Drill Press Table Elevator

[rgsparber]

Adjusting the height of the table on my drill press is an awkward lift. Using some pulleys, ball chain, and a counterweight, I built a little block and tackle. Pulling up or down on the ball chain with the table unlocked does the trick.

If you are interested, please see

http://rick.sparber.org/DPEBC.pdf

Your comments are welcome. All of us are smarter than any one of us.

Thanks,

Rick

[mklotz]

I've used ball chain a few times in the past and was disappointed when it pulled apart if exposed to much force. Hopefully that won't happen here but, if it does, you may want to think about some thin nylon rope. Yes, it stretches but in your application that's not really a problem.

Back in my childhood (early Jurassic) folks had canvas awnings that were deployed and stored with those little double pulley blocks. Every hardware store stocked them but I haven't seen them in ages. Where did you find them?

[rgsparber]

Marv,

I was a bit Leary of the ball chain too but it sure looks nice. If it breaks, that weight will take a chip out of the concrete floor but can't reach me. I think those pulleys came from MSC a long time ago.

Rick

[sossol]

We have those type of blinds in our house. Custom-sized from Hunter Douglas, ordered through Lowe's circa 2000. Sadly, they have been discontinued for a long time.

[Frank S]

I don't believe you mentioned the size of the chain there is a US manufacture that makes all sizes from .072" 1.8 mm through 5/8" 16 mm they number their size from #1 to #50 if for instance your chain is 1/8" 3.2 mm or #6 made out of stainless it would have a maximum tensile of 45 lb, 30 lb for carbon steel
#13 or 1/4" is the smallest industrial rated ball chain at 115 lbs
https://ballchain.com/chain_sizes.html

[Ed Weldon]

Looks like ball chain is readily available although I haven't yet checked price and availability. The manufacturer in Frank's link has a good set of engineeering specs on various sizes. I think the counterbalance idea for the drill press table is really cool. Almost countless ways of doing this if you are willing to make your own "pulleys" which may not even need rotating sheaves if you are willing to carve up blocks of teflon and use nylon cord. Me, I like things that are a bit "antiquey" so I'd go with brass pulleys with lathe turned wheels and frames bent and soldered together from .031 sheet brass even though I've been collecting those miniature pulleys from garage sale offerings for some years now to use for pulls on the hanging light switch cords from overhead lights. 'Cept the one on the overhead track lights in our family room. That one has a 2-1/2" long mother of pearl antique fishing lure spoon for a pull. Not much use for the freshwater fishing I do. .... Ed Weldon, Los Gatos, CA

[Okapi]

Thanks for your well made PDF rgsparber, I use another system but your idea is really good and simpliest, I suppose it's possible to use another type of chain without too much modifications, the "hollow" type pulley type with classical chain like we found in clocks which is easy to reproducting on milling machine for example.

[rgsparber]

I don't believe you mentioned the size of the chain there is a US manufacture that makes all sizes from .072" 1.8 mm through 5/8" 16 mm they number their size from #1 to #50 if for instance your chain is 1/8" 3.2 mm or #6 made out of stainless it would have a maximum tensile of 45 lb, 30 lb for carbon steel
#13 or 1/4" is the smallest industrial rated ball chain at 115 lbs
https://ballchain.com/chain_sizes.html

The ball chain came from my junk drawer. All I know is I hung the counterweight on it and it did not snap. I did originally use nylon cord and it was fine but I liked the look of the ball chain. Not very scientific...

Rick

[rgsparber]

Thanks for your well made PDF rgsparber, I use another system but your idea is really good and simpliest, I suppose it's possible to use another type of chain without too much modifications, the "hollow" type pulley type with classical chain like we found in clocks which is easy to reproducting on milling machine for example.

Cord, ball chain, or maybe even chain could do it. I did find that having the two pulley blocks have me the necessary mechanical advantage to easily pull up or down on the chain to move the table. A single pulley didn't do that.

Rick

[NortonDommi]

Marv,
Boat shops, ships chandlers, and rigging supplies all carry a good range of pulleys in various sizes and materials. The best ones to use for a multiple snatch system is to purchase at least one with a Becket. Your local hardware store has probably never heard of them but they do make life easy.Attachment 19510Attachment 19511