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Re: Competitive Times for Nationals

Posted: May 2nd, 2018, 6:41 am
by MadCow2357
shrewdPanther46 wrote:Sorry for double posting.
MadCow2357 wrote:
jcmarcus0816 wrote: I don't think that is right, like I said im my last post the more mass you have the more inertia and the harder it is to stop, thus it skids more.
To reduce skidding you really need to increase the time the car takes to stop or decrease the speed.
Yeah I think the same thing. I am building a CF and 3D printed battery buggy that will be a lot lighter. I can always add weight later, so...
Yes, you are going to have to add weight to it just as a heads up. I also suggest you work with your old car and play with the distribution on the back of your car (which is bouncing up and down or something lol). You need more downforce/traction. Put weight on it and just give it a try. It will be very, very difficult for you (or anyone for that matter) to fully construct and test a CF and 3d printed buggy starting 2.5 weeks ish before a big competition..
I have all of the CAD files done, and all of the parts have came in. I might not get too much testing done, but I'll try I guess.

Re: Competitive Times for Nationals

Posted: May 2nd, 2018, 6:50 am
by builder83
Comparing a heavier electric vehicle brake system to battery buggy is a moot point. Remember that they could take their sweet time braking well past the target point (to reduce skid) and back up.

Re: Competitive Times for Nationals

Posted: May 2nd, 2018, 7:06 am
by shrewdPanther46
builder83 wrote:Comparing a heavier electric vehicle brake system to battery buggy is a moot point. Remember that they could take their sweet time braking well past the target point (to reduce skid) and back up.
We can always brake earlier too, it is just that we would be paying the price of time instead, so i dont understand your point.

Re: Competitive Times for Nationals

Posted: May 2nd, 2018, 7:26 am
by windu34
shrewdPanther46 wrote:Also, reading back, I am pretty sure conditioning wheels is analogous to just cleaning them so there isnt a lot of dirt on them.
No Im not just referring to cleaning them. I used belt conditioner https://www.amazon.com/CRC-05350-Belt-C ... B000M8PZB4 which actually softened the wheels and dramatically increased friction for ~3-4 minutes after each application.
builder83 wrote:Comparing a heavier electric vehicle brake system to battery buggy is a moot point. Remember that they could take their sweet time braking well past the target point (to reduce skid) and back up.
This is true, however there were VERY FEW teams at nationals that did this and I am pretty certain 1st, 3rd, and 6th did NOT back up and I think Solon (4th?) also did not.

Re: Competitive Times for Nationals

Posted: May 2nd, 2018, 7:37 am
by shrewdPanther46
What are your thoughts on my mass theory windu34? I recall there were similar discussions in the past. I'm curious to see what you think :D

Re: Competitive Times for Nationals

Posted: May 2nd, 2018, 8:37 am
by windu34
shrewdPanther46 wrote:What are your thoughts on my mass theory windu34? I recall there were similar discussions in the past. I'm curious to see what you think :D
Your explanation is correct and mass should theoretically be irrelevant to braking, however it is certainly important in the fact that it contributes towards the inertia of the car which will make accelerating at the same rate of a lighter car require more power from the motor. That said, mass contributes to the inertia of the device in the lateral directions as well and I found that having more mass reduced error from imperfections on the track and made it easier to keep a straight trajectory due to the increased lateral inertia.

Re: Competitive Times for Nationals

Posted: May 2nd, 2018, 8:53 am
by shrewdPanther46
Yea in theory I completely agree.
For some reason, increasing lateral inertia as you termed it didn't help us for fishtailing/the curving of our car once the brakes are applied :(
We tried adding 1kg blocks on top of our drive axle, but it didnt help, and for some reason unknown, it only made it worse (from our experimentation)

Re: Competitive Times for Nationals

Posted: May 9th, 2018, 6:59 am
by megrimlockawesom
Methinks that a time under 10 seconds should be good

Re: Competitive Times for Nationals

Posted: May 9th, 2018, 7:26 am
by windu34
megrimlockawesom wrote:Methinks that a time under 10 seconds should be good
More like < 3.5 seconds depending on accuracy

Re: Competitive Times for Nationals

Posted: May 9th, 2018, 11:13 am
by 4Head
windu34 wrote: This is true, however there were VERY FEW teams at nationals that did this and I am pretty certain 1st, 3rd, and 6th did NOT back up and I think Solon (4th?) also did not.
iirc solon did. I believe I saw their run waiting for scrambler. I remember it bc it went back and forth like 10 times lol