Myth of hi-speed rotary tumbler & tumbling

[salpal48]

I was always perplexed on why my regular speed 1500-1700 rpm machine polish better than my 3000 rpm machine
I tumble rocks as well as cases. , with Rocks The longer it stays in contact with the Grit , the more it smooths
after a while I found that slower speed machines gently fold the cases on the media with a rolling action. While the Hi- Speed . slam the cases on top of each other. This would included dry media and pins.
True a Hi speed might take s a little less time. . But myself I do all my Tumbling @ night , overnight.
Realizing this it seems to make no difference what tumblers you have.. I have many machines some faster and slower than other. I took my slowest Machine " Craft- tool" loaded 200 30/06 and polished. This machine only turns 19-20 RPM. Within 4 hours Clean and polished. Taking My Thumler Hi Speed , The same results in the same time
I have encloses some Photo of my Craft tool and Others

[Bzcraig]

Dang brother, I think you have one too many tumblers! :drinks:

[slide]

Can't have too many!!!:bigsmyl2:

[woodbutcher]

:shock: Me thinks he needs maybe another dozen or so:roll::).
Good luck.Have fun.Be safe.
Leo

[Oily]

salpal I need to pm you about your rock tumbling. Got my granddaughters enthused about rock tumbling with a starter kit with a small 1 quart tumbler kit but it is old and motor quit. Fun hobby even with the limited river stones we can get from the local sand pit. Oily

[mdi]

I've not consider RPM too much as long as the cases don't stick to the ID of the drum because of centrifugal force. I haven't timed my tumbling is many years...

[blikseme300]

I noticed the same thing. I have 2 Thumlers, one standard and one high speed. Pistol brass in the high and rifle in the standard. I noticed damage on the case mouths of rifle brass when tumbled using the high speed unit. I use timers so over tumbling won't happen.

[runfiverun]

I watch my tumblers while I'm adding brass and walnut to them.
I'm trying to balance out the contact of the nuts [which is basically scraping the sides of the cases] to the volume of cases and the weight.
there is a visible point where the tumbler slows the roll but the cases hang up and the media just flows around them before sucking them under again.

when I get the balance to this point I put the lid on and go do sumthin else for about 1.5-2 hours.

I can't see the roll inside the pin tumbler so have to go by the results after some experimentation.
adding another pound of pins makes a huge difference and can cut the time down to just over an hour.

[jmorris]

I was always perplexed on why my regular speed 1500-1700 rpm machine polish better than my 3000 rpm machine

I don't think you can directly relate motor speed to feet per second of tumbling action. There will be some method(s) of gear reduction that all have to be accounted for. If the drum were actually turning 25 times a second (1500 rpm) all the cases would be flung to the outside of the drum from centrifugal force and little tumbling would occur.

[Carrier]

My son and I tried various speeds on our homemade tumbler and found 70 rpm for the drum to work best.