[CAD226B]

I need to replace a mechanical phase of a machine with a stepper motor operation, so if I could use my cnc program software by just replacing the start button on the software with a mechanically activated start button on the machine I could accomplice this. Is this possible, if so, how. Thanks

[Jim Dawson]

From a control logic perspective I don't see a problem doing what you want.

The question is: Can this be implemented with your existing machine controls? Knowing nothing about your machine or controller, the question is impossible to answer. We need more information.

[CAD226B]

Using my x axis plugin with mach3 or uccnc and uc100 controller, with BOB (China) driver. I'm assuming I need an impulse switch on the machine. let me know if you need further information. thanks

[Jim Dawson]

If I understand correctly, the machine makes some moves then when it reaches some point you want to cause the new stepper motor to perform some action. If I understand Mach3 correctly, you could map an input to the on screen ''Program Run'' button. The input could be wired to any suitable limit switch or prox sensor.

I assume this is not a ''normal'' CNC machine like a milling machine?

[CAD226B]

The machine is a wire bending machine (not cnc) which currently has an ejector that moves back and forth 1.75 " in about .67 sec. the current set up is not working so well. Is there a pin or pins on the BOB that could be wired to a momentary switch on the machine that will replace the program run on the software to run the gcode. I do not understand "map an input to the screen". thanks

[Jim Dawson]

OK, this makes more sense. I assume this is a cam operated machine? So you want to eject the finished part at the end of the bending cycle? Given that the machine is not CNC, then trying to hang a full CNC type solution onto the machine might be more trouble than it's worth.

I would look at the problem a little differently. The first question I would ask is why the ejector does not work as it is? Then design a non-CNC solution to the problem. It could be mechanical, or pneumatic. It is possible to use a stepper motor in an application like this also. It is not necessary to control a stepper with G-code, especially for a repetitive task like this, there are inexpensive stepper controllers available. Something like this https://www.ebay.com/itm/11495128796...gAAOSwU-ZhJIon

There are other more industrial controllers available also, that include both the fully programable motion controller and stepper (or servo) drive in one neat little package.

Can you provide a picture or better yet a video of what the problem is?

[CAD226B]

Hey Jim, here are some photos, don't know if it will help a lot. The machine is not running now. The machine is a two step die operation so the ejector actually moves the piece 2 times from the first die to second die and then ejects the piece. The stroke is the same for each movement. The ejector actually picks up the piece and moves it. The main die is not in place and is shown in a photo provided. The ratio between the cam movement and the arm movement is to high and puts to much stress on the bevel gears which has caused breakage. I really think it would be a lot easier to use my cnc to run a mechanically operated stepper motor. My main goal at this point is to get more exposure for the product so that some major manufacturing company that produces related products would be interested and maybe wind up some kind of deal and or receive royalties. Please furnish all your thoughts and recommendations. Thanks

[Jim Dawson]

Actually the pictures help a lot. Looks like a four slide press or similar.

Do you want to replace the bevel gear drive with a stepper motor drive on the driven shaft? Judging from the sprocket sizes, it looks like that bevel gear drive shaft could have a lot of torque available.

Is the action you need to duplicate with a stepper?

[Jim Dawson]

I have spent a few hours studying your photos while watching TV this evening. And the really easy way to do what you want is to simply drive an encoder directly from the driving bevel gear shaft. The encoder would then be connected directly to the stepper motor driver pulse input. Then drive the driven shaft with the stepper motor. This would have exactly the same effect as the gear coupled shafts. The downside of using a stepper motor in this type of application is that the timing is critical and if the stepper motor loses steps due to mechanical binding or something it would throw the timing off. That might be bad.

The other question is how much force is required to operate the ejector? From the pictures and your figures of 1.75'' stroke in 0.67 sec I can guesstimate the the acceleration force required, but I have no idea what actual working force is required of the ejector.

I assume that what you are proposing by using Mach3 means that you have Mach3 running on a CNC machine. And wish to use the same computer to run the stepper on your wire bender. Using Mach3 in an application like this would be difficult at best, the time lags involved would make timing very difficult if not impossible.

You could probably use Mach3 to run a CNC wire bender with G code. CNC wire benders are really pretty simple devices. A table top size driven by steppers would be a heck of a lot cheaper to build than your existing machine, and much simpler.

You asked about mapping inputs to screen buttons, I had to look this one up. In Mach3 you can assign onscreen buttons to inputs. You have to set it up in 2 places, on the Configure>Inputs Signals tab, and on the Hot Keys screen, OEM Codes, the OEM code for Cycle Start is 1000. So on the Input Signals tab you would select OEM1 and set the Port and Pin, then on the Hot Keys screen you would set OEM #1 to 1000. This should fire the Cycle Start when you trigger that input. This input could be operated by any compatible device.

[CAD226B]

Thanks a lot for your time and input. it all sounds too complicated for me right now. I think I will just restore the machine to its original condition. It did work before and produced thousands of pieces at a rate of one piece per 4 seconds. I will utilize the remaining materials that I have and leave it at that. When I built the machine, I did not know what a stepper motor or g code even was. I did not have a cnc milling at the time, just a lathe, but I wanted to produce the product that I patented. Thanks again Thomas

[Jim Dawson]

Too complicated? I think much simpler than what you built there. But that is a matter of perspective. That is an incredibly complex machine you built and you did a great job on it. Looks like the stuff I was building about 40 years ago, but the difference was that I had a very well equipped tool & die shop to work in. I can well appreciate the amount of time and work you put into that machine, especially given the tools you have available.

It's my pleasure to help out when I can.

[CAD226B]

The reason it looks that way is because I worked in machine shops and Weaver Scope back in the 60s. have good one....