Technical advise.
What are the advantages of 3D printers having rods in the axis X Y Z as opposed to other 3D printer manufacturers that seem now to be
using extruded aluminium rails with opposing wheels to steer along the channels and that can be adjusted for contact preload.
I have purchased several different manufacturers 3D printers and before I select a new machine which possibly will be my last at 78 years old, I need
to ensure I am on the right track. Pun intended, The cost of a new printer is not really an issue, but for 3 times the price from Prusa as opposed to a
multi print Chinese machine, I currently feel that I will be buying old technology having rods (non adjustable) as opposed to extruded rail systems that
can be adjusted for wear,
Secondly the forum at this moment appears to have a lot of extra "noise" from dissatisfied members in reference to add on or upgrade kits or is this normal
chatter from Prusa users not sure what they are doing or trying to achieve.?
Thanks,
RE: Technical advise.
You are asking machine design questions. There are a lot of opinions on printer design, but few have machine design experience. I would not avoid a machine that has rods. They are one of the easiest ways to get a precise diameter and straight surface. Rod columns are used on precision NC machines. The key is the rod diameter big enough. Prusa changed the Z rod to 10mm diameter on the MK4 to stiffen the machine.
Wheels on an extrusion? Has the extrusion been machined? What is the tolerance that was held? What tolerances are held on the extrusion? Wheel deflection, bearing durability and many more factors determine life and accuracy.
Neither would I dismiss a bedslinger for a core XY machine. Prusa has a blog where they mention the problems of core XY machines that was suprising to many, belt stretch on long belts, slack from bearing wear and more.
Prusa works well to assure good grade parts. They will even wait for good parts, something many companies may not do. In todays supply chain this is critical for a good product.
Then there is tempurature. The temperature may vary on our machines 20C. How does that effect the machine. Example a steel rod 300 mm long will change length by .08mm with a 20C temperature change. Aluminum will change by .15mm. How does the design handle this? Twist, bend, give? I know most don't consider temperature, but I was in an industry that held 0.002mm tolerances and temperature fluctuations can scrap parts.
I have an MK3S+ that is now an MK3.9 and also a MK4 with a MMU3 that is working well. I will admit the original MMU2 was not great, but the problems I saw were fixed in the MMU3.
Many have run a Prusa for years with regular (3-6 month) standard oiling and cleaning. Also Prusa still updates firmware on many older machines. The Prusaslicer is well suported.
As for the Forum complaints, this is normal for a forum. In some other forums comments are watched and may be deleted. I think there may be a schill or two on the forum also. Ones that point out brand B is better than Prusa all the time. Many of the big sounding problems have a simple answer. For me it was an incompatible USB3 drive that many users said would be ok. It caused problems, I went back to a good grade USB2 which is what the Prusa recommends. Problems gone, but there was some discussion in-between. We try to help others, the forum is nice but it usually takes many iterations to get to an answer that a face to face discussion would do in a few minutes.
I have tried a cheaper 3D printer route, it was not a good experience. I look for quality, on going support and ongoing software support. Also can I use supplies from anywhere or am I locked into 1 supplier? Prusa may not be the cheapest, but the MK4 works well. I spend my time printing, and very little fiddling with the machine.