Proportional XY Line Chart
Proportional XY Line Chart
(OP)
Hello,
I am plotting a torque curve for the design of a hairspring to counterbalance a roll up door. Because the door rolls up on itself, the radius changes. I am plotting torque versus degrees of rotation. The degrees of rotation are taken from how many degrees the wheel must rotate to raise the door 1 slat. As the doors roll up, there is a point where the radius will "jump" up to a new dimension when the previous layer stacks up under the new one. Therefore there are several groupings of incremental angles. When plotting this curve, excel takes all of these angle and torque data points and places them on a grid. The problem is that one grid difference may be a 29 degree increment one place and a 41 degree increment somewhere else on the x axis. This leads to a non-proportional chart. I have Excel create a trend line as a best fit curve for figuring out a linear spring rate. If the X axis is off, so is the trend line.
What I'm looking for is a way to have Excel display the X axis data on a proportional grid. Is there a way to do this?
Thanks,
Kyle
I am plotting a torque curve for the design of a hairspring to counterbalance a roll up door. Because the door rolls up on itself, the radius changes. I am plotting torque versus degrees of rotation. The degrees of rotation are taken from how many degrees the wheel must rotate to raise the door 1 slat. As the doors roll up, there is a point where the radius will "jump" up to a new dimension when the previous layer stacks up under the new one. Therefore there are several groupings of incremental angles. When plotting this curve, excel takes all of these angle and torque data points and places them on a grid. The problem is that one grid difference may be a 29 degree increment one place and a 41 degree increment somewhere else on the x axis. This leads to a non-proportional chart. I have Excel create a trend line as a best fit curve for figuring out a linear spring rate. If the X axis is off, so is the trend line.
What I'm looking for is a way to have Excel display the X axis data on a proportional grid. Is there a way to do this?
Thanks,
Kyle





RE: Proportional XY Line Chart
XY (Scatter)
chart type rather than the Line chart type.
RE: Proportional XY Line Chart
Thanks for the tip! I think that worked. Maybe you can help me with another question. My y intercept for the trend line is at y=40. Is there any way to extrapolate the trend line so that I can find out how many degrees negative the value goes to 0? I'll use this to determine the preload I need to apply to the spring.
Thanks again,
Kyle
RE: Proportional XY Line Chart
Hope this helps!
RE: Proportional XY Line Chart
Thanks for the tip on the equation. The equation gives me the spring rate and a more accurate intercept than I could eyeball from the chart. Dividing the intercept by the spring rate will give me the preload. I also found where I could have Excel forcast the trendline backward until it reaches zero. Having the formula let me punch in how many units to forecast [or "backcast" in my case ;)]. Is there a way for Excel to calculate the exact number of units so that the trendline reaches zero base on the the formula it generates?
Thanks again,
Kyle