Sunday, July 29, 2012

Prusa Build I

Someone recently licensed the mathematical expression parser I've written about before.  The license fee, combined with some additional features that I added for their application, summed to a not insignificant amount.  Although I'm a poor graduate student, I thought that I should reinvest this money in my hobbies since it effectively fell in my lap as a result of my hobbies.  I decided to buy a Prusa Mendel after all of about 10 minutes of thought.  I had looked at other 3D printers before, e.g. printrbot, solidoodle, and so on, all of which looked attractive, but they had massive leadtimes and crazy-expensive shipping options to Canada.  UPS? Nuts to that! To EBay, and the Makerfarm Prusa kit, for an impulse buy!

Immediately after confirming payment, I regretted my decision. Perhaps I should have researched my options better, been patient with shipping or bought from a more established outfit. Spoiler Alert: My fears were unwarranted, it was an excellent choice and I heartily recommend the Makerfarm Prusa kit.

Approximately ten days later a parcel pickup notice was on my door and after a jaunt to the local post-office, had this box on my coffee table. Opening the box, I spread out everything on the table to take an inventory of what was there:

Note that the motors are my own.  I immediately opened the printed parts bags to see what the quality was like, and was pleasantly surprised to see that it was excellent.

There were two casualties in shipping however.  Two of the retaining legs for the linear bearings on (what I would learn was called) the X-carriage had cracked off.  However a bit of ABS plumbing glue had that fixed in no time.

It was at this point that I looked at the shipping notice and realized that I had in fact bought the metric kit, when I had intended to buy the SAE kit.  I was horrified: it is nearly impossible to source M8 threaded rod in Vancouver, and if you can find it, you will pay through the nose.  Plus I already had a bunch of 5/16-18 threaded rod.

Luckily I already had 8mm precision linear shafting from the ongoing CNC project, and realized that 5/16 of an inch is actually 7.9375mm. In other words all the threaded rod would fit, with slop of about 6 thou. But the prints are nowhere near this accurate, so in fact the cheap, readily available and on-hand 5/16 rod would work just fine, I would just need some appropriate nuts.  Which cost about $5.

Next post: Assembly.

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