Proof of Concept Powered Drill Press Table

[rgsparber]

I'm looking for opinions on whether this is a risky way to implement a powered drill press table. Could this potentially damage my drill press?

If people have well reasoned arguments on why it could hurt my drill press, I will drop this line of development. But if the community feels it is safe, it could be a rather cool way to power my drill press table.

Thanks,

Rick

[Toolmaker51]

It clearly works, but kind of fiddly. Sufficient counterweight and sheave makes more sense to me. I'd extend a notched bar and quite heavy weight to accommodate varied setups. If it works on Tony Foale's Bridgeport pattern mill. . .

[Saltfever]

Not knowing the design of your drill press I can’t forecast the effect of your idea. However, I see some considerations. You are reversing the thrust of the Z axis. Are the spindle bearings suitable for this change? Normally, I grip the collar around the column to lift the table up. You have created a bending moment that is now putting stress on both the table collar and the column. How will this affect wear of these two parts?

[rgsparber]

Not knowing the design of your drill press I can’t forecast the effect of your idea. However, I see some considerations. You are reversing the thrust of the Z axis. Are the spindle bearings suitable for this change? Normally, I grip the collar around the column to lift the table up. You have created a bending moment that is now putting stress on both the table collar and the column. How will this affect wear of these two parts?

Very good points that I had not considered. It makes sense that the bearings were not designed for a downward force.

The center of gravity of the empty table should be close to that center hole so this would be the ideal lifting point with respect to bending forces. However, it is a terrible place to lift because it is right in the middle of the action when subsequently drilling. Place a heavy vise on the table puts even more weight near the center of gravity.

I've started to think about keeping the jack screw idea but not driven by the drill press. Although it adds complexity, a pinion gear that let me turn this screw from a drive shaft under the table would be cool. I could turn the drive shaft with my battery powered drill.

I like lifting the table near its center of gravity but the mechanism must be out of the way. It could swing out as needed under the table if not too much hassle. Maybe it could stay there. Clearly, thrust bearings would be good.

More comments from others plus think time will refine this.

Thanks!

Rick

[Toolmaker51]

Main problems with Vee-thread, combinations of diameter and pitch won't be very rapid lifting action, and Vee's have little tolerance for dirt and chips. I'm still a hold-out for ACME, which translate torque to movement quickly compared to a multi-start Vee.
Most round column drill presses use a rack and pinion. Bottom edge of rack is mitered, it rides in a chamfered ring encircling the column. Below that ring is another to take thrust. All it takes is a small handle, spins a worm/ pinion combination to climb or descend the rack. And when you let go it remains in that position, but table can still rotate about the column.

A couple Martin or Browning gears, matching rack, aluminum billet housing and a couple oil-lite bushings, and two stubs of thick wall pipe; if I insisted on mechanical positioning.
Aforementioned notched lever, stripper bolt, some chain and and a slug of rod stock for weight. Far simpler and equally effective.

How about a dedicated winding motor; provided 12v DC, attach a auto window or power seat motor. Substantial torque, controllable [single speed] RPM, hypoid-geared, reversible; need I continue?

[Saltfever]

Agree about the CG but . . . There is friction between the collar and the column. That friction is multiplied by the moment. Again, don't know the quality of your drill press and the amount of friction. Love your creativity. :-)

[skibo]

I don't know what brand of drill press you have but if it's a moris tapper it might pull the chuck off the qwill! I have rather large bench model drill press and it has a #3 moris tapper and I have had it come off a couple times,just saying!

[Toolmaker51]

I don't know what brand of drill press you have but if it's a moris tapper it might pull the chuck off the qwill! I have rather large bench model drill press and it has a #3 moris tapper and I have had it come off a couple times,just saying!

Wouldn't THAT surprise an operator. Right before the table lands on his toes, formerly resting comfortably on the machines foot.

[EnginePaul]

Interesting, but my motor is forward only and I don't think it would be worth the change for me. That would keep that center hole centered, so that part is good.

[wizard69]

If people have well reasoned arguments on why it could hurt my drill press, I will drop this line of development. But if the community feels it is safe, it could be a rather cool way to power my drill press table.

Thanks,

Rick

Hi Rick;

I'm thinking this the first idea of yours that I don't like. Here are a few concerns:

• Morse tapers and even a Jacobs taper really don't like to be pulled. In the lifting mode you are pulling on those tapers, potentially breaking one loose and spinning it. This could lead to taper damage.
• What happens if you forget to lossen the table Clamp? In any sort of solution for table lift that involves a motor I'd really would like to see some sort of slip clutch or other over load mechnism.
• I suspect you will have greater reliability by adding a lift aid that is close to the clamping collar as possible. My great fear is snagging something and snapping a casting.
• If something where to break loose you run the risk of the table dropping a considerable distance and that is a big safety issue in my mind. Getting hit by dropping cast iron is never fun even if only a few inches.

One approach that might work would be a chain or belt drive with a separate motor to drive the collar up and down. Yes a bit of fabrication work but it should eliminate any potential damage to the taper that might happen. If you need to maintain table rotation then it gets a bit more involved because you need another collar to lift the table collar.

In any event my big concern is pulling the arbors out. Having had this happen with sanding drums and other tooling I can say it is more excitement than you will want to have in the shop.