Why parallel arms required for delta 3d printer

That design allows for a lot of effector freedom which would be great if you can control it, bad if you can't.

If you read the last line of the pdf, they state that the joints were a problem, so while they could control it with some degree of precision, it wasn't enough for say, 3d printing. Granted, this was 14 years ago and you can say things have progressed, but one could also say what we use, is what evolved from those experiments.

Looking at older designs can be good for ideas, but you have to be careful that you aren't working backwards.

As for the pneumatic actuation, that could be interesting (and fast!), but probably not quiet.

or

as regards the precision of the delta should theoretically be very accurate if:

- The frame is very stiff
- there are no inaccuracies in the construction and assembly
- Very low backlash in the joints

of course it is not easy to get all this

The reason why I want to realize it and design it by me is that I have not yet seen a delta that I really like and want to make.

Many of delta frames that I see around with high aluminum pillars and connection beams only on top and bottom are very few stiff

Also those delta with parallelogram made by carbon fiber with a diameter of a few millimeters are very undersized in my opinion, it is true that they are very light and have little inertia, but they are also very flexible and will never be fast and accurate at same time.

I prefer to have a precise machine, even if slow.

The parallelograms made of tubes aluminum or carbon fiber are a good choice, but I hate rod ends because they have working angles very limited.

The magnets seem to work, but do not give me confidence.

Some time ago, I started to design my delta, but I'm still very uncertain on how to make the parallelogram and if I have the right idea I could even try to do it.

Otherwise reconsidered the idea of a Cartesian printer, most likely a core xy.