A question about the Ultra3000 capabilities

Hi everyone it's been a while since I've been on here. I guess that's a good thing, since I haven't been stuck in a while.
Anyway, we have a machine that takes two rows of cups that used to sit on the bottom end of the cup. They would fill up and at a certain point (an eye was made), it would start letting cups pass. What did this were (what we call) 'Star Wheels', which are basically like gears of a machine that allow cups to go through and when the eye is unblocked it would stop. But there is a catch. The machine would either count 1 or 2. 1 being for a 2 pack (since the machine would stack the cups on top of each other) and 2 would be for a 4 pack (same reason).

This star wheel is run by a servo drive an Ultra3000 2098-DSD-010 and motor W-4030-M-H.

Well we made a change to the machine where one lane flips the cup upside down so they package top to top.

The problem now lies that it since the top has more diameter than the bottom, it can throw off the timing. After the star wheels each side goes onto its own chain which have "fingers"(for lack of a better term) that push the cups in time with each other and with the star wheel.

What I to do to resolve this problem is have the Servo motor turn on (after the conditions are met of cups being there), only at a certain degree and shut off (or nearly shut off say 1Hz or a really low rpm) during the rest of the time.
Is this possible or even plausible?

I've attached the Ultraware, rslogix, and a somewhat picture of whats going on.
*I hope this makes sense to you.*

To answer your question about the Ultra3000 itself, yes, I do believe it is possible. Unfortunately, I don't have RSLogix on this computer, so I can't look at your logic. However, I'm thinking that if you modify the parameter that controls the Jog speed when you need to slow down, then the motor should slow down to the requested speed.

There's a reference manual for the Ultra3000 that has all these parameters, as well as other programming information. It should be available on AB's website.

I think you have to be using a certain input and output assembly format to change parameters from the logic without using an explicit message. The interface provides a location for the parameter number, the new value that you want, and a bit that you have to set high to initiate a parameter change. All these formats are also described in the aforementioned manual.

I'm not sure if you have to drop the jog command before the change takes effect, because I've only have used this drive once, and our needs did not require us to change the speed on the fly. For this situation though, the smoothness is probably not critical (it's not a test system, for example).

Be careful of the scaling of the parameter value... It's not the same for all parameters.

This should be easy

gappvembe said:

What I to do to resolve this problem is have the Servo motor turn on (after the conditions are met of cups being there), only at a certain degree and shut off (or nearly shut off say 1Hz or a really low rpm) during the rest of the time.
Is this possible or even plausible?

Click to expand...

What you need to do is figure out if the drives support camming. One star wheel must execute a cam profile as a function of the other star wheel. There are other way of doing this beside camming but all methods will use some means of gearing and executing a motion profile on one star wheel as a function of the other star wheel's position, velocity and acceleration.

There are others like Gerry that have much more experience at Rockwell motion control than I do. Once you figure out the profile you need the rest should be is easy.

First check if the drives support camming as a function of the other axes position and velocity. Post the desired motion profile on a pdf that would help. If the drives support camming then Rockwell has a cam tool that will make it easy to enter in the cam profile.

Sorry I haven't gotten back to you all. I got the machine running rather well, better than before.

How it used to work, is it would feed the cups in at a set speed.
This caused all kinds of timing issues.

Basically how it works now, is I used a spare cam setting and let the servo motor only be on for a specific time, the time i wanted the cups to be pushed in the star wheels.

Instead of constant turns, it pushes 1 cup (1 on each side) for 2 packs of product or 2 cups (2 on each side) for 4 packs of product.