[ThinkItBuildIt]

Just joined CNC Zone, I find this site to be the best resource for gaining correct advice. And I need some of that advice now that I'm designing and building my own CNC Router. I've attached a picture of my CAD model, This design is not set in stone, and open for technical criticism and advice, I've only spent 2 hours modelling this rough design. I studied mechanical engineering, and work for a manufacturing company in Canada. I am going to have my company manufacture most of the parts for me. There are a few areas that I am having difficulty with and I will outline those as well as what capabilities I want my CNC Router to perform.

My Background
- Very experienced Wood Worker (Cabinet/Furniture)
- I do know how to operate a Metal lathe/mill
- Mechanical Engineer
- Zero welding experience

Parts I have Chosen
- NEMA 23 Stepper Motors (If I need to use NEMA 32 to machine Aluminum and Steel I will)
- 12mm Linear Guide Rails, with Pillow Bearings, for all AXIS
- 1/2'' Ball Screws for all AXIS

Machine Objectives
- I want to be able to cut Wood, Acrylic,MDF, Etch Glass, Aluminum, and thin Steel.
- Building Cost $1500-$1800
- Build Envelope, 24''x20''x4''

Areas of Difficulty
- I am finding it hard to find the right Spindle Motor that is capable of having a high rpm for wood/MDF , and lower RPM's for Aluminum and thin Steel recommendations would be appreciated. ($200-$350, might go higher if the benefits are worth it)

- The company I am working for has the capability to manufacture any sheet metal component. And since I get a major discount to get these parts produced i want to be able to use as many sheet metal parts as I can, as well as aluminum extrusions. I am going to use 12 or 10 gauge CRS as the material for these parts. My concern is that the Machine will not be ridged enough to cut Aluminum and thin steel. Most of the DIY CNC I have seen use Aluminum for there frames/gantry's. So I would appreciate any suggestions on how I can improve my design, so that it is as ridged as possible. Ignore the spindle plate on the gantry I just quickly modelled that to estimate my build envelope.

Thanks in advance for any help you guys can give me.


-This is the site that I have got my design from. This guy built an amazing CNC Router, the best I've found so far online.

GHQP Projects

[ger21]

I am finding it hard to find the right Spindle Motor that is capable of having a high rpm for wood/MDF , and lower RPM's for Aluminum and thin Steel

They don't exist, at least not without spending thousands of dollars. You can cut aluminum with a router, but steel generally requires a different spindle, lots of coolant and much more rigidity.
Remember, a CNC router is just a tool. Use the right tool for the job. You wouldn't try to cut down a tree with a screwdriver. I wouldn't try to cut sheet metal with a router.

- 12mm Linear Guide Rails, with Pillow Bearings, for all AXIS

These aren't the most rigid rails. Use at least 20mm and you'll be much better off.

I am going to use 12 or 10 gauge CRS as the material for these parts. My concern is that the Machine will not be ridged enough to cut Aluminum and thin steel.

It won't be. The gantry sides need to be much thicker. The bearings at the base of the sides should be spread at least twice as far apart as you have them. You'll lose travel distance, but it'll be a lot more rigid. As you have it, the gantry will be very prone to racking, especially when cutting near the sides.

Spend a few months reading everything you can here, and look at all the different machines, and you should get a better understanding of what you need.

This guy built an amazing CNC Router, the best I've found so far online.

You can probably find 50 machines here that are far superior to that one.

[ThinkItBuildIt]

Thanks ger21 for your feedback, I appreciate the constructive criticism and advice. Milling thin steel is out of the picture now, thats ok. Is there a spindle that you would recommend then? And can you post some links to some well designed CNC Routers? Thanks Again.