Grizzly G0678 8x30: Repair, Scraping and Alignment

[AndySomogyi]

Bought this Grizzly mill used about a year ago, big mistake, buying used.

I’m not a machinist, and didn’t realize the idiot I bought it from removed the way wipers to install a DRO. Ha ha, guess that makes me an idiot also for not checkin.

Huge mistake buying used, not doing that again.

Of course the ways were all gouged up, and took it apart, just planning on stoneing it, and cleaning it out.

But from the factory, OMFG what a disaster! The ways literally look like they were cut with an AXE!

Factory ways were massively gouged, and iout of flat by about 0.015”! Yeah, the big dips here are almost fifteen thousands deep.

After some scraping, with angle die grinder, got it from 0.015 dips down to basically flat and 0.001 taper.

Still needs some work but getting there

Before ways looked like they were literally cut with an axe, so big improvement

The mill doesn’t need to be perfect, just needs to work well enough to make some parts.

I have some other most posts on this, but figured I’d put them together in one thread Incase anyone wants info on these machines.

 

[AndySomogyi]

Argh!!!!

Freaking Grizzly!

I got the saddle scraped essentially flat, I go to test it on the knee and it ROCKS back and forth.

Triple check the saddle on the surface plate and it’s dead on.

So I measure the knee ways, put a test indicator on the spindle. The right side way is dead on, out of square by 0.0005 over 10”.

But the left side is FREAKING SIX THOUSANDS HIGH in the front. No wonder the saddle rocks and this is why I couldn’t Machine a square part.

So I guess I need to scrape 6 thousands off the front corner

 

[AndySomogyi]

My renegade level, Starrett 099 with a 199 vial confirms the ways are twisted badly.

Interesting thing is the that top surface is parallel with the flats, so it was ground all screwed up.

 

[AndySomogyi]

Ha ha, sweet, I can use the saddle upside down and rotated 90° as a straight edge to verify the knee .

The top of the saddle is pretty decent, basically needs about an hour or so of scraping to get it nice, but it’s flat now, just needs a touch up.

 

[AndySomogyi]

Started with about 6 thousands twist in the knee ways. It was ground that way from the factory, IDK, maybe clamped it weird?

Anyways, that explains why I couldn’t make a square part.

After a few hours hand scraping, twist is zero, and continuing flattening them. Made sure they are square with the spindle.

I don’t have a straightedge, but I found flipping the saddle upside down makes a perfect standard to scrape to. Yes, I trued the top is the saddle up on the surface plate first.

 

[markba633csi]

Now you've done it- you've made it so good you won't want to sell it.
-Mark

 

[Larry$]

Any idea how old the machine is?
Was it used as a production machine?
I've had both good and bad luck buying used. Some of my best production equipment was bought used.

 

[mattthemuppet2]

I'll be following along. I have a smaller version of this mill (6x26) and I need to take the knee off to clear out an oil passage. No other obvious issues but you never know what you might find!

 

[AndySomogyi]

Any idea how old the machine is?
Was it used as a production machine?
I've had both good and bad luck buying used. Some of my best production equipment was bought used.

Looked it up, and I think it was made in 2010, and was used by a home gunsmith guy, was never used in production.

There's no real true wear on it, all the issues with it are a combination of horrendously bad work at the factory, like with the saddle ways cut with an axe, and knee ways ground with a 0.006 twist., and stupid things by the previous owner like removing the way wipers to install a DRO.

So, a combination of no way wipers, bad and twisted ways allowed chips to get lodged between the ways, and this just destroyed them.

 

[AndySomogyi]

I'll be following along. I have a smaller version of this mill (6x26) and I need to take the knee off to clear out an oil passage. No other obvious issues but you never know what you might find!

Jim has a write up on your exact machine here:

Benchtest.Com - Workshop - Rebuilding the Grizzly G3103 Part 2

www.benchtest.com

I think if yours is anything like mine, you’ll me appalled at the “quality” of factory work.

Some tricks I’ve found are:

Have to make sure knee ways are perpendicular to spindle. In theory they should be perpendicular to column also, but since these machines don’t have a nod adjust on the head, the spindle is most important.

I don’t have a large precision square, so what I did was use a test indicate in the spindle and measure 4 points on the ways. This confirmed why the freshly scraped saddle was rocking.

I also don’t have a big straight edge, but turns out that the saddle flipped upside down and rotated 90° works perfectly and is even better because it lets to do both the ways as the same time and makes sure that both ways are in the same plane.

Other thing is if you measure / work the knee, MAKE SURE it’s loaded, I.e. z screw has compression and is holding. The knee will rock about 2 thousands / 12” when you go from loaded to unloaded.

I was working until about 4 AM last night on this, just inking the saddle and scraping the ways. I just tested it this morning and wow, got them both parallel and square to the spindle to within 0.0005 over 12”.