Stepper/lead screw combo


#1

One of my lead screws has developed a fair bend, and it is badly impacting my prints :frowning:

So I need at least a new lead screw, but I don’t want to have to replace again in 6 months.

Has anyone used the stepper motors with inbuilt lead screws? What has been your experience?

Either that or any other suggestions?
I could use one of those anti z wobble parts from thingiverse but​ I don’t love that idea, or @ant0ny and I discussed moving to a tevo Tarantula style z motor set up.


#2

I was going to do the Tevo style on the new printer on my desk… a OpenBuilds 300x300x300 (just a copy of the 500x500x500 I recently finished) but I decided I am going to do Dual Independent Extruders instead.

The issue I had with the Tevo style is you need to build the printer around a GT2 Continuous Belt Loop… I tried to join a GT2 belt and it was a fail and that was as far as i got. The Belt loops have all of a sudden become easier to get now and much bigger like over 1m but there is not enough hours in the day.


#3

I think I’m going to give the Tevo style a go, I may as well fix it properly - so I don’t need to do it again!.

I am too impatient for a custom belt to be made/delivered, so I might try my hand at welding.


#4

Does someone want to check my maths? This assumes that I modify the motor mount from: http://www.thingiverse.com/thing:2014187/#comments such that the to idler pulleys line up and keep the belt square.

Tevo Leadscrew-Lead Screw 350mm
My Leadscrew-Lead Screw 555mm
Diff = 205 * 2 = 410mm

Wilson 2020-> lead screw:~48mm
Tevo- 2020-> lead screw: ~42mm
Diff = 6 * 2 = 12mm

Required belt size = 900 + 410+ 12 = 1322

A bit of trig tells me if I don’t modify the bracket, I’ll need an extra 3-4mm each side for the lead screw to idler run.


#5

Since doing all this - I removed the top bearing and prints have drastically improved, but I’d still like to lick this problem.

I’m considering a belt driven Z axis, but I think it might be beyond my design skills! :slight_smile:


#6

Either that or I’d like to incorporate something like this:

Into the x-axis tensioner - to remove the strain on the rods/screws.


#7

Ahhh MazaaFin that takes me back to my Geeetech Acrylic i3… nice guy I contributed a bit for the Geeetech flavor.

hey have you seen the sub $300 Anet and Tevo printers… they get around the Dual - Single Z motor by not having a second motor. They counter lever the Xaxis from one side relying on the strength and accuracy of the extruded aluminum.

Cool but limiting!


#8

See my other post - I got this working on the wilson, and with my rather bent lead screws it is producing good results!

I have new lead screws on the way, and I’ll combine this and a bottom support bearing to try and keep things straight.