Yet another G0704 to CNC (was CNC Conversion Grizzly G0704 V.S. G0759 )

Ball screws arrived from Chai barely one week from the date of my order! I am impressed at the quality and finish. Note that the X-axis ball nut is machined and not ground as in the past. I placed an order for the motors and electronics - went with Hoss heavy duty digital. Now I need to find a suitable enclosure.

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Question regarding the grease fittings: are these only used to lubricate the nuts before the ball screws are installed, then removed and holes plugged? I imagine they would be hard to access after the conversion is finished.

Regards,

Frank

DSC07516.JPG DSC07517.JPG DSC07518.JPG DSC07519.JPG DSC07520.JPG DSC07521.JPG
 
hi frank
who did you order your screws from I like the double nut instead if the set screws.
steve
 
Ball screws arrived from Chai barely one week from the date of my order! I am impressed at the quality and finish. Note that the X-axis ball nut is machined and not ground as in the past. I placed an order for the motors and electronics - went with Hoss heavy duty digital. Now I need to find a suitable enclosure.



Question regarding the grease fittings: are these only used to lubricate the nuts before the ball screws are installed, then removed and holes plugged? I imagine they would be hard to access after the conversion is finished.

Regards,

Frank

Frank,
Manual machines only require a small amount of lubrication on the lead screws and Way Surfaces. Your CNC'd Mill is going to require a CONTIUOUS supply of way oil to the Ballscrews, and probably to the Ways also. You got some plumbing to run....
You'll need something like the One-Shot Oil System or similar.
Here is a link to see some pics of what the oil plumbing will look like. Pics are on like page 5.
http://www.cnc-arena.com/en/forum/grahams-optimum-bf20-build--172388-5.html


Pat
 
hi frank
who did you order your screws from I like the double nut instead if the set screws.
steve

Hi Steve! Hope you are doing well. So, the ball screws came from Chai Guixuan linearmotionbearings2008@yahoo.com.cn in China. After paying for them on pay pal, they arrived in one week. From what I have seen in the past Chai used to grind down the X-axis ball nut. Now he machines it to fit.

Best regards,

Frank
 
Frank,
Manual machines only require a small amount of lubrication on the lead screws and Way Surfaces. Your CNC'd Mill is going to require a CONTIUOUS supply of way oil to the Ballscrews, and probably to the Ways also. You got some plumbing to run....
You'll need something like the One-Shot Oil System or similar.
Here is a link to see some pics of what the oil plumbing will look like. Pics are on like page 5.
http://www.cnc-arena.com/en/forum/grahams-optimum-bf20-build--172388-5.html


Pat

Thanks Pat

- - - Updated - - -

Not a good time for this to happen.

DSC07526.JPGDSC07530.JPG

Grizzly is out of stock. Is there a metal replacement for this gear?

Strangly, the spindle still rotates, but noisy!

Thanks,

Frank

DSC07526.JPG DSC07530.JPG
 
Thanks Pat

- - - Updated - - -

Not a good time for this to happen.

View attachment 75465View attachment 75466

Grizzly is out of stock. Is there a metal replacement for this gear?

Strangly, the spindle still rotates, but noisy!

Thanks,

Frank


Well after 2 more hours of machining tonight, this gear is toast! RIP

How is it, that the part most likely to fail in this machine, is seldom available for immediate shipment. Is this some kind of odd joke. First available replacements are not due until mid June. They charge $10 each for these plastic gears but I doubt if it cost them more than $.50.

I have ordered two steel gears from QTC, KSS1-36 @ $12.67 each, and will do the Hoss modification.

Regards,

Frank





 
I ordered metal gears for mine from qtcgears online. You can chart down from the home page by choosing Spur Gears/Steel Spur gears. I went with a 42 Tooth/30 Tooth set because the plan was to up the speed some from stock as well. Other ratios are possible but the key is that both gears add up to 72MM.

I have not actually installed these gears yet, so verify on your machine what mods you think it will take. It should be a matter of a couple of basic operations...

Face off part of the hub on both gears (They are too thick), cut a keyway OR drill/tap for setscrews and bore the one for the intermediate shaft out to 15mm.

I'll try and figure out the closest match to the stock ratio. (Looked it up, I get 25/47 as the closest set to what comes on the machine.)

Info on www.g0704.com under projects.

Again, note that I have not completed this myself, but it's worth looking at I think.
 
Thanks Pat

- - - Updated - - -

Not a good time for this to happen.

View attachment 75465View attachment 75466

Grizzly is out of stock. Is there a metal replacement for this gear?

Strangly, the spindle still rotates, but noisy!

Thanks,

Frank

My first gear let loose shortly after I got my machine from Grizzly. I waited 6 months for a replacement - I bought two that time, and went through both of those pretty quickly. I ended up doing a belt drive that seems to be working just fine so far.

http://www.hobby-machinist.com/showthread.php?t=18468&highlight=g0704+belt+drive
 
Frank,
Glad to see you found a metal replacement. In the future, you may want to consider a belt drive conversion as Dan mentioned.
I went through 2 motors, a speed controller board, and the plastic gears before I did the belt conversion.
I went with Hoss's Treadmill motor mount & KB Electronics KBMM-125 speed controller.
I went the timing pulley route first, but ended up designing my own 2 speed pulley set-up for 6 rib micro j series belts.
The machine is so much quieter now. You can actually talk at a normal level while it's running.
My RPM's now:
Low Speed Max 3500 RPM
Hi Speed Max 9700 RPM
If you do change your gear sizes or do a belt conversion to get more RPM's, make sure you change to some good quality angular contact spindle bearings.

BELT DRIVE1.JPG

BELT DRIVE1.JPG
 
Dan & HS, thanks. I'll be converting to belt drive eventually. It seems like a no brainer to anyone intending to make use of their G0704 mill!

Regards,

Frank
 
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