Info sought...

Hi all,

I'm away from home at the moment but sketching out a design for a universal CNC type machine, was pondering making it so i could fit a hot bed and bolt on an extruder.

Could anyone fill me in on what the step resolution for X, Y & Z is or should be for a decent 3D printer, also what sort of top-end speed is needed in X & Y??

Many thanks

Dave

Edited 1 time(s). Last edit at 02/08/2016 02:58PM by Davek0974.

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

Anyone??

---

Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

I'd say that resolution in Z should be at maximum 0.05mm otherwise it will be too difficult to set up the first layer (zero) distance. For X and Y you could probably get away with 0.1mm or even a bit higher. Maximum X & Y speed is unimportant, though I'd say anything slower than 40mm/s is likely to cause frustration over the long print times. The Ormerod has a max speed of around 100mm/s, though the limit is caused by the extruder skipping rather than X & Y travel limitations, so the thicker the layer the slower the max. speed (because thick layers need more plastic and so higher extrusion speeds). With 0.25mm layers and a 0.5mm nozzle my Ormerod's max print speed is around 70mm/s. Smaller nozzles need a slower speed, thinner layers can support higher speeds.

Dave

Edited 1 time(s). Last edit at 02/10/2016 07:29AM by dmould.

Brilliant, many thanks, just what i needed

The machine i am contemplating has a Z res of 0.025mm and X&Y of 0.0375mm per step.

Limited in height but thats the way it goes, probably max 100mm tall maybe 125mm.

But a big area of 400x500 to play with


Dave

---

Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

Quote
Davek0974
Brilliant, many thanks, just what i needed

The machine i am contemplating has a Z res of 0.025mm and X&Y of 0.0375mm per step.

Limited in height but thats the way it goes, probably max 100mm tall maybe 125mm.

But a big area of 400x500 to play with


Dave

Sounds do-able so long as the motors can be interfaced to a FFF controller such as the Duet. Trying to adapt its existing CNC controller so that the extruder is driven correctly is not likely to be easy. You will need to ensure that you slice with layer heights that are an exact multiple of 0.025mm to avoid banding, but that's no disadvantage.

Dave

I have a spare axis and motor drive so as long as it uses the correct rel/abs moves i think I can just fit a suitable extruder and try it.

I did have a go before i got my Ormerod, this was on a small plasma cutter table, and it did work but i knew nothing of heated beds, good or bad nozzles, layer heights etc so i gave up, i did manage to print a small nut though and still have it somewhere

The nozzle was a cheap lump i got off ebay but it blocked all the time - i now know this was because it had a too fine nozzle, no PTFE liner and a weak-ass motor, still got it in the junk box.

That was all controlled via Mach3 software so I am confident it can be done.

Dave

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

If you mean that you intend to use a spare axis drive from the existing CNC controller, that is not likely to work because I doubt that the CNC controller will have firmware that is suitable for interpreting the extrusion commands, though I may be wrong.

Dave

Hmm, now I know I had this working before on Mach3, I have the video to prove it somewhere

From what I recall, it was simply a matter of making sure Slic3r and Mach3 both used relative movements for the axis connected to the extruder motor so it continually moved forwards only, don't quote me on that though

But it really did work, just hampered by useless nozzle and lack of knowledge.

---

Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.

This Company modified their CNC router to act as a 3D printer.
They have a PDF User Manual for it here.
I think the info should be useful. It covers the use of Mach3.

Thanks for that, nice little pdf there

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Another RS Ormerod Mk1 meets the world

Retired now but I used to make....
CNC Machined Mk1 aluminium bed support plates for the Ormerod
CNC machined X-plates and ribs for Mk1 & Mk2 Ormerods
CNC machined bed support arms for the Mk2 Ormerod.
Dual Hot-End heatsink blocks.