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Juggular

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  1. I'm surprised! But that's good to know! Low gear ratio? How's the hot day performance off-road?
  2. Alvin is right, those won't work for TBLE-02S. It's designed for 25t or greater. 21t would cause it to shut down. [1] Tamiya Sport Tuned would work. Even though it's 23t, it works with TBLE-02S (unless you run it on a very hot day on tall grasses). [2] Or, you can get Hobbywing quicrun 1060 ESC. That ESC can handle 21t. [3] You could also get a 13.5t sensored brushless motor. TBLE-02S can handle both brushed and brushless. I have extra motors like 12t, but for light chassis, I tend to stick with Sport Tuned. It's more powerful than Lightly tuned and Torque tuned. It's a good motor for most Tamiya chassis.
  3. I think it's a bit more than that. For example, you can have pinion 10, spur 20, spur to diff is 1:1.5. Gear ratio is 2.5, but it's a bit too tall to be smooth. What if the spur to diff is 10:20, would it be less smooth because the FDR is 4? What if you have a bunch of 1:1 gears like Konghead? What if you stretch the chassis to include 10 more 1:1 gears? Even if you lower the gear ratio, It's not going to accelerate smoothly because it's got so many gears. But you are onto something. To reduce internal gear's resistance, I replace the lubrication of bearings with something lighter. Let's say each rotation of a bearing can add 0.01g of friction. The motor can turn 12,000 rpm. That'll add 120g of resistance. That's as heavy as a stack of 20 quarter coins per minute. If the gear ratio with spur is 1:3.5, then the spur gear turns 3400 times per minute. Only 34g of resistance. If the spur to diff is 1:2, then it only turns 1700 rpm, only 17g of resistance. This is why you could find a worn out pinion gear, but you'll never find diff's ring gear worn out. It's seeing only 1/8th of the action the pinion is seeing. I pick out 2 fastest rolling bearings and assign them closest to the motor. If you need 22 bearings, there is no need to spend $220 for full ceramic bearings. You just need 2 of them, closest to the motor where they will see the most rotation, and the rest can be ordinary steel bearings... Actually, you don't even need ceramic bearings at all. You can just take off shields and apply tiny bit of Teflon grease. If the gearbox is sealed, no need to cover the bearings either. For 90% less price, you can approach 90% of ceramic bearing's efficiency. But it involves 90% more hassle. (there is no free lunch!) The other thing is the gap between teeth. Gears slide on each other's surfaces. If you look at below GIF for minutes like I do, first, you'll get dizzy. Second, you'll see that the wear is not uniform between pushing and pushed tooth. By the time the contact point moves half way on the pushing tooth, it has gone 2/3 on the pushed tooth. For the other half on the pushing tooth, only 1/3rd is moved on the pushed tooth. For 10 meters of tire rolling, there could be 1 meter of gears skidding on each other, if you count all the gears. You can almost double that for 4x4, triple it for Konghead. For Dynahead, for 10 meters of tire rolling, gears could be skidding 10 meters. (37 gears, as opposed to 3 gears of the Lunchbox)... Talk about drivetrain resistance! The more gears you have, the more important the grease becomes. (I use Teflon). Fine tooth gears are smoother. Big tooth gears have more gaps. (some of it is engineering too) Slops in several gears can also add up. If there are more gaps between dog bones and drive cups, they could add up. So, Kyosho might be using finer gears and there might be less gap in dog bones/driver cups (belts don't have gaps like metal parts do). But it's not hopeless for Tamiya drivers. If you want, you can re-lubricate bearings. I choose the fastest turning ones for the gearbox. You could use Teflon grease for gears. I don't have any Kyoso to compare, but doing those two things can make things a lot smoother.
  4. 1) This double sided tape is like chewing gum. It tends to stick well to slick surfaces. Yet, it's easy to remove. It will ball up when you tear it off. You could use some of this on the underside and then cover it up with aluminum tape? https://smile.amazon.com/gp/product/B0852XL3CC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1 2) You could try low-temp hot glue. ABS melts, so you do not want to use high-temp hot glue. Only a tiny dab of low temp stuff might work. 3) UV glue. If you've ever broken a tiny plastic hinge like this, you know it's nearly impossible to fix it. But UV glue seems to work. This is hard resin, but you might want to try soft resin.
  5. "Efficiency." That's what I would call it. A piece of plywood can slide a bit when you put your weight on it. But a skateboard works a lot better with wheels. I don't leave bushings. They can eat up steel axles over time and make it difficult to fit bearings. I see RZ costs about $34 now! With bearings, it could have better torque and speed than TZ and BZ without bearings. So, if I wanted to keep things Tamiya, I'd be tempted to get one myself. I want to compare it with Sport Tuned and 13.5t. And I like the splash of red on the label. 13.5t is $37 also. Soldering is a bit of a hassle, but Tamiya TBLE-02s and 04s work. So this could be a good option for those who want more torque. https://hobbyking.com/en_us/turnigy-trackstar-13-5t-sensored-brushless-motor-3040kv-roar-approved.html
  6. I think there might be a certain range of crystals you could use. For example, if your radio is for 72.010, but you buy a receiver that used to have a 72.990, that might not work well with a 72.010 receiver crystal. I tried something like that back in the days, and it didn't work. Only then I discovered that it doesn't work well if the frequencies are too far apart (between the receiver crystal and what the receiver used to have. It's like receivers are tuned for smaller range out of entire frequencies). But if you get a receiver that used to have 72.230, then put in the 72.010 crystal, that might be close enough to work. (I know it's baffling. What's the purpose of having swappable crystals?) On the other hand, what if you change the transmitter crystal instead? I have no idea.
