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Re: Mousetrap Vehicle C

Posted: September 10th, 2018, 4:57 am
by antoine_ego
Otkrlj wrote:Hey what material do you think is going to be best for building the body this year. I would assume balsa wood or carbon fiber, but with the weird rules this year, I wanted to make sure those were still viable.
I used CF last year, but I'm moving to aluminum this year, since CF flexes a little too much for my liking, and especially with the distances involved and long vehicle lengths, I want something a little more robust.

Re: Mousetrap Vehicle C

Posted: September 10th, 2018, 9:19 am
by retired1
Last time I helped build one of these we used 1/4" hard balsa reinforced diagonally with 5,000 carbon fiber tape.
Do you think that the aluminum will be heavier than the carbon fiber structure. What effect would you expect on the time?
In the past, we built a 3 wheel car with cord and turnbuckles to warp the long axis of the car. It had 4-40 threads so was quite adjustable. It did need t be relaxed after an event and re calibrated before impound. With good data, you can easily adjust the car for the unknown distance.

Re: Mousetrap Vehicle C

Posted: September 10th, 2018, 1:14 pm
by windu34
antoine_ego wrote:
Personally, I think that the minimum times will be around 10 seconds, and even this might be an underestimate. At Nationals last year where we traveled around 7 meters total, the fastest runs were about 8 seconds, with only one exception that used extremely strong, though still legal traps.

However, note that instead of having to travel only about 3-4m with the power of the traps, unless someone comes up with something really clever, a team needs to travel a minimum 9 meters. This means that the power of the traps needs to be spread out over a longer distance, reducing the speed substantially. Hence, I think that 7 second times are pretty much impossible.
I thought i remembered hearing about 5-6 second times last year at Nationals, but I could be mistaken.
thewaffleguy wrote:(In your own opinion) Is it against this years rules to use electric measurement tools to align your vehicle before a run?
Yes: "Only non-electric sighting/aiming devices are permitted"

Re: Mousetrap Vehicle C

Posted: September 10th, 2018, 1:52 pm
by antoine_ego
windu34 wrote: I thought i remembered hearing about 5-6 second times last year at Nationals, but I could be mistaken.
There was only one vehicle that did it with high accuracy as far as I know, but they used oversized mousetraps which have been banned this year, so I doubt we'll see that kind of performance. This was the first place run. The second place run was about 8.5 seconds, and my 6th place run was about 9 seconds.

Re: Mousetrap Vehicle C

Posted: September 10th, 2018, 2:35 pm
by windu34
antoine_ego wrote:
windu34 wrote: I thought i remembered hearing about 5-6 second times last year at Nationals, but I could be mistaken.
There was only one vehicle that did it with high accuracy as far as I know, but they used oversized mousetraps which have been banned this year, so I doubt we'll see that kind of performance. This was the first place run. The second place run was about 8.5 seconds, and my 6th place run was about 9 seconds.
I know of others outside the top 6 that had <8 second runs with varying levels of success in accuracy, certainly not atrocious though. I still believe teams are not using the mousetraps efficiently, and that there is potential for much better performance, albeit with a more complicated design (not necessarily all that much heavier though).

Re: Mousetrap Vehicle C

Posted: September 11th, 2018, 8:11 am
by dcambrid
So I am wondering how teams will align their steering if you use the set steering like EV. You cannot use a digital caliper attached to the vehicle since no electronic parts are allowed. For EV we used a non attached caliper to set the steering, but the rules this year state that you can have an electronic calculator and no other electronic tools, which means no digital calipers that are non attached either. Setting the steering without that degree of accuracy will be difficult. You can use a manual caliper, but that will be tough.

Re: Mousetrap Vehicle C

Posted: September 11th, 2018, 12:06 pm
by windu34
dcambrid wrote:So I am wondering how teams will align their steering if you use the set steering like EV. You cannot use a digital caliper attached to the vehicle since no electronic parts are allowed. For EV we used a non attached caliper to set the steering, but the rules this year state that you can have an electronic calculator and no other electronic tools, which means no digital calipers that are non attached either. Setting the steering without that degree of accuracy will be difficult. You can use a manual caliper, but that will be tough.
Why would that be tough? Dial calipers are used very commonly in industry and have comparable levels of precision

Re: Mousetrap Vehicle C

Posted: September 11th, 2018, 6:33 pm
by 4Head
windu34 wrote:
dcambrid wrote:So I am wondering how teams will align their steering if you use the set steering like EV. You cannot use a digital caliper attached to the vehicle since no electronic parts are allowed. For EV we used a non attached caliper to set the steering, but the rules this year state that you can have an electronic calculator and no other electronic tools, which means no digital calipers that are non attached either. Setting the steering without that degree of accuracy will be difficult. You can use a manual caliper, but that will be tough.
Why would that be tough? Dial calipers are used very commonly in industry and have comparable levels of precision
they're insanely precise. I'm just worried about the weight. Metal calipers are pretty heavy?

Re: Mousetrap Vehicle C

Posted: September 11th, 2018, 6:59 pm
by Unome
4Head wrote:
windu34 wrote:
dcambrid wrote:So I am wondering how teams will align their steering if you use the set steering like EV. You cannot use a digital caliper attached to the vehicle since no electronic parts are allowed. For EV we used a non attached caliper to set the steering, but the rules this year state that you can have an electronic calculator and no other electronic tools, which means no digital calipers that are non attached either. Setting the steering without that degree of accuracy will be difficult. You can use a manual caliper, but that will be tough.
Why would that be tough? Dial calipers are used very commonly in industry and have comparable levels of precision
they're insanely precise. I'm just worried about the weight. Metal calipers are pretty heavy?
...oh yeah...

From some quick research, they weigh about 120-150 grams. Clearly a lot more important for this event than for EV.

Re: Mousetrap Vehicle C

Posted: September 11th, 2018, 9:02 pm
by windu34
Unome wrote:
4Head wrote:
windu34 wrote: Why would that be tough? Dial calipers are used very commonly in industry and have comparable levels of precision
they're insanely precise. I'm just worried about the weight. Metal calipers are pretty heavy?
...oh yeah...

From some quick research, they weigh about 120-150 grams. Clearly a lot more important for this event than for EV.
There are also plastic dial calipers, although those have a different problem that will need to be overcome