I want to couple the output shaft of an "AC" Powered "Reversible" gearmotor to my drill press table raise/lower chank shaft (5/8" with flat). I can build a plate to mount the motor on that mounts to the table collar. I need it to be very low RPM and as small as possible. I know I'm asking alot so I'm asking the eyes and ears here for input. I'll wire into the DP for power and use an on-off-on switch for forward and reverse to raise and lower.
Any ideas? I'm doing this as I have limited reach from a wheelchair and low hand strength. And a little bit of laziness thrown in. And...if we can make things easy...why not.
Sorry....let me make myself more clear. This is NOT to use as a power feed. It's simply to raise and lower the table (when not drilling) instead of reaching to the back and turning the crank. Some of the things I do require frequent table height adjustements and it's difficult for me to use the crank.
I've seen a drill press that was modified like this but it was very crude and thrown together for my taste. It had a huge motor and used sprockets and chain as the drive. I don't want to go that way. I just don't know enough about motors yet to run out and get one. And...can't make the mounting plate until I get one.
Hi, Ken. Lots of good posts for an interesting project.
I have an AC gear motor that came from a LARGE rotating Christmas tree stand. Years ago I built a rotating welding table using the frame and motor, adding a circular steel plate. No, I never used it, it's still under the work bench.
My point is, the gear motor is variable speed, no capacitors. It has, I think, a 50 Ohm pot in series with the motor field winding. Goes from 0 to max using just the pot. This was a commercial design.
I have not tried reversing the rotation.
You need to tell us the make and model of the gear motor. Somewhere I have an old catalog of gearmotors. It has wiring diagrams for lots of motors, etc. I will look for it and see what it says about reversing.
I don't have a gearmotor sourced yet. That's basically the reson for the post to get information from people who know more than I about motors to give me some advise.
Not sure if you've ever seen a linear actuator of the type that raise and lower a sattellite dish but it's basically a gearmotor/box that actuates an acme screw. I've wondered if I could remove the acme rod and coulple the drill press crank shaft there. The thing that makes these attractive is the size. The thing I DON'T know about them is if they can continuously rotate or do they have internal limit switches: You can cust and ;paste this eBay link into your browser to see one style.
Oh, I thought you already were on the way to a solution.
Lets start over. I assume you have the drill press. Is it a floor or a bench mount version? How much table movement do you need? How much weight will be moved (table + vice + project)?
Would you have room under the table for a device similar to a screw jack? How much room?
Yes, I know a little about linear actuators. I used a 24 volt unit used to control aircraft flaps in a prosthetic device to allow a paraplegic girl to operate the sustain pedal on a piano. The unit is still leaning against the wall. It was too noisy and another group came up with a pneumatic version that would operate faster/quieter when she pressed her back against an air bag. I have not looked closely at the antenna actuator unit.
If you are anywhere near Central Oregon, I will give you the gear motor unit.
You should start by determining the torque it requires at the crank to lift the table. Double that at least and then you know what motor you need. You don't need a small motor, you need a motor not to small.
I was wondering about the the torque requirements. Seems like this will be heavily dependent on the smoothmenss of the column, the tightness of the clamp and other variables. I'd gues the crank on mine at 5 ft pounds (60 inch pounds)
Iggy br> I want to couple the output shaft of an "AC" Powered "Reversible"
Remove the pinion from the rack and mount the gear motor on the base on the floor... Run a cable from a drum on the gearmotor up to the top of the press to a pullie and then down to the table you want to lift... Works just fine...
Hi, Ken. I had problems sending pictures and email to you. I use Google to access this newsgroup and they apparently discuise email addresses. But when I started this reply, your email address came in clear. So, now I have sent you the pictures!
First, I found the Bodine book and last night looked at the gearmotor I have. It is a series wound, universal AC/DC motor. A large variable resistor is in series with the motor for speed control. By the book, there are many different types of motors used in gearmotors. The series wound is the only one easily controlled by a resistor.
To change direction, you would have to get inside my motor and bring out separate leads for either the armature or field coils and reverse those connections to change directions.
I have two Asian made drill presses. The lock and crank part of the table are cast metal and are tapered. I am not sure there is enough material on either machine to drill and tap to mount a motor. A person might have to remove that part of the mechanism and machine it to allow a clamping collar to hold the motor/mechanism to the table.
Perhaps we are creating a nightmare when a simple spring from the head to the table would reduce the power needed for you to crank the table. Anything added to the drill press will attract swarf and will need to be enclosed, somehow.
I have a couple linear actuators that I'd give you if they'd do what you want done. They are 28VDC units from US gov. aircraft application. They extend about 6 inches and seem to be able to lift a drill press table. I'm in the Los Angeles area.
Let me know if you have interest in these linear actuators. They weigh about 5 pounds each