Vehicle curving

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Re: Vehicle curving

Post by MadCow2357 » April 3rd, 2018, 4:45 pm

I have a similar issue with drifting. It has not affected us too much, but I think that the car being too heavy could be the reason, instead of being too light. See, if the vehicle was heavier, it would be harder to stop the buggy consistently after the motor turned off, the reason being that the momentum would cause the car to keep moving forward even after the wheels lock. If the vehicle was light, the momentum would be less, therefore making it easier for the buggy to stop after the motor turned off.

I think reducing weight could help, but I am not entirely sure. If you wanted to try reducing weight, maybe you could drill holes through the plywood? A little risky though...
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Re: Vehicle curving

Post by windu34 » April 3rd, 2018, 4:55 pm

sciolyrules107 wrote:
shrewdPanther46 wrote:Hi guys,

We are dealing with an ongoing issue with our vehicle which is limiting our accuracy. We managed to get the car to go straight, but when the power is cut from the motor, our car starts curving to the right. Our car is front wheel drive. When dynamically braking, the car "fishtails" a lot (10 cm to right), but if I simply cut the power, its probably around 5 cm. Regardless, it is resulting in a lot of variance in testing. I'm relatively sure this is simply due to wheel slippage/lack of friction. We tried adding a lot of weight (we doubled the mass of the car using a total of about 1kg of blocks) and we tried distributing the weight in different spots on the car. It still had no impact :(

Is anyone else experiencing similar issues? Please advise!

Thanks :)
This is an easy fix: just move your dowel rod the number of cm to the left that it's curving. We built and centered an attachment at the front of the car so that we could slide the dowel rod to the left and right.
Reasons this is a bad idea:
1.) Drifting in the way described will not necessarily be consistent. Simply "moving the dowel location" will not necessarily consistently fix your problem.
2.) MOST supervisors should require your dowel to be directly above the starting point (not starting line). I am not super familiar with the battery buggy rules, but I know such is the case with EV.
3.) You are still neglecting to solve the underlying problem

Are both wheels affixed to a single axis? Are the points where the wheels are connected to the axle solid and not slipping?
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Re: Vehicle curving

Post by shrewdPanther46 » April 3rd, 2018, 5:00 pm

they are both on the same axle and we have them secured w/ a set screw and glued down as well

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Re: Vehicle curving

Post by windu34 » April 3rd, 2018, 6:59 pm

shrewdPanther46 wrote:they are both on the same axle and we have them secured w/ a set screw and glued down as well
I would check to make sure they arent somehow slipping by exerting a torque on one wheel while holding the other stationary. If this isnt the problem, then I would think its a weight distribution or frictional problem that that has resulted in oversteer.
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Re: Vehicle curving

Post by sciolyrules107 » April 3rd, 2018, 6:59 pm

windu34 wrote:
sciolyrules107 wrote:
shrewdPanther46 wrote:Hi guys,

We are dealing with an ongoing issue with our vehicle which is limiting our accuracy. We managed to get the car to go straight, but when the power is cut from the motor, our car starts curving to the right. Our car is front wheel drive. When dynamically braking, the car "fishtails" a lot (10 cm to right), but if I simply cut the power, its probably around 5 cm. Regardless, it is resulting in a lot of variance in testing. I'm relatively sure this is simply due to wheel slippage/lack of friction. We tried adding a lot of weight (we doubled the mass of the car using a total of about 1kg of blocks) and we tried distributing the weight in different spots on the car. It still had no impact :(

Is anyone else experiencing similar issues? Please advise!

Thanks :)
This is an easy fix: just move your dowel rod the number of cm to the left that it's curving. We built and centered an attachment at the front of the car so that we could slide the dowel rod to the left and right.
Reasons this is a bad idea:
1.) Drifting in the way described will not necessarily be consistent. Simply "moving the dowel location" will not necessarily consistently fix your problem.
2.) MOST supervisors should require your dowel to be directly above the starting point (not starting line). I am not super familiar with the battery buggy rules, but I know such is the case with EV.
3.) You are still neglecting to solve the underlying problem

Are both wheels affixed to a single axis? Are the points where the wheels are connected to the axle solid and not slipping?
I understand that this is a temporary fix and its not necessarily going to hit centerline every time but at least it does something.
This was a problem for us too when we were in invitational season and we used this adjustable dowel rod to figure some things out while taking data.

Btw, this year at Solon and West Liberty Salem invitational the proctor for nationals was the ES for both tournaments and approved it. Of course, the dowel rod was over the dot and was perpendicular to the floor when we ran it, but he had no problems with the design.

