Page 18 of 33
Re: Mousetrap Vehicle C
Posted: November 4th, 2018, 8:37 pm
by DarthBuilder
sciencecat42 wrote:Is a 2.375" wheel big enough? We can only get about 25 spins on our axle right now. I did the math and that means the car can only go like 187" (circumference * rotations) when it needs to go 8m. In practice, our car actually goes about 7m, but I think this is from gliding. Isn't it best to have the car be able to go about 15m so that it can go forward and back the required distances without gliding?
Same problem here.
From the tip of my drive arm to my back axle is 55 cm and my wheels are 2-7/8. It only gets 17 winds. Any suggestions? I know it’s probably the length but I’d rather find out first before i go out and buy a new one.
Re: Mousetrap Vehicle C
Posted: November 5th, 2018, 2:46 pm
by DarkSparklyUnicorn
Try bigger wheels or a smaller axle then. Judging by the wheel size, you probably have banebot wheels, so using a smaller axle is your best bet. You can build up the axle where the hub connects using tape.
Re: Mousetrap Vehicle C
Posted: November 5th, 2018, 5:24 pm
by cheese
Is using a extremely long drive arm allowed?
3.f. Wheels/treads in their entirety in the ready-to-run configuration must fit in a 40.0 cm x 40.0 cm space
of any height. Axles, drive arms, and other parts of the vehicle may extend beyond these parameters.
So can I use a 60cm drive arm? It increases string length which allows for furthur travel.
Opinions expressed on this site are not official; the only place for official rules changes and FAQs is soinc.org.
Re: Mousetrap Vehicle C
Posted: November 5th, 2018, 5:47 pm
by antoine_ego
cheese wrote:Is using a extremely long drive arm allowed?
3.f. Wheels/treads in their entirety in the ready-to-run configuration must fit in a 40.0 cm x 40.0 cm space
of any height. Axles, drive arms, and other parts of the vehicle may extend beyond these parameters.
So can I use a 60cm drive arm? It increases string length which allows for furthur travel.
Opinions expressed on this site are not official; the only place for official rules changes and FAQs is soinc.org.
You can... But I don't see why you would. You'll still have a maximum of 40 cm of string wrapped around an axle. Not to mention that a 60cm arm would have ridiculously low torque.
Re: Mousetrap Vehicle C
Posted: November 5th, 2018, 6:59 pm
by cheese
I'm thinking something more like this. Though the low torque, it increases the overall distance, please correct me if I am wrong.
Re: Mousetrap Vehicle C
Posted: November 6th, 2018, 3:17 am
by antoine_ego
cheese wrote:
I'm thinking something more like this. Though the low torque, it increases the overall distance, please correct me if I am wrong.
Hmm. I seem to have misunderstood your design in my previous post.
I'm assuming that the label is intended to read 40cm. This is legal by the rules, but the torque is going to be so low that your wheels are going to have to be extremely light.
You might want to consider a pulley system like in Mark Rober's famous YouTube video.
Re: Mousetrap Vehicle C
Posted: November 6th, 2018, 7:04 pm
by Visvix
this is my first year with mousetrap vehicle and im kinda confused about rule 3e/5d. If the dowel is perpendicular to the floor, how can it touch the cup? If you put in on front it'll fall off easily, but is that the point?
Re: Mousetrap Vehicle C
Posted: November 7th, 2018, 5:07 am
by DarthBuilder
Visvix wrote:this is my first year with mousetrap vehicle and im kinda confused about rule 3e/5d. If the dowel is perpendicular to the floor, how can it touch the cup? If you put in on front it'll fall off easily, but is that the point?
Some people glue the dowel and some people 3D print the dowel which is what my partner and I did last yr.
Re: Mousetrap Vehicle C
Posted: November 7th, 2018, 11:17 am
by Things2do
DarthBuilder wrote:Visvix wrote:this is my first year with mousetrap vehicle and im kinda confused about rule 3e/5d. If the dowel is perpendicular to the floor, how can it touch the cup? If you put in on front it'll fall off easily, but is that the point?
Some people glue the dowel and some people 3D print the dowel which is what my partner and I did last yr.
I drill a pilot hole and put a small screw in it. If you get the screw just tight enough, and if it's small enough compared to the dowel, the dowel will remain perpendicular to the floor, and it won't crack.
Re: Mousetrap Vehicle C
Posted: November 7th, 2018, 1:10 pm
by DarkSparklyUnicorn
Since this year's dowel has to be wooden, most people will probably drill a hole really close to the edge, push the dowel through, then glue it.