Clausing Drill Press (new to me)

[hman]

You could set the pot so somewhere near the "get started" point, disconnect it, and measure the resistance between the wiper and each of the ends. Get a pot whose full range matches the "useful" range of your current pot. Wire the ground lead to the new pot in series with a fixed resistor of appropriate size. I've done this trick several times when kludging up new controls for salvaged equipment. Sometimes I've even added fixed resistors to both sides of a pot.

As for linear or non-linear response, I guess that would be something you'd have to figure out by careful measurements at a number of pot settings. Plotting the yellow wire voltage against RPM (assuming you have access to a tachometer) should tell the story.

Fixing startup error might be accomplished by adding a normally closed pushbutton between the pot wiper and the yellow lead. Hold the pushbutton momentarily when starting the motor. Or else, maybe use a spring return SPDT switch, with the yellow wire to the center terminal, the pot connected to the normally closed terminal, and the black wire paralleled to the normally open terminal.

PS - I took too long to write my response, so @brino beat me to it!

 

[rwm]

Well...look like I blew the board somehow. I have no idea how. Maybe static. New board on order. When I get that I will get voltage measurements from the Hall output and see what the range is. Then I can construct an appropriate voltage divider circuit.
Robert

 

[rwm]

While we are waiting for my board I can show the shiny new pulley I made:

I had to cut a 5 mm keyway. So first I had to make a cutter out of a broken center drill:

Here it is starting the keyway:

Finsihed:

Perfect fit:

...on the non working motor.

Robert

BTW - Homebrewed is being kind enough to consult with me by PM on the control board issue and an appropriate bypass circuit. Most appreciated!
R

 

[rwm]

I got the new board. It was a perfect fit and the motor runs again! I need to figure out the speed control, build a motor mount and mount the controller.

I measured some voltages from the Hall sensor in use. At full speed the Signal voltage is 4.2V. At zero rpm it is 1.5V. I need to build a voltage divider with a pot in the middle that approximates this.

Robert

 

[rwm]

SW1 is RUN/STOP
RP1 is the speed control.
R3 Sets the minimum speed.

Robert

 

[hman]

WOW! That took a bit of analysis. Glad you got to there!

 

[rwm]

Mounted the stuff:

Hard to believe this little motor provides such torque:

Having speed control is really awesome already.

Robert

 

[hman]

Has anyone set up a linear actuator to raise and lower the table? Seems like it would be very convenient.
Robert

I know this is a pretty old post ... but you might want to look over this thread:
https://www.hobby-machinist.com/threads/what-motor-do-i-use-for-raising-a-drill-press-table.89706/
... especially post #5, where I describe the addition of a gear motor to the table lift crank. Other posters have made some excellent suggestions about linear actuators.

I absolutely LOVE having a powered lift on my DP table.

 

[rwm]

Thank you. I saw that already. I am somewhat torn because I really like the old iron lifter in this machine even if it takes a little work. I would like to note, none of the upgrades I have made so far has permanently altered the machine. I have not drilled a single hole in it.
Robert

 

[mattthemuppet2]

that's a really cool retrofit. I'd be interested to hear what you think after you've had some time with it.

Rather than a table life for my Walker Turner (no easy way to add one) I went the other direction and added a counterweight to the table. 5 cans of dog food and one can of peaches filled with lead balances out the table and XY vise pretty well.