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  2. markbt73

    Ever have those days..?

    I'm with you on the touch-screen thing for sure - I can't stand those things. As for ESCs, there are two points I'd like to make: 1. ESCs are not "new." They've been around since the late 70s, and even in the mid 80s had become the standard for racing to the point where a lot of race-leve cars no longer came with a mechanical speed control (including Tamiya's own Avante, if I recall correctly). Same with motors; plenty of kits didn't include them. There's no reason not to fit a vintage ESC and motor into a vintage car that originally came with neither; in fact, it's probably the most "correct" way to set them up. 2. They needn't be difficult, especially not today. Turn it on, push a button to set it up (if you even need to do that), never mess with it again. And even the old ones that had a potentiometer to set the end points only took a minute to set up. Yes, you can go nuts with programming this and that, tweaking all sorts of paramters, but you don't need to. Especially if you're just plugging in a silver-can motor (of which I am also a devotee; I rarely bother with anything faster these days). I liken it to fuel injection and electronc ignition more than touch screens or "smart" devices: I'm not about to get rid of the carbs and points in my old weekend fun car, but for daily driving, I want to turn the key and go. Just playing devil's advocate...
  3. nbTMM

    Gear ratio

    unloaded wheel speed (kmh) = V * K * Tpinion / Tspur / Rdiff * Wdia * pi * 60 / 1000 Where: V = battery voltage K = motor kv Tpinion = number of teeth on the motor pinion gear Tspur = number of teeth on the spur gear Rdiff = the differential gear ratio Wdia = the wheel/tyre diameter in meters pi = 3.1415 As an example we can calculate it for my TT02 which has a 5130kv brushless motor, 2S Lipo pack, 61tooth pinion gear, 69tooth spur gear, and touring car wheels/tyres which measure about 65mm diameter. Therefore: V = 8 <---- 4 volts per cell is a good guesstimate for a freshly charged lipo, accounting for some voltage sag under load K = 5130 Tpinion = 61 Tspu = 69 Rdiff = 2.6 <----- this is the standard diff ratio for a TT02. Unless you use over/under-driven 'drift' spools with different numbers of teeth of the diff crown/pinion gears, it will be 2.6 Wdia = 0.065 unloaded wheel speed (kmh) = 8 * 5130 * 61 / 69 / 2.6 * 0.065 * 3.1415 * 60 / 1000 = 171kmh So if I hold the car in the air and floor the throttle the wheels will spin at 171kmh. Will the car actually go that fast? No. In reality the fastest it's gone on GPS is 100kmh. This is because DC electric motor power peaks at half the unloaded rpm.so the motor power is starting to reduce when the car exceeds about half of the unloaded speed, ~85kmh. At some point, the amount of power the motor is producing will become exactly equal to the forces of aerodynamic drag and friction from the drivetrain and the tyres rolling on the road. At that point, the car will not go any faster and you want this to occur where motor power is maximum to achieve the fastest possible speed for your setup. You can calculate drag and motor power and so on, but honestly the simplest way to work out if you have the right gears is just to do a speedrun and then compare the actual top speed to the calculated unloaded speed. Since my car already goes faster than 85kmh it means that I'm undergeared - the motor power has already reduced somewhat when it hits the maximum speed of 100kmh. I could put a pinion with more teeth and/or a spur with less teeth to achieve an unloaded speed closer to 200kmh, so motor maximum power would occur around 100kmh where my car currently tops out. Unfortunately I physically can't fit a bigger pinion or smaller spur so the only solution for me to go faster is to get a motor with higher Kv, or wheels/tyres with a larger diameter. A more aerodynamic body shell might get me a few kmh too. Similarly, if my car topped out at 60kmh with the current setup it would mean that i'm overgeared - the motor wouldn't be reaching maximum power before the effects of aerodynamic and mechanical drag became too much. In that case, a smaller pinion and/or larger spur would be required to go faster. If it topped out at exactly 85km/h the gears are probably just right and the only way to improve it is a more powerful motor, more aerodynamic shell or higher voltage battery. Be warned that running your motor full throttle for long periods near half it's unloaded speed or less will cause it to get very hot! Most RC cars need to be undergeared to keep the motor rpms up and therefore motor temps under control. The gears that achieve your maximum top speed will generally not allow you to run the car for very long before overheating the motor/esc. The TT02 is very undergeared out of the box (22t pinion 70t spur) so you will find that the actual top speed with those gears is very close to the unloaded speed. Effectively the top speed out of the box is more limited by the gear ratio and kv of the motor because it's going so slow that aerodynamics and motor power are barely a part of it.
  4. markbt73

