foot controlled 1 axis vertical rails for router

[Derek Lenard]

Hey guys been many many years since I have been on the site. Lost in trying to building this contraption in my head and was looking for some advice.

I want to make a router that moves up and down on the vertical plane via a foot switch. There are a lot of vertical rail system out there but unsure how to get the motors to work with a switch. I have had a number of pneumatic and chain type of routers in the shop but would like to get more automation without diving into the full CNC. I will be using this to do build an inlay pin router machine.

Where I am getting lost is in the controller section. I have the motorized rails and a power supply, what kind of switch would do the back and forth movements? I can't seem to find anything that exists or I am looking in the wrong places with the wrong terms...

anyone point me in the right direction?

Thanks!!!

[Eric Baack]

What kind of motor is on the rails?

[Derek Lenard]

Looks like its a Nema 23 stepper motor 3 amps.

[Eric Baack]

then you need a controller for it. Something that can convert the input from a switch into pulses.

[Andy Birko]

Interesting project.

To drive a stepper motor, you'll need some type of drive and as Eric said, something to give it step and direction pulses.

The drive is what converts the step and direction pulses into power signals that will move the motor in the right direction, e.g.: http://www.geckodrive.com/g251x.html

You don't necessarily need a computer to make the step and direction pulses but in your case, it might be easiest to go with some type of micro controller to read the foot switch and create the appropriate control signals. Steppers don't like sudden starts and stops and need to be accelerated and decelerated for smooth motion. This by the way might really complicate your plans but for a single axis, stalling might not be a problem.

The way the driver works is that whenever it receives a pulse on the "step" pin, it advances the motor one step (or microstep depending on the driver). With the direction signal high, it will move in one direction, with it low in the opposite direction.

Something as simple as a pulse generator built on a 555 timer chip could make the pulse train to turn the motors and could potentially work with some additional circuitry to be able to change direction etc. http://www.electroschematics.com/5834/p ... -with-555/

I did a quick search and found this: http://www.instructables.com/id/Arduino ... r-Control/

So, you'll to fine an appropriate foot switch - possibly a double foot switch, one for up and one for down.

You'll have the arduino read the foot switch and then generate the pulses to send to the driver to move the motor either up or down.

Generally speaking, this sounds like a pretty challenging project to use in practice because controlling depth like this will be difficult unless you have some sort of speed setting for movement, or perhaps a continuous pedal so that you can control speed with your foot. Another idea would be to to have a depth knob or something but in that case, stalling the motors will make you lose position.

So, long story short, you've got to come up with some sort of controller, be it a 555 or an arduino with home made software to read the switches and generate a pulse train to move your motor.

[Derek Lenard]

Thank you for the replies! I did find a electric chairlift with a switch that I am going to tinker with. That has a forward and a reverse and they work under a load.

I have a Stanley pin router I want to automate and make another station as well for something else.

I will post some pics when I am done

[David King]

Can't this just be done mechanically? That's the way all the other pin router's I've seen do it. Adding a stepper motor is ridiculously overcomplicating the task and there's a lot of room for fatal error.

If you have to go that route then look at the new Gecko G215 driver/ motion controller which can be programmed with simple G-code and run autonomously.
It happens to be on sale this week:
http://www.geckodrive.com/gm215-step-mo ... oller.html
You'll still need a PC to program it and a hefty power supply to run it but it would save you a whole lot of trouble messing around with Arduino BS and it would be bulletproof.

[Andy Birko]

If you have to go that route then look at the new Gecko G215 driver/ motion controller which can be programmed with simple G-code and run autonomously.

Good call on the 215 - I had just read about that a few months ago and forgot completely about it as it's of really no use for what I'm doing.

Although I haven't looked at all at how to program it, it's got a few ins and outs so wiring in a foot switch would probably be pretty easy. Getting different heights maybe not so.

Generally though, I agree with you. Adding a stepper for a simple up/down like that seems pretty dang complicated.

[David King]

I have some older stepper drivers that came with an on-board oscillator to generate steps. It's a pretty simple setup with just a pot for speed. The footswitch could send the direction signal and perhaps limit switches could control the depth in a inexact and precarious manner.

[Clay Schaeffer]

Why not use a pneumatic linear slide and an air switch as a conventional pin router uses? If you are only looking for up and down with a foot switch and set depths with a depth stop that might be simpler. For inlay cutting, a relatively small air slide combined with an air spindle or trim router could work fine .

[Eric Baack]

or just hand crank a screw drive? possibly incorporate an over-center clamp type of mechanism for repeatable positioning.