MadModder

The Shop => CNC => Topic started by: MadModder on December 30, 2016, 04:25:46 PM

Title: My desktop CNC router's first cuts
Post by: MadModder on December 30, 2016, 04:25:46 PM
So this morning I mounted the last end stop and ran the first test.
A little bit slow I guess. I could have doubled the feedrate. But hey, It's my first!  :clap:
Title: Re: My desktop CNC router's first cuts
Post by: Brass_Machine on December 30, 2016, 05:36:36 PM
Nice!

Some more info on the router? Self build?

Eric
Title: Re: My desktop CNC router's first cuts
Post by: MadModder on December 30, 2016, 06:08:32 PM
Thanks!

Yes it's a self build. Kind of.
There was this old guy (RIP...) I got to know through another forum, that made these kits.
He had a giant router with which he cut out parts for smaller ones. He sold the kits with MDF-parts (and HDF for the thinner parts), nuts'n'bolts, motors and motor controller.
We were quite a bunch buying kits, (9 years ago) but only a few ever assembled all the parts.
I helped him develop a newer version of the electronics afterwards, so I'm the only one having the upgrade.
The old ones don't have the enable signal to the motor controllers, so they're on all the time until you cut the power...
Aaaaaand my building pace has been very slow...

I modified the parts to my liking, painted them, assembled them, added some micro switches and electronics, shoved the cables through flexible conduit, and built this control/interface box:

Which has the PSU, a spindle relay, the break out board, motor controller (motor driver chips Allegro A3979SLP), emergency stop circuitry and everything else.
Connected with a parallell cable to the computer, running Mach3.

Here's a wider shot when I test the three axes.


It's as close to ABB robot-orange I could get.  :D

Three bipolar stepper motors (57STH41), M10 threaded rods as feed screws, and mostly backlash-free nuts out of delrin.
And the spindle motor is a Kress FME 800.
Title: Re: My desktop CNC router's first cuts
Post by: Biggles on January 04, 2017, 11:44:15 AM
Nice one buddy, be interested in the details. :clap:
Title: Re: My desktop CNC router's first cuts
Post by: MadModder on January 04, 2017, 01:23:33 PM
What kind of details do you want?
Spindle RPM ranges from 10000 to 30000.
Table size is 40x64cm.
X travel  is 30cm, Y travel is 49cm, Z travel is 8,5cm.
The Y length was shorter in the original plans, but my wish was to at least be able to engrave 19" front panels, and everybody agreed.
Because it's made out of wood, and the linear bearings are pipes and ball bearings, it's not sturdy enough to do metal milling. Copper laminate and aluminium engraving is the limit there I think.
Title: Re: My desktop CNC router's first cuts
Post by: NeoTech on January 05, 2017, 02:14:44 AM
If i rememer correctly those machines were called "lillasyster" mening "Little sister" - where quite popular on the other forum and one of the earliest home built cnc machines i can actually remember. =)
Title: Re: My desktop CNC router's first cuts
Post by: MadModder on January 05, 2017, 06:37:15 AM
Yes, you are absolutely right, my fellow moderator. ;)
The project threads for them were still quite active when you registered there back in '08.
Title: Re: My desktop CNC router's first cuts
Post by: Biggles on January 05, 2017, 06:34:34 PM
The construction drawings or supplier and the electronics would be helpful in reconstructing a duplicate.  :dremel:
Title: Re: My desktop CNC router's first cuts
Post by: MadModder on January 06, 2017, 06:07:30 AM
Well, as I implied by the "RIP", the supplier has gone west, faded away, and assumed room temperature.
Nobody has taken over. I believe a nephew of his helped with the cleaning of the house and has all the equipment in possession, but nobody has heard anything from him ever since. So, I guess the information is lost.
I don't have the mechanical drawings.
I don't have the schematics for the motor drivers (plug-in modules)
This will be so much fun the day the magic smoke lets itself out...

I do have the schematic for the break out board though, that the motor driver modules mount onto. I just have to convert it from Orcad to Altium. It may work well, i hope...  :scratch:
Title: Re: My desktop CNC router's first cuts
Post by: Biggles on January 07, 2017, 01:32:32 PM
OK Modder, hope it doesnt also go west.  :Doh:
Title: Re: My desktop CNC router's first cuts
Post by: MadModder on January 10, 2017, 11:17:18 AM
The import of the breakout board schematic did not go very well. It looks ok, but whatever I do all components become black opaque squares when I try to export it to PDF or something.
I found a PDF of it from 2008 though. The explaining texts are in swedish, but you'll get it anyway I suppose. The symbols are universal. :D
Title: Re: My desktop CNC router's first cuts
Post by: MadModder on January 10, 2017, 11:59:25 AM
I actually found a PDF with the schematic for the motor controller. In a mail from 2007. Yay for backups  :thumbup:
It's mostly taken fom the datasheet.
One of these for every motor, and they plug in to J3 / J4 / J5 / J6 on the breakout board.
The chip is Allegro A3979.
Title: Re: My desktop CNC router's first cuts
Post by: MadModder on January 10, 2017, 12:34:34 PM
An old photo of the first test of the boards:
Breakout board under, and the motor driver modules on top.
(http://madmodders.se/temp/Lillsyrran/Nya_BOKet_test.jpg)
Title: Re: My desktop CNC router's first cuts
Post by: Biggles on January 13, 2017, 12:50:51 PM
looks like something for the future, thanks for the pdfs.  :thumbup:
Title: Re: My desktop CNC router's first cuts
Post by: Manxmodder on January 14, 2017, 06:48:43 AM
Thanks for showing this project. I don't have room for anything like this at present time,but I really appreciate how useful an addition a CNC router would be. Great project,well done  :clap: :clap: .......OZ.