BF20 / wmd30 / Grizzly 0704 CNC Conversion

[ellik]

A buddy of mine is getting a BF20 clone from Busy Bee (Canada) and asked me to help him with the conversion. I already have converted my X2 and based on that experience and the size difference between the two mills I came up with the following recommendations for him. I might be going a bit overboard on the X and Y axis steppers (bigger is not always better) but I think the Z axis stepper needs to rather beefy as the plan is to use the original acme lead screws, to begin with anyway. I hope to have the mill in house this weekend and will post pictures as soon as possible.

I know Hoss and maybe others are starting a similar project so I was hoping to get some feedback on this.

Mill
http://busybeetools.ca/cgi-bin/picture10?NTITEM=CT129N

Brake-out board $109
http://www.cnc4pc.com/Store/osc/prod...products_id=46

3 G201 Stepper Controllers
http://www.geckodrive.com/product.aspx?c=3&i=14458, 3*$114 = $342

Z axis stepper, Nema 34 960 oz/in Stepper Motor Model #RS34-960 $129.00
X and Y steppers, Nema 23 570 oz/in Stepper Motor Model #RS23-570, 2*$73 = $146
http://homeshopcnc.com/RSstepperMotors2.html

Power Supply, KL- 7212 Unregulated Power Supply 864W, 72VDC/12A, $149
http://www.kelinginc.net/SwitchingPowerSupply.html

Thanks for stopping by,
EK

[sfrankland]

If I am going to make a first post it should be here in my mills build thread. Cannot wait to get started.

[ellik]

Guess what I got in my garage... I wish it was mine.
Got some cleaning to do and then start designing the motor mounts and make some chips. Cant wait to see this one CNC'd






The Saddle is very low profile, it might prove difficult to fit a ballnut in there. Notice the tapered gibs...



Compare the table size and finish difference between the BF20 and X2...

[ellik]

I spent the weekend cleaning and taking measurements for modeling. Here is a little preview.

[sfrankland]

I have decide to go ahead and replace all three axis with ballscrews and mount the y axis stepper in the rear. I figure in the long run it will serve me better this way.

[sfrankland]

ellik's cad drawings of the rear mounted stepper setup





Parts were dropped off today to get machined for the rear stepper and ballscrews have been ordered.

[sfrankland]

Here are a few pics of the tear down.















A few solidworks drawings

[hoss2006]

Looking good, teamwork yeah.
I figured the rear mounted Y stepper would be pretty easy, will look more like a VMC too.
Hoss

[BobWarfield]

That base wants to be filled with epoxy/granite. You know it does!



Cheers,

BW

[sfrankland]

I really wish I lived closer or this would be a group build but a ocean and a 1000 or so kilometers makes it a little difficult to work on this together.

Ellik made a few modification to the X-axis to increase travel from 11" to 12 5/8".

[mattbesquare]

my 0704 is on order. so i am following this like a hawk.....

[sfrankland]

Column and base back from milling. Ballscrews are ordered and should be here in the next two weeks I hope. The steppers are still not ordered but then again I am not 100% sure what to get. Many options but I want something that will do the job and won't have to be replaced and time soon. I would rather get it right the first time around.