[aghil4u]

hi, im new here.. so pls don't mind if im doing this totally wrong...
im working on a Portable/Foldable + PlugNplay + User Friendly + Desktop cnc router mainly for wood working..
ive done some basic google-ing/reading and come up wid a design...
iv also making a program that can interface between he user and the machine and also generate G-codes from the provided diagram
planning to use an arduino to interface between the computer and machine (mostly coz i kno lil bit of arduino)
im not much of a hardware guy so that is where i have problems and doubts

1-planing to fab it with MDF of thickness 12 -15 mm.. not sure if it will be sturdy enough
2-planning to use stepper motor of NEMA23 frame size...not sure what torque requirement would be
3-using lead screw system not sure how much backlash would contribute to the accuracy
4-what should i use for the milling head

the work plane dimension is currently set as 430x470
i want to cut wood/mdf of at least 12 mm thickness for the demo
ive gone ahead and rendered the designs ive made...attached them below

[Lee DeRaud]

Those pictures look like a fixed-gantry/moving-table design, which has a larger overall footprint than a moving-gantry design of the same working area.
Seems like that's the wrong path to take if portability is a requirement.

[aghil4u]

oh! i dont quiet understand wht model u are suggesting can u maybe show som samples? link?

[Lee DeRaud]

Ok, here's one (and a good one at that) that uses a moving table
And here is a typical moving-gantry machine

[awerby]

That looks like an interesting idea. I don't see that the moving table design would limit portability much - it takes a little more room to operate in, but folds up easier. If you're going to use unsupported rods, though, I'd say make them thicker, and use acme leadscrews. Is that an specific router you've indicated, or just something you imagined you could find? I'd suggest measuring one that you can actually buy, so you can make sure it really fits, along with the mounts that hold it in place. See if you can fit the control box in there someplace, so it would stay a single compact package. Plywood would probably be better than MDF to construct it with as well as more attractive - it's stronger and will hold fasteners much better. See if you can figure out an interface that connects with USB, so you can use a laptop to run it. But aside from those relatively minor points, I'd say go for it - and put a suitcase handle on the side.

Andrew Werby
www.computersculpture.com

[aghil4u]

thnx thicker rods and acme lead screws - will do that
Router- actually im not sure what specs to use.. advice wud b appreciated
control Box-ive made sure it fits in
Plywood- i happened to read somewhere that plywood expands with moisture and causes problem, thought mdf was better? i can get mdf lazer cut here easily so that's another reason..but cud try plywood if its comparatively that good choice.
USB interface- yes im planning to use Arduino which will be just like a printer...so basically plug and play...nd as im making a custom software that can interact with the arduino in real time interfacing shouldn't be a problem

[aghil4u]

Lee DeRaud
thnx but i really cant find a simple way to make it fold-able....so i guess id rather go with moving table system

[aghil4u]

[Lee DeRaud]

but i really cant find a simple way to make it fold-able....so i guess id rather go with moving table system

It shouldn't be any harder to hinge a moving gantry than a fixed one. Just split the sides into two overlapping pieces held together with a pivot point and a couple of removeable bolts.

[BAMCNC.COM]

Do a Kickstarter project.

[awerby]

If you seal the plywood, it shouldn't change much with atmospheric moisture. If you get MDF wet, it totally comes apart -exterior-grade plywood's more forgiving of that. But certainly aluminum would be better than either one.

Routers designed for hand operation tend to have short lives as CNC spindles, but they're inexpensive. If you swap out the bearings they come with for better ones, they last longer. And some clever people around here have come up with a way to regulate their speed without compromising torque as much as simple electronic speed controls tend to do. Look up "Super PID" on this site for a long thread on the subject. Some people here say they've had good luck with Chinese 3-phase spindles (though less of it with the cheap VFDs they typically are bundled with). But if that's too much to get into, look at "trim routers", which are smaller than the usual type.

Andrew Werby
www.computersculpture.com

[wwendorf]

Consider using Baltic Ply. It is very strong, few voids, and some places use it for some kind of mold making, I think fiberglass.

I also know some quilting machines are made of it.

Very strong stuff!

Wade