Grizzly G0678 8x30: Repair, Scraping and Alignment

[Radials]

They did you oil passages just a little differently on your mill than mine.

On mine the feed groove connects all the way across to the supply holes for the Y-axis lubrication grooves below. Not that this is probably much better. I have contemplated reworking the oil supply lines on mine when I get around to taking the mill apart again to correct problems I am now noticing after using the machine fore quite some time. I have just resorted to manually applying oil in addition to the one shot to make sure everything is lubricated.

Also, the oil supply line on my knee going to the gib side for some reason delivers oil to the back side of the gib only. No oil actually makes it to the sliding surface of the gib as there are no passage ways thru the gib itself. I'm not sure how this is typically correctly done and is something else I would check on your machine.

Maybe while you're at it add a lubrication supply to the leadscrew nuts? I have contemplated reworking mine with a small manifold with a couple valves to direct all the oil flow and pressure to specific locations on the mill.

My X-axis dro is mounted to the front of the table as you mentioned you were considering. Things start to get tight with the scale but its doable.

The gib locks don't work in my finding with the scale and cover in place. It was impossible to reset the handle tab positions. I purchased resettable handle locks from MC and they work great. https://www.mcmaster.com/6848K36/



With your saddle off the machine it would also be much easier to drill and tap the mounting holes for your Y-axis scale. I milled the casting flat where I wanted these hole located as it was pretty rough.

 

[AndySomogyi]

They did you oil passages just a little differently on your mill than mine.
View attachment 370287
On mine the feed groove connects all the way across to the supply holes for the Y-axis lubrication grooves below. Not that this is probably much better. I have contemplated reworking the oil supply lines on mine when I get around to taking the mill apart again to correct problems I am now noticing after using the machine fore quite some time. I have just resorted to manually applying oil in addition to the one shot to make sure everything is lubricated.

Also, the oil supply line on my knee going to the gib side for some reason delivers oil to the back side of the gib only. No oil actually makes it to the sliding surface of the gib as there are no passage ways thru the gib itself. I'm not sure how this is typically correctly done and is something else I would check on your machine.

Maybe while you're at it add a lubrication supply to the leadscrew nuts? I have contemplated reworking mine with a small manifold with a couple valves to direct all the oil flow and pressure to specific locations on the mill.

My X-axis dro is mounted to the front of the table as you mentioned you were considering. Things start to get tight with the scale but its doable.
View attachment 370291
The gib locks don't work in my finding with the scale and cover in place. It was impossible to reset the handle tab positions. I purchased resettable handle locks from MC and they work great. https://www.mcmaster.com/6848K36/

View attachment 370292

With your saddle off the machine it would also be much easier to drill and tap the mounting holes for your Y-axis scale. I milled the casting flat where I wanted these hole located as it was pretty rough.
View attachment 370296

Thanks for the info.

My gib side way is the exact same way, with the oil going onto the backside of the gib. I’m going to drill a hole though the gib, to make a path for the oil to get to the face of it.

I’m trying to find out what size these tubing is, looks like a 4mm. I think what I’ll do is

They did you oil passages just a little differently on your mill than mine.
View attachment 370287
On mine the feed groove connects all the way across to the supply holes for the Y-axis lubrication grooves below. Not that this is probably much better. I have contemplated reworking the oil supply lines on mine when I get around to taking the mill apart again to correct problems I am now noticing after using the machine fore quite some time. I have just resorted to manually applying oil in addition to the one shot to make sure everything is lubricated.

Also, the oil supply line on my knee going to the gib side for some reason delivers oil to the back side of the gib only. No oil actually makes it to the sliding surface of the gib as there are no passage ways thru the gib itself. I'm not sure how this is typically correctly done and is something else I would check on your machine.

Maybe while you're at it add a lubrication supply to the leadscrew nuts? I have contemplated reworking mine with a small manifold with a couple valves to direct all the oil flow and pressure to specific locations on the mill.

My X-axis dro is mounted to the front of the table as you mentioned you were considering. Things start to get tight with the scale but its doable.
View attachment 370291
The gib locks don't work in my finding with the scale and cover in place. It was impossible to reset the handle tab positions. I purchased resettable handle locks from MC and they work great. https://www.mcmaster.com/6848K36/

View attachment 370292

With your saddle off the machine it would also be much easier to drill and tap the mounting holes for your Y-axis scale. I milled the casting flat where I wanted these hole located as it was pretty rough.
View attachment 370296

Thanks for the info. My gib side column way is the exact same way, with oil going on the back side. What I’ll do is drill a hole though the gib to get oil to the face.

