jm
starting to spend too much on rocks
Member since October 2015
Posts: 101 
|
Post by jm on Dec 24, 2022 23:20:19 GMT -5
Hi everyone, I decided to document the process I use for making spheres. I realize that there are many ways to make spheres, this just happens to be the one I use based on the equipment, space, and time that I have. Here I'm working with a chunk of obsidian that I picked up at Glass Buttes, OR. Hopefully the videos are clear enough. First is cutting a cube using a 14" masonry saw I picked up recently. Then I use a jig to cut the preform. I got the idea for the jig from wader . He shows how it works on forum.rocktumblinghobby.com/post/966338/thread. The jig is adjustable for cutting different size preforms. Then I throw the preform into my sphere machine to grind it into a sphere. I painted it orange to show the grinding process better. Then I swap out the grinding cups for the polishing cups. I rinse off the sphere and polishing cups between grits to reduce the chances of cross contamination. After running through the various grits, it's done! (Edit) In case it's not clear, I sped up the video during the polishing segments. I ran the 50 grit for 7 minutes and all the rest of the grits for 4 minutes each. Sometimes I use a polishing compound after using the 10,000 grit pads, but I didn't in this case because it already had a mirror finish. Anyway, that's my current sphere making process. Hope you enjoy. |
|
|
|
Post by jasoninsd on Dec 24, 2022 23:42:47 GMT -5
James, those are awesome videos! Thanks for sharing these!!  |
|
|
|
Post by Rockoonz on Dec 25, 2022 9:57:21 GMT -5
Pretty cool using the power drills for the sphere maker.
|
|
|
|
Post by hummingbirdstones on Dec 25, 2022 10:30:23 GMT -5
Those are awesome videos. Thanks for showing the whole process!
|
|
|
|
Post by rockjunquie on Jan 1, 2023 8:33:23 GMT -5
Way cool! Thanks for sharing the videos. I have not seen anyone coat the rough like that. I was like- where'd THAT rock come from? |
|
|
|
Post by DirtCleaner on Jan 2, 2023 10:18:25 GMT -5
Hey, that is not the way I do it. Nice work. Glad you figured out your process.
|
|
|
|
Post by Rockoonz on Jan 2, 2023 10:54:15 GMT -5
I notice on the first grind video you have a hand on one of the heads periodically, is that to keep the random motion going on the ball, or to ensure it doesn't pop out?
|
|
jm
starting to spend too much on rocks
Member since October 2015
Posts: 101
|
Post by jm on Jan 2, 2023 13:42:36 GMT -5
I notice on the first grind video you have a hand on one of the heads periodically, is that to keep the random motion going on the ball, or to ensure it doesn't pop out? Mostly I keep a hand on one of the drills to keep the random motion going by pushing it a bit to one side or the other. There's enough side to side slop in my setup that I can't always count on it having random rotation all by itself, so I need to babysit it. I have a speed controller for each motor and I've found that if I turn the speed way down during the first part of the grind when there's still lots of corners on the preform then I don't have any problems with the preform popping out. Once the corners get knocked down I can start turning the speed up to make the rest of the process faster. |
|
jm
starting to spend too much on rocks
Member since October 2015
Posts: 101
|
Post by jm on Jan 2, 2023 13:58:19 GMT -5
Way cool! Thanks for sharing the videos. I have not seen anyone coat the rough like that. I was like- where'd THAT rock come from? What, you haven't heard about the vein of bright orange obsidian at Glass Buttes?  Normally I don't paint the entire preform like that but it sure makes the grinding process easier to see on video. Usually when the initial grind is about 3/4 done I'll pull the preform out and slap some bright colored paint on the remaining flat spots. That way when I'm doing the last stages of the grind I don't have to keep stopping the machine to check if all the flat spots are gone. I just keep it going until I don't see any more paint spots. I was using spray paint until recently my wife gave me some of her acrylic craft paint to try and now I'm sold on it. The acrylic paint is dry enough to handle in 15 minutes or so and it sticks to the rock really well. That's much better than waiting for hours for spray paint to dry ( although I discovered that any kind of paint dries much faster if you put the rock in a food dehydrator and crank the temperature up to 150 degrees F). |
|
jm
starting to spend too much on rocks
Member since October 2015
Posts: 101
|
Post by jm on Jan 2, 2023 14:01:14 GMT -5
|
|
jm
starting to spend too much on rocks
Member since October 2015
Posts: 101
|
Post by jm on Jan 2, 2023 14:05:26 GMT -5
Hey, that is not the way I do it. Nice work. Glad you figured out your process. Sorry, what I meant to say was "This is the way I do it, so therefore it is the "correct" (or " proper") way to do it!"  |
|
vwfence
has rocks in the head
Member since January 2013
Posts: 567
|
Post by vwfence on Jan 3, 2023 10:31:04 GMT -5
Instead of paint , i use colored magic markers to define the flat spots . they also dry fast . right or wrong they work for me
|
|
|
|
Post by Rockoonz on Jan 3, 2023 10:33:51 GMT -5
Instead of paint , i use colored magic markers to define the flat spots . they also dry fast . right or wrong they work for me I use my aluminum tig wire marking sticks on cabs to show the flat spots, no risk of them soaking in to porous stuff. |
|
vwfence
has rocks in the head
Member since January 2013
Posts: 567
|
Post by vwfence on Jan 3, 2023 14:54:07 GMT -5
aluminum knitting needles work well for marking out cabs also
|
|
jm
starting to spend too much on rocks
Member since October 2015
Posts: 101
|
Post by jm on Jan 5, 2023 0:01:14 GMT -5
Instead of paint , i use colored magic markers to define the flat spots . they also dry fast . right or wrong they work for me That's a great idea. I'll have to give that a try. |
|
agatewhisperer
freely admits to licking rocks
Member since May 2020
Posts: 837
|
Post by agatewhisperer on Jan 12, 2023 0:27:18 GMT -5
Thanks for posting this and taking the time to make the videos. Really interesting to watch!
|
|
