best threaded rod frame ?

I am looking at building my 2nd printer and whould like to make if from threaded rods (I have LOADS laying around) ive had a look at the prusa mendal but is the a better threaded rod frame that will give a bigger build space or is more rigid ?

Thanks Nikki

Bigger diameter is stiffer but in my opinion aluminium extrusions are more ridgid and easier to build a frame out of, scale it to suit or change at a later date. I'm considering a rebuild or second printer myself and aluminium extrusions is the way to go. There are parametric builds out there based on alu extrusions.

Prusa I2 uses more threaded rod but has lower Z height and is less rigid laterally. The Prusa I3 uses much less threaded rod but is more rigid laterally (in X), and less rigid along the Y axis. Fortunately there are many examples of Y axis stiffeners for the I3 using threaded rod. I would think that an I3 with stiffeners would be a good bet. I did see someone came up with an I3 type frame using threaded rod instead of board but I can't find it now. I think it was on Thingiverse. If you really want to use up the threaded rod you could try building a darwin

You could also look at the Reprappro mendel 3. It is basically a Prusa I2 that they modified to use a vertical X axis and Bowden extruders so it would be easy to add multiple hot ends.

Or go ahead and do up your own. It's kind of fun but very time consuming. Most current kits have moved away from full threaded rod frames in favor of either aluminum extrusions or sheet wood/sheet metal.

Hi guys,

Actualy threaded rods frame fight to be at the first place
of weak frames with acrylic sheet frames... Just be aware about that.

Forget the original Darwin and Mendel threaded rod frames,
if they're not built a lot these days, this is for purpose.
You want very big diameter to avoid issues.
There's no existing design for large diameter threaded rods frame.

If you realy want to use threaded rods, use them for what they're built to do : tightening.
To simplify a lot, threaded rods are springs, and you want some elasticity to tight well.
But that property makes it weak for making frames.

Otherhand, using threaded rods to put materials or tubings in compression is wise !
A thin aluminium tubing or a PVC pipe are flexible. But if you thighten their ends in compression,
they become much more ridgid. You can insert threaded rods into boxes to makes them stronger by compression.
Or use threaded rods to assemble a stack of offcuts firmly to make strong beams or structures.

To me, you can find some sheet material on the shop too for an Itopie, it will be simpler and better.

++JM

Edited 1 time(s). Last edit at 11/04/2015 09:53AM by J-Max.