Also, I don't think I elaborated enough before. I'm talking about moving the dowel rod as well as positioning the car differently too. Though this may not be the best idea, If you want to keep this car, you can angle the wheels to adjust to the curve (I've told u how before in our hangouts) while keeping the dowel rod over the dot ( I meant to sort of imply that in the last post). I'm not saying to move the dowel rod crazy places in the competition in the heat of the moment; I'm just saying to perhaps change the position of the dowel rod, run it, and adjust the dowel rod/angles while taking data

I'm sorry if this doesn't help but it worked for our team which is why I recommended it.
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Re: Vehicle curving

Post by windu34 » April 3rd, 2018, 7:02 pm

sciolyrules107 wrote:
windu34 wrote:
sciolyrules107 wrote:
This is an easy fix: just move your dowel rod the number of cm to the left that it's curving. We built and centered an attachment at the front of the car so that we could slide the dowel rod to the left and right.
Reasons this is a bad idea:
1.) Drifting in the way described will not necessarily be consistent. Simply "moving the dowel location" will not necessarily consistently fix your problem.
2.) MOST supervisors should require your dowel to be directly above the starting point (not starting line). I am not super familiar with the battery buggy rules, but I know such is the case with EV.
3.) You are still neglecting to solve the underlying problem

Are both wheels affixed to a single axis? Are the points where the wheels are connected to the axle solid and not slipping?
I understand that this is a temporary fix and its not necessarily going to hit centerline every time but at least it does something.
This was a problem for us too when we were in invitational season and we used this adjustable dowel rod to figure some things out while taking data.

Btw, this year at Solon and West Liberty Salem invitational the proctor for nationals was the ES for both tournaments and approved it. Of course, the dowel rod was over the dot and was perpendicular to the floor when we ran it, but he had no problems with the design.

Also, I don't think I elaborated enough before. I'm talking about moving the dowel rod as well as positioning the car differently too. Though this may not be the best idea, If you want to keep this car, you can angle the wheels to adjust to the curve (I've told u how before in our hangouts) while keeping the dowel rod over the dot ( I meant to sort of imply that in the last post). I'm not saying to move the dowel rod crazy places in the competition in the heat of the moment; I'm just saying to perhaps change the position of the dowel rod, run it, and adjust the dowel rod/angles while taking data

I'm sorry if this doesn't help but it worked for our team which is why I recommended it.
Okay yeah but having to reorient the car in addition to moving the dowel is basically just trying to compensate for error rather than getting to the root of the problem. Of course if competition is in a week or 2, this might be a good option, but generally, its better to actually fix the problem at its source.
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Re: Vehicle curving

Post by sciolyrules107 » April 3rd, 2018, 7:16 pm

windu34 wrote:
sciolyrules107 wrote:
windu34 wrote: Reasons this is a bad idea:
1.) Drifting in the way described will not necessarily be consistent. Simply "moving the dowel location" will not necessarily consistently fix your problem.
2.) MOST supervisors should require your dowel to be directly above the starting point (not starting line). I am not super familiar with the battery buggy rules, but I know such is the case with EV.
3.) You are still neglecting to solve the underlying problem

Are both wheels affixed to a single axis? Are the points where the wheels are connected to the axle solid and not slipping?
I understand that this is a temporary fix and its not necessarily going to hit centerline every time but at least it does something.
This was a problem for us too when we were in invitational season and we used this adjustable dowel rod to figure some things out while taking data.

Btw, this year at Solon and West Liberty Salem invitational the proctor for nationals was the ES for both tournaments and approved it. Of course, the dowel rod was over the dot and was perpendicular to the floor when we ran it, but he had no problems with the design.

Also, I don't think I elaborated enough before. I'm talking about moving the dowel rod as well as positioning the car differently too. Though this may not be the best idea, If you want to keep this car, you can angle the wheels to adjust to the curve (I've told u how before in our hangouts) while keeping the dowel rod over the dot ( I meant to sort of imply that in the last post). I'm not saying to move the dowel rod crazy places in the competition in the heat of the moment; I'm just saying to perhaps change the position of the dowel rod, run it, and adjust the dowel rod/angles while taking data

I'm sorry if this doesn't help but it worked for our team which is why I recommended it.
Okay yeah but having to reorient the car in addition to moving the dowel is basically just trying to compensate for error rather than getting to the root of the problem. Of course if competition is in a week or 2, this might be a good option, but generally, its better to actually fix the problem at its source.

Yeah, that's sort of what I was implying. Maybe it wasn't clear enough.
However, who am I to speak. We've never gotten below 8cm at a tournament.
"my brain is fossilized"

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