Finishing parts

[Janger]

For my ELS project I ordered some drive couplers. For such an inexpensive product the finish is just amazing. Is this glass bead blasting? I wish my parts looked this good. How did they do that?

Hardly a tooling mark anywhere with a very consistent and smooth feeling finish. It is aluminum.

 

[Former Member]

Likely tumbled.

 

[PeterT]

Hard to say. Maybe medium blasted? The bore is still machined/shiny so must have plugged that off either way. This pic kind of indicates underlying machining marks & matte finish of secondary abrasive.

 

[Stellrammer]

I think Degen is correct, vibratory tumbling, some machine work after.

 

[Janger]

Ok I’m going to throw some aluminum in the tumbler and see what happens.

 

[gerritv]

I get a Mitutoyo look on my aluminum parts by glass bead blasting. Hides a lot of tooling marks.

 

[PeterT]

I forget what I used one time but it was one of the environmentally friendly zesty lemon smelling biodegradable degreasers. I normally dilute in water & used as a non hydrocarbon way to clean aluminum parts. Anyway either I used a high concentration or maybe even sprayed directly & kind of forgot about it for 5 minutes. It turned the 6061 into a dull grey matt finish. Not quite like that but it was no longer shiny. Like I tell my wife when she falls for the overpriced all natural organic schtick - snake venom is all natural too.

 

[kstrauss]

I agree that glass bead blasting is an easy way to remove (or least make less apparent) machining marks on aluminum. However, the perfect matt finish is easily blemished with the slightest rub against any hard surface.

 

[Former Member]

Based on the finishing I would say that it was finished on a grit vibrator. The center polish is done last as a final finish. Look at the crisp edge.

 

[RobinHood]

Citric Acid with pumice (like in GoJo hand cleaner), gives aluminum (and other metals) a really nice finish. It’s cheap and works very well.

 

[Darren]

Citric Acid with pumice (like in GoJo hand cleaner), gives aluminum (and other metals) a really nice finish. It’s cheap and works very well.

in a tumbler?

 

[RobinHood]

in a tumbler?

Just by hand with a white scotch bright pad is how I have it done in the past. I don’t know if it would work in a tumbler as I don’t have one.

 

[Janger]

This part was about 10-15 euros. So no time or money for anything laborious. Tumbling or beat blasting or some sort of chemical treatment it would have to be.

@gerritv when you bead blast are the results durable? What size glass beads and what psi? Got an example?

 

[Janger]

I put the part in the tumbler with the ceramic media it came with. The media feels gentle it does not have sharp edges. After half an hour the part came out better. I’m going to put it back in. The part at the top is the one that went through the tumbler. Bottom one is from the mill. The commercial drive coupler is surprisingly resistant to finger prints.

 

[Janger]

Rocketronics got back to me and says the part is anodized. For anodizing I expect a vibrant colour. Is there a “silver” dye or is this just anodized without colouring?

 

[Susquatch]

This is what I know John.

Anodizing is an electrochemical process. It is not like painting at all. It is more like bluing. But anodizing uses an electric current to oxidize the surface of the metal. Different colours can be achieved using different anodizing baths. Generally speaking, it retains the original surface finish. You can anodized any metal, but aluminium is more commonly anodized than other metals.

 

[DPittman]

Rocketronics got back to me and says the part is anodized. For anodizing I expect a vibrant colour. Is there a “silver” dye or is this just anodized without colouring?

Oh yes that coloring (or lack of) is common with anodized aluminum. I'm not sure if they use a color to get it that way but my hunch is that's it's "natural". My ultralight airplane frame is all that same anodized finish.

 

[Susquatch]

My ultralight airplane frame

Ultralight???

You are FULL of surprises!

Pictures?

 

[JustaDB]

Ultralight???

You are FULL of surprises!

Pictures?

BAHAHAHAHAHAHA!!! You guys are hilarious. It's like being at a party with dozens, nay, hundreds! of loud voices clamouring to be heard over all the others, when the place goes quiet for a split second and one voice stands out, "New, heretofore unheard of project!" Suddenly every head in the joint swivels to said speaker, someone calls out, "Say, what?!" & the voices rise again.

 

[Susquatch]

Suddenly every head in the joint swivels to said speaker, someone calls out, "Say, what?!"

Ain't that the truth!

More fun to be had on here than watching monkeys at the zoo!

I am always totally in awe of the skills, knowledge, experience, and the infinite variety on offer here.