So this is partly a “follow along” of Marvin watching over filming of polishing some ColorFabb and Proto Pasta models for my next part polishing video. This time we are going to be using Marvin at 125% scaling in Proto Pasta Stainless Steel and ColorFabb bronze fill. Today was spent just making the models up as I am waiting on some ceramic tumbling media to ship from Washington State. Hopefully it will make it here end of this week beginning of next so we can film.


Also we have a size comparison of the Marvin’s. White Marvin is 100%, Stainless Marvin is 125% and Wood Fill Marvin is 150%.


Check back regularly as I hope to update this post as more filming gets done. So far nothing can be done until my smaller media arrives!

Update 1: The media I have tested with currently is some massive ceramic media intended for tumbling steel parts smooth. While this is great and actually quite effective on metal models it is also incapable of reaching into tiny areas very well. Here is a test tumble with a tarnished ColorFabb Copperfill model before and after. The model was waxed post-tumbling for about 24 hours but the color difference is huge!



One drawback to a tumbler is the price/time. For the setup I run it would set you back about $160 for the tumbler. The Thumblers Tumbler AR-12, while it will set you back about $180 > $200 I have no complaints with it. A large capacity + capability to run for days on end without worry is ideal! The other main drawback to a tumbler is the time. While it can take me say 20-40 minutes to polish up a small item the time required for a tumbler is measured in hours > days. On average I let a model tumble in ceramic media 24 - 48+ hours, or until I like what I see. Then I switch to a stainless steel pin media used for brass reloading and let that run another 24 - 48 hours. So while the process is autonomous it is time consuming and has somewhat of a high startup cost.

While a tumbler of the capacity of mine is not necessary, it is helpful to get the largest you can. That said a small tumbler is great if you only do small parts. No need to pay more for what your not going to need! So while a tumbler maybe somewhat expensive starting out, they are very useful if you find yourself needing to finish mass quantities of prints and you don’t feel like sitting there and sanding them for hours on end. Also tumblers can reach into areas that maybe difficult for hand sanding. They will not handle fragile models well so keep that in mind!

Ok last update on the models for now:

Preferred polishing process for the Stainless Steel:

Tumble in ceramic media for about 24 hours

Switch out for stainless pins and tumble with a little water for about 8+ hours (models were tumbled 8 hours as shown). The photo doesn’t do the models justice for how glossy they are. There was no polish on the models. I found the ProtoPasta stainless steel was the easiest item to polish up.


Preferred polishing process for the Bronzefill:

Sand the model semi-smooth with coarse sandpaper to remove any rough patches/remove the layer lines. This is critical for polishing!

Tumble in ceramic media for about 24-36 hours

Switch out for stainless pins and tumble with water for another 24+ hours

Rub model down with a t-shirt rag and Mothers Mag Polish I found Brasso did not work well!

Remove all the old polishing compound from the model. This is critical OR the model will turn white and haze up…

I then vigorously rub the model down with a clean t-shirt rag and NuFinish car polish I find this helps to give the model a final buff and remove any leftover polishing compound left on the model.


The reason why removing the layer lines is critical in my opinion is they trap the extra compound and it leaves the model hazy. I will try removing the excess compound with Odorless Mineral Spirits but I do not want to remove any wax left on the model from the compound.


Looks like a really cool setup, can’t wait for the video! Nice idea to bring all these materials together, it’s definitely a good way to show off the filament you use in your Hub.


Thank you! I have more metal filaments but I chose one from each brand so that away everyone was covered fairly.

Impressive prints! How do you find printing Colorfabb vs Proto pasta filament? Never tried any exotic materials, which one would you recommend out of the two?

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Running both prints at the same exact settings (50 MM/S @ .2 layers) I have to say the ProtoPasta Stainless went down smoother than the bronze fill down underneath the legs but then again I was printing the bronze faster than I normally do! I would say in terms of ease of printing I would say the ProtoPasta stainless is a little easier to print just because of the thermal properties of stainless steel. If your going to run it start at a low temp on a test print and check the flow. If it doesn’t seem like the layers are sticking try re-running the test 5*C higher and keep doing that until you find the temp that works best. I found 220*C @30-50 MM/S and .2-.25 layers works good. I have gone down to .1 before that isn’t always needed as the material lays down some smooth layers!

That said all metal filaments are a little trickier to print than regular PLA since they flow a LOT faster! The metal conducts heat really well so you have to make sure the plastic stays liquid ONLY in the nozzle or you run into all kinds of hot-end issues. Also a fan(s) on the model is a MUST for ok bridges/overhangs. If you can run supports as the model will need it. One other thing to note is these filaments will chew up a brass nozzle so keep that in mind when printing and look into a wear-resistant if possible. E3D and protoPasta have nozzles out/in the works.


Awesome insights, thanks so much for taking the time to answer. Can’t wait to try’em!

I’ll keep an eye out for your posts, mate :slight_smile:

Thanks! I’m going to do a video soon about working in the filaments. Don’t be surprised if your first few tries look pretty bad but once you mess with it your going to like it. Also check out my sanding polishing video for how to on getting shiny prints with sandpaper.

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Oh, I can’t wait for this series! Really looking forward to it :slight_smile:

What is the goal of the video series, educating other makers, or / and exploring the different methods for polishing?


That is the general idea. Right now I am focusing on metal print finishing since the previous video was so popular and I feel like there are ways we can streamline the process. While I don’t feel tumbling will replace sanding a model I feel it can help improve workflow if you are patient.

In the future I am hoping to branch out into more filament reviews, maybe interview some makers in SF who use 3D printing in various ways as well as offer tips for people looking into running a 3D Hub and getting parts printed. Like basic etiquette such as please don’t take 4 days to reply to a question I ask that is urgent… and then get annoyed at me when the order didn’t ship…

Love the update, Calvin! I’m glad the shipment arrived sooner rather than later :wink:

Moving forward it would be good to start new threads for future updates, so they don’t get lost in this one. As long as you always refer to the initial post, things should be fine. Looking forward to the next one!

Good thought! What ended up happening is the seller marked the stuff as “shipped” but that was Sunday so I will be getting the material mid-week and then frantically filming! In the meantime I got some pretty interesting results I will be posting up shortly.

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