Tuesday, December 28, 2010

Firing results: Top speed of 51m/s

Now that we've got the 3d printer, I'm able to mount the firing boards. It did turn out, however, that home depot only had 2 more of the brackets I use to mount the capacitors. I'll have to work something out there.

In the meantime, I was able to easily get 2 more magnets working (for a total of 4). They worked the very first time I fired them up and now I've got some test results with both a large projectile and a smaller one.

I think the larger projectile didn't fire efficiently at the beginning because it wasn't moving fast enough to see the returns from the subsequent gates firing. I think the smaller projectile fired less efficiently at higher voltages because it was already moving too fast and the later gates were able to add less and less to it's velocity.

The large projectile should have a higher top speed because it takes longer to move through the magnet and thus the magnet can be allowed to fire for longer. In either case, we will begin to see diminishing returns on those projectiles.

Assuming we don't want to change the barrel, this leaves essentially just one option: Reduce the size of the capacitors so they fire faster. However, this also means they have less energy to drive into the process. The only way to get that energy capacity back is to raise the voltage. Odds are the projectile is already well into magnetic saturation but might as well try it.

All that said, we still have to test the timing of the firing of later magnets to show that they really are lagging behind the projectile. That shouldn't be too hard.

Large projectile

Voltage (V)Time (S)Velocity (m/s)Proj E (J)Cap E (J)Efficiency

Small projectile

Voltage (V)Time (S)Velocity (m/s)Proj E (J)Cap E (J)Efficiency

No comments:

Post a Comment