Intake Conveyor Ideal Speed
 

Hello all and thanks for reading.
For our fuel intake and shooter feed-conveyor we will likely be using 1 1/2 in. Aluminum rollers and 1 inch wide orange belting from McMaster Carr.
We will also likely be using a 775 pro with a versaplanetary to power both.
This said, does anyone have a approximate ideal spead for the belts to be moving?

Re: Intake Conveyor Ideal Speed
 

Mach 10

Re: Intake Conveyor Ideal Speed
 

Still too slow.

In seriousness, I would suggest prototyping. In this case, I'd grab a cordless drill and use it on the drive of the intake to see what is likely to work.

Re: Intake Conveyor Ideal Speed
 

you want the linear speed of your intake to be faster that you can drive forward. One of my build members, now an alum, has a rule of thumb that it should be twice as fast as your drive. Once you get it there, you can tweak it to suit your needs.

Re: Intake Conveyor Ideal Speed
 

So what I'm getting is fast as possible without;
Breaking/slipping a belt
Burning up/ stalling a motor
Obtaining liftoff?

Re: Intake Conveyor Ideal Speed
 

It is difficult to know without seeing your design, and even then the land of theory does not translate perfectly to the real world. As far as prototyping goes 400-800rpm should pull that fuel off the floor like a hot d*mn...

Re: Intake Conveyor Ideal Speed
 

Thanks! Duly noted

Re: Intake Conveyor Ideal Speed
 

basically.

I'd aim for 1.25x robot's top speed. Also, a 775pro is likely overkill. I'd probably start with a bag motor first, and if i don't get the power i want move up to some other banebots options. though if you are using lots of 775 pros and want to maintain interchangable spares, it's not a bad plan.

Re: Intake Conveyor Ideal Speed
 

This was the idea. Same reason for (hopefully) using the same ratio for both conveyors.

Re: Intake Conveyor Ideal Speed
 

A general rule for intakes, I've found, is to give them as much power as you can spare. With modern FRC motor rules, there isn't really anything holding this back other than how much your motors are drawing (over the course of a match and when considering the draw of all your motors running simultaneously). Without looking at the final design being suggested, while I might say a 775pro sounds like overkill, it is possible that it's what is necessary.

You intake should command that the game pieces it touches enter your robot, not lightly suggest that they do.

Re: Intake Conveyor Ideal Speed
 

This is now my favorite quote.
Thank you.

Re: Intake Conveyor Ideal Speed
 

+1 Touch it. OWN it.
Liftoff is fine, encouraged even.

We like our intakes going over 1000 RPM. Sometimes even faster, time waiting to intake is time you are not scoring. Touch it. OWN it.

Re: Intake Conveyor Ideal Speed
 

3500 RPM too fast?

Re: Intake Conveyor Ideal Speed
 

You will have to test it and make sure it won't stall out, but it just depends on your surface speed requirements.

Re: Intake Conveyor Ideal Speed
 

I second the recommendation for AT LEAST 2x robot speed. The reason being that if the top of a ball is moving at 2x robot speed, the cewnter of the ball will move at 1x robot speed while the bottome of the ball touches the ground. Thus the FUEL will get get pulled into the robot significantly faster than the robot can drive.

The FUEL won't get knocked away and the robot won't jam the FUEL into its own intake with forward inertia. Perhaps most importantly in this year: if the robot interacts with a sea of game elements it won't push the bulk of FUEL away as it collects FUEL on the perimeter of that sea.

Strongly recommend the highest powered motor(s) you can stand for the application, even if you run it on an under-sized breaker (like a 775 pro on a 30A circuit). No one has ever said 'my intake can collect [game element] too quickly.' More to the point: the faster you can collect FUEL/GEARs/whatever the more time you have to score it, and there are fewer things more painful to a scout than watching a team spend time collecting game element.

My $0.02 anyway...

Re: Intake Conveyor Ideal Speed
 

Second this.
Every ball intake I ever designed had a linear speed that at least matched our robot in high gear forward speed. This allows all the balls to clear the intake at the speed you're travelling so you don't start plowing them and pushing them out of the way.

Re: Intake Conveyor Ideal Speed
 

on the exterior 3" wheel, that would be over 71000 RPM. Scary.

