Proof of Concept Powered Drill Press Table

[rgsparber]

Rick,

I think that this is an ingenious idea, but as others have pointed out there are serious issues. The reverse load on the tapers probably being the killer. My first reaction was a worry about the offset load causing jamming at the column but your video shows no sign of that happening. Your lift force is close to the CG.
I faced the same problem with an elderly Craftsman without a rack and pinion lift. I have largely, though not totally, fixed this with a counterweight.

Attachment 29290 Attachment 29291 Attachment 29292 Click images for full size versions.

This system could easily be powered, the top pulley could be replaced by a motor driven drum. The motor could be quite small because the counter weight reduces the lifting force necessary. The counter weight will not be at the CG so there will still be some jamming moments on the column. These moments will vary with load on the table. Of course if you make such an arrangement, with one finger on the "lift/lower" button you have a free hand to assist the lift and better balance those moments.
I can say from my experience that just the static counter weight has made lifting the table so much easier. Prior to adding that I used to avoid moving the table by using blocks under the work piece to get the height necessary. Now I move the table instead.

The high speed sensitive drill that I recently made needed the motor balancing, the table was fixed and so there was no weight variation to cater for and I put effort into balancing the moments.

Attachment 29293

As described in http://www.homemadetools.net/forum/d...947#post129563 and the movie at

Tony,

Having a nice action on the lifting mechanism certainly depends on connecting to the center of gravity. One idea I had was to add extension arms out the back of the table and put weights on the ends. This would shift the COG to the column where a counterweight mechanism would connect.

Thanks,

Rick

[tonyfoale]

Tony,

Having a nice action on the lifting mechanism certainly depends on connecting to the center of gravity. One idea I had was to add extension arms out the back of the table and put weights on the ends. This would shift the COG to the column where a counterweight mechanism would connect.

Thanks,

Rick

Rick,

You can see from the pic of mine that I have a table out the back side as well so it brings the CG closer to the column than yours. Putting weights out the back combined with a heavier counterweight would seem to be a great idea. If you watched the video on my sensitive drill press you will see how much difference you can get when the system is balanced correctly, taking the moments into account.
The problem then is only if you move the table after putting a heavy vice and workpiece on the table. Set the table when it is empty and you can get a near optimum system.

I wish that it was practical to counterbalance the knee on my Bridgeport. I have added pneumatic springs which help considerably but their force varies with knee position and so are far from optimized but still a huge help.

http://www.homemadetools.net/forum/k...5951#post82823
Now I just need some form of assist for my own aging knees, too many falls from motorcycles have done them no good at all.

[dkutzner]

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

the idea is great but would not work for you most of the time because, most of the time you need to move the table is when you have something clamped to the table and have to adjust the hight between working with small bits then using larger bits on the same hole or after you clamp something to it and find out the travel is just not long enough or short enough

[Paul Jones]

Rick,
I enjoyed your posting but had to laugh. How hard is it to lift or lower a drill press table? The most important feature is to ensure the up-down table movement stays centered with the drill press table center hole. Often, I did not noticed the slight off-shift on my drill press table after adjusting the table height and ultimately drilled a hole in the table. I think the up and down alignment position is more important than making it easier to lift the table.
Regards, Paul

[skibo]

I have lost a chuck before when using a sanding drum or a spade wood bit, my drill press is a large bench model about 40 years old and perfect condition! I would be aiming for a small 110 or a 12 volt reversible gear drive motor to run the table up or down, like maybe a gear drive 12 volt! They sell these on E-bay,cheap and most are reversible!
skibo

[tonyfoale]

Rick,
I enjoyed your posting but had to laugh. How hard is it to lift or lower a drill press table? The most important feature is to ensure the up-down table movement stays centered with the drill press table center hole. Often, I did not noticed the slight off-shift on my drill press table after adjusting the table height and ultimately drilled a hole in the table. I think the up and down alignment position is more important than making it easier to lift the table.
Regards, Paul

Paul,

Lowering is no problem but I can assure you that some tables can be a pain to lift. On the other hand I find aligning the centre hole to be a trivial exercise.

[Toolmaker51]

I do have a length of ACME threaded rod. I played with it on the end of a small electric screwdriver and it does appear to work. It would work a lot better if my ACME nut was in a pinion gear so the screwdriver was horizontal.

My RF-30 mill/drill has the arrangement you describe and it works well enough. Once I changed to CNC, I have not needed to move the head much.

I forgot that I have a window motor from a car. That shows a lot of promise! It has a lot of torque so would add a mechanical fuse to the linkage to protect the drill press.

Thanks,

Rick

re ACME nut; there have been occasions 'we' bored one gear and turned another to assemble a different drive. A matching pair of miters would be simplest of all.

I don't have a conventional round column drill. I use one at work once in a while, my go-to for chamfering/ de-burring, and table is never at convenient height. 50's era but very sound, and the column is clean.
Much harder to slide the table up holding the table than handling it adjacent to the clamp. Center of gravity might be middle of table; but real issue is close fit of clamp and column, ~.002 max. Holding table imparts angularity [likely in 2 planes] on the cylindrical fit; binding is unavoidable. I find swiveling it helps normalize the disparate axis but doesn't last very long.
I'd think propelling the table via a screw in the spindle would do same thing.

[DIYer]

Thanks tonyfoale! We've added your Drill Press Lift System to our Drilling and Drill Presses category,
as well as to your builder page: tonyfoale's Homemade Tools. Your receipt:

Drill Press Lift System by tonyfoale

tags: pulley, drill press, lifting

[rgsparber]

the idea is great but would not work for you most of the time because, most of the time you need to move the table is when you have something clamped to the table and have to adjust the hight between working with small bits then using larger bits on the same hole or after you clamp something to it and find out the travel is just not long enough or short enough

dkutzner,

You are right. Most of the time I am raising the table to be near the end of a drill. So having the table's center hole aligned with the spindle won't work. What if the table was rotated to one side? Then the chuck mounted threaded rod would not pass through the work area. I would have to eyeball my clearance from a greater distance but maybe it isn't that critical.

This is not the ideal location table position because the center of gravity of the table would not be aligned with the lift point. But it is closer than lifting at the column.

Thanks,

Rick

[rgsparber]

Rick,
I enjoyed your posting but had to laugh. How hard is it to lift or lower a drill press table? The most important feature is to ensure the up-down table movement stays centered with the drill press table center hole. Often, I did not notice the slight off-shift on my drill press table after adjusting the table height and ultimately drilled a hole in the table. I think the up and down alignment position is more important than making it easier to lift the table.
Regards, Paul

Paul,

My drill press table is a bit heavy and is a bad lift. Toss on my vise and it is hard to lift the table with one hand while keeping the other on the column lock. As Tony said, aligning the table is the easy part. It is especially easy if there is a locking collar under the table.

Although I have tagged my table once and it was right at the side of that center hole, I do try to drill in a vise or put down some MDF before clamping the part.

Thanks,

Rick