Optimum BF20L CNC conversion

[JanHenning]

Welcome!

I have just started the conversion of my BF20L. I will post pictures as the project moves along.

Manufacturer: www.optimum-maschinen.de
Machine: http://www.optimum-machines.com/prod...rio/index.html

Things I have done so far:
- Made Z-axis motor mount in steel
- Made block between Isel ball-nut and headstock
- Machined the ends of the Z ball-screw
- Made more room around the upper part of Z thrustbearing, and shimed the lower part of it with thin shrink tubing to snug fit
- Mounted the original thrust bearing for Z-axis under the top plate to eliminate slack.
- Made room for the Y-axis ball-nut in the base of the mill, and modified for 200mm Y-travel
- Made Y-axis motor mount in aluminium at the back of the mill
- Made a temporary housing for the controller
- Assembled the Z-axis and tested it. Lift 95kg easily (Me)

Parts used:
www.homeshopcnc.com : RS34-960 (3)
www.homeshopcnc.com : G203V (3)
www.homeshopcnc.com : Opto-isloated breakout board (1)
www.homeshopcnc.com : 65V, 12A Power Supply (1)
www.homeshopcnc.com : MPG 101B 28 Function Hand Controller + MINI-IO (1)

www.worldofcnc.com : ISEL 16 x 05 Spindle (X/Y)
www.worldofcnc.com : ISEL 25 x 05 Spindle (Z)
www.worldofcnc.com : ISEL3 16 x 05 (2)
www.worldofcnc.com : ISEL3 25 x 05 (1)
www.worldofcnc.com : ISEL Ballnut Housing 16mm Base (2)
www.worldofcnc.com : ISEL Ballnut Housing 25mm Base (1)
www.worldofcnc.com : ISEL Ballnut Wipers/Seals (3)
www.worldofcnc.com : Energy Chain (1 for X)
www.worldofcnc.com : SRJ-30C-RD-10 X 12.7 (2)
www.worldofcnc.com : SRJ-30C-RD-12 X 12.7 (1)
www.worldofcnc.com : Grease

www.fag.com : Extra thrust bearing for Z-axis

CNC Software:
www.artsoftcontrols.com : Mach 3
www.candcnc.com: Plugin for IO and MPG 101B

Credits to my cousin Jon, who is my mentor in mechanical engineering and design, and of course to all you posters on CNC Zone!

[JanHenning]

Desktop wallpaper 1920x1200

[JanHenning]

- Y ballscrew machined to 10mm on both ends
- M8 threads and key for handwheel machined on the front end
- No bearing support in the back of Y-screw
- Mounted the ballnut on Y-screw and assembled the thrustbearings.
- Y-screw moves smooth and free of slack

Next: New support plate for X/Y ballnuts. We have to remove some of the material under the table, to make room for x-ballnut. The table is 9,5mm at it's thinnest, and 3mm have to be machined away.

Good fun!

[ataxy]

the little block with the red screw driver is it for your z axis i am wondering cuz the plan i got i got from weiss in china shows that the block that attaches to the head and the screw of the z axis is like press fited in the z saddle if you can let me know exactly how you connected the ballscrew to the z saddle i would appreciate

[JanHenning]

the little block with the red screw driver is it for your z axis i am wondering cuz the plan i got i got from weiss in china shows that the block that attaches to the head and the screw of the z axis is like press fited in the z saddle if you can let me know exactly how you connected the ballscrew to the z saddle i would appreciate

Hi,

Ball nut base

Ball nut

- The Isel base is locked to the nut with a set screw.
- The mounting holes in the base could not be used, so we had to drill and tap 4 holes.
- The block is then bolted to the base. The base fits precisely between the "tabs" in the block.
- The block fits the saddle, and we used the original screws.

There is no shims or sliding parts. Just a block that fits between the ballnut base and Z-saddle.

[ataxy]

ok thx, thats what i tought
so how do you like your bf20

[JanHenning]

I haven't tested it much yet, but it seems like a rigid machine for it's size. I will give a full review when the conversion is done, and it's up running again

[JanHenning]

A little progress with the control box tonight. The casing is from a charger that was rated at 70/90A @ 12V, so the heatsink is massive. A fan mounted over the drivers will suck out warm air. I plan to make a filtered air intake at the back.

New frontplate and mounting bracket for the two parallel interfaces will be among my first CNC projects.

[JanHenning]

Almost finnished with the conversion now.
- Made a adapter plate for x and y ballnut
- Machined room for the ballnut fixing plate in the xy saddle
- Machined away 3mm along the underside of the table
- Mounted the x and y ballnut
- Machined the ends of the x ballscrew

Next we will make a stepper mount for X, and then it's time for tuning and setup. Will start mounting limit switches this weekend.

[tmarks11]

Did you scrape the ways or did it come like that?

Beautiful job, I like the y-axis stepper motor mounted in the back; much more elegant then hanging it off the front.

Did you build the base yourself? How about a couple of pictures of it?

What type of manual mill is that? Sort of looks like a horizontal mill with a vertical attachment.

[pinussen]

Hi Jan,

Nice conversion! I have a BF20L bought from top-maschinen.de last May. Got the Optimum ball screws though and only made the motor mounts myself. Works nicely, just ca 0,05 mm backlash.

The hard part is making the G-code for my 3D-parts

Regards Björn
Stockholm, Sweden

[ataxy]

how much is the ballscrew kit for the bf20-L