Re: Intake Conveyor Ideal Speed
 

Here's an article that was done about an intake that was designed for the 2014 game that touches on this same concept, along other tips for designing an intake.

http://www.buildblitz.com/team-copioli-intake-design/

Re: Intake Conveyor Ideal Speed
 

+1

Re: Intake Conveyor Ideal Speed
 

Why not Warp 10 ?

Re: Intake Conveyor Ideal Speed
 

https://youtu.be/kXjiOVkhPv8

Here's a little video of a prototype we made, it's pretty fast but it could be even better once the compression distance is fixed right and belts are tightened.

Re: Intake Conveyor Ideal Speed
 

So just to be clear...
We are planning on using 1" diameter rollers with belts on them, and a 10fps drivetrain. We therefore are shooting for 15fps linear speed on the belts, which would mean a roller speed of ~3400 RPM. Does this seem right/plausible/safe?

*We are using 2" wide urethane orange belts with 3D printed crowned pulleys on the drive axle.

Re: Intake Conveyor Ideal Speed
 

I have your RPM's at 3400. someone check my math. But that's fast. try a larger roller.

Re: Intake Conveyor Ideal Speed
 

It looks ok to me based on those numbers. You can always change the gearing later. If it's running that fast you will not need very much compression to move the balls. The speed is fine, but make sure you are not at risk of stalling(when you test).

Re: Intake Conveyor Ideal Speed
 

I don't think liftoff should be ruled out.

Re: Intake Conveyor Ideal Speed
 

This is good advice.

It is also important that your FUEL elevator be fast enough to keep up with your intake, so FUEL doesn't jam. My team made that mistake in 2012.

Re: Intake Conveyor Ideal Speed
 

When our intake grabbed a boulder last year the robot jumped, achieving momentary liftoff. it was perfect.

Make the game piece disappear from where it is on the floor to someplace inside your robot.

Sent from my A0001 using Tapatalk

Re: Intake Conveyor Ideal Speed
 

I would use a vex planetary gearbox so you can adjust your reduction ratio after building the robot. Honestly, I think you'll want a medium speed, but...

Re: Intake Conveyor Ideal Speed
 

Good discussion,

I'm thinking that we're going to use a 10:1 Versa Planetary reduction with a 775 for our intake and elevator.

With 31 RPS, I think we'll be intaking fuel pretty fast.

Although I'm worried that we wont have enough power to lift palls up our elevator. Any experience with this?

Also, if we have wheels on our roller (1/2 shaft) how would I incorporate them into my calculations? Specifically on JVN.

Re: Intake Conveyor Ideal Speed
 

Personally I would have your intake and elevator on seperate motors. It's probally best if you are capable of controlling them seperatly if a game piece jam happens. This should also take some of the stress off of that 775pro (even thogh it is overkill anyway)

Re: Intake Conveyor Ideal Speed
 

You can guess how much force your intake will experience from lifting game pieces, compression, wheels on the shaft providing inertia, and a variety of other factors, but the best way to see if it will work is to prototype. If you haven't built a model of your intake with approx. the gear ratio you want, I would suggest doing that. If you don't have access to the right motor and gearbox, at least try with a hand drill on drill speed to make sure that you don't need too much torque.

Re: Intake Conveyor Ideal Speed
 

Take your shaft speed (rev/s), multiply by wheel circumferential travel (ft/rev), and you'll get the collector 'surface speed' in ft/s. Compare to robot maximum speed, ...? Profit!

Re: Intake Conveyor Ideal Speed
 

That makes sense, although I'm still unclear on what you mean by circumferential travel.

Thanks.

Re: Intake Conveyor Ideal Speed
 

The circumference.

Re: Intake Conveyor Ideal Speed
 

Strong Necro is strong.
Aside from that, the 15:1 versaplanetary that we are using with 1 1/4" rollers and an orange poly belt is now throwing them over the back of our bot.

Re: Intake Conveyor Ideal Speed
 

775pro on a VP 10:1 seems to devour fuel at a good rate for us.

Using Banebots blue wheels (2-3/8"), and yellow urethane round belt.

Test: https://drive.google.com/file/d/0B7z...ew?usp=sharing

[Note: I'm the mentor putting my forearm in harms way]