A Question About Tumbling I Have Not Seen Addressed Before...

[hdwhit]

ponchh, thank you for the pictures.

 

[hdwhit]

Sunray wrote:
"...what's wrong with a glass jar..." They break.

I first built a tumbler using the printer drive mechanism in the early 1990's. During the years I was using grass jars, I never lost a single one to breakage.

...Don't think you'll get much in the way of RPM's with a printer,...

I currently get about 70 RPM with a batch of rifle (i.e. 50 cases + media) and 60 RPM with a batch of pistol (i.e. 100 cases + media) brass. So far it has been sufficient.

 

[ponchh]

ponchh, thank you for the pictures.

Here is another. That is sch80 pipe. I lucked into about 30 feet of 6 and 8 inch for 25 bucks. 8inch runs about $25 a foot and big problem is they don't sell a couple of feet You have to buy 10 or nothing

 

[hdwhit]

mdi wrote:
With a glass jar ("drum") the media/brass will prolly just slide to the bottom side of the drum with out mixing or tumbling...

That is one of the concerns I had with glass, or plastic (which has a similarly low coefficient of friction) drums that prompted this post in the first place.

 

[Blue68f100]

[QU"mdi, post: 10628792, member: 58464"]I wouldn't use agitators so large, mebbe 1/2 or 1/4 the size of those...

I don't think so, the idea is to scoop as much as possible and take it to the top and dump it down the center.[/QUOTE]

The idea is to tumble the brass in the media. Not picking it up and dropping it, doing so will put dings into them. Besides you loose contact with the media.

 

[ponchh]

I don't think so, the idea is to scoop as much as possible and take it to the top and dump it down the center.

The idea is to tumble the brass in the media. Not picking it up and dropping it, doing so will put dings into them. Besides you loose contact with the media.[/QUOTE]

It is in water and only falls 6 inchs, no dings. The media gets picked up with the brass so there is lots of contact. If is wrong please don't tell all of that spotless brass that has been coming out of it for three years.

 

[HEAVY METAL 1]

While I don't have the mechanism you have I have found my tumbler to run quieter with a full load of brass and media as close to full as possible.

 

[Spade5]

I use a rotary tumbler built from parts salvaged from a Texas Instruments dot matrix printer. Having no prior experience with rotary tumblers, I just threw 50 or 100 brass cases into the large glass jar I was using as a tumbling drum, filled it about half-way with media, put the lid on it and set it to work. Because it was noisy, I would usually start tumbling before I went to bed and then stop it the next morning. The results were always quite satisfactory, so I never had any reason to question whether what I was going was "right".

But then, a post on another thread started me wondering if I should have stopped to take the time to evaluate what I've been doing. My questions are:

1. How full should the drum be? Half-way? Completely full? Is there a preferred ratio for brass to media?
2. Should the drum have internal baffles to help stir up the brass and media?
3. Is there an optimal tumbling speed? If so, what is it?

Thanks.

Love it, using what you have to make what you need. I would think you need some open space but have no clue what the ratio is. I guess you could make a baffle by gluing a small piece of wood on the side of the jar.

 

[hdwhit]

HEAVY METAL 1 wrote:
I have found my tumbler to run quieter with a full load of brass and media as close to full as possible.

Thank you for the advice.

 

[ponchh]

If stainless pins are used, there should be more weight in pins than brass. 5 lbs. of pins to 4 lbs. of brass ( about 300 rounds of 223 ) with about 1 gal. of water and tablespoon of dawn.

 

[mdi]

[QU"mdi, post: 10628792, member: 58464"]I wouldn't use agitators so large, mebbe 1/2 or 1/4 the size of those...

I don't think so, the idea is to scoop as much as possible and take it to the top and dump it down the center.[/QUOTE]

Not necessary, you're "tumbling" brass not mixing cement. Tumbling brass wasn't started as a reloading procedure as parts have been tumbled waaay before reloaders started tumbling cartridge cases. I worked around machine shops for many years and most had some sort of deburring/cleaning process that use a rotating drum and none had vanes that took up 1/2 of the ID of the drum, just not necessary. Parts/cases don't have to be lifted up to the top of the drum and dropped to the bottom (and that action may be too aggressive and dent cases or leave a rough/matte finish). I my experience with rotary brass cleaners, many don't use any vanes/agitators and just rely of the friction of the ID of the drum or the shape of the drum's ID to mix the media/brass. My home made drums have vanes that extend into the drum mebbe 1/2"-3/4" (of a 10" drum). As I said previously I wouldn't use the vanes in the pic (lifelong machinist/mechanic here), but it's you toy and you should use it as you feel best...

 

[jmorris]

I built a half dozen really large tumblers for an ammunition manufacturer a few years ago and the speed question came up. It's not just an RPM equation as feet per minute of tumbling action also depends on the distance they have to travel inside the drum (circumference).

Instead of bogging down in endless theory and testing I just built them with 3 ph gear motors and used VFD's to run them so they could pick any speed they like anytime they want.

I imagine they have figured out a speed they leave them set at now though.

 

[ponchh]

As I said previously I wouldn't use the vanes in the pic (lifelong machinist/mechanic here),

Well heck I didn't know I needed qualifications but I am a 22 year aircraft structure mechanic
by day and building race car 30 years by night if that helps. I am trying to get a handle on this here fabrication stuff.

 

[hdwhit]

As far as I am concerned, the only "qualification" necessary is the ability to answer the OP's questions.

In my years practicing as an engineer, I learned the value of taking into consideration everyone's knowledge and perspective and even though I didn't include everyone's perspective in my final analysis, reasoning why I should discount someone's experience in a particular instance made the results all the more certain.

Thank you all for your contributions.

 

[mdi]

No need to apologize as I was just explaining my statement about the size of the agitators. I mentioned my background to help explain my thoughts on the design ( worked with fabricating metal since Jr High and using commercial grade tumblers in machine shops). Personally, I don't care if the design incorporates 37 vanes that take up 97.53% of the drum's interior. Just sharing my experience and trying to help ponchh...