Lapidaryforum.net

Please login or register.

Login with username, password and session length
Advanced search  

News:

Welcome new members & old from the Lapidary/Gemstone Community Forum. Please join up. You will be approved after spam check & you must manually activate your acct with the link in your email

Congratulations to wheatguy and his Pietersite Cab!

 www.lapidaryforum.net

Another cabochon contest coming soon!

Pages: [1]   Go Down

Author Topic: Water Swivel Stone Core Drilling  (Read 1386 times)

0 Members and 1 Guest are viewing this topic.

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2145
Water Swivel Stone Core Drilling
« on: February 16, 2016, 08:22:38 PM »

Stone core drilling is possible without a water swivel fixture, but it takes much longer because you must raise the core drill frequently to cool it and wash away the swarf from the drill hole. This lengthens the time it takes to drill a hole and puts the core drill itself at risk because it is very easy to overheat the drill and thereby strip diamond from the drill. A much more efficient version of core drilling is achieved with a water swivel fixture. Core drills designed to be used with water are hollow throughout so that the water can be introduced to the interior of the core drill as it is being used. This allows you to adjust the volume of water for each type of material and it allows you to continuously drill. The water swivel fixture pictured has a solid shaft on the top which is intended to be put in a drill press. The opposite end of the fixture has a threaded shaft. Bits may be put inside the shaft and locked down with a set screw. These would be rather small bits. Larger bits are threaded onto the shaft and then the nut that is affixed to the shaft is run down and tightened against the core drill. The water delivery feature sticks out from the body of the water swivel at a right angle and has a hose attachment and an arm to adjust the water flow.
This will be a very long post with many pictures and due to my limited stamina I will have to post over a number of days to complete the tutorial. Feel free to comment at any time.
Logged


Gergis

  • Global Moderator
  • Hero Member
  • *****
  • Offline Offline
  • Posts: 645
  • "I MILK MY ROCKS"
Re: Water Swivel Stone Core Drilling
« Reply #1 on: February 16, 2016, 09:29:07 PM »

SWEET!!!

Sent from my LGLS990 using Tapatalk

Logged

kent

  • Full Member
  • ***
  • Offline Offline
  • Posts: 203
    • Fine Woodwork and Lapidary
Re: Water Swivel Stone Core Drilling
« Reply #2 on: February 17, 2016, 06:09:58 AM »

What would be the minimum size bit this unit could handle ?

 
Logged

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2145
Re: Water Swivel Stone Core Drilling
« Reply #3 on: February 17, 2016, 09:06:34 AM »

I will find the web site of the company I am using presently for bits and you can check with them.
Logged

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2145
Re: Water Swivel Stone Core Drilling
« Reply #4 on: February 17, 2016, 10:03:11 PM »

2nd Installment

Top image:
The top of the water swivel fixture is a solid steel shaft that is chucked into the drill press. The drill pres is set at a moderate speed. Start out conservatively by running the drill slower than you might like initially to make sure there are no problems.

Middle Image:
The lower end of the fixture has exterior threads and is hollow so that water can come through the fixture and irrigate the drill from the center. This hollow threaded shaft can accommodate bits threaded on the outside or slotted up the inside and affixed to the fixture with a set screw.

Bottom Image:
The final step is to securely attache the fixture to the drill press.

Logged

LithicStrings

  • Full Member
  • ***
  • Offline Offline
  • Posts: 114
Re: Water Swivel Stone Core Drilling
« Reply #5 on: February 20, 2016, 06:28:52 PM »

The Third Installment :
The next step is to hook a hose to the water swivel. I prefer to use a valve between the hose and the water swivel, despite the fact that the water swivel fixture itself has a valve. Since it is a brass fixture and valve, they can get pretty sticky and hard to turn. The rotation of the drill press will make the whole fixture and hose and everything else try to turn. The force doing this is not great but it still has to be mitigated and I find the best way is to simply use a piece of wire to hold the hose to the shaft of the drill press. Before we put the bit on. We should talk about a couple of issues. Run out or wobble, and the proper speed for drilling. Machinists measure the wobble of a drill bit that is in a drill press or other fixture with a machine and they call the amount of wobble the runout. Runout is a bit problem in most cases but for lapidary purposes the usual runout that we find is not a great problem. If the spindle of your drill press is worn or has been damaged wobble can be a problem and the hole that you are trying to make round would be elongated in one dimension. A major issue with core drilling is the speed of the machine. Most drill presses have variable speeds and I have never worried about the speed because I have always been quite conservative and used the drill press at the lowest speed that is available for core drilling. The particular bit that I am using in this tutorial was made by the company Smart Cut, a company which has excellent information about how to use your core drill safely and effectively. This bit is a 1 ¾” outside diameter bit and the Smart Cut speed chart says it is to be used at either 550 rpms or a speed that you find more comfortable. I have been using it at 250 rpms and feel quite comfortable using it at that speed.
Logged

