tumbling sphere preforms-new pictures

[Saskrock]

Anyone ever tried tumbling a sphere preform?? I was thinking I could cut a preform on my saw (they don't look too difficult to cut) and tumble it to get something fairly sphere like. What do you think?

[LCARS]

Sounds good in theory but the more obtuse an angle is the less it will wear in the tumbler so it may require a bit more time than you think to totally even out to the eye. Definately worth a try though, and don't forget to update us including some pics on how that goes.

[Saskrock]

I will try to remember to post some pics but with my homemade saw (very wet) and the weather in Canada this time of year (below freezing) it will have to be a spring project . Basically if it isn't cut now I am waiting for spring. Although I am thinking about the workforces everyone else seems to use. Probably a little drier. Maybe Santa will bring one. And it never hurts to plan ahead.

Maybe someone with better weather or a drier saw will let me know if it works.

[Jack ( Yorkshire)]

Hi Scott

I know you are on about tumbling BUT if you want to make spheres check out this link

tomaszewski.net/Kreigh/Minerals/Homemade.shtml

He has some great ideas

There was a thread on Lap Tips a while back on sphere making

Jack
Yorkshire UK

[rollingstone]

Small spheres should be no problem in a rotary tumber -- a rotary tumbler works by preferentially removing the high points on a stone, so everything is slowly guided to a spherical form. Of course, 99.9999% of the time we stop the rounding process well before reaching spherical, but if spherical is what you are aiming for, then starting with a roughly spherical shape and combining that with a fair degree of patience should give you what you want.

Bigger spheres (say 2" diameter and up) should be okay too, but they will take longer, and you will really only be able to do one at a time with other stuff in the barrel, or else they will beat things up too much and end up chipped and disappointing.

I just checked the weather forecast for Saskatchewan -- for the next 5 days most of the province should see below-freezing night temperatures, but daytime highs of 4-7 C (or 40-45F), so you could easily cut a few rough spheres outside during the afternoon. Go for it, and test out a few in a tumbler over the winter. My two cents, from Alberta.

-Don

[stefan]

tried it once- not real successful- hold on and I'll try to find a pic---- Hmmm I can't find a pic- which leads be to wonder if the dang thing is still in a barrel somewhere? I'll be checking all but polish this weekend- If I see it I'll take a shot or 2

[Tonyterner]

Interesting idea. I love spheres (I have 125 wooden ones that I've made) so I might just try this. With the cold weather and the problem with my fingers I won't be able to try it until the spring either.

[Saskrock]

Your more cold tolerant than me rollingstone. My saw gets you running though a sprinkler wet, great on a hot summer day. But not for me even if it is slightly above zero this time of year!!

[BuiltonRock]

Hey Scott,

Easy way to stay dry,



It has never been that clean again!
john

[Steve]

I have tried this with a jasper partial preform - I stopped after 10 cuts instead of the usual 26 cuts. I got a polished preform with rounded edges. I had to run it through the polish stage twice as one of the flat sides siphoned against the bottom of the barrel. I put the preform in with a lot of small well rounded small beach agates and was generous with my use of plastic pellets. I knew I wouldn't get a sphere. This particular partial preform came out so nice that I wanted to keep the 8 sided column shape. You can make a sphere and then polish it in a tumbler. I've seen it done. But it is much faster and less risky to polish it on the sphere machine. Steve

[Saskrock]

So cold, so very very cold...... I got out the saw and cut 4 sphere ish shapes. will post pictures if I ever warm up. 40 deg F today and soaking wet. If I don't make it tell my wife I love her and don't let her sell my rocks......

[agatemaggot]

Scott,
If you cut a Sphere preform and try to tumble it , it will get polished , but it will still have the flat facets on it , or worse yet, it will get pretty much eaten up over a period of time. You will have to round ALL the corners off that were made when you trimmed up your original cube shape to form the sphere when you began. Also, you cannot under any conditions, tumble a sphere that has any Druzy exposed on the outside. Tried it, don't work. The Druzy dissapears and what is left amounts to nothing more than a very pretty , well polished interesting looking , for lack of a better word, LUMP. I have rough ground several spheres in a three headed machine and then finished the polishing steps in my Vibro tumbler with excellent results.

Harley

[Saskrock]

Well here are some pictures.



This is to start with. They are wet down. Agate on top, jasper on right, no idea what the other two are, all local stuff. Maybe somebody knows what the other 2 are. The bottom one is more green in real life.



This is as spherical as I could cut them. It's harder than you would think.

It will be about 2 weeks before I have a tumbler free to go further.

A couple more questions for everyone also:

1- How fast does a lap spin at, I might give Jack's homemade site a
try. Doesn't look too hard to build.
2- BuiltonRock where did you get the plastic sheet? Great idea.

[darrad]

I made a sodalite sphere that way about 1 inch dia. I cut the preform like you did then ground the edges to get it as round as I could and it came out really nice. (it was before I had a digital camera) I put it on a little stand on the coffee table and I think one of my cats knocked it off and played soccer. The brats do that with anything round. It's under something in the house somewhere.

[Tonyterner]

Dang Scott you went out and cut those in 40 degree weather? You are more of a man than I am. LOL Don't forget to post pics as they progress.

[stefan]

I know I posted this before- but here is a neat site on marble making- scroll to the bottom to see a water powered marble mill!
www.marblemuseum.org/articles/tenn.html

[Saskrock]

Neat marble site. I might try that too but I think maybe I'll use a mask or some water. I can't believe those guys are dry grinding without a mask, crazy.

[Saskrock]

No safety glasses either when I look again!! Crazy.

[Sabre52]

I really want to see how your experiment turns out. I met a guy at a dig in Stone Canyon once who said "How'd you like to see my rock collection?" I said "sure" and darned if he didn't pull a cool leather pouch from his pocket that was all full of small spheres. For his collection, he'd hand polished little spheres from the best and most definitive example of each gem material he'd hunted. Every since he showed me that collection, I've wanted to give it a try and wondered if it could be done in a tumbler. Seems to me it should work and would be pretty neat.....Mel

[Saskrock]

I will post pictures for sure as I go through each step. The weather here has been hot and balmy for this time of year (no snow yet!!!), so I think I will be able to maybe start a load tomorrow in my big tumbler in the garage. Its too loud for the house but if I insulate it a bit the heat off the motor should keep it from freezing. So there should be some pictures around Nov 12.