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Re: Mousetrap Vehicle C

Posted: January 28th, 2019, 10:21 pm
by TheGhghp
PM2017 wrote: Well, the pitch needs to match perfectly, and even if the pitch matched, a size mismatch would mean more play, and therefore less accuracy.
Ok, thanks. In that case, a 6mm-1.0 wing nut would be good if I have a M6-1.0 threaded rod?

Re: Mousetrap Vehicle C

Posted: February 2nd, 2019, 9:48 pm
by sciencecat42
TheGhghp wrote:
PM2017 wrote: Well, the pitch needs to match perfectly, and even if the pitch matched, a size mismatch would mean more play, and therefore less accuracy.
Ok, thanks. In that case, a 6mm-1.0 wing nut would be good if I have a M6-1.0 threaded rod?
Yes. M6 is just the metric designation for 6mm when talking about screws and stuff. The stuff after the dash is the pitch. If they match you're good.

Re: Mousetrap Vehicle C

Posted: February 17th, 2019, 6:32 pm
by 19sawickin
I have a ton of questions that I just haven't been able to solve for a while now and I'm hoping someone could help:

I don't think anyone ever really gave a clear answer to the issues raised about the wing-nut braking mechanism not functioning as it should. I too have found that when I chop off one of the wings of my wing-nut, the wingnut just dangles on the axle with its sole arm pointing at the ground, regardless of what direction the vehicle is traveling in. What am I doing wrong here? Is it even necessary to cut off one of the arms if I have two rods parallel to and on either side of the axle – one for the way forward and one for reverse where there's the obstruction? I'm tired of regulating reverse braking with string winds, but I just can't seem to figure out the wingnut system.

In regards to wheels and axles, I purchased Banebot T40 2-3/8" wheels and my axle is a #8-32 aluminum axle. I measured with a caliper and its diameter seems to be 4mm, so should I order the 4mm shaft hubs from Banebot for this? 3mm shaft or 6mm shaft hubs certainly won't cut it, but I don't know if 4mm shaft hubs will work either.

Have people been using caliper steering this year? And if so, how have they gone about attaching the caliper to the vehicle?

Lastly, is there any way besides zip ties that people have been attaching their rods to their mousetraps? My rod never stays secure at the end of the mousetraps when it's folded over and it twists at an angle while unwinding the string.

Re: Mousetrap Vehicle C

Posted: February 18th, 2019, 7:04 am
by falcon1236912
19sawickin wrote:I have a ton of questions that I just haven't been able to solve for a while now and I'm hoping someone could help:

I don't think anyone ever really gave a clear answer to the issues raised about the wing-nut braking mechanism not functioning as it should. I too have found that when I chop off one of the wings of my wing-nut, the wingnut just dangles on the axle with its sole arm pointing at the ground, regardless of what direction the vehicle is traveling in. What am I doing wrong here? Is it even necessary to cut off one of the arms if I have two rods parallel to and on either side of the axle – one for the way forward and one for reverse where there's the obstruction? I'm tired of regulating reverse braking with string winds, but I just can't seem to figure out the wingnut system.

In regards to wheels and axles, I purchased Banebot T40 2-3/8" wheels and my axle is a #8-32 aluminum axle. I measured with a caliper and its diameter seems to be 4mm, so should I order the 4mm shaft hubs from Banebot for this? 3mm shaft or 6mm shaft hubs certainly won't cut it, but I don't know if 4mm shaft hubs will work either.

Have people been using caliper steering this year? And if so, how have they gone about attaching the caliper to the vehicle?

Lastly, is there any way besides zip ties that people have been attaching their rods to their mousetraps? My rod never stays secure at the end of the mousetraps when it's folded over and it twists at an angle while unwinding the string.
1. I found that you don't have to cut off a wing but there must be enough room for the wing to rotate to the other side of a platform where it will interact with a stopper.
2. 4mm hubs should be fine. Although you may need to either sand the hub bores or tap them with #8-32 threads fro them to properly fit as a size 8 axel is slightly larger than 4mm.
3. Most teams I have seen aren't but I am sure that competitive team are. You can drill a hole in a caliper place a bearing a axel in the caliper (as seen in bazinga's video)
4. I have had success by using wire to tightly wrap the rod on to the mousetrap and then secure the rod using glue.

