Day 15 & 16: Launcher Tests & Climber Tests

Launcher Tests

Our initial tests on Saturday involved our double-top roller launcher. We then realized we could flip it upside down and we got much nicer-looking shots. We designed and cut new plates for a double-bottom roller launcher that we tested on Sunday, and by varying side wheel speeds, we got some nice-looking launches. We still have a ways to go before we are consistent, but we believe we can get a setup like this to be competitive once its velocity and angle are controlled. We have room to do a top and bottom roller and may end up eventually moving in that direction.

Launcher Stats

• 12x 3in REV Compliant Wheels

• Just the wheels we tested first, nothing special about them

• 2 Rows of 3 wheels each on each side

• 14” spacing between the side walls

• Haven’t tried compressing 12” width but it’s on our list

• Top and bottom flat surfaces covered in PTFE sheet

• Double stick taped to the wood

• Purchased off Amazon in 2020, other vendors exist for it, McMaster also sells adhesive tape version

• Compression

• Top Roller - 1.75” wheel to wood

• Bottom roller - 1.875” wheel to wood

• Powered by Falcon motors belted 36:18 for a 2x speed increase at the wheel.

• We believe we want to launch between 4k and 8k RPM at the 3” wheel

• Top Wheels tests were done with motors driven in follower mode, so relatively similar speeds

• The good launches from the double bottom roller tests had different speeds, we were doing it with a PWM generator so we don’t know what the speed difference was, just trying to induce spin.

Double Top Roller

Double Top Roller - Inverted Test (still at the same speeds)

Double Bottom Wheels Launcher

Climber Tests

This is a more complete climber test, we still aren’t settled on how we are going to pull down the chain but we wanted to make sure it worked with the full elevator, etc. This test showed we don’t need to pull the chain to the bumpers to get our amp-trap mechanism above the bottom edge of the trap.

Climber Test Video

Weight

Our alpha robot with nearly all its components and motors weighed in at around 90 lbs. It will gain 10-15lbs when we switch everything to aluminum and polycarbonate. We likely aren’t going to run a steel belly pan this year and instead opt for 090 aluminum to keep our overall weight down. Our chassis is going to be ⅛” extrusion in most places as we had some issues with bending last year.