Proof of Concept Powered Drill Press Table

[wizard69]

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!

This is my biggest concern friction fit Morse tapers, with no draw bar, really don't like operations that pull on the taper. I've had them pull out using drum sanding attachments and even had a case where the drill bit cork screwed into the material being drilled and dislodged the taper. A cork screwed drill bit generally results in in a bit of frustration but a sanding drum and arbor is extremely dangerous flying around the room and results in dodging the free drum and nasty words from ones mouth.

To put it another way I'm not real comfortable with this approach.

[VinnieL]

I have I believe a very similar if not identical drill press to yours. Mine is a Craftsman built by King-Seeley Tool Co. I have not yet done it but am going to make the counterweight assembly for mine. I would be worried about something binding up and breaking the table casting using the threaded rod arrangement. With the age of these machines you'd probably NEVER find a replacement table.

[Duke_of_URL]

My 15" Rockwell Delta variable speed drill press did not come with the optional raising and lowering rack for the table. I've decided to make an electric mechanism to accomplish this using an 18" Linear Actuator, DC Power Supply, and Actuator Controller, all affordably available on eBay. I'll post it here when designed and built.

[tonyfoale]

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.

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.



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

[stevesfeet]

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

Hi Rick,
Only problem I can see is that if you forget to unlock the table before the move you end up with a crabbed table and if the long screwed rod is strong enough you will crack the table close to the column. Even with the table unlocked I suspect it might be a risk- noy sure I would do it.

[rgsparber]

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. . .

My counterweight set up works well and I may end up just making a few minor improvements to it. But it is always healthy to take a fresh look at stuff.

Thanks,

Rick

[rgsparber]

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?

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

[rgsparber]

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. :-)

The collar to column interface is not an issue when the table is raised at its center of gravity. But when lifted at the column, friction can be a killer. As an experiment, I cleaned the column and applied some way oil. The table moves easier and quieter when lifted at the column yet the clamp still works fine. It is interesting how way oil can do that.

Thanks,

Rick

[rgsparber]

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!

I agree. If the chuck was on there with a taper, this would not work. Mine is on there with a clamping collar that prevents the chuck from coming off.

Rick

[rgsparber]

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.

Lots of good insights. If I was using a taper, that would be a deal killer. If I do pursue using the spindle, I would have to add a mechanical fuse to protect the rest of the drill press. However, I would also need some way to prevent the table going into freefall. This could be a counterweight system which would also deload the spindle.

My existing counterweight arrangement is well balanced when the table is empty and good enough when the vise is on it. I help it along by either lifting up the front of the table or pulling on the chain going to the weight. No need for a motor. My chain is just stainless steel ball chain and of unknown strength. It has held for a few years and shows no sign of weakening. But it is a little hard to grab. One option would be to go with a thick nylon rope and make new pulleys.

Thanks,

Rick