Some Tumble specifications

I have found an old Lewis Electric Motor, hp 1/10 and it gives 1400 rpm

- Belt-driving
- Pulley, 50 millimetre [1.97 inch] and 100 millimetre [3.94 inch].
- Driving shaft 17 millimetre [0.66 inch] (1:2 above makes 700 rpm)
- Tyre, examples :
    * 165R14, diameter 580 millimetre [22.85 inch] (17:580 gives 1:34)
        it makes 21 rpm
    * 205/70, diameter 630 millimetre [24.82 inch] (17:630 gives 1:37)
       it makes 19 rpm

Then you need bearings and for example some old bicycle hub wheels. (see picture)
You can also take a wheel barrow inner tube and pump up
(lower noice and splash guard).

Explanation to the picture
Below on the tyre I have the cheap solution, bicycle hub wheels and wheels from an old furniture that for some odd reason had wheels. And on the bar there are side roller bearings to avoid wobbling. Thus totally eight bearings stabilizing the tyre. (after I took the picture I have thus added two more wheels from the old furniture to stabilize the direction).

As you can see on the picture I have the driving shaft and a rolling shaft but also a third "shaft" but for that I used a bicycle hub wheel to help me avoid problem when staring the machine and it also help the tyre to behave very well if the stone mass behave bad, for example if one have to little water, in the rolling tyre.

Once I got "splash" into one of the bicycle hub wheels and I found that the grinding was very effective on steel too ;-) After that incident I covered my "bearings" with scissored plastic bottle parts to avoid future damage.

Good luck !
Lennart Widmark

Below some further tip and suggestions about how to develop the "Tire Tumbling Technique"

* Hi,
I read your articles with interest. The photos show a fine looking rig! Here is a suggestion for you- have you tried wood cleats, straight across or angled, inside the tire using screws throught the tred from the outside? They might allow you to use a tire much longer. You could experiment with height of wood and screw length would not matter as they would get ground down. Also a note on grit- I used 30 grit years ago in a tumbler. The result after several weeks of continuous tumbling- the grit did not look like it had been used and the rocks were semi-polished.
Bob Edgar edgarr@mccc.edu

* NEW   Some interesting insights about how to get a Tyre-tumbler go
...... and now also A Fifty-Pound Truck-Tire Rock Tumbler: Specifications and Experiences

* Se also Kreigh's Homemade Lapidary Equipment for further knowledge about : Cutting Spheres, Drilling Holes in Stones, Make Your Own Classic Rock Tumbler, Make Your Own Open Top Rock Tumbler, Make Your Own Rock Saw, Some Thoughts On Horizontal Laps, Make A Pressure Sprayer for Cleaning Rocks, Grow your own Crystals, Make Your Own Elutriator to Recover Tumbling Grit, Polishing Rocks by Hand ... etc.

* Tumbler with multiple source of rotations - pat. pend. Further information contact 08-6240283@comhem.se

* Some books about tumbling (Swedish):

Smyckestenar & stenslipning	Slipa stenar
Caise Chetty, Sam	Olson F, David
ICA Bokförlag	ICA Bokförlag

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Lennart.Widmark@fek.umu.se