Delta mechanism as router

dortyuz

Hi all,

We built a large delta mechanism as a pet project in the office, with screw drives and servos and Duet3 . Now the idea popped up, which is to convert it to a router to machine wood and similar material.

Does anyone have any experience with the delta mechanism and the available cnc mods?

In case it's too wild for Duet3, does anyone have any experience with other available cnc controllers that will support the delta mechanism?

Br,

Burak

jay_s_uk

@dortyuz RRF supports both delta and router control. There is nothing stopping you controlling a spindle as that control is independent of the kinematic mode of the machine

EasyTarget

@dortyuz The issues you may encounter are not controller related; as noted above RRF will do this very well (I once used my delta for laser engraving very successfully).

The issues are likely to be mechanical, and very dependent on your build and what you plan to cut.

I (personally) do not think the delta mechanism is a good fit for the sustained sideways loading of a router. You should at least have the spindle passing through the delta effector plate to keep the bit as close to it as possible (motor above plate, chuck/collet below) and minimise the twist you are applying here.

Also calibration needs to be really spot-on to get good dimensional accuracy on delta mechanisms, depending on what you need to cut, and what it needs to fit to, this could become a issue.

o_lampe

I guess it's obvious that you shouldn't use magnetic ball joints.
But other joints have limitted angles, so you reduce the useable area. IMHO, a Delta is the worst mechanic for precise and powerful motion.
A feltpen-plotter might work, but not a router. Engraving might work, too. But there are so many better options to do that.

EasyTarget

@o_lampe said in Delta mechanism as router:

A feltpen-plotter might work, but not a router. Engraving might work, too.

TL;DR;

Thats very very much what I was thinking, other options include a Knife-Cutter (especially if you have a spare stepper to rotate a flat knife instead of a drag-knife).

or get a cheap lightweight 5/10w Diode laser online, I think the deltas speed is a really good fit for laser engraving, especially for image rastering (doing them line-by-line) and filling areas.

caveat: a full light-proof enclosure is a must, with external ventilation. Even paper and wood have glues and additives that are harmful, plastics can be deadly.
wiring and setup should be easy, chose a module that matches your motor voltage (12/24v) and iirc there are excellent wiring and config guides in the Wiki.
PS: I really mean it about the enclosure; but the good news is that diode lasers are focussed, their beam rapidly diverges, and their 'base' power is low (2.5w diode with good focus is sold as a '10w' (equivalent) module. This means a 'heath-robinson' enclosure is acceptable. Good cardboard and packing tape will be fine. Put a USB webcam in to follow progress.
PPS: I'm a big proponent of 'compressed' Diode Lasers over on makerforums.info, but also a big detractor; they are useful, and fun, but have big limitations, serious safety concerns and are then horribly oversold to the gullible online. Like a sharp knife they need a sharp user.
disclaimer/spam: I'm biased towards the above. I'm the maintainer of LaserWeb, I own two diode laser machines and am a moderator at https://forum.makerforums.info/ Which is a good place to go for help and advice on general laser, CNC and workshop mechanics and use.

o_lampe

@EasyTarget Maybe I chose the wrong words, but with engraving I meant using a small router and a chisel. Their tips are tiny and they rotate slightly offcenter.
The load to the effector would be light enough. You can also engrave metal and fumes or dust are no problem.

EasyTarget

@o_lampe said in Delta mechanism as router:

Maybe I chose the wrong words, but with engraving I meant using a small router and a chisel

No, my misunderstanding. I forget that there is more to engraving than lasers..

And you are right, there is a load of light rotary engraving that could be done.. PCB cutting and drilling springs to mind.