Second MDF machine build. Free METRIC plans!

[Metalfusion]

I don't see much love for the MDF machines here nowadays but here is my second machine that I built last fall. The main structures are made of 19mm & 12mm mdf strips that I ordered pre-cut to the correct width. Z and Y axis carriage & some other smaller parts are made from 15mm baltic birch plywood, cut with my first diy machine.

I used about 50 hours in cad planning (solidworks) and 80 hours building this thing. Total price to build it from scratch would be about 1000-1300 euros (at least here in Finland).

The machine uses chinese linear rails and ballscrews from ebay seller linearmotionbearings2008. With my 1.8Nm stepper motors and geckodrive g540 it can achieve 10m/min rapid and 5m/min feedrates.

For project log please visit: AllTheMods - Hardware Modding & Tuning Gallery

All the solidworks source files ( + edrawings ) & drawings as pdf are available here: 3 axis CNC router MDF ( metric ) by Metalfusion - Thingiverse

The project is now 95% finished. I just need to assemble the box for electronics, fix some problems with second X-axis motor, add limit switches and some cable management etc. small stuff.

[mmcp42]

nice looking build
tried to see more on your build log
but the link is a bit broken

[Drools]

Yes, very nice!
A good coat of coloring would really make this one stand out!
Machine grey or maybe green.

[Metalfusion]

Allthemods was down yesterday, now it seems to be working again.

Personally I don't really understand why people paint their MDF machines to look like metal. I know mdf releases some stuff to the air if left unfinished but it really can't be as bad as all the dust flying around.

[mmcp42]

excellent
link working a lot better today
and a very good log as well as machine!

[Drools]

The paint was more to prevent the MDF from taking on moisture that giving off fumes. I think it is important to seal MDF be it with paint or some sort of sealant.
I suppose if you live in an area that never rains or gets very minimal rainfall it might be ok.

[Jason Marsha]

Excellent machine Metalfusion. I also have a love for MDF machines as I built a JGRO a while back and it served me well.

Jason

[flyhigh]

I see you posted this when the machine was still in construction. How did it work out for you in terms of precision and durability? Thanks!

[Metalfusion]

I haven't had much time to work on the machine and so the progress has been slow. X and Y home switches are now installed and the machine is running with both motors on the X axis. I also had some problems with vibration/resonance when doing rapid moves on the X. Re-aligning the x ballscrew pretty much eliminated that thought.

The project on Allthemods.com has been updated.

I don't know yet about the precision but those cuts that I have already made came out pretty good. I should square the machine and then run some measurements to find out. The router also needs better mounting as it isn't exaclty perpendicular to the table surface.

[Metalfusion]

Version 2.1
Parts made from aluminium: Z-plate: 10mm, router mounts: 12mm, Z-nut mount: 12mm and top plate stiffeners: 6mm.

All parts were cut by the machine itself.


[nomedia="http://www.youtube.com/watch?v=Z4-Z0269LxI"]YouTube - DIY CNC 2 Aluminium z plate milling timelapse and machine breakdown[/nomedia]

[Metalfusion]

I finally got around to release the updated solidworks files and drawings that include the aluminium parts.
Aluminium upgrade kit for CNC router by Metalfusion - Thingiverse

[Metalfusion]

I did some measurements with a chinese dial indicator that has 0.01 mm accuracy.

Measuring one axis at a time I jogged the machine to a position, reset the dial and mach3 coordinates and run it to different coordinate along the axis. Then back to zero and took measurement.

X and Y axis seem to have position accuracy of about +/- 0.02 mm WITHOUT ANY LOAD.

X had backlash of about 0.04 mm.

The bad news is that these don't really matter as it is easy to inflict enough force by hand to make the dial turn +- 0.2mm.

Also, I noted that after leveling the spoilboard with the machine itself it had about +- 0.1mm variation in heigh which is pretty good for me.

However, along the X-axis, on the other side of the table the height was about + 0.5mm which could easily ruin details on V-carvings and halftone patterns that I have been making lately.

Maybe the solution is to replace more parts with ones made from aluminium


http://www.youtube.com/watch?v=REu3MBDsNWo]‪Diy cnc cut halftone pattern‬‏ - YouTube