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Re: Mousetrap Vehicle C

Posted: September 5th, 2018, 3:59 pm
by MangoTTT
How do you make a mousetrap go straight then turn/tilt to the vtp that's 0.1m away from the centerline though??? I can think of ways but those aren't really efficient when it comes testing...

Re: Mousetrap Vehicle C

Posted: September 5th, 2018, 4:55 pm
by Aristotle
One way I can think of using an adjustable steering mechanism (similar to electric vehicle in the past) so the car curves to travel to the CTP and curves back to stop at the VTP.

I like the idea of the one sided wingnut. Thank you mnoga. I was wondering if anyone had any ideas for the aligning of the vehicle. String and measuring tape between the two points works but it's a long process and takes time during practice. Anyone have any other ideas?

Re: Mousetrap Vehicle C

Posted: September 5th, 2018, 6:21 pm
by Things2do
MangoTTT wrote:How do you make a mousetrap go straight then turn/tilt to the vtp that's 0.1m away from the centerline though??? I can think of ways but those aren't really efficient when it comes testing...
Perhaps you could wallow out the left front axle hole so that the reversing would shift the axel to make the car turn. You could also make some shims to adjust the angle to account for the variance of distances within the different competitions. It would take a lot of practice to determine the proper hole size, but it might be worth it. This would eliminate the adjustments for the forward curve in addition to the reverse curve, though.

Re: Mousetrap Vehicle C

Posted: September 5th, 2018, 8:03 pm
by windu34
MangoTTT wrote:How do you make a mousetrap go straight then turn/tilt to the vtp that's 0.1m away from the centerline though??? I can think of ways but those aren't really efficient when it comes testing...
IMO, the only reasonable and repeatable way to do this is using a fixed-curve trajectory similar to what was used by competitors in EV 2017

Re: Mousetrap Vehicle C

Posted: September 6th, 2018, 7:17 am
by MangoTTT
windu34 wrote:
MangoTTT wrote:How do you make a mousetrap go straight then turn/tilt to the vtp that's 0.1m away from the centerline though??? I can think of ways but those aren't really efficient when it comes testing...
IMO, the only reasonable and repeatable way to do this is using a fixed-curve trajectory similar to what was used by competitors in EV 2017
For the EV competition didn't most people code their vehicles tho?

Re: Mousetrap Vehicle C

Posted: September 6th, 2018, 7:35 am
by falcon1236912
I think he was referring to the use of calipers for steering.

Re: Mousetrap Vehicle C

Posted: September 6th, 2018, 10:06 am
by windu34
MangoTTT wrote:
windu34 wrote:
MangoTTT wrote:How do you make a mousetrap go straight then turn/tilt to the vtp that's 0.1m away from the centerline though??? I can think of ways but those aren't really efficient when it comes testing...
IMO, the only reasonable and repeatable way to do this is using a fixed-curve trajectory similar to what was used by competitors in EV 2017
For the EV competition didn't most people code their vehicles tho?
falcon1236912 wrote:I think he was referring to the use of calipers for steering.
^Correct. I know of only two teams that coded the steering, and neither team was in the top 6 at Nationals. I tried it near the beginning of the season, but realized it was impossible to achieve the level of accuracy compared to fixed-steering for SO events. It works in real life because an error of 15 cm is "no big deal", but thats considered bad in SO at higher levels of competition.

Re: Mousetrap Vehicle C

Posted: September 7th, 2018, 12:59 pm
by mnoga
Aristotle wrote:One way I can think of using an adjustable steering mechanism (similar to electric vehicle in the past) so the car curves to travel to the CTP and curves back to stop at the VTP.

I like the idea of the one sided wingnut. Thank you mnoga. I was wondering if anyone had any ideas for the aligning of the vehicle. String and measuring tape between the two points works but it's a long process and takes time during practice. Anyone have any other ideas?
Yes, I think you just setup your vehicle to turn slightly left on the forward run (and aim to the right of the CTP) and when your vehicle reverses it will backtrack approximately over its forward path. Furthermore, you will be running either Regional, State, or National Rules, which will allow you to make some minor adjustments in your path for best accuracy. I haven't done the math, but the curvature for each should be roughly the same.

To adjust your vehicle on the fly (after impound) is very difficult and you need very high precision components/measurments (calipers) to even have any chance of success. Remember you only have a few minutes for each run. Maybe you could have some preset positions, say 1.0, 1.5, and 2.0 for Regionals, that would allow you to change the curve slightly with decent precision, but, as our team found out in practice with the EV, adjusting the wheels to run a slightly different path led to too much imprecision. Another thing to keep in mind is that on your 2nd run you will be able to adjust your path slightly and still cover the CTP, which in turn might put you closer to the VTP.

Re: Mousetrap Vehicle C

Posted: September 8th, 2018, 6:13 am
by terence.tan
what is the jaw and hammer from rule 3a ?

Re: Mousetrap Vehicle C

Posted: September 8th, 2018, 6:59 am
by Unome
terence.tan wrote:what is the jaw and hammer from rule 3a ?
I think the jaw is the plastic part and the hammer is the arm that snaps down.