Re: Mousetrap Vehicle C

Posted: February 18th, 2019, 5:03 pm
by PM2017
So, I have what I think is a car that has the potential to be extremely accurate in terms of curvature. However, I don't really know how to test the curve/ create data to run through some regressions. So, I don't really know how to figure out how to get the correct angle between my axles to get the car to go in the exact curvature that it should.

(Note, using this http://www.davdata.nl/math/turning_radius.html, I know what the angle should be, I just don't know how to adjust my car to get that angle.)

Re: Mousetrap Vehicle C

Posted: February 24th, 2019, 2:45 pm
by 19sawickin
Just wondering, what have people been using as their block to have their vehicle brake? Any recommendations? I've been using an office clip and it's been sort of no bueno...

Re: Mousetrap Vehicle C

Posted: February 26th, 2019, 8:35 am
by MadCow2357
Thought that I might as well post my questions here as well as in Battery Buggy, since you guys probably have experience in the sighting department as well. So I plan to start sighting with a rifle scope, but I know literally nothing about them.
1. I'm aware that they need to be non-electrical, though I'm not sure how to tell if scopes online are electrical or not. If I bought one that implements electricity, could I still use it without?
2. Would an electrical rifle scope without batteries meet construction parameters (it would be an electrical aiming device but I guess it wouldn't be without batteries)?
3. Finally, how much could I get out of a <$25 scope? I'm tight on money right now so I can't spend much.
4. Any super cheap rifle scopes you recommend?

Re: Mousetrap Vehicle C

Posted: February 26th, 2019, 9:04 am
by sdececco
19sawickin wrote:Just wondering, what have people been using as their block to have their vehicle brake? Any recommendations? I've been using an office clip and it's been sort of no bueno...
I have been using a 3d printed piece but I have no doubt that a small piece of wood or cf would get the job done

Re: Mousetrap Vehicle C

Posted: February 26th, 2019, 9:06 am
by sdececco
MadCow2357 wrote:Thought that I might as well post my questions here as well as in Battery Buggy, since you guys probably have experience in the sighting department as well. So I plan to start sighting with a rifle scope, but I know literally nothing about them.
1. I'm aware that they need to be non-electrical, though I'm not sure how to tell if scopes online are electrical or not. If I bought one that implements electricity, could I still use it without?
2. Would an electrical rifle scope without batteries meet construction parameters (it would be an electrical aiming device but I guess it wouldn't be without batteries)?
3. Finally, how much could I get out of a <$25 scope? I'm tight on money right now so I can't spend much.
4. Any super cheap rifle scopes you recommend?
To your first two questions both would be illegal since you cannot use an outlet for anything and most scopes are none electrical just make sure it doesnt emit a laser or something along those lines

Re: Mousetrap Vehicle C

Posted: February 26th, 2019, 11:30 am
by dragonfruit35
PM2017 wrote:So, I have what I think is a car that has the potential to be extremely accurate in terms of curvature. However, I don't really know how to test the curve/ create data to run through some regressions. So, I don't really know how to figure out how to get the correct angle between my axles to get the car to go in the exact curvature that it should.

(Note, using this http://www.davdata.nl/math/turning_radius.html, I know what the angle should be, I just don't know how to adjust my car to get that angle.)
Honestly, you might want to just give it your best guess and then find an angle that works through trial and error. Even if things seem like they’ll work because the math works out, they may not work in practice, so it’s good to actually test your device and confirm its behavior, which probably can’t be modeled all that well with simple equations (or maybe mine is just special like that).
19sawickin wrote: Just wondering, how have peiple been using as their block to have their vehicle brake? Any recommendations? I’ve been using an office clip and it’s been sort of no bueno...
I’ve used a small piece of wood and it’s been working just fine :)