You can buy rods of appropriate length, VXB is where I got mine, and they carry the good rods (hardened and chromed). Cheap rods and bearings work, but will slowly grind each other to death and are noisier than the already noisy good ones. Mcmaster also carries the good ones, but for a lot more. Keep in mind, the good rods can be quite costly.
Almost every delta on the market is a bit undersized or under-built, particularly the Rostock. It's capable of good prints, but like many early repraps, keeping it dialed in takes some effort because it lacks rigidity. To go taller, you REALLY need to use larger rods. Kolergy on Thingiverse has done a lot of work on putting larger rods into a Rostock. [www.thingiverse.com] I can't speak for the quality, just that he has upscaled it.
While the Rostock worked, it was an exercise to see if if would. Like I said, it prints good, but we have moved on from that design. The Rostock was temperamental, noisy and expensive. I would highly encourage you to look at the 3DR, Cerberus Pup, Wolfstock, Griffin, and to a lesser extent, the Kossel Mini (the sliders drive the price up). While each has it's advantages and disadvantages, each is a definite step up from the Rostock and cheaper to build (except maybe the Kossel Mini). Personally, i prefer the Wolfstock and Griffin as they are more rigid designs and therefore handle movement and speeds better.
Whichever you build, look for the ability to adapt a probe for auto-level and auto-calibration. While building a delta is easier than a cartesian, manually calibrating a delta is a VERY time consuming process. The probe systems takes a 6 hour+ labor intensive process and makes it a half hour automated process.
Almost every delta on the market is a bit undersized or under-built, particularly the Rostock. It's capable of good prints, but like many early repraps, keeping it dialed in takes some effort because it lacks rigidity. To go taller, you REALLY need to use larger rods. Kolergy on Thingiverse has done a lot of work on putting larger rods into a Rostock. [www.thingiverse.com] I can't speak for the quality, just that he has upscaled it.
While the Rostock worked, it was an exercise to see if if would. Like I said, it prints good, but we have moved on from that design. The Rostock was temperamental, noisy and expensive. I would highly encourage you to look at the 3DR, Cerberus Pup, Wolfstock, Griffin, and to a lesser extent, the Kossel Mini (the sliders drive the price up). While each has it's advantages and disadvantages, each is a definite step up from the Rostock and cheaper to build (except maybe the Kossel Mini). Personally, i prefer the Wolfstock and Griffin as they are more rigid designs and therefore handle movement and speeds better.
Whichever you build, look for the ability to adapt a probe for auto-level and auto-calibration. While building a delta is easier than a cartesian, manually calibrating a delta is a VERY time consuming process. The probe systems takes a 6 hour+ labor intensive process and makes it a half hour automated process.
