How to add stepper to table saw???

[flybynight]

Hi. I am a carpenter and want to add a stepper or equivalent motor to the blade heigth crank of my table saw. I can figure out all the mechanics but am wondering if someone could suggest what would be needed. I was hoping for something as simple as a stepper motor and a push button. Is there a stepper that uses AC instead of DC?? That would elimante a power supply. You get the picture. Any help would be appreciated. BTW, the saw is a Bosch with 10inch blade that one man can tote with ease. Its not one of those heavy shop monsters or one of those little Home Depot cheapies for a $100 bucks. Thanks, Tom

[jjwl89]

Hi,

I dont believe AC steppers are made. It seems that since you are looking for button-control, you don't need computer controlled motion so you could use a DC or AC motor with a speed control. Unless you need the accuracy of a computer in which case you would need a servo or stepper motor with driver and computer.

Hopefully this will point you in the right direction.

[jmytyk]

ya know, you could use something like dave's stepper driver w/joystick- might be a neat combo, then you wouldn't need a computer. Also you could then use the extra 2 channels for otherr movements, like the rip fence maybe?

or- a simple hobby motor and some gearing if counting steps isnt a priority.

http://www.buildyouridea.com/hardwar...in/arcsin.html

-hopes this helps

[smarbaga]

a small dc motor with a tooth belt drive will work.
you could still hand crank it with the motor in tact.
or have a leaver on a cam to dis-engage the motor drive
a double pole center off switch to change direction

[Smackre]

Why not just get a linear actualor? it would take your motor up and down with a push button and its simple. all you would half to do is mount the actualor to the motor and the frame and wire it up.

http://cgi.ebay.com/New-Linear-Actua...QQcmdZViewItem

I have used the one i linked to you. I wired it up at 12 volts and it worked like a charm. All you half to do is reverse the wires to make it go in the other direction. You can buy buttons that make it go up and down with one switch.

[ViperTX]

Okay.....I've got to ask "Why?" Handicapped? You'll be spending alot of time going up and down before you get to the correct saw blade height.

[pminmo]

I've had similar thoughts, but I believe an ac rotary actuator would be more suited.

[Al_The_Man]

Originally Posted by jjwl89 Hi, I dont believe AC steppers are made.

Actually many stepper manufacturers make low-speed synchronous motors that run off of 120vac. They are identical in construction to 2 phase 1.8d or 0.9d steppers motors, just higher voltage winding.
These motors run at 72rpm and 36rpm and are synhronized to the incoming frequency.
The have excellent stop,start and reverse operation on ac.
They can usually be had very cheap on ebay as they are not much use for the general low voltage stepper applications.
Al.

[HayTay]

Tom,

I know it's not AC, but, how about one of the 12 VDC motors from an automobiles power window. That should have enough power to do the job. It also has it's own switch mounted in the door panel (up/down or forward/reverse, if you prefer). They can't be too expensive. I've even seen the local collision repair shops just throw them away (note: FREE!!!).

Just a thought,

HayTay

[jleiwig]

Originally Posted by ViperTX Okay.....I've got to ask "Why?" Handicapped? You'll be spending alot of time going up and down before you get to the correct saw blade height.

Because you would know your height to be exactly what you tell the computer to make it. If you need to cut through 3/4" board so that only a 1/16" is left then you wouldn't have to make test cuts or have expensive blade height gauges.

[HayTay]

As long as your going to put one motor on the table saw, why not go all out and use two? One for the cut depth/height and another for the cut angle.

Both of the cheapo plastic hand wheels on my table saw broke a long time ago and I've been using an adjustable wrench as a replacement. It works but it takes a long time to make adjustments. I think your motor idea has merit. One of those, "I wonder why nobody's done it before" kind of ideas that makes someone a lot of money. Hmmmm!

Something to think about,

HayTay