Scioly.org

Wabbit wrote:So I'm essentially done with a rough prototype of my vehicle which I made without too much thought going into its weight. I plan to redesign and/or modify in order to cut down on the total mass as it feels fairly sluggish right now and I'm unable to increase drive axle size without running out of string. Can someone provide me with a rough estimate of how much a decent car would weigh so I can know what to shoot for?

My current vehicle is sitting at around 350g and is constructed in part from balsa, although most of the weight is coming from the metal wing-nut stopping system and from Lego pieces which I used for part of the frame. Do people have recommendations for materials or construction methods which would minimize weight while not sacrificing too much strength? I, unfortunately, don't have access to a 3d printer.

Thanks!

dragonfruit35 wrote:

DarthBuilder wrote:alrighty, thanks! what is a good grip for wheels? I have CDs right now. I think balloons should do something for right now until i figure out a better solution?

I've used CDs in all the other vehicle events (Wheeled Vehicle, Scrambler, EV) and they've worked very well- some skid is bound to happen . The only other thing I'd consider would be those Banebots robot wheels (or similar), though CDs might still be better since they weigh less.

windu34 wrote:

dragonfruit35 wrote:

DarthBuilder wrote:alrighty, thanks! what is a good grip for wheels? I have CDs right now. I think balloons should do something for right now until i figure out a better solution?

I've used CDs in all the other vehicle events (Wheeled Vehicle, Scrambler, EV) and they've worked very well- some skid is bound to happen . The only other thing I'd consider would be those Banebots robot wheels (or similar), though CDs might still be better since they weigh less.

I would look into the 0.4 in banebot wheels and drilling out parts of the plastic to reduce inertia

4Head wrote:

windu34 wrote: I would look into the 0.4 in banebot wheels and drilling out parts of the plastic to reduce inertia

I think foam wheels would be best for lightness. You can increase the grip with balloons or tape and it probably would be quite a bit lighter than even a drilled out banebots wheel (which would end up around 30 grams still).

RJohnson wrote:

4Head wrote:

windu34 wrote: I would look into the 0.4 in banebot wheels and drilling out parts of the plastic to reduce inertia

I think foam wheels would be best for lightness. You can increase the grip with balloons or tape and it probably would be quite a bit lighter than even a drilled out banebots wheel (which would end up around 30 grams still).

30 grams for one wheel or for the set? According to their website, each 2-3/8in wheel weighs approximately .62 oz (17.6 g). With some skillful drilling you could probably get it down to 12 g or so, maybe even better. Not entirely sure of the relative density of the plastic vs. the rubber. Use a 1-3/8 wheel and you start at 7.1 grams... I'm not ruling the banebot wheels out yet.

4Head wrote:

windu34 wrote:

dragonfruit35 wrote:
I've used CDs in all the other vehicle events (Wheeled Vehicle, Scrambler, EV) and they've worked very well- some skid is bound to happen . The only other thing I'd consider would be those Banebots robot wheels (or similar), though CDs might still be better since they weigh less.

I would look into the 0.4 in banebot wheels and drilling out parts of the plastic to reduce inertia

I think foam wheels would be best for lightness. You can increase the grip with balloons or tape and it probably would be quite a bit lighter than even a drilled out banebots wheel (which would end up around 30 grams still).

windu34 wrote:

4Head wrote:

windu34 wrote: I would look into the 0.4 in banebot wheels and drilling out parts of the plastic to reduce inertia

I think foam wheels would be best for lightness. You can increase the grip with balloons or tape and it probably would be quite a bit lighter than even a drilled out banebots wheel (which would end up around 30 grams still).

Not a fan of using balloons for grip. While a good low-end option and very cheap, if you are looking to get a high level of performance out of the vehicle, I would not recommend that. The few extra grams will be worth it. Tape sounds inconsistent.

4Head wrote:

windu34 wrote:

4Head wrote: I think foam wheels would be best for lightness. You can increase the grip with balloons or tape and it probably would be quite a bit lighter than even a drilled out banebots wheel (which would end up around 30 grams still).

Not a fan of using balloons for grip. While a good low-end option and very cheap, if you are looking to get a high level of performance out of the vehicle, I would not recommend that. The few extra grams will be worth it. Tape sounds inconsistent.

that makes sense. A few grams is quite negligible and I get your point about grip.

antoine_ego wrote:Let's get this thread rolling again... What sized axles are people using? I've been using 1/4in, but I'm considering moving down to save weight. Also, has anyone found light threaded rods that don't bend a lot?