I will keep this post as a catch all post for all machining (milling, turning, CNC or otherwise)
A list of what I need to get up and running in converting my BF20. This should be the bare minimum to get the machine CNCed.
And from CNC4PC:
C35 Breakout board : $39
6 x Limit Switches : Mechanical : $78 (3 home and 3 limit)
E-Stop button : $10
3 x Ethernet to Keling driver adapter : $4 ea
a PC running Mach3
Lots of ethernet cables to interconnect drivers.
Cables to power steppers + Connectors (DB9 or XLR). DB9 connectors are much cheaper, so bought lots of those from Digikey.
Enclosure for drivers
I currently have Hoss’ plans for conversion, so I’m not including the cost of that hardware that is outlined in those plans (things like nuts/bolts, shaft couplers, pulley/belt for Z-axis)
Video series of installing the linearmtion ball screws (here)
Just purchased the 3D models of a PM25MV (BF20 style machine) from this page. At $20 it’s well worth it. It would take me
days weeks to take everything apart, measure it, draw it. Good value.
– Milling aluminum – some feed and speed numbers to start with (link)
– Loads of great ideas on work holding small/thin parts (link)
– Tool for calculating feeds and speeds; choose stock material, tool material, and lots of other details and get feed rates (link)
– How to mill a contour part (link)
– Flood cooling table idea (link)
– Rhino to MasterCAM tutorial (link) : and more links to other fabrication and modeling tools (link)
– CNC Cookbook: great resource- this link is for building an enclosure (link)
— more interesting reading material from CNC Cookbook site (link)
– Interesting way to hold down carbon fiber sheet (link)
– Machining foam for “lost foam” casting (link)
– Lots of reasonably priced carbide end mills on ebay from seller ‘yourtoolroom” best of all, he ships out of ontario! (link)
– Kodiak Cutting Tools I have heard has decent prices; out of the US (link)
– Precisebits.com has a lot of small to tiny bits (link)
– drillciry is another great place for small bits (link)
– A canadian (local to toronto) supply store (link). Need to compare prices.
– For tools and machining supplies in general TraversCanada has a very diverse selection of metal working tools, cutters and supplies. Busy Bee Tools has a more limited selection. There is also Princess Auto with even less selection, but lots of stores and cheap prices.
– Another tool supply place out of Canada is KBC Tools. Haven’t bought from them yet, but it’s another option to check out when shopping around.
– Another online Canadian tool supply shop is KMS Tools. Haven’t bought anything from them yet
As McMaster Carr doesn’t ship to residential addresses in canada, other suppliers for materials:
– I’m using the KL23H2100-50-4B stepper motor. The torque vs rpm curve provided shows the motor putting out between 2.5 to 3 N-m which works out to 354 to 424 oz-in (between 100-400 rpm). The motor it rated at 570 oz-in, but that’s likely the torque at 0 rpm (holding torque). This is discussed briefly here.
With my converted BF20, using the stock screws (which produce 0.100″ of movement per revolution), at 400 rpm, I would be getting about 40 ipm table movement. I know that I was driving the table faster then that, and it would make sense that the sometimes the table would stall out at higher speeds. The motor torque was way too low.
So the top speed of my current machine should be set to no higher then 40 ipm (or 1000 mm/min).
– adding an air supply line is helpful. Doing it in copper makes it easy. A great thread here about copper and air lines.