    The Day eBay Killed RC

    I actually hate eBay just because of the nature of auctions. If I want a thing that's for sale, I either have the money to buy it or I don't. I know immediately if the thing will become mine or not. With an auction, I have no idea whether I'll ultimately end up with the thing or not, based on how much money someome else has, which is a factor I have no control over. It doesn't matter how much I want it; if someone else can throw more money at it, they get it. The very nature of auctions monetizes and commoditizes hobby items in a way that really turns me off. Usually if I want a thing, it's because I have some feelings attached to the thing, and I happen to have enough money in one place at one time to acquire it. But the money isn't the important part of the equation, not to me. I hate money. It's a stupid way to measure the world. And reducing an object I really appreciate and want to a battle of bank accounts and timing and (at least a little) luck just gets me angry and frustrated, whether I "win" or not. I don't want to "win" it. I want to own it and cherish it. It's never a matter of who "wants" the thing more; it's only about who can out-spend whom. And the only words I have to accurately describe my feelings about that situation are words that would be bleeped out if I typed them. So you folks have fun with your auctions, and don't worry; I will never be trying to out-bid you. Been there, tried that, hated every second of it.
  5. DK308

    Gear ratio

    As long as you have all the numbers you need, just use a gear ratio speed calculator. The math is simple, just boring. The trick is grtting the actual speed correct. I like to divide the theoretical speed with the motor efficiency and I tend to calculate motor rpm from 75% pack capacity. So get these numbers and use the following calculator. Motor kv Motor efficiency Batt voltage Tyre dia Motor gear reduction Final drive reduction http://www.apexgarage.com/tech/gear_ratios.shtml
  6. Today
  7. unixphreak

    The Day eBay Killed RC

    example one, way high price, really crappy condition and not very popular for said price. https://m.ebay.com/itm/Vintage-Kyosho-Stinger-MK-Nitro-4-Wheel-Drive-with-Hitec-Challenger/283495695378?epid=97052527&_mwBanner=1&_rdt=1 second one, person did not know what the model was until I discussed that he research and drop the price was 384.00. btw, I bought two of theses for 110.00 with radios and other extras.the the guy is a gold digger and the price keeps falling, was 284 yesterday. https://m.ebay.com/itm/VINTAGE-KYOSHO-STINGER-Nitro-4-Wheel-Drive-Chain-Drive-Remote-Control/183810446956?epid=97052527&_mwBanner=1&_rdt=1
  8. Hibernaculum

    The Day eBay Killed RC

    I thought of this thread recently, as I watched a nice, used Fox project with period radio, parts, manual and original box... sell for an absolute steal under bidding on eBay, for just AU$117. A Fox empty box alone is normally worth $70! https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F143246270144 I also thought of this thread recently, when I saw a nice Frog set (with cut but unpainted body), undergo a strong bidding war and sell for a strong AU$454. That’s almost exactly 4 times the price of the Fox. https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com.au%2Fulk%2Fitm%2F223496964133 .:. Both of these examples kinda dispute this thread. The first because every person only has themselves to blame if they are not paying attention when things sell for ridiculous low bargain prices under bidding sometimes. (14 bids on Fox by 5 bidders) The second, because it shows how there is also plenty of genuine demand under bidding, to drive prices high, when people are actually awake and paying attention. (43 bids on Frog by 8 bidders)
  9. nbTMM

    WR-02CB straight steering

    I actually find that some amount of slop/flex in the steering is required to track perfectly straight without having to constantly re-trim the steering servo. This is because no matter how good your steering servo and servo saver are, they will never return to exactly perfectly centred after performing a turn. The trick seems to be to make sure that the slop is only in the steering axis (toe). Slop that can cause significant changes to caster, camber, offset, or shift the entire wheel forwards and backwards in the chassis, seems to hurt stability. The rear wheels obviously should not have any slop in the toe axis. A little slop/flex in the steering, when combined with positive caster will allow the wheels to self centre even if the servo/servo-saver are doing their best to steer slightly off centre. More caster = more straight line stability. After removing unwanted slop from all four wheels, it's the single most important thing to tweak for straight line stability on a flat road. Note that increasing positive caster increases oversteer when turning due to jacking forces which unload one of the rear wheels - when you turn the wheels with a lot of caster one wheel literally gets lifted up and the other forced into the road, which changes the weight distribution across all four wheels. I'm not familiar with the WR chassis but on the other tamiya chassis I've used the bump steer was far from optimised. As far as I know, in a double wish bone suspension you want the the tie rod to be as close as possible to the geometry of either the upper or lower arm to minimise bump steer. Looks like they are drooping down on an angle with respect to the wishbones in the above picture - that will probably give more bump steer than if they are parallel with the wishbones. Are the tie rod ball ends supposed to be on the top side of your knuckles? You can space the ball joints up/down as required to improve the bump steer with washers, or if they need to be spaced a lot I use brass standoffs (below photo). If you increase caster, you will need to space the ball higher off the knuckle end to correct bump steer. Note the tie rod and upper wishbone/arm being parallel. Personally I've never noticed any improvement in straight line stability by toeing in the front. Slight toe out produces sharper corner turn in so I usually adjust the front to either 0 toe or slightly toe out. Toeing in the rear wheels produces a noticeable improvement in straight line stability on my cars - just don't go too crazy (>3deg) with it or you'll scrub speed and wear out tyres.
  10. bjmulford

    xr311 body colour?

