THE GRIZZ

[atomarc]

.............

(the black makes it look more official! )






(cleaned up the faces on the surface grinder, ready for fitting.......)



Cheers!

- duh grizz

[CS900]

looking good! glad those end mills are getting some mileage as well.

[atomarc]

looking good! glad those end mills are getting some mileage as well.

Cliff,

Thank you, and thanks again for all those very nice end mills, they did come in handy.

A little side note, as we dive into redoing the ball nut preload and installing a new screw with motor end bearing I had a chance to fiddle with the table in a upside down position and I found a interesting thing. The end of the table that holds the stepper motor mount is not at a perfect 90 degrees to the axis of the linear rails. It's off by a good few degrees at least. I think this could be part of the reason one half of the coupling worked its way apart..as the motor turned the coupling joint was sort of...well, swerv-a-ling, for lack of a better word. It looks like I'll have to take a skim cut along that end to make it at a right angle to the rails. I don't know why that was missed during construction.

This 'Grizz' project is turning out to be one of those things where you never actually turn out any work, you just keep screwing with the machine itself..oh well!

I think that's called "tinkeritis"

Stuart

[Fastest1]

Unfortunately that is the process for many of us. Trying to make a manual machine CNC'd takes patience.

Cliff,

Thank you, and thanks again for all those very nice end mills, they did come in handy.

A little side note, as we dive into redoing the ball nut preload and installing a new screw with motor end bearing I had a chance to fiddle with the table in a upside down position and I found a interesting thing. The end of the table that holds the stepper motor mount is not at a perfect 90 degrees to the axis of the linear rails. It's off by a good few degrees at least. I think this could be part of the reason one half of the coupling worked its way apart..as the motor turned the coupling joint was sort of...well, swerv-a-ling, for lack of a better word. It looks like I'll have to take a skim cut along that end to make it at a right angle to the rails. I don't know why that was missed during construction.

This 'Grizz' project is turning out to be one of those things where you never actually turn out any work, you just keep screwing with the machine itself..oh well!

I think that's called "tinkeritis"

Stuart

[CL_MotoTech]

More than two years on and I'm still tuning my G0704. Every time I decide that things have gotten really good I then realize that if I adjust item X it will be even better. Next thing I know, the machine is apart and I'm adjusting it. Then a few days later I'm adjusting something else. Sometimes I wish I had bought a Novakon or Tormach or something, sometimes I'm really happy with how my learning curve has progressed. I love making stuff though, I machine stuff multiple nights a week, and it's a joy.

I inherited another mill a few weeks ago. The process starts over again, this time I have 2 years of experience to build on.

[Fastest1]

CL Or you see someone else do a better job and you rip your machine back apart for the umpteenth time to "improve" it or its results ;-)

[maxspongebob]

I totally can relate. Oh well. At the moment I have another motor on order for my G0704 cause I smoked the last one which was an upgrade from the original.

At this point I just want to get it back together so I can make stuff. Last week I received a Precision Mathews lathe, PM-1228 which has already started the same process of improvements.

From what I can tell, the main reason that we are always tweaking is that the machines simply are not made very will in the first place. If the quality was better then there would be no reason to make these changes. Yes, I understand, the machines didn't cost a lot in the beginning so you can't really ask for a lot.

[CS900]

CL Or you see someone else do a better job and you rip your machine back apart for the umpteenth time to "improve" it or its results ;-)

Yup...this thread is cause of my recent tear down....haha

[Oakenfeld]

CL_MotoTech This is also great when you are constantly improving your machine, spending evenings and nights. This means that you are a big fan of it, and it's not about what kind of machine you have

[gd.marsh]

Ah Yes, the quest to 'make it better' .. Started my ZX45 conversion in 2010 & still 'making it better' today ..
'Tinkeritis' is a nice way to put it .. I've been calling myself a 'tweaker' over my obsession to improve this machine for some time now ..
But hey, not that it's habit forming or anything like that right?

[atomarc]

"Getting screwy with it"

After a trip to Dave in Arizona we now have a new STRAIGHT un-machined length of screw with nicely balled nutz =) Thank you Dave! Really appreciate it. Machined one side of the screw with the 12mm od for the bearing as well as 7/16 -20 threads. The screw was turned hard, the lathe being pretty beef cake / rigid had little problem pushing through the hard outer case using conventional insert tooling (broke a few before finding the right setup). Comparing the new screw to the old Im feeling more confident about "version 2" =) Note to self: next time you build a cnc machine, buy the hiwin screws and be done with it.



Video....



(The plan)


(spindle liner to support end of screw in lathe)




(split tube to protect the screw from the jaws of the chuck)




(setting up to cut the 7/16 -20 threads)








.................

[atomarc]

Cleaned (squared) up the ends of the table... not sure why this didn't initially happen...


(Screw installed on non motor sided)


(now its time to size up the motor side of the screw)


(some mocked up bearing OD's for the motor side of screw to see what kind of room we are working with to incorporate a bearing housing, screw will have matching 12mm OD fit for bearing. Bearing on order 12x24x6mm)




(new motor / screw coupling)




("You're wrong Colonel Sanders.... mommas' right")


(alighnment spacer in prepration for "pinning": the motor mount block to the table end plate)


(something like this..... =) )


( "till" the next time! )

[CS900]

how did you go about straightening the screw?

[atomarc]

how did you go about straightening the screw?

Cliff,

Straightening the screw was super easy...I just called Dave, aka "arizonavideo" and said "Dave, can you re-ball the nut and straighten the screw?". Of course he said 'yes', did both to perfection and didn't take a dime for doing it. Top notch kind of guy. The screw was perfectly straight.

Stuart

[CS900]

interesting. I have one of the cheapo ebay ballscrews that was originally on my mill until i upgrades to some nice thomson screws and it's also a bit bent. I was always afraid of just bending it the opposite way as i thought the pitch of the screw there would elongate a bit. Maybe he'll chime in and let us know the secret, haha.

Any ways it looks great as always!

[arizonavideo]

I use the quill on my mill.

Set the screw on a pair of V blocks about 12" apart and use a thick parallel across the vice and screw. The screws and the parallel need to be higher than the vice top plate.

Set the indicator at the far end of the parallel and rotate the screw looking for the high spots. Press on a high spot and rotate to see what you get.

Sort of like this.



This guy looks to have a IH mill like mine and you can tell he has not done many screws but he gets there after a bit of fussing around.

[atomarc]

Wrapping up "work" on revision two of the X-axis ball screw....


(trying out some tool post grinder action on the coupling side of screw)



(coupling support bearing housing in the works)





















(completed retrofit bearing housing)

[atomarc]

Clearance for the larger diameter coupling.

[atomarc]

Had to move the oil fitting hole to the other side of the nut, the new nut was opposite the original. Soild carbide drill and tap had no problems.







(grinding ball nut mounting face)



(assembly / fitting)

[atomarc]

Assembly time.....

(ballscrew after having shims fit ready for a test drive)





(getting ready to put the table back on machine)





( "Hey!! I just want a little cornbread" )





(Motor and coupling ready to go on)



(made new grease lines even length, in hopes for more even flow)



(ready to install table)



(kinda sorta like.... bobs your uncle.)