Harbor Freight vibratory tumbler for 6061?

[Caprirs]

http://www.harborfreight.com/cpi/cta...emnumber=96923

I have little experience with finishing so have read through this forum to try to learn. It seems most interest is in polishing.

I'm in need of removing tool marks from aluminum parts I'm milling. Polishing is not required, just a matte finish. Nothing is dimensionally critial either, no threaded holes. And the parts will be anodized. Will the above HF tumbler be cost effective? If so, what is a reasonable media and expected time for just removing machining lines? The little green plastic things? An aggressive media is ok with me.

Or am I better off just using a blast cabinet?

Thanks in advance.

[Kool Parts]

One of the many problems with small bowl types is the bowl itself. Because of the curves the parts have to be fairly small. Of they will wedge in and just sit there. Also they don't have much power so they don't put much power into the part or media. Which means it might work for you but you might have to let it run for 48 hours or so.
Gary

[LeeWay]

I do have this tumbler. Just got it maybe a few weeks ago.
Tried the green plastic media for deburring 6061. Wasn't all that good at two hours. Went with some mild ceramic type media and the result is much better for me at 1 hour cycle time. Deburred all the parts but leaves a dull surface. I don't have tool marks as my parts are profiles, but they are smooth.
The parts get powdercoated so the surface finish is perfect. I do have to wash the parts.
I haven't yet tried it with the liquid dripped in, but will at some point.
For now, I'm impressed with this machine.

[Caprirs]

Thanks for the input. The parts I am considering this for are about .75" x 1.5" x 4.5" so I think they should fit decently inside the bowl of that 18lb HF unit. I do all the deburring on the mill already so I'm only chasing the surface finish issue at this point. A blast cabinet would be faster but requires more human attendance. The appeal of the tumbler is to drop the parts in and be free to go work on something else.

Leeway, what is the ceramic media you are using?

[Geof]

Originally Posted by LeeWay ... Deburred all the parts but leaves a dull surface... ....The parts get powdercoated so the surface finish is perfect...

I suggest trying to get some samples before spending the money. We have a bigger version of this type of vibratory finisher and it is does deburr nicely and the parts are dull and we think they look horrible after anodizing. I can see it would work with powder coating and could even give some 'keying' on the surface for better adhesion, but for us it is the category of failed experiment because we anodize almost everything.

[LeeWay]

So far I get good results with the PCing. I do want to do a test of just wiped down or blown off versus rinsed of with water. I will also test when I start using the cleaners inside the bowl. That would keep the dust rinsed out of it. Just do soemthing like a few drops per minute.

I only used 10 pounds to start with, but feel I need a little more for my larger parts.
They are 5" by 1" by 3/8".


The ones I have tested are about 2" by 2.5" .063" sheet.

I get the media from Mcmaster Carr.
A little pricey, but should last quite some time. Not that costly when you consider the man hours it is actually saving me.
I am using the small 3/8" by 3/8" 60 degree triangular fine ceramic media.

http://www.mcmaster.com/#about-tumbling-media/=338hsh

[Caprirs]

Originally Posted by Geof I suggest trying to get some samples before spending the money. We have a bigger version of this type of vibratory finisher and it is does deburr nicely and the parts are dull and we think they look horrible after anodizing. I can see it would work with powder coating and could even give some 'keying' on the surface for better adhesion, but for us it is the category of failed experiment because we anodize almost everything.

Geof,

Can you elaborate on "horrible"? Do you have pictures for comparision perhaps? How do you finish your parts now?

Powder coating is not a viable option for these parts unfortunately.

[LeeWay]

I wouldn't really use it for anything but powdercoating.
I can do a decent job of deburring these parts by hand using about a 120 belt sander or even a ROS. I will try to get some pictures of my parts as soon as I can.
I'm now not so sure it will work that well to remove machining marks with the fine ceramics. I think you would need to use medium to coarse or a combination of those. These little drums aren't really designed for the rough stuff. The little manual actually warns against it citing premature drum wear.
The finer stuff may work for you, but take longer cycle times. I haven't ran mine more than an hour at a time. I have an electric timer that it plugs into.

I am building a larger one with coarse ceramics for my steel parts. No quite yet done with it. Actually my first iteration worked, but was a poor design. Few little changes should make it much better.

[Geof]

Originally Posted by Caprirs ...Can you elaborate on "horrible"?.... ...

Do you not like my technical terms?

Dull and mottled, not an even mat finish. Sorry I don't have any pictures.

We were trying to using tumbling for removing burrs not for finishing the surface but the surface effect was so negative we had to try a different approach. Normally we anodize parts with the as-machined finish.

[Caprirs]

Leeway,

I don't mind the cost of the media if it would do the job. How coarse do you think is "too" coarse for these bowls?

Originally Posted by Geof Do you not like my technical terms?

I am familiar with the technical terminology. However, I wasn't sure if you were using metric or English units of "horrible". Would I mulitply or divide by 25.4?

Here's what I'm making. There is one more operation to do yet. The part will be attached using bolts through the slots. If the part is powdercoated, the paint will chip off when the bolts are snugged down. Thus the anodizing.

When it comes off the mill, there are no sharp corners as all deburring happens on the machine but I was hoping to get rid of most of the machining marks prior to anodizing.

Should I just blast these instead?

[Geof]

Originally Posted by Caprirs ......When it comes off the mill, there are no sharp corners as all deburring happens on the machine but I was hoping to get rid of most of the machining marks prior to anodizing. Should I just blast these instead?

Why is it necessary to do anything? Maybe I am a bit quirky but I find nothing wrong with a smooth machined surface.


Incidentally your factor of 25.4 would probably work; if my horrible mottled blotchiness was scaledd down by this amount then it would probably translate into a nice even mat finish which would be okay. But I suppose the way to get this is with very fine glass bead blasting.

[Caprirs]

Originally Posted by Geof Why is it necessary to do anything? Maybe I am a bit quirky but I find nothing wrong with a smooth machined surface. Incidentally your factor of 25.4 would probably work; if my horrible mottled blotchiness was scaledd down by this amount then it would probably translate into a nice even mat finish which would be okay. But I suppose the way to get this is with very fine glass bead blasting.

I am the same way about tool path evidence. However, the retail market disagrees and prefers no clues about manufacturing. Philistines and heretics they are.

A friend sometimes asks me to make things for him. He prefers maximum tool path lines be visible in the finished piece so that it is clear a CNC was used to produce the part. I am happy to oblige.