    Thanks Aerobert, i do apologise if its in the manual, i must have missed that!!! BW Barry
  11. Nicadraus

    So, What Have You Done Today?

    Beautiful build!
  12. graemevw

    Lunchbox wheel wobble

    If i had any to hand id also use it, but i havent. Ill find something in the garage with no stretch that will do the job. Might try platerboard scrim tape, thats glass fibre, flexible and has no stretch. Just need to glue it on well. I have some tyre glue, lots of rubbery adhesives, silicones, polyurethanes etc. Ill test a few and see what looks like it will work well. I know some people use duct tape but i couldnt get it neat, or to stick well. I think the tyres need a good internal clean and a scuff up.
  13. DK308

    Lunchbox wheel wobble

    What I use to belt tyres is actually not cloth tape. I use actual kevlar aramid fabric. Much lighter, stronger and softer. This is what I use. https://www.fibermaxcomposites.com/shop/aramid-fiber-fabric-br-k220p-p-100135.html You could use an even lighter weave. I just used 220 as I had it on hand. 165 will be plenty for what you're doing.
  14. graemevw

    Lunchbox wheel wobble

    No, nothing in the tyres. Brand new, never been run. This is ok at half throttle, starts to vibrate after that, then gets so bad i think it will snap the gearbox (no exaggeration). The axle holes in the wheels are a bit of a loose fit. I think im going to make a jig to hold the wheel square and fill the gap around the axle so the wheel is forced to stay square, then machine the locating lugs perfectly true. That, along with cnc adapters and some tyre balancing may get it under control. I think the wheel itself may be reasonably ok, just a combination of plastic adapters and slack in the axle hole means the wheel never bolts up true to the axle.
  15. graemevw

    Lunchbox wheel wobble

    Thats them. I searched but couldnt find them. Thanks.
  16. Kamikuza

    The Day eBay Killed RC

    Oh, Amazon Japan is great for price weirdness: I started a wee FB page to log the doozies. Pretty sure it's a money laundering scam... https://www.facebook.com/amazondrunkpricing/
  17. ThunderDragonCy

    Brushless Motor & ESC recommendations

    I really rate the hobbywing 10bl120 ESC. If you don't want to solder then buy from a shop that offers the service. Modelsport offer a soldering service for about 5 pounds, for example. Get a DT03 17t steel pinion and that will sort gearing and durability. See what 10.5 motors your chosen shop has.
  18. svenb

    TB Evo 3 Surikarn build

    I think your right about the dampers being re anodized, the red trf damper set hop up has grey anodizing on the threaded section. Either the damper parts have been replaced with 49313 and 49314 or they've had the blue stripped off and done in red. Looking smart anyway 👍
  19. Timr100

    Gear ratio

    Hi all is there is there a formula to work out gear ratios to get the approx top speed of my tt02,
  20. Dirt-540

    Brushless Motor & ESC recommendations

    Rules are very relaxed as its open. Dont think i need programmable. Unsure what blinky, FDR and mod are? I think 10.5t is what im after. I checked out the Surpass rocket v4s motor and skyrc esc, both only available in hong kong. Am I right in saying im looking at about £100 if i buy both? Would i be better off buying a Hobbywing combo that retail for about 75-80?
  21. Hi everyone I have for sale my lowered mystery machine lunchbox for sale comes with instructions ,battery ,transmitter which is not tested ,all radio gear in vehicle works nicely also have a set of monster wheels which I can include for a fee. I am looking for £80 OBO + £10 postage If you need more pictures and info please ask.
  22. Picked up a DF01 wreck to fix up. To get the gearing for a 13.5 i need one of the spurs from the speed tuned gearset, but either would work for the gearing i want. Has anyone got the set and has either the 66t or 69t spur going spare? Like i say, doesn't matter which one.
  23. ThunderDragonCy

    FS brand new wheels from GF01 Toyota

    Sent you a PM. definitely interested
  24. graemevw

    Super astute rebuild

    Pink isnt a fave of mine either, but works on this. I have a driver, just not fitted it yet. The window tint was a bit dark, if i can find a lighter one id do it again.
  25. graemevw

    Vanquish rebuild

    I like the bronze, but no idea what car id put them on!
  26. Aerobert

    xr311 body colour?

    According to the manual it should be TS-28 for the Body and XF-1, XF-10, X-11 and X-6 for the attaching parts.
  27. Hi everyone I am selling my holiday buggy it comes with battery and instructions and esc/receiver as well. it is a bit battered and has a crack in one wing I am looking for £60 or near offer + £10 postage. I don't know how well the battery works. if you want more info please get in touch.
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