What is the difference between a Kossel and a Rostock RepRap?
The above pictures are from RepRap, it can be read that on the left is a linear shaft and linear bearing combination and on the right is a aluminum profile and linear rail delta robot.
1. Both are delta robot RepRap built in 2012 by Johann in Seattle, USA. And the difference is that Kossel is based on his Rostock prototype. Does that mean Kossel is upgraded version of Rostock? RobotDigg think if Mr Johann agree with the point, then the answer is Yes.
2. Choice on linear motions, Rostock adopts linear shafts n linear bearings, pulley n belt or even fishing line and v bearing. Kossel use Aluminum Profile and linear rail, pulley n belt.
3. Results from the 2nd, the Rostock is cheaper than the Kossel, especially using material from China. You can find there is Rostock 3D Printer cost no more than 200USD from lots of Open Source RepRap 3D Printer stores. Kossel use linear rail, aluminum profile and vertex enhance it to be firm and stable but cost 50% higher than Rostock.
Personally, I recommend Kossel 3D Printer with Aluminum Vertex and quality stainless steel linear rails.
More detailed discussion on Rostock and Kossel
1. Talking about cheaper Rostock 3D Printer builds, the main concern would be the linear bearing and linear shaft. Firstly the material for linear bearings are varied from carbon steel, Gcr15, ST14, stainless steel and their combination, ball bearing and retainer also different quality.
Secondly, the match between linear bearing and linear shaft either too loose or too tight, especially a oil-free bearing adopted. In usual, the linear bearing factory do Not manufacture the linear rod, neither the linear shaft factory manufacture the linear bearing, then the tolerance would be a problem from every purchase.
Thirdly, even though 12mm smooth rod is still too thin for a large volume Rostock Delta Robot, Rostock Mini 8mm 492mm smooth rod used. And for a larger Rostock, 762mm linear shaft, no question 12mm will be recommended.
2. Kossel is firm and stable than Rostock, before RobotDigg Aluminum Vertex, printed vertex are widely applied in RepRap makers. In long run the printed vertex are out of shape and for large volume Kossel XL or XXL, the result is obviously.
Aluminum profile and linear rail used improves the performance, it's more like linear modules that are adopted, the stability are quite enhanced even though a hardened steel or Gcr15 linear rail involved.
Without limit on the cost, damper for stepper motor are applied for lower the noise and vibration. All of this helps the Kossel getting out of Rostock in Delta Robot to be more popular choice in RepRap Delta Printers.
