Easy lift drill press table

[tonyfoale]

There is nothing new in adding counterweights to machine tools to ease movement. Drill presses without a rack and pinion lift mechanism are prime targets in need of assistance.

It would seem like a simple enough job to do, which it often is but there is a little science attached if you want the best results. The tendency of the table to jam on the column is the main cause of problems with and without a counterweight assistance. Another issue with adding a counterweight is that if it helps with lifting the table then it will likely increase the difficulty of lowering the table.

I have prepared a 7 minute video showing the problems and a solution which make table movement so much easier and faster than winding the handle on rack and pinion system. I will add a second video later going into detail of the physics involved.

Here is the link

Here are some sample pix.

Click for full size.

[RetiredFAE]

Nice solution!
I took the lazyman's way out, on my 1936 Rockewell Delta 15" variable speed drill press, I put a long ram hydraulic jack under the table, rigged it with a foot pedal and release, I can raise and lower the table with my feet.

[ironwrx]

That’s a terrific idea. Thank you!

[tonyfoale]

Part 2 is now ready.
It is important to see part 1 first, otherwise this second part will make no sense. Here is a link to part 1. • EasyDrill
Part 1 showed the physical aspects and how it worked in practice, this second part examines the science behind counterweighting, particularly for a drill press but the principles are also applicable to counterweighting in general. Getting the best results from counterweighting is not just a matter of adding a counter weight and hoping for the best. A little science and understanding is a big help for getting an optimised solution.

[tonyfoale]

I had already added an external counterweight to a Craftsman drill press, which I think that I posted here some years back.

Click images for full size.

Although that improved the lifting it was still difficult to lower the table.
Motivated by the success of the Startrite modifications I added a handle to the rear of the table. That made the Craftsman as easy to raise and lower as the lighter Startrite. Sometime in the future I may re-cast the counterweight to fit in the column as per the Startrite. The long travel of the floor mounted Craftsman means that the external weight hits the floor when the table is right up and fouls with the clamp handle when the table is lowered too much. The high 30s temperatures here at the moment means that I will wait for winter to do any re-casting.

[tonyfoale]

Making the weight for the Craftsman.

Firstly I calculated the volume of lead needed to give the required weight. I then cut off a length of 100mm diam steel tube to give that volume plus a bit and welded a plate to the bottom and lifting handle at the top.

Click image for full size.

I was having a bonfire to get rid of garden waste and that was ideal for the melting. I weighed some scrap plumbing lead and added it to the pot as previous lot melted down. I waited until the fire had burnt down and then I dropped the pot into the coals, on a long pole for safety.



The old scrap lead was full of dirt, from its years of waste pipe duty, which floated to the top. I removed what I could and I sealed the rest in with a layer of resin.