A couple of small roundtoits today.

[websterz]

While I am waiting for the electrician to return I figured I would get a few whatnots knocked off the list.

First I am starting to fine-tune my mill.  My extended Z axis rack will be here tomorrow. In the meantime I eliminated a BIG hunk of Z axis backlash:



I never understood why they put a u-joint on the fine feed mechanism...to get past the p**s-poor alignment of the rest of the system perhaps? Here's the solution:



When I change out the rack and replace the torsion spring with a counterweight I will shim the rack to get better engagement. By changing out the u-joint with a solid rod and peening the castleated clutch (I forgot to mention that) I got my backlash down from almost .070 to a much more acceptable .025.

And finally a rack for my R8 tooling, collets on the spinner endmill holders in the back:


Not huge projects but they were fun.

[sbwhart]

Hi Websterz

Interesting couple of modifications you've done there 

Have Fun

Stew

[Stilldrillin]

2 nice mods there Websterz! 

I too wondered about the coupling....... 

Fortunately, mine is still unworn. Backlash is at around .020".

Must remember your mod, for later..... 

David D

[Bernd]

Websterz,

I have the Grizzly version of that mill. I could never understand why they had the u-joint either. Kind of makes sense now that you mention it.

Nice little projects by the way.

Do you know if your lead screws are 16TPI or 20TPI? There's a mod to change them to 20 TPI from Micro Mark. Check out my website on the write up I did of the my mini-mill.

Regards,
Bernd

[Brass_Machine]

Nice. Those are 2 I have to do.

Eric

[Darren]

Wonder why they didn't do that in the first place, nice mod 

[Brass_Machine]

... and peening the castleated clutch (I forgot to mention that) I got my backlash down from almost .070 to a much more acceptable .025.

...

Could you explain how you peened the clutch?

Thanks
Eric

[websterz]

... and peening the castleated clutch (I forgot to mention that) I got my backlash down from almost .070 to a much more acceptable .025.

...

Could you explain how you peened the clutch?

Thanks
Eric

Simple really. Pull the handle assembly off the mill and turn it, castle-side up, on a hard surface like the anvil on a bench vise. Take a small ball-pein hammer and a center punch and put a small punch mark in the center of each little square face on the handle portion of the clutch. This swells the face just enough to tighten the fit, a little goes a LONG way. If you get it too tight just tap it gently in place on the mill with a mallet and remove the same way. Rotate to different positions tapping the handle on and off to make sure it is not too tight and you are done. There is a set screw in the center hub of the handle (on mine anyway...YMMV) that presses a spring loaded ball against the shaft, make sure not to lose the ball or spring when you remove the handle assembly.

[websterz]

Websterz,

I have the Grizzly version of that mill. I could never understand why they had the u-joint either. Kind of makes sense now that you mention it.

Nice little projects by the way.

Do you know if your lead screws are 16TPI or 20TPI? There's a mod to change them to 20 TPI from Micro Mark. Check out my website on the write up I did of the my mini-mill.

Regards,
Bernd

Mine are 16 tpi. I was going to convert to 20 tpi but I plan to add homebrew DRO's so the .0625 thing is not going to be an issue much longer. Aside from a finer feed I personally don't feel the need to change the leadscrews.

In addition to the longer Z rack I also have replacement nuts for the X and Y axis coming. I am going to do the anti-backlash mod to my old ones and keep the new for spares. For those that don't know that mod you take the brass nut and slit 90% of the way thru, starting from the square edge. This leaves a small portion on the radiused end that holds, what is now basically two thinner brass nuts together. Drill a hole thru one side and tap for a setscrew. The pic calls for 10-24 but I prefer 10-32, especially in brass . You tighten the screw to spread the nut apart, tuning out backlash.  It also stops the annoying harmonic whine that seems to plague the X axis.



My electrician was a no-show so I started on another long-overdue project...X axis power feed. I managed to recycle part of the Z axis fine feed mechanism, using the worm-gear end of the old U-join as a coupling to join my cordless drill motor to a spring loaded clutch for disengaging the power feed. The little bit of Chinese steel was already the right OD for the bronze bushing I had in the mounting plate so the part was good for something after all! I tossed the rest in the odd bits box for a rainy day. I will post up pics of the power feed project tomorrow. 

[Stilldrillin]

Nice nut mod! 

Thanks..... 

David D

[Bernd]

I like that mod you did to the nut. Never thought of that when I had mine apart. Looks like the next project after rebuilding/modding the Grizzly lathe will be the mini-mill.

Bernd

[websterz]

I like that mod you did to the nut. Never thought of that when I had mine apart. Looks like the next project after rebuilding/modding the Grizzly lathe will be the mini-mill.

Bernd

Not my idea...I got it on a Grizz mini mill Yahoo group.

[shoey51]

nice mods there I muct keep them in mind 

[Stilldrillin]

nice mods there I muct keep them in mind 

So very many ideas on here....... 


So little memory capacity....... 

David D

[Bernd]

So little memory capacity....... 

David D

      
You or the computer?

Bernd

[Stilldrillin]

So little memory capacity....... 

David D

      
You or the computer?

Bernd

Oi Mate!!!

I`ll av you know there`s nowt wrong wi my computer........ 

       

David D