Praise for Prussa and some thoughts  

Praise for Prussa and some thoughts

I've been working with machine tools for a long time. I'm mechanically inclined and have been building things (mechanical and electrical) for most of my life. With that background out of the way, I have to say that this is one of the best kits and sets of instructions I've experienced. I've also spent the last week or so reading these forums and the comments on the build instructions.

I get that a lot of people have problems with it. Unfamiliar concepts, not familiar with tools and assembly, etc. I think the instructions even do a pretty good job with that, but I'm not the most qualified to say (although some of the user comments in the build docs are very telling). They are definitely "streamlined" for minimal tools and measurement, which makes sense. The only thing that I feel the instructions don't always highlight is that printed parts sometimes need to be cleaned up, especially when they were intended for higher toleranced parts like hardware (bolts and nuts). They do cover cleaning out pocket holes for nuts, etc but I didn't see any general warning of: hey....the plastic stuff is PRINTED. If you've never worked with printed parts before let's explain how this works, not only to make your assembly easier but also so you know what you're in for when you start printing your own.

Also as many have mentioned, the standard procedure for all bearings of this level of quality not just for this printer in particular is to dump them in alcohol to remove the chinese gutter honey they come with from the factory and re-pack with something good that is continually available to you in the future so you can use the same lubricant. As with many others, I find Super Lube great for applications like this. You may have something else that makes more sense for you, but I can find this stuff at the hardware store 5 minutes from my house, so that makes it generally and easily available for me. That may not be the case elsewhere.

Also, stop saying (I'm talking to you Prusa staff) that there is no way to accurately describe or measure belt tension. You just don't provide the tools or methods. This is a solved engineering problem, and something that is done hundreds if not thousands of times a day in both industry and car maintenance. There are many ways to accomplish this from actual tension/deflection measuring devices to a smart design for a tensioner which can be accurately set with a torque wrench/driver.

That being said, back to the praise. This is a very nice kit that ends up with a very nice printer. Such a huge upgrade from the Monoproce Maker Select that was gifted to me and got me into this to begin with.

My advice is to go slow, study the photos AND the words for a step completely, then lay out your parts and go. Still have parts left at the end of that step? Go back. Figure out why.

I couldn't get my frame to level completely, and that's entirely down to tolerances: the cuts on the strut material aren't great. At least they weren't on mine. I decided to continue assembly rather than go out to a cold machine shop in the winter and put them on the mill to make them triple 0 level and parallel. I can't imagine it will matter much (it hasn't in my day of testing) and I also wanted to just assemble the thing first to understand how it went together and worked......it's entirely possible I'll still pull the frame apart to do that type of potentially unnecessary work.

I look forward to prototyping on this printer and feel like I've gotten an exceptionally good value for the money spent. I never assumed this would have the tolerances of a $10k+ lathe or other "proper" machine tool, but I certainly still got something that is a lot closer than I hoped or expected.