3D printers and CNC Routers

[jeb92]

hello everyone,

i have been interested in owning a CNC router for a very long time have read as much as i can about them before i actually go and build my own.

In my search for knowledge i found of 3D printers that caught my eye and was amazed by them!

i decided that i want both a CNC router and a 3D printer

Since i am building my own i was curious as to whether i would be able to make a hybrid of a CNC router/3D printer. To me it seems like they both run off the same mechanics and use gcode, the only difference is the software, and of course, the tool being used.

Would i be able to have one set of motors and use the same machine to do both as long as i have the proper software.

Here are some of the 3D printer sites i found:
RepRapWiki
Fab@Home - Make Anything | Fab@Home
MakerBot Industries - Robots That Make Things.

Any comments or help would be appreciated

[Dean448]

I have both. I built the cnc router last year and just finished up a bootstrap mendal this summer. I used the router to build the mendal. In my experiance the cnc router was very easy if you go with all the popular components. Mach3 has been amazingly reliable compared to what it avaiable for the reprap. G540 is rock solid, etc..

The challenge with the reprap was the extruder. I believe that a number of companies are trying to sell this stuff. They give you an idea how it works (because its all open source) but I found that these extruder designs don't work. I think they hope that you get frustrated and buy their product.

The software needed to reliabily drive the hardware was the next big problem. I eventually got ReplicatorG to work. Be ready to do a lot of searching to find key tips on free open source software.

I won't recommend trying to use the software/hardware currently on the market (except EMC2) that is designed for a 3D printer on a CNC router of any size. It extrudes at 31mm/sec which the router is capiable of but the controller is very crude compared to Mach. Jerks the steppers around is best I can descrbe and I really don't trust it to drive a gantry machine safely. Again EMC2 might drive both machine but I'm not a Linux fan.

Good luck
Dean

[Jay C]

Dean, wish I had asked the same question. I have the Mendel built, wired and working, but for the life of me I can't make a decent Wades worm feed. So I'm buying the new extruder model from Makerbot. Frustration describes the software and extruder well

[Dean448]

I like many, think the stepper based extruder is the best route but Wade controls his rig with Linux EMC2. In replicatorG using code based on Skeinforge, it actually doesn't pause anyware for the extrustion process. So I simply set the rate on my extrusion stepper at about .56 rpm (that depends on the hobbed dia, nozzle dia, material, ect) using an external stepper driver where I can set the rate. All I use the extruder board for is to control temperature. I tried driving it directly from my Techzone hardware but couldn't get it to work without diving deep into firmware.
I simply put a relay on the fan output which is on/off for the stepper & fan so you don't have to be around when it finishes.

By the way for the 39 tooth wades extruder gear... a post using Skeinforge produces about 80K lines of code. To my earlier post all those short segments would drive a router with an mass crazy.

BTW I think that Reprap would draw enough interest to be a new topic for this site.
Dean

[jeb92]

i agree Dean. i was actually surprised to not see any 3D printing topics when i posted this originally. we should start up a 3D printing topic with all the popular DIY printers

From what i have gathered from you guys. building a 3d printer/router is plausible but probably wouldn't work out to well because of the size that a router cnc would require. is that right?

[Dean448]

I wouldn't say its impossible considering all the varites of CNC routers. These printers are more like plotters in that they have small steppers that are generally belt driven. Belts don't transmit much torque. Screws transmit torque but are slower and tend to wip over long lengths at high speeds... lot of trade offs depending on what you want the machine to do. I see more similarities between a laser cutter and a 3D printer then a wood router.

I'll bet that you could find a small cnc router with nema 17's designed to run a very small cutter that might double for a 3D printer. If you were only interested in cutting soft woods (or foam) with small cutters you might get it to work for both. Then you have to deal with the extruder vs cutter and the hardware that runs both.. it might end up being more of a hassle then its worth.
Dean

[jeb92]

Alright thanks for the input. i thought i would try to save some time and money, but i think it would be better to have separate machines so that i dont get frustrated and drop it all together haha.

Now i just need to decide which one i want more haha

[Jay C]

From experience, I'd say go CNC router first

[RedskinsJBS]

Also from experience, I'd say go router first.

I helped with design of the Darwin, the first in the line of RepRaps. It was a cumbersome and very fiddly device, but it got the job done. The newer Mendel is a much more elegant and stable design.

I don't yet have a router, but here is my reasoning for building a router first. Its quite simple and it goes along the lines of why the RepRap project exists. Your router can build your printer for you! Yes you will need the motion control and the electronics, but a router can easily make the parts for a CNC FDM printer.

However, a CNC FDM printer cannot make the parts for even a small sized router. The forces that nearly every CNC router is exposed to are much too great for the pile of plastic parts that would add up to be whatever sort of router you could design.

As was stated earlier, 3D printers are essentially plotters with a Z axis. If you are capable of building a square box, then you can easily fill it with a 3D printer (see the Makerbot CupCake).

The Makerbot Cupcake was designed to be cut out with a laser cutter and the plans are freely available online: CupCake CNC.

I'm sure that one would be able to alter the design to be able to cut it out with a CNC router.

Hope that this helps with the decision process.

Jay Swift

[Dean448]

For me the router was the better tool to build. However you have to consider budget and space constraints. For a decent machine that I built, cost me around 2500. It takes up a 3'X4' area right in the middle of my shop. The reprap mendal might be about 600 and is hanging above my router and is very portable.

They are both programmable and both can build things but very differently.

I havn't found many sites containing projects build by a cnc routers however
one of my favorite sites for the printer is Thingiverse

I'd recommend taking a look and checking it from time to time.

Dean