Tips for Faster Prints and Less Purge
I've been multimaterial printing for a while, and I thought I'd pass along some things I've learned about how to get faster prints and less wasted material in a multimaterial print. I hope this helps some people just starting out!
Every time you change materials it takes time (a little over a minute for the MMU) and requires purge. So the most important thing you can do for faster prints and less purge is minimize the number of material changes. Here's some ways to do that:
Once you've minimized the number of material changes, you want to try to minimize the amount of purge per layer:
Re: Tips for Faster Prints and Less Purge
thanks again for doing the science so we don't have too 😀
I have a Prusa,therefore I research.
Re: Tips for Faster Prints and Less Purge
Very nice info!
I would phrase it slightly stronger: if you have a first object that has 20 white layers at the bottom and 20 black layers at the top, and a second object that has 20 black layers at the bottom and 20 white layers at the top, you would have a colour change on every layer if you print them together. Whereas printing them separately results in just one colour change (on each print).
This is a simple example, it may be more complicated to figure it out for more realistic models... 🙂
Re: Tips for Faster Prints and Less Purge
[*]Tune your purge settings. For most color changes, the default purge settings are much more than you need. Slic3r's default is for 140mm3 of material purged on every material change, but if you're changing between similar colors (black to brown, white to pink) you may need as little as 60mm3. On the other hand, there are times when you need a lot more: going from white to black may need 250mm3. Taking the time to test and adjust your purge settings can save a lot of material.
[*]Arrange your filaments from dark to light. Going from a dark filament to a light filament needs more purge (sometimes a lot more) than going from light to dark. Slic3r seems to go through the materials in order rather than optimizing for minimum purge, so if you put your darkest material in Filament 1 and your lightest in Filament 5 you will minimize the number of times you switch directly from your darkest to your lightest filaments.
[*]Turn on Purge to infill or purge to an object. This helps reduce purge, especially if your infill settings are high. In some cases it can get rid of nearly all the waste. But never 100%, since there is some waste material from ramming.
[*]Print multiple copies. It takes the same amount of purge to print two of something as one of something. So if you know you will want more than one, try to do multiples at a time. [/list]
Thanks for all that! Of course I've been using it for a while before reading this, but I thought I'd comment anyway
I often use less than 60. Do you find that to be a minimum?
Also, as a weird aside, I've had some convincing skin tones by not purging my red before printing white - this is dependent on copies and other things.
I assumed the minimum purge case was used, I didn't even think to change the order of the filaments. I guess I should!
I almost always increase copies until it's less than half purge. It does slow things down, so it's bad for testing but great for material usage.
Lastly: Be careful with purging to infill. It CAN show through. On darker colors this isn't an issue, but my internally stripped SpongeBobs are annoying.
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