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2145
Re: Water Swivel Stone Core Drilling
« Reply #6 on: February 23, 2016, 07:13:22 PM »

Rather than inserting the male part of the bit and adapter into the water swivel, my swivel requires unscrewing the adapter from the bit and threading the female part of the bit onto the water swivel. After carefully threading the bit onto the water swivel fixture you bring the nut down against the bit and tighten them against each other. After the bit is securely placed on the fixture we can start an adequate water flow through the center of the fixture and bit as shown. The difficult part of the water swivel drilling with larger bits other than affording the bits is trying to figure out a way to hold the stone in a vice while in a pan on the drill pres table. Any great ideas would be appreciated. With very small bits (1/2" or less) you can hand hold slabs on a piece of wood in the pan, but much larger than that and you take the risk of having the bit cause the stone to spin violently if the core drill gets bound up in the hole at all. Bits under 3mm normally are not hollow and while they will fit in the water swivel fixture the water through the drill shaft function doesn't work. One way to solve the vice problem is to get a really old guy to suck it up and just hold the rock.
Logged

hummingbirdstones

  • Opalholic and General Rock Nut
  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 1959
    • Hummingbird Stones Lapidary Services
Re: Water Swivel Stone Core Drilling
« Reply #7 on: February 24, 2016, 06:24:43 AM »

There has got to be some way to make a square sliding adjustable jig to hold those bigger pieces.  Wish I was an engineer type person, but alas, I'm not.  Maybe some of the others on the forum who are inclined that way can figure out some type of contraption for you.  Cool tutorial, though, Frank.  I'm really enjoying learning about this. 
Logged
Robin

LithicStrings

  • Full Member
  • ***
  • Offline Offline
  • Posts: 114
Re: Water Swivel Stone Core Drilling
« Reply #8 on: February 25, 2016, 07:59:31 PM »

Very nice tutorial
It appears that you need to turn the large handle on the side of the drill to apply correct pressure in a downward direction.  Any suggestions on how to know how much pressure is correct so the drill doesn't bog down, yet keeps drilling?
Logged

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2145
Re: Water Swivel Stone Core Drilling
« Reply #9 on: February 25, 2016, 08:46:22 PM »

Mostly intuition. About 30 lbs of pressure is maximum .
Logged

wampidy

  • Hero Member
  • *****
  • Offline Offline
  • Posts: 583
  • A ring on the hand is worth two on the bush
Re: Water Swivel Stone Core Drilling
« Reply #10 on: February 26, 2016, 11:02:12 AM »

As far as down pressure goes I use the smoke/ground-up-rock method. If the water is white coming off the drill bit I have enough pressure.

You need a forked tongue and large clamp to hold the stone. DO NOT go out and have your tongue split.

I cut a V groove in the end of a one by four like a boot jack that I can slide up close to any size bit. I block up the other end of the one by four then clamp it to the drill press base keeping my clamping point between the rock and the block. A board under the drill press base lets you clamp anywhere if your clamp is big enough.




I am drilling slabs so with rough stones you may need to come up with something (wedges maybe) to keep the stone from tipping.
Jim
Logged
I threw a stone into the air.
It came to earth "ouch"
I now know where.
You can quote me on this, I have the scar.

lithicbeads

  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 2145
Re: Water Swivel Stone Core Drilling
« Reply #11 on: February 26, 2016, 05:15:48 PM »

Sweet!
Logged

hummingbirdstones

  • Opalholic and General Rock Nut
  • Administrator
  • Hero Member
  • *****
  • Online Online
  • Posts: 1959
    • Hummingbird Stones Lapidary Services
Re: Water Swivel Stone Core Drilling
« Reply #12 on: February 26, 2016, 05:44:21 PM »

I KNEW someone here would have figured it out!   :notworthy:
Logged
Robin
Pages: [1]   Go Up
 

Page created in 0.115 seconds with 46 queries.