Hello,

Here's what I have:
Price is right IGT slot machine wheel connected to....
K179 Stepper driver (which controls speed and direction of wheel)
Light control board (controls chasing light speed)
VLT130 AC/DC power supply
TDK-Lambda DSP30-12 power supply

Video here

As you can see by the video, the wheel spins albeit slowly. When I manually increase the stepping speed on the K179, the spinning stops and just freezes. My goal is to have this spin fast and then slow down and stop on a random number which I believe I will need some sort of a trigger for.

Goals:
Spin faster without freezing
Have the unit connected to a button when pressed would slow down and stop randomly

Is there any arduino hardware (or similar) I can use to replace the existing hardware that would accomplish this? I'm not sure the current hardware will accomplish what I'm looking to achieve.

Any help is appreciated

To spin the wheel faster, you would need to increase stepper current if possible.
Or adding some kind of acceleration control would help.
Don't know, if your hardware offers such options?

Both would be possible with an arduino and a suitable driver.
Also slowing down and stop randomly would be easy to program.
-Olaf

edit: The k179 driver has a step-generator chip. Remove it and use an arduino to generate the steps with acceleration/decelaration and random stop. DONE

Edited 1 time(s). Last edit at 11/02/2015 04:08AM by o_lampe.

The K179 is an old constant-voltage design for driving unipolar stepper motors, and its step pulse generation is fixed frequency. The first step to getting higher speeds is to ramp up the speed gradually instead of trying to go instantly from standstill to full speed. To do this, set the switch or jumper on the K179 to EXT and feed in a pulse train with a gradually increasing frequency, as o_lampe says. You can generate this on an Arduino.

To get really high speeds, you will also need to use a constant current stepper motor driver instead of the constant-voltage K179.

Edited 2 time(s). Last edit at 11/02/2015 04:54AM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thank you for that information.

Do you know which model of Arduino would best suit this?

If you have no experience of Arduino, then I suggest the Leonardo or the Uno.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Hello Olaf,

You mentioned the k179 driver has a step-generator chip and to remove it. Can you tell me where it's located in the attached pic?

Thank you.

Edited 1 time(s). Last edit at 11/03/2015 02:48PM by cmjb13.

According to this schematics you can't remove the chip because it also takes care of stepper-direction.

But as dc42 suggested, you can use the external step input.
If I were in your shoes, I would use a different stepper driver with current control.
-Olaf

I ordered the arudino uno.

Can you recommend a different stepper motor driver instead of the K179?

Olaf suggested a different stepper motor driver, but I didn't yet for two reasons:

1. Without knowing the specifications of your stepper motor, I can't say whether or not you can use one of the low-cost stepper motor modules typically used in 3D printers. If your stepper motor needs more than about 1.5A in order to drive it in your application, you will need a much more expensive driver. Is there a label on your stepper motor with a part number that we can look up the data for? How many wires are there coming out of the motor?

2. Whether you use a new stepper driver or not, you will need to generate an accelerating pulse train. So I suggest you start by doing that. Then, if the maximum speed you can get is still not high enough, look into getting a different stepper motor driver.

Edited 2 time(s). Last edit at 11/04/2015 04:06PM by dc42.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

First off, I want to thank everyone for their assistance with this. It has been most informative.

Second, there are no part numbers visible. I believe this is proprietary IGT information.

Third, how do I generate an accelerating pulse train?

Quote
cmjb13
Third, how do I generate an accelerating pulse train?

I suggest you ask here [forum.arduino.cc]. You may find this library useful [www.airspayce.com].

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].