  7. I suspect Gool RC 17 turn isn't really 17t as we know it. It may have thinner wires. It might be weaker than Sport Tuned, but I haven't compared the two. I think Super stock would be much faster and stronger than Gool RC 17t. But is there any reason why you'd want Super Stock motors? That's where the benefits might not outweigh the cost. With the same exact gearing, brushless 13.5t would be the closest to Super Stock motors in performance. However, for brushed motors, it is recommended that you install a smaller pinion. Because the top end doesn't have much torque, brushed motors tend to lose the RPM at the top. Brushless is the opposite. As Jonathon said, you can use a bigger pinion on brushless, because torque is stronger. Even though 13.5t would be exactly at the same performance as Super Stock (using the same pinion), if you use a bigger pinion, 13.5t would be faster. That'd be the limit on Tamiya ESCs. But if you have a brushless ESC, you can get a 10.5t and limit its performance as you see fit. If you are using a 1060 ESC, and if you can get a Super Stock under 30 USD, that's a good deal. I'd put in a couple of bearings and be very happy with it.
  8. Welcome to Tamiya Club! Your shells are done better than things in hobby shop display windows! It's fun rediscovering Tamiya, isn't it? And it's nice to fund it without dealing with extra conditions parents love to impose on! Have you discovered that ball bearings and axle pins love to take a dip in coffee/tea? It happened to me a couple of times, the slippery ******s. (Necessity dictated that I combine RC and fishing at those times...Magnets make best baits. They don't bite anything else, you know. It's better to fish in the mug than trying to fish down the drain pipe. Not that I admit doing that...no, no.)
  9. I would make sure that the transmitter trim is centered. And then undo the servo horn, just to make sure it's mounted close to the center. The horn must be centered when building. Most builders power on the servo before building the steering part. If the servo isn't centered, the first thing it will try to do is to center itself. But if you built it thinking it was already centered, but it wasn't? Then it could try to go to one extreme end. That could cause a problem. If the transmitter trim is centered, but when you turn it on, it moves to one direction on its own? Yep, I would re-do the servo horn. P.S. I keep cut one end of a cotton swab and jam it in the unused orange wire. The contact wouldn't get too dirty that way. Just in case you want to go with a brushless motor later.
  10. I'm used to seeing a spark, I haven't paid much attention to it. Most ESCs are made to withstand at least 60A of burst. Against short sparks like that, maybe up to 320A (as they advertise often). So I think it's fine.
  11. I feel most comfortable with Sport Tuned. The 38 year old chassis is not as capable as 21st century chassis. I don't know if I would be entirely comfortable with Super Stock... But if your mate would let one go cheap, why not give it a try? Even if you end up stripping the gears (I doubt it), they are inexpensive to replace. For the most part, many vintage chassis (and re-res) can take a 13.5t brushless. I think Super Stock's performance is very close to 13.5t. So I think it's worth giving a try. As a rule of thumb, I would use the smaller pinion to get the lower gear ratio (FDR 9) because Super Stock is a brushed motor. If you went with a brushless, I would choose the higher gear ratio (FDR 7.5). But that's only a general rule. Considering that it's a lightweight chassis, it won't matter too much either way. The bigger concern I experienced was the gap in the diff gear. (In the vintage model. The re-issued gearbox might not have this problem.) The stronger the motor is, the more force the differential has to endure. I would use at least AW grease if not something better. Thicker and stickier grease prevents bevel gears from skipping. I would also see how much gap the diff gear has in the gearbox. If there is any, I would use a shim or two (I trust Tamiya instruction only 99%). If you run a hot motor with some gap, you'd hear the dreaded clicking noise. (Oddly, my vintage Blackfoot never had this problem, but my vintage FAV has it. Both mounts a Sport Tuned or something similar.) Getting that right in the vintage kit was a pain.
  12. I would be careful with automotive stuff. Petroleum based stuff can damage plastic parts. I hear Red 'n Tacky is lithium based, it might be okay to use, if it's sticky enough for your need. I have black diff putty, but I haven't used it on open diffs. Diff bevel gears tend to squish and move the clay around. I only use on closed diffs because I'm afraid that it might fling out and jam somewhere else. I use "bad horsie diff lock" on open diffs. (the photo is of a closed diff, though...that much is enough for buggies.) The one on the left was from 2002 or 2003? It yellowed somewhat, but it's just as tacky. It's hard to fling, which makes it useful for open diffs. But I still use sparingly on open diffs. If my Wild Willy 2 stands on one rear tire, I can reverse on that one tire and set it right. You can't do that with regular grease. I don't think you could it with AW either. It's a US based company. But the price is the problem... $10 is expensive. With shipping, it's like $17. For about $7, the other thing I use is 3Racing Ultra High Viscosity Gear Diff oil. This is also whole lot stickier than AW. I bought cars with closed diffs since I got it, so I haven't tried this on open diffs. But if used sparingly, it wouldn't fling either. I do use AW grease on diffs, but only on M-chassis. AW feels perfect for on-road, but too weak for off-road.
  13. It seems every vehicle has spotless spray. You are using regular Tamiya cans, right? Are they discriminating against me or you've got the Midas touch?
  14. Another test with UV glue. I made a ghetto-cowling. I didn't like the nose of the autogiro being a flat vertical piece. It does a solid job gluing Lexan parts, without fogging up the clear parts like superglue would. My brush set donated the Lexan piece... anything for art... I mean, RC...
  15. Hold on, are you saying this is Pearl White? I thought it would be good when warm colors are next to it. I stand corrected. Pearl white looks very good next to a cool color too!
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