So I was wondering how much of an edge, if any, your bottom plate would need to have to allow the gear to pick up the gear. We are using 1/4 inch aluminum, and we can’t change it now, so how would we have to cut it to get the plate to at least slide under the gear so the wheels can pull it in the rest of the way?
Thanks!
Edit: It’s 1/8 inch aluminum on our bottom plate.
Thanks!
Our bottom plate was 0.09 and that is was too thick so we taped thin lexan film 0.020 to the leading edge and that easily slid right under the lip.
Similar to IndySam, one of the teams at champs had a composite plate for their pickup.
The meat of the plate was 1/8" aluminum. On top of that plate sat a thin (0.02/0.03") plate of polycarbonate as the leading edge. The intake assembly was angled slightly down, so the polycarbonate was pressed into the ground and flexed enough to ride along the floor. It was also easy to replace.
If you don’t mind me asking, did your team actually tape it to the leading edge, and how did you guys attach it to be as efficient as possible? If you have any pictures to show, that would be extremely helpful.
Thanks!
Be sure your bottom plate makes contact with the gear before whatever roller you are using. The force of the wheels pushing the gear into the ground can make any edge insurmountable.
^
Our team uses 1/8" lexan and sanded the front lip down so it slides under the gear.
Do you guys have a specific angle you cut it at? or did you guys just make it a shallow angle and a knife edge thickness at the end?
We ended up using 1/16th in polycarb for our bottom plate sanded down at the front edge a bit. The 1/16th held up fairly well, but we did need to replace it once or twice between our last regional, worlds, and IRI.
There were two things that were key in making our pickup consistent. The first was having the plate contacting the gear before the roller (as mentioned by our friends from 1732). The other thing we did was use a heat gun to bend the polycarb towards the carpet slightly (10-15 degees). The geometry of our pickup had the plate flush with the carpet, so this modification put some positive pressure on the front edge of the plate which forced it into the carpet.
You can have the wheels first, but then your wheels need to have a lot of flop in them and you have to nail the geometry.
It’s probably just easier to put your tray in front.
We did something similar. I don’t have a great picture right now, but here’s one where you can kind of see it: https://i.imgur.com/ajWJOMah.jpg
That’s an early version of the gearmanip, and we’ve changed a decent amount of geometry and materials since then, but the leading edge construction is generally the same. There’s a thin piece of polycarb that’s spring loaded so it digs into the carpet by adding a thin strip of foam under its back. You can kind of see that angle in the picture. That polycarb and foam are then literally taped to the main plate, with some tape wrapping around the side to keep it from flopping upside down. It isn’t the most aesthetic, but it worked well.
Those leading edges were pretty much disposable, and we had a lot of spares. Two main failure types were when we went too thin with the plastic and they got kinked on a gear or gust of wind, and when they were taped improperly and flopped upside down. Even while they were working properly, after enough matches they’d start to wear and bend a bit but still work, so we preemptively replaced them.
Less scientific.
One of our students sanded down the edge until he could lay it flat on the floor and slide it under a gear without resistance.
We did this too but we sanded it down so much it was like a razor… Never would get through inspection so we ditched it.
Instead, we went to HEB and bought a couple $2 dustpans. Worked flawlessly - gear slides right into the dustpan ::safety::
We riveted 0.040in/1mm HDPE sheet to ours, with the coil bow ‘frowning.’ Worked like a charm.
