broadbill
off to a rocking start
Member since September 2019
Posts: 5
|
Post by broadbill on Nov 5, 2019 6:40:18 GMT -5
Ive been reading these forums for years getting some great ideas. I thought it was time to show some of what ive picked up from all the great posts Ive read. My latest project was to build a sphere machine which I got most of my ideas from this forum. I also build a coring rig to make it easier to make the preforms. The last photo shows some of the spheres Ive made this week. Thanks for all the great info everyone on these forums provide.    |
|
|
|
Post by HankRocks on Nov 5, 2019 7:16:14 GMT -5
Very nice work on that rig. What's the purpose of the chains?
I would like to see your rig to make the preforms.
Thanks
Henry
|
|
broadbill
off to a rocking start
Member since September 2019
Posts: 5
|
Post by broadbill on Nov 5, 2019 7:21:27 GMT -5
I use the chains with springs when I want to apply a lot of pressure. Ive learnt that the pressure can be a cure or a gift. I can grind a hard rock to round in under 10mins with the high pressure but have to be careful on softer rocks as if it grabs it drills straight into the rock.
|
|
broadbill
off to a rocking start
Member since September 2019
Posts: 5
|
Post by broadbill on Nov 5, 2019 7:27:02 GMT -5
here is the rig I made for making quick preforms.  |
|
|
|
Post by rockjunquie on Nov 5, 2019 8:57:16 GMT -5
Dude! That's awesome! Thank you so much for sharing! I'm really glad RTH could help you in realizing your goal. That sphere maker looks very professional and able- the proof is in the pudding. Nice spheres. 
EDIT TO ADD- What would you add to help anyone else lurking to learn?
|
|
|
|
Post by captbob on Nov 6, 2019 12:50:02 GMT -5
Color me impressed!
Really need to get off my butt and get into making spheres.
|
|
jamesp
Cave Dweller 
Member since October 2012
Posts: 36,602
|
Post by jamesp on Nov 20, 2019 15:17:00 GMT -5
Are those cupped diamond pads broadbill ? Can't think of a better way to shape and polish a sphere. Especially if you can get them in 30 to 60 grit for shaping. |
|
broadbill
off to a rocking start
Member since September 2019
Posts: 5
|
Post by broadbill on Nov 21, 2019 8:55:10 GMT -5
Are those cupped diamond pads broadbill ? Can't think of a better way to shape and polish a sphere. Especially if you can get them in 30 to 60 grit for shaping. They are flat but i cut them from the centre up to the second row. I bored out the middle of the backing pad but found that with the pressure i used it broke the backing. I now just add a few layers of valcro around the edges of the backing pad and that makes a great cup for the pads. |
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,602
|
Post by jamesp on Nov 21, 2019 10:14:56 GMT -5
Are those cupped diamond pads broadbill ? Can't think of a better way to shape and polish a sphere. Especially if you can get them in 30 to 60 grit for shaping. They are flat but i cut them from the centre up to the second row. I bored out the middle of the backing pad but found that with the pressure i used it broke the backing. I now just add a few layers of valcro around the edges of the backing pad and that makes a great cup for the pads. Understood. They do make concave pads and backers fyi. May cost a good bit more. They sure last longer on hard lapidary rocks than when used on sandy concrete. I found some 30 grit pads and must say they can remove some material from Mohs 7 rock quickly. |
|
NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,688
|
Post by NRG on Nov 21, 2019 16:31:16 GMT -5
Are those cupped diamond pads broadbill ? Can't think of a better way to shape and polish a sphere. Especially if you can get them in 30 to 60 grit for shaping. Granite pads are awesome for finishing. To rough a sphere the very best way is with segmented coring bits. By far the fastest. As you found with segments, 100 grit pad cuts like 200 grit loose. |
|
broadbill
off to a rocking start
Member since September 2019
Posts: 5
|
Post by broadbill on Nov 21, 2019 19:33:20 GMT -5
Are those cupped diamond pads broadbill ? Can't think of a better way to shape and polish a sphere. Especially if you can get them in 30 to 60 grit for shaping. Granite pads are awesome for finishing. To rough a sphere the very best way is with segmented coring bits. By far the fastest. As you found with segments, 100 grit pad cuts like 200 grit loose. Totally agree. Ive been using cheap segmented coring bits from china for the first stage and they work a treat. It looks like ill be able to get over 120 75mm spheres from one set so they work out very cheap. |
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,602
|
Post by jamesp on Nov 22, 2019 8:19:42 GMT -5
Are those cupped diamond pads broadbill ? Can't think of a better way to shape and polish a sphere. Especially if you can get them in 30 to 60 grit for shaping. Granite pads are awesome for finishing. To rough a sphere the very best way is with segmented coring bits. By far the fastest. As you found with segments, 100 grit pad cuts like 200 grit loose. I found 30 grit pads Scott. Would they work for initial shaping ? They use crushed diamonds in those pads, much sharper and faster cutting than roundish loose diamond crystals. Perhaps you use crushed loose diamonds. Just saying, crushed are wicked sharp as opposed to most crystals. |
|
NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,688
|
Post by NRG on Nov 22, 2019 11:21:19 GMT -5
Granite pads are awesome for finishing. To rough a sphere the very best way is with segmented coring bits. By far the fastest. As you found with segments, 100 grit pad cuts like 200 grit loose. I found 30 grit pads Scott. Would they work for initial shaping ? They use crushed diamonds in those pads, much sharper and faster cutting than roundish loose diamond crystals. Perhaps you use crushed loose diamonds. Just saying, crushed are wicked sharp as opposed to most crystals. I haven't been able to get pads to work on my machines at any stage. But obviously, that's me. Others have been successful. They could test this for you. The segmented cores allow for greater pressure on the cutting surface easily making up for different diamond shapes. I have also turned to oil instead of water coolant. Not as messy as water (doesn't fling everywhere) and it actually quite simple to clean up. So far I have used mineral oil and rancid corn oil. No difference in cut as far as I can tell. We are just hogging material at this stage. Nothing special. |
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,602
|
Post by jamesp on Nov 23, 2019 9:30:14 GMT -5
NRG"The segmented cores allow for greater pressure on the cutting surface easily making up for different diamond shapes." I get you. Concentrated force due to core being hollow = faster cutting The oil makes good sense with the free drip/evaporation arrangement. Rancid corn oil is moonshine ?
|
|
Fossilman
Cave Dweller
Member since January 2009
Posts: 20,722 
|
Post by Fossilman on Nov 25, 2019 9:43:36 GMT -5
NICE!
|
|
NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,688
|
Post by NRG on Nov 26, 2019 17:49:08 GMT -5
NRG"The segmented cores allow for greater pressure on the cutting surface easily making up for different diamond shapes." I get you. Concentrated force due to core being hollow = faster cutting The oil makes good sense with the free drip/evaporation arrangement. Rancid corn oil is moonshine ? No, rancid corn oil is corn oil that sat in the pantry way tooooo long. Smells bitter and musty. Still lubes the cuts well on the sphere machine. Manual drip from a bottle with a small hole in the lid. No auto feed yet... 😎 |
|
