Hoss's G0704

[hoss2006]

I have both the BF30 (not the Optimum BF30 but Weis-like BF-30) and the BF20. I've had the BF20 since 2005. (they've been around here in Europe for quite some time) The results you're talking about are normal.

Like Hoss said use a four flute for side millling. Generally I take the side cut and then leave the settings as is and reverse ( not the spindle) the cut so it does a finishing climb milling cut. You'll notice that the cutter has deflected during your first cut because it takes off another couple of hundreds of mm when you move the bed back. Even if you run the cutter back and forth several times side cutting with the same setting it keeps cutting a tiny bit because of deflection. This is not necessarily the result of the machine but for a large part caused by the deflection of the cutter itself. The result is often much better. I also use this trick when I really need accurate dimensions and I'm off some hundreds of mm. Generally, I also use the biggest diameter cutter that fits in my machine for sidecutting. The bigger the cutter, the more rigid it is.

On Aluminum you want flood or at least a generous amount of WD40 to get a relative smooth side cutting finish. Aluminum is sticky and tends to stick to the flutes and get in the way while cutting, resulting in a poor finish. Blowing the chips with air is also a great help. Don't however, expect the finish you get with flycutting. It's going to be somewhat wavy. Just except it to a degree.

David

Excellent advice, thanks for sharing.
Hoss

[diyengineer]

Looking goood!!

[mrcodewiz]

...
A couple pics below show the ballnut pocket needed in the saddle, I used my RF45
but it doesn't have to be pretty.
Just have at it with a grinder or use an endmill in a drill press and make a bunch
of plunge cuts to get the stock out of the way.
The dimensions are not critical.
...
Hoss

Just in case anyone was wondering. I had to do something similar to mine and I did it on the X2 so if you have one available, it will fit on the table.

[duzallcnc]

Hi Hoss,

Are you using the stock retaining method where the two bolts just put pressure against the ballnut mounting block?

Thanks
Sean

[duzallcnc]

Hi Hoss,

I looked at your dimensions for the X ballscrew mod. I have a G0704 from Grizzly but your measurements would result in interference on my machine. I think the difference may lie in the clearance / height of the space under the table where the X ballnut will reside. My height before milling a pocket for the ballnut is .800 , I am guessing your space may be closer to 1.00
or your Roton nut is smaller than my Thompson which is 1 in sq + the ball return on one side. I compared my measurements to yours and they were the same except that I had the pocket at .260 deep and a small slot to clear the ballscrew. If I remember correctly this gave around .050 clearance between the ballnut and the table. My table has a 3 stamped in the right end. Hope it helps.

Sean

P.S. would you mind to post the Gcode for the oil slots?

Thanks

[hoss2006]

Hi Hoss,

I looked at your dimensions for the X ballscrew mod. I have a G0704 from Grizzly but your measurements would result in interference on my machine. I think the difference may lie in the clearance / height of the space under the table where the X ballnut will reside. My height before milling a pocket for the ballnut is .800 , I am guessing your space may be closer to 1.00
or your Roton nut is smaller than my Thompson which is 1 in sq + the ball return on one side. I compared my measurements to yours and they were the same except that I had the pocket at .260 deep and a small slot to clear the ballscrew. If I remember correctly this gave around .050 clearance between the ballnut and the table. My table has a 3 stamped in the right end. Hope it helps.

Sean

P.S. would you mind to post the Gcode for the oil slots?

Thanks

The Roton nuts are 1 inch square too, with the screws in the original end brackets, I still have about .050 under the nut in the pocket.
One of those variances folks will have to take into account between machines. It's not a critical bit of machining. Thanks for the info.
I can give the dxf for the oil grooves, same for all 4 flats on the saddle,
haven't done the z yet, it'll be different.
The Phase 2 prints are done.
http://www.g0704.com/phase_1_and_2_cnc.html
It's gonna be a good while before I move on to Phase 3,
I want to have some fun just using the mill under CNC for a while first.
Need to get it all plumbed for oil and then build a console, a Voight-Kampff machine clone perhaps.
Hoss

[hoss2006]

Just in case anyone was wondering. I had to do something similar to mine and I did it on the X2 so if you have one available, it will fit on the table.

Good point.
Probably a lot of us have and X2 to handle some of the work
now that we upgraded to the 0704.
Always nice to have a 2nd machine.
Hoss

[hoss2006]

One more rapid test.
This isn't a baseline test with Mach 3 at the minimum 25000 Hz kernel speed like before.
I ran a cable to a good PC and jumped the kernel speed to 45000 Hz.
With the driver at 1/8 microstepping, 300 IPM came easy with the column still on the table.
Good enough for me.
Here are the electronics used.
570 oz/in Nema 23 Stepper motor, Keling KL6050 driver, 48V.
http://www.g0704.com/G0704_electronics.html
Motor tuning settings - Steps Per 8000, Vel. 300, Accel. 60.
Also shows the motor on the left side of the table as an option.
Hoss

[nomedia="http://www.youtube.com/watch?v=3639EIzUc6w"]YouTube - G0704 Max Realistic Rapid Speed[/nomedia]

[tmbg]

Hoss,

do your phase2 plans include information on AC bearings for the ballscrews, where to buy them, and prints for bearing blocks and preloading them properly?

If so, how much are the bearings that you're recommending?

[hoss2006]

Hoss,

do your phase2 plans include information on AC bearings for the ballscrews, where to buy them, and prints for bearing blocks and preloading them properly?

If so, how much are the bearings that you're recommending?

Yes to all, the most expensive AC's are for the Z axis at $8.43 for Nachi's.
Hoss

[tmbg]

Excellent. I placed an order for a g0704 and a
G0602, but they're both backordered. I figure I'll snag the plans from you so
I can keep the wheel reinvention to a minimum. Intending to go with roton screws and oversized balls. I have a Bridgeport clone and an old
Clausing 12x40 lathe so the conversion should be a piece of cake.

[mwood3]

will the precut stock kit come with the phase 2 plans as well? the link goes to the phase 1 and 2 plans together just didnt spell it out in the stock kit link...