On the saddle, I’m currently trying to figure out what size these tubing is. Looks like the tubing is 4mm and compression fitting are M8x1.0. But the threaded elbow into knee are 1/8NPT.


I think what I’ll do is try to drill some holes on the inside of the saddle that’ll interest with the oil galleries, and feed pressurized oil to them with another one-shot T junction like this:

 

[Radials]

I’m trying to find out what size these tubing is, looks like a 4mm.

Looking back at my MC orders it is 4mm. This is what I went with and it worked just fine.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[AndySomogyi]

Looking back at my MC orders it is 4mm. This is what I went with and it worked just fine.

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

Thanks,

I think I've got an idea to get oil to the bottom, without drilling any additional holes. Basically it involves extending the upper troughs to connect with the existing drainage reservoir. Going to do a bit of science, and calculate capillary length of an oil column for a given surface tension. I'll make a post when I've got the math worked out explaining it.

 

[AndySomogyi]

Turns out these mills never had any way wipers on the column ways. Considering the original ways were cut with a freaking axe and had about 0.030 wallows on them, figure the designers must have thought it wouldn’t make any difference.

So what I did was make a bracket here to bolt on the back of the knee, and attached it with some M6x1.0 cap screws. It was a real bear making sure the holes and tap are perpendicular when all you’ve got to work with is a hand drill.

So when I get the mill back together, I’m going to make a bridge bracket to bolt to this that will secure some way wipers for the column

I do have a good plan worked out for the one shot oiler, I’m going to make a video when I discuss the roles of surface tension and capillary length WRT holding a column of fluid, and how I’ve modified the saddle to deliver pressurized oil to both the top and bottom ways.

 

[AndySomogyi]

First coat of primer after bondo and sanding. I brushed this coat on because I wanted it thick to fill a few rough spots I didn’t bondo. Will sand down tomorrow, then spray a coat and final paint.

 

[jwmay]

I’m not a machinist, and didn’t realize the idiot I bought it from removed the way wipers to install a DRO

Turns out these mills never had any way wipers on the column ways.

Well I hope you called that guy and apologized for calling him an idiot. Haha!

While it's obvious this has been frustrating for you, it's been very interesting to me. Another person with a Grizzly mill that has never made a square part. I assumed it was me. Maybe it's not?

 

[Richard King 2]

You know the old saying....."You get what you paid for" right. It's to bad people don't ask about the machines on the forum before they invest money is these pits...lol But they fill a knitch ...sighhhhhhhhhhhh

 

[Richard King 2]

Andy you did a fine job after a lot of trial and error. I am looking forward to your next project. The first one is always the hardest. Like my Dad used to say. "You learn something everyday and when your done learning your dead" . I say when you think you can't learn anymore your a fool as I learn everyday from people. I recall when I was working on a Cincinnati Mill and I was under the knee installing a shaft. My apprentice Gordy was helping me by handing me tools and helping support a shaft I was having issues with getting in. I was under there what seemed an hour trying to get it in. I had to go to the bathroom and got a cup of coffee, got up and and walked over and came back 5 minutes later and the shaft was in and Gordy was waiting. I said how did your do that? He said I slid it back and then it slid forward and bingo.. I shook his hand and we both had a big smile on our faces. Thanks for showing the forum how to rebuild. Rich

 

[AndySomogyi]

Got all the parts sanded and painted, working on the saddle oil system and assembly.

I had to re-design the oil system to address some design flaws, I’m putting together a video where I talk about the physics of fluid films and columns. I just make the occasional vid for fun, I don’t have a commercial account nor will I ever, so I don’t make a cent off this content. Anyways, some interesting physics in the oil system, but it’s pretty simple to explain, will try to get to that this week sometime.

painted all the parts using red oxide primer, and catalyzed Rustoleum that I mixed myself to match this color, used an HVLP gun. Very important to first shoot a light dust coat, let that flash off, then shoot the main color coat. The initial coat creates a sticky surface for the main coat to stick to and prevents runs and fisheye.

let the parts cure for a few days to harden, then verified dimensions. Checked and the knee is still square to within 0.0002, LOL, big improvement over the 0.0300 out of square that I started with.

But noticed the flange nut at the base didn’t line up correctly, and the lead screw was binding at the bottom, so enlarged the holes with a die grinder, and not it moves smooth.
The knee moved like butter using the lead screw. However there’s a bit of backlash in the gears that I don’t like. I’ll need to find some way to shave about 0.010 off that plate, but I don’t have a surface grinder so not sure how. I checked with the only local machine shop and they quoted me the usual “we don’t want your business price”, ha ha, the clowns wanted $1000 to slap a 6” plate on a surface grinder and shave a few thousands off it. I can buy a brand new benchtop surface grinder from China for just over $1000.