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30YrsL8r

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Posts posted by 30YrsL8r

    Re-releases are KILLING the hobby

    in Re-Release Discussions

    Posted

    Not sure I see the point of this thread.

    If re-releases upset someone then surely they should take it up with Tamiya directly?

    Tamiya is the one doing the re-releasing and consumers are simply responding to the availability of a product, for whatever reason motivates them.

    Nobody is going to read this thread, think "you know, I've been wrong all this time" and change their mind on whether re-releases are good or bad.

    I can see this thread lasting as long as the "postman brought me" one, though, only a lot less interesting and a lot more confrontational.

    • Like 2

    Two small nubs...

    in General discussions

    Posted

    Perhaps there's a language/interpretation problem here. I would not assume that "never run" meant "new" so, by definition, it's "used".

    Of course, you didn't buy it, so you've saved yourself from disappointment. I don't think you can extrapolate your feelings on this point to everyone else.

    • Like 1

    DT-02 understeer

    in General discussions

    Posted

    I noticed the softness/stickiness - not the kind of tyres I'd like to run on tarmac.

    The DT-02 just needs more weight toward the front now; I've noticed that when the back end bounces off the ground and shifts the weight to the front wheels whilst cornering, the car's turn-in is significantly increased.

    Half Track build

    in The Builds

    Posted

    That's going to be awkward. If you could remove the shaft you might be able to turn the end down to 5mm, then put an M5 thread and an oversize nut on the end, but you'd need a lathe for that, and you'd still need to be able to drill the shaft to fit a pin for the drive hub for the rough rider wheel. A more modern wheel with a 12mm hex might have been a slightly easier proposition. Could you butcher the old tank sprockets to fit tyres on, or attach wheels to the sprockets, as this is just a testbed ?

    My facilities are very limited. Last night I drilled out the existing hole and put in a new thread so that I can screw in some TB-02 axles I have, so the output shafts now have drive cups for dog bones. I'll update my build thread later.

    Half Track build

    in The Builds

    Posted

    You are, indeed, doing the opposite to me. I'm trying to figure out how to mount Rough Rider rear wheels to output shafts, with flats and threaded holes, that aren't the same diameter as the Rough Rider ones. If they were, I'd just put RR UJ's on the ends.....

    DT-02 understeer

    in General discussions

    Posted

    I bet Dad is too at that price - £4 to transform the handling :lol:

    Yep :)

    In case they ever run out on ebay, the part # is "A-7203 S" (don't know what the significance of them being the "silver" variant is).

    2.2" tyres, though, rather than 2.16" but they seem fine and I don't suppose it's such a big deal on the front.

    DT-02 understeer

    in General discussions

    Posted

    I adjusted the steering extremes on the transmitter, greased the dampers all round, dialled in a bit more toe-in and replaced the front tyres with a cheap pair of Team Losi ones (£4 delivered off ebay, including foam inserts). I just took it around the back garden a few times and the DT-02 now drives like a whole new buggy. My son will be very pleased.

    R0011183_zpsb1d93527.jpg

    Four-Motor Crawler

    in General discussions

    Posted

    You're really giving this a lot of thought, MadInventor! I should be able to incorporate the v-tail mixer function in software once I get my prototyping board connected up to the buggy.

    I intend to get a bit more adventurous with the hardware once I've proven that my micro-controller programming skills are up to the traction control challenge but, for now, I'm sticking with my low-budget DT-01/tank hybrid. A custom crawler build will (might) follow.

    I've swapped the output shafts and raided a Meccano box to mount the gearboxes to the chassis - will do a better job now that I know they fit.

    I didn't bother swapping the offending motor as I need to extend the output shafts to give a DT-01 sized track, which means the motor won't foul the wheel (see comparison with a DT-01 gearbox in the photo.

    R0011182_zps6f857b69.jpg

    Four-Motor Crawler

    in General discussions

    Posted

    Thanks for the information, MadInventor. Yet more terminology and technology to get my head around!

    My Heng Long gearboxes arrived just now. Over the weekend I raided my bits box and found/made enough to get the front end of a DT-01 together.

    Not exactly a classic crawler base, but enough for me to mess around with traction control (once I steal my son's kit DT-02 front tyres when the new ones arrive).

    I researched (watched youtube videos about) how servos work and they look VERY low tech, so not much to fear there.

    The picture below should give you an idea of how I want it to hang together.

    I was hoping that the 380 motors would pass each other when each wheel's suspension acted, but they are too close and their magnets attract each other.

    As a result, I'll have to swap the output shafts so that the motors and wheels are on the same side (and relocate one of the motors to clear the wheel).

    Should have gone for the other type of Heng Long gearbox. Oh well....

    R0011180_zps6b10e735.jpg

    Four-Motor Crawler

    in General discussions

    Posted

    It gets interesting at 2:39!

    Great, I was already considering what would happen if I tried to turn a crawler like a tank - now I'm thinking about the fact that I can put each wheel into reverse individually and maybe I need a steering servo per wheel, too. Thanks!

    I'd thought about the fact that I wouldn't want to completely stop a wheel that was in the air, as I might not know when it was down again - especially if I was using a drag brake on the ESC.

    On the suspension front, maybe I could have a combination of independent and solid axle - IS up to a point then the whole axle articulates beyond that. All this before I even try out my traction control!

    Four-Motor Crawler

    in General discussions

    Posted

    I'd be happy for crawler gurus to set me straight (the following is based on a little reading and a lot of thinking), but:

    In order to navigate an obstacle, a crawler needs to overcome the force caused by gravity acting on its mass.

    To do this, it imparts its own force on the obstacle using traction. If this force is greater than the gravitational force, it climbs.

    So, I assume the idea is to have as much surface area and all four wheels in contact with the ground at all times. This spreads the force around and, hopefully, ensures that each tyre's share of the force is not greater than its traction.

    If you lift a wheel with a locked diff, the force can now only be shared between the remaining three wheels. This is made worse if the diff isn't locked, as the other wheel on that axle won't turn either. So, there's more chance that the traction won't be enough and the wheels will skid.

    Hence the need for lots of articulation, which makes sure that a wheel going over an obstacle doesn't lift its lower partner, too. In case it does, people use a locked diff to lessen the impact.

    If I manage to get traction control to work, the crawler will intelligently share the force between the wheels based on how much they can handle. I also overcome the spinning wheel problem that drives the need for a locked diff.

    Here's my question, though: do I need to still have a solid axle, or would independent suspension be better because it doesn't have a camber problem?

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