[Build Thread] Ballisticarmsco's G0704 build

[BallisticArmsCo]

It's alive!

[hoss2006]

Great job! Any 80% lowers in it's future?
Hoss

[BallisticArmsCo]

Great job! Any 80% lowers in it's future?
Hoss

Thanks Hoss! Definitely some 80's, maybe even some 0% billet lowers. I also have plans for a few different edc items I would like to produce, possibly a knife as well.

Still have some mods on the to do list.
MAD or PDB
New motor
Enclosure
Flood coolant

[Fastest1]

and the fun begins.

[BallisticArmsCo]

any ideas on the rattling coming from my x axis ballscrew?

[Connor]

any ideas on the rattling coming from my x axis ballscrew?

Sounds like grit in the screw, or possibly a ball not in the circuit. You may want to remove the ballnut and clean, and reload the balls..

[BallisticArmsCo]

Sounds like grit in the screw, or possibly a ball not in the circuit. You may want to remove the ballnut and clean, and reload the balls..

I took it apart and cleaned the balls and reinstalled and im still getting a lot of rattling. Im actually having a lot of trouble now with the x axis. I cant get over 180ipm without it loosing steps now, i was at 280ipm. Does the side you install the balls in the ballnut matter?

[Connor]

I took it apart and cleaned the balls and reinstalled and im still getting a lot of rattling. Im actually having a lot of trouble now with the x axis. I cant get over 180ipm without it loosing steps now, i was at 280ipm. Does the side you install the balls in the ballnut matter?

That's really odd. Did you put the white wipers on correctly or perhaps over tighten the set screws for the wipers? They can add resistance to the ballnut. Did you clean the ballnut too? It could have junk in the races..

[BallisticArmsCo]

Im pretty sure i put it back together correctly, same as i did the y axis and it runs smooth. I cleaned it out as best i could, im going to pull it back apart tonight and see if i missed anything. I may go ahead and order oversized balls as both my x and y are missing some, any recommendations on the size to get?

[arizonavideo]

You need to either measure the balls exactly and measure the backlash or just take a guess by feel.

Remove the seals and see if you can rock the nut. They all come with a bunch of grime in them from the factory so you have to clean the screw first before you can get a real feel of how loose they are.

I have had a bunch of screws that seem fine when they come in but after you clean the screw and nut and remove the seals you have .002" of lash.

Most of the screws are bent too.

Noise is most likely the nut or screw not being mounted perfectly square. The tighter the nut the harder it is to get them to run smooth and quiet. In fact with tight nuts it will always make a fair amount of noise. If the nut spins totally free when clean and with no seals it will have backlash unless it is mounted out of square which will reduce lash but will not use all the balls evenly under load.

Packing nuts is a problem without a good micrometer or extra balls of a known size. I often have to re pack them 3 to 4 times to get a nut tight and I have done it a hundred times and have a thousand balls to pick from. If you can rock the nut on the screw then .0005" larger is a save bet but often less is needed. The balls are almost never the same size from lot to lot.


Loosen things one part at a time and see if it quiets down, if so that is the part that is not square with the rest.

The stepper make less than 1/2 power at 150 IPM so if you have drag it might drop steps. At 300 IPM they make about 150 oz so a new mill with tight ways and tight nuts will almost always drop steps.

I would plan on 150 IMP rapids with a good driver at 50V to 60V after break in. Less on the Z if you use a 50V supply because of the higher inductance.

[BallisticArmsCo]

So i reground the ballnut to give a little more clearance under the table, repacked, and oiled with some vactra 2 and its running a little better now. Still some noise coming from it, but not like before.