charts for you in perfect, HD clarity (I think it has the potential to hit 86km/h on 2S with the current gearing and standard size wheels). I'd be able to pick a much nicer vantage point, showing the car passing the camera at absolute full speed, as well as the return journey back to the camera, showing the victorious DB01 in all its glory. And the speed would be more clearly readable... Want me to PM you my address? As much as I enjoy this sort of thing, it's time-consuming and hard on the gear. Normal bashing requires little to no prep; I literally drive the car out the front door and go explore with my son. Speed runs require walking to the right place, awkwardly trying to balance my phone somewhere, or wedge it in a tree with the road in view, while onlookers think I've lost my mind. All-the-while I have a 16 month old strapped to my front, making this as difficult as he possibly can because he thinks trying to grab everything is going to somehow make the car move sooner. And no, regardless of how sneaky I am, I can't leave the house with my RC gear without him knowing - he has a 6th sense for it. But when I do eventually get new tyres, I think there is still more speed to be had with 2S before going to 3S. I think 2WD is still worth investigating at these speeds. A better Lipo Better wheel alignment - somehow removing the rear toe-in would net a big improvement. The tyre wear is that bad... Remove steering slop (steering knuckles bind ever so slightly, and the servo mounts are moving, so aluminium servo mounts would help me keep it straight) A better stretch of road. A short steep hill followed by a long, wide straight, minimising power needed to accelerate, leaving the battery fresher for the top end We'll see...
  10. That's fine... Got to love the sound of that egg shaped spur gear... And he's 15 months, in case anyone was wondering...
  11. 82km/h with the 23T pinion... But.... The camera on my S7 wouldn't focus so I didn't get that run on video (the reason infuriates me - cracked rear camera glass about a month ago for no apparent reason, then Samsung didn't call back after several attempts, so I went and got the glass replaces myself yesterday and the knob didn't clean the inner lens - It's dirty on the INSIDE lens. On top of that, I think he cracked my screen... I'm so ticked off right now). I stupidly reset the Max Speed before taking a photo, and by then I'd taken the edge off the battery, so I've only got 81 video (and you can barely make it out). I'll make another attempt later if I get a chance, but that was a perfect run and may not get 82 again...
  12. Double stacking didn't make much difference. I think added weight (lowers the effect of ballooning) and wind resistance from the shell sitting so high reduced the improvement... But you can update my speed by a couple at least.
  13. Reduced front toe and camber all around. Shimmed all the the things. The spur, the steering rack, checked all wheels, balanced them again, plus it was damp through the highest speed section, not the acceleration phase. Damp = fast. It mitigates the 45° toe in angle at the rear, and any remaining toe angle at the front. I wasn't GPS tracking this run, but it really did look faster. Anyone care to guess the speed, before I run it again in an attempt to break 80?
  14. A couple of things I didn't mention yesterday - my slipper clutch was slipping more than usual during only moderate acceleration after the run last night. I don't think it was slipping at Vmax, but I can't rule this out completely either. I may have overcooked it on a previous couple of back and forths on the previous pack, and since the spur RPM would be drastically higher with the current gearing, this may have punished the clutch beyond recovery. I'll tighten it, run a couple of tests and double check whether or not this was an issue - I may need to clean it up or flip the pad - does anyone have any recommendations for higher performing (friction and thermal limit) slipper clutch pads? If Scientific purpose is the name of the game, then here's a random list that I'll be making up as type... Suspension: Lower so driveshafts are horizontal, stiffen, increase rake slightly, reduce camber and toe where possible (I have a spare set of 4 suspension blocks - I'm willing to destroy two of them to reduce rear toe, in the name of science. Does anyone have any ideas that are workable and consistent that could achieve this?) Shim everything. The spur gear has slop (which I've shimmed partially), the hinge pins have slop, and the axles may have developed some by now as well. Shim it all. RWD conversion...** Inspect/clean all bearings Re-glue and re-balance tyres if possible/necessary Can I run without a wing, and still secure my phone to the car? Not sure... ** RWD conversion idea There are potential issues with this. The front and rear belt tensions are critical for balancing the yawing moment at the spur, this will need to be addressed. If acceleration is gentle enough, and I shim the spur just right, it may be possible to run just the rear belt without needing to significantly increase its tension. The rear diff will be under significantly more stress running RWD only as well, need to be gentle there (tighten it a little). It could get twitchy, especially if I've stiffened everything up. May need to run a little front toe in to help with this. I don't know, the balance between risk/reward/effort required isn't quite where I want it. It's something to think about, at least...
  15. If I get a chance before Christmas to run the 23T pinion, I will. However, I expect the voltage sag due to the added load will reduce the speed increase to around 3, maybe 4km/h... In a perfect world, a 2 tooth increase on the pinion with this final drive ratio would result in more like a 6km/h increase... I have an idea - can we relax the rules regarding having the shell on? If we can, then I'll run 2x identical 4000mAh batteries in parallel with an open top to reduce the voltage sag... Let me know.
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