3 replies to this topic

[MrFlippant]

Magnetic Downforce Scale Apparatus

 

Inspired by several similar devices made by others using other materials (wood, metal, etc), and attempting to simplify and democratize the design and construction of a basic device to compare magnetic downforce between multiple cars, I've designed this model and provided the Fusion 360 file for quick and easy manipulation to accommodate different types of rails (from track as shown, or just bar steel if you want) as well as different scales. By just changing the parameters in the Fusion 360 file, this design can be easily adjusted for any combination of those things, and then printed out and put to use in a single day of printing.

 

The files are free to download at the link below, which also includes additional detail on design and construction. If you already have a Magnet Marshal, then you certainly don't need this. But if you've wanted one without spending nearly so much, this might be for you.

 

https://www.printabl...scale-apparatus

 

 

[Eddie Fleming]

I am sure I am missing something, but it looks like you are weighing the car and the block it is sitting on. Magnetic attraction between the block and the car should not effect the weight of the combination. At least that is the way I see it.

 

Is there more going on than I see or what? 

[MrFlippant]

You might not see that the piece of track rail under the car is mounted firmly by the legs at the ends.

If you don't tare out the weight of the car and the plate it sits on, you are ALSO measuring the weight of those things, along with the magnetic pull.

 

Normal procedure, just as it is with the much more expensive Magnet Marshal 2 product, is to place the car on its side, off of the rails, and then tare the scale, thus removing the weight of the car (and in this case, the plate) from the final reading. Then, place the car on its wheels, and the number shown reflects how much magnetic pull the car exerts on this scale.

 

Note that this is designed for comparison purposes only, and that the numbers one may get from their apparatus may differ from the number on another apparatus, for all the same reasons magnetic downforce changes in any other situation.

[MrFlippant]

I updated my design to include a way to adjust the height of the rails in order to "calibrate" to another scale. The models provided are for Scalextric Sport track rails and a 30mm tall scale. If you have a scale of a different height and/or want to use different rails, you can edit the parameters in the included Fusion 360 file, or PM me to adjust the models for you.

https://www.printabl...atus-adjustable