Cnc Build Underway

[Randy803]

I know some of you ask for some pictures and I apologize it took so long to get them up. Work has begun on my CNC milling machine here are some initial pictures. One is a picture of the spindle I made taken apart on the table.

BASIC INFO
3 Phase 1.5hp motor VFD controlled for Spindle (PWM controlled by CNC software)
NEMA 34 1600oz steppers 3 Axis
USBCNC Controller and Software (PLANET CNC)
1" 1/4" column lead screw
1" X and Z Axis lead screws
Using THK Linear rails and blocks
Building Custom Anti Backlash Nuts
AIR Actuated tool changer of my own design
ATC possible in the future but not initially

More to come....

 

[Randy803]

The linear rails arrived today! By far one of the more pricey parts of this project. I am getting excited for the weekend to get here so I can get back in the shop!

 

[Randy803]

I need to take some pics as I progress but I have made progress. The Y Axis is on and the X is close to being on. It is really amazing how slowly this build is going. I spent 9 hours last Saturday in the shop and when I was done I looked back at what I think was very little for the time spent. I try to work on it at least an hour a day after work also. I will get some new pics up soon....

On a side note, I have learned to power tap on my mill without a tapping head! Makes tapping the hundreds of holes go so much faster. I know you old salts are laughing but it is new to me

 

[Randy803]

I purchased some 1.5 x 3/8 flat bar. I surface ground it, drilled and tapped 1/4 20. I then aligned as perfectly as humanly possible to the 2x2 square tube (dial indicator used) clamped and welded. The weld were spaced and each let cool to avoid warping. I then mounted the linear rail to them. This gave me plenty of meat to bolt into and added support.

For the X Axis I am bolting 4x4 1/4 plates to the y axes bearing blocks. I will then build my X axis table and align then weld.

The Z axis will be mounted in a similar fashion.

My son and I have also been wiring and soldering connectors on the step motors.

All for now...

 

[Metal]

Just a note, I have heard of people filling the tubing with sand to help absorb vibration

 

[Randy803]

Metal, that is not a bad idea, maybe even cement? Would add weight to the machine and in turn some rigidity. I would have made it out of solid bar if I could have afforded it but metal is expensive!

 

[chevydyl]

i forsee some serious issues, IF you plan on milling steel, the "column" is not near, well none of it really is going to be sturdy enough, if I were to do this I made make the column with 6 4x4 tubes, all filled, 1/4 thick, to add the needed mass needed to steady that milling head. harmonics and vibration could be a major player. what do you plan to use a table? check ebay, you can get used mill tables for around 250-400 bucks that you could adapt to your machine rails.
with 3 4x4 tubes that gives you 12" of column width,8" deep which when you mount the rails to the outer edges will give them more rigidity, and resist deflection better, you need to add a TON of triangulated tubes to the base frame, and seriously reconsider the column design, you wont regret it, weldment machines are superbly doable, check out the machine made by Fadal founder, its a small guy forgot the name of it, but its on youtube, and its a steel weldment machine
I dig the idea tho man, I was in the same position about year and half ago, I still got my screws and rails, but decided to buy and convert my Acer knee instead. ill use the hardware for something someday

 

[Randy803]

Work continues (I will post pics later today). I have the linear rails on, the table is mounted, the anti-backlash screws made, the X and Y lead screws are on the machine. The machine is so heavy now it has become impossible for me to move alone. I know some of you have stressed concerns about rigidity and weight and I have the same concerns but I am beefing it all up as I go along.

 

[Wreck™Wreck]

At the shop where I work we have a Haas TM1 2 1/2 axis mill with linear ball ways, this has proven to be a shaky machine at best, chatters if you stare at it to long, excellent for engraving part numbers however.Very slow spindle at 4000 RPMs, one would think that a small mill aimed at small parts would have at the very least a 15000 RPM spindle if not faster, small maximum feeds as well, rapid moves are 200 IPM max. Glaciers move faster.

There is also a 20 X 40 Fadal with box ways and a 10,000 RPM spindle, slow tool changes yet rigid as can be with fairly excellent accuracy and repeatability. It has a Fanuc control which no one likes.

If I were designing a mill I would lean toward the fastest possible rapids as a lot of air will be cut, depending on programming and finish requirements of course. A full enclosure is a big plus as well as a tool changer. The Fadal spits coolant on the floor even with the full enclosure.

Looks like this.
http://www.ebay.com/itm/Fadal-VMC-4020-CNC-Vertical-Machining-Center-/121982775702

 

[John Hasler]

I assume that there is a great deal of cross-bracing yet to be added.