|
Post by rocklicker on Dec 9, 2011 18:21:20 GMT -5
I was reading on another post about the danger of wearing out bearings on a tumbler if the shafts are not true. Sure enough, I constructed a homebrew tumbler using 5/8 inch rod stock from home depot. The tumbler jiggles and I can clearly see the deflection in the shafts. So it's time to get new shafts then. I don't know much about what type of shafts to use. My choices are: Alloy steel, carbon steel. I am looking for something that will easily hold 2 1/2 large barrels, 35 pounds of rocks (so 17.5 pounds each) over a 2 foot span. Here are links to each. www.grainger.com/Grainger/Rod-Stock-2HJH8?Pid=searchwww.grainger.com/Grainger/Rod-Stock-2HKR3?Pid=search Does anyone know the best type or are neither going to work? Steve
|
|
|
Post by jakesrocks on Dec 9, 2011 18:38:22 GMT -5
Use cold rolled steel. It's ground true and straight.
|
|
|
Post by johnjsgems on Dec 9, 2011 18:57:34 GMT -5
Any machine shop or metal fabricator shop in your area should have cold rolled shaft stock. Even a bearing supplier should have short lengths (3 feet or so). As long as you are building I would use 3/4". It would be a more common size as it is used for small coolers, etc. Stronger too than 5/8". May even find 3/4" bearings easier as well.
|
|
Steve
has rocks in the head
Member since June 2005
Posts: 506
|
Post by Steve on Dec 9, 2011 19:08:53 GMT -5
My homemade uses 3/4 inch cold rolled steel. Runs 4 twelve pound Lortone barrels. The configuration is: barrel - bearing - barrel - barrel - bearing - barrel Been running full time for 3 years with no problems after solving the usual startup issues - getting everything adjusted, lined up straight, properly tightened, properly loosened.
As John said, it should be easy to find a local source.
|
|
|
Post by johnjsgems on Dec 9, 2011 19:29:12 GMT -5
The 40 lb. HP tumbler I had had cheap, bronze bushing bearings. I don't remember what shaft size was but my 12T has 5/8". It isn't very long though. Seems like wholesale 3/4" pillow block bushing type bearings were pairs for under $20.
|
|
Steve
has rocks in the head
Member since June 2005
Posts: 506
|
Post by Steve on Dec 9, 2011 20:13:35 GMT -5
|
|
|
Post by johnjsgems on Dec 9, 2011 20:29:04 GMT -5
And if you ran the 5/8" bearings in the old shafts they are likely not round anymore either. Any time anyone put new bearings on worn shafts they never lasted long when I was in the HVAC trade.
|
|
jspencer
freely admits to licking rocks
Member since March 2011
Posts: 929
|
Post by jspencer on Dec 10, 2011 11:46:06 GMT -5
I see bushings mentioned as well as bearings. Bushings are an invite to hell with a tumbler. They are not a sealed unit and trust me that grit and crud will get in the bushings soon. Sealed bearings will last decades instead of months or years for bushings. And cold rolled is for sure the material of choice for the shafts. Another option in place of pillow blocks on the ends is an end cap bearing mounted to a surface or frame. Also available from Grainger.
|
|
|
Post by johnjsgems on Dec 10, 2011 19:57:40 GMT -5
The sleeve bearings on my HP were holding up well. I bought it from a friend that bought it used and used it for several years. I only ran a few loads through and themn sold it to another friend. I took it all apart and put new Tygon hose for him and had to reverse the shafts as the bearings were good but shaft was worn. Ball bearings are infinitely better than sleeve bearings. I've installed actual sealed bearings called "wash down bearings" made for equipment you wash with a hose. The typical sealed permanently lubed bearings would be good. The sealed bearings with zerk fittings are only sealed until someone greases them until grease comes out of the bearing. They should be greased until seal expands only. No matter what type bearings proper maintenance has a huge affect on how long they last.
|
|
|
Post by rocklicker on Dec 14, 2011 14:37:47 GMT -5
Yeah, I am going to ditch the shafts for cold rolled, only thing is I don't know if cold rolled and "Temper Cold Finish" are the same thing. I am going to stick with the 5/8 in bearings I already have on there and hope the are OK. The span between bearings is 24 inches.
If Graingers does not have them I know McMaster Carr has cold rolled steel shafts, I was just hoping to be able to buy them in town and not order them. I am going to try a machine shop as John recommends. Steve
|
|
|
Post by jakesrocks on Dec 14, 2011 15:06:34 GMT -5
If you can get the material in town, ask for cold rolled shaft stock. It will have a semi polished or machined look on the outside, as opposed to hot rolled which will have a rough black or rusted finish.
|
|
|
Post by johnjsgems on Dec 14, 2011 18:21:02 GMT -5
My advice would be to make sure the old bearings fit snug on new shaft. If they wore at all from using them with the round stock either the new shaft or bearings or both will wear out quickly.
|
|
morsefire
noticing nice landscape pebbles
Member since November 2011
Posts: 83
|
Post by morsefire on Dec 16, 2011 18:40:56 GMT -5
I'm currently using zinc rods and zero bearings with zinc tubestock. Yes I know crude but three cycles and a little oil....works perfect. Yes I will be buying pillow bearings very soon.
|
|