My New Grizzly G0678 Knee Mill

[Silverbullet]

After a 1000 miles, six months of CL look see disappointments, last week I drove up to Grizzly Billingham, WA and had a G0678 follow me back home. Four pieces of black pipe, two hours of messing with a come alone (up hill driveway) I was finally able to roll this little gem off a u-haul trailer and into my garage. Now the fun and question start. I am new to this forum and will be asking for help.
So far I really like the quality of the mill but had to ask Grizzly Tech for help regarding the gibs misalignment.

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Livin large man livin large ,yupp in my opinion this mill is about the most perfect size for the small shop. if you could get it with a 40" table it would be absolutely perfect. On the alibaba dealer site I recieved some offers on some mills the prices were cheap but the shipping arrangements I never got to in my looking. One of the companies there offered longer tables on the smaller mills at a very minimum charge. I almost bought one but our financeses took a giant hit this year so no go. but someday I'll have the mill of my dreams to . So I'm glad you have the perfect mill ,now make some chips but take good care of her and she will last dang near forever. Good luck it's great ,remember saftey first but have fun.

 

[Ironken]

Seemed that the gibs never where seated.View attachment 128006 View attachment 128007

I have a G0695 with a messed up way wiper just like yours. Total noob question here.....what would I be looking for to verify that my gibs are seated?

 

[tmarks11]

Seemed that the gibs never where seated.

Looking at the pictures, I am not really sure why you are concluding that. Does the table wiggle when you pull it back an forth?

 

[DoogieB]

It's kinda hard to tell from your pictures, but if all that was wrong with your mill was loose gibs than you got a good one. Adjusting the gibs, along with tramming the head to the table, is one of those final adjustments the owner is expected to do.

The gibs exist to take-up the slack in the dovetails. If they are too tight, you wear the dovetails excessively. If they are too loose, the table flops around in the breeze. This is something you need to take some time with and get right, but the good news is that after they are adjusted that setting should be good for a long time. Assuming, of course, you use the oiler regularly.

The general approach that is mentioned in the manual is to tighten the gibs with the adjustment screws until you feel some resistance and then lock them in place. This is usually fine, but my mill had plenty of sticky Chinese cosmoline built-up around gibs and dovetails which was making the adjustment process tedious. I had to pull the gibs and clean them on the workbench with solvent. The dovetails were cleaned as best a I could with solvent, Vactra from the oil pump and moving the table back and forth to loosen-up the gunk as I didn't want to pull the table off. In the end, it might have been easier to just pull the table anyway but I got it in decent shape in-place.

When adjusting the gibs, as an aid I used a dial indicator to help measure the slop in the dovetail. Basically, you lock-up the other gibs and pull and push the table to see how much play is in the gib/dovetail you are adjusting. I dug back into my camera's memory card and found some old pictures I took of the setup I used back then.







You can see I moved the table to one edge for more leverage. And yes, it would have gone easier if I had pulled the vise, but I am a lazy bastard at heart.

The gibs were adjusted with the indicator until there was under .001 of slop and then the final gib setting was done by feeling the amount drag at the wheels. The indicator doesn't supply an absolute measurement, it's only tells the difference between one gib setting to another. If the wheel feels tight and you still see slop on the indicator, you have a problem. Plan on moving the table, saddle and knee to both extents and back again quite a few times. Take your time and do it right as you will be living with these settings for awhile.

Tramming the head to the table is basically the same as any other vertical mill and doesn't need explaining. You can and almost certainly will need to adjust the "nod" of the head and you do that by shimming between the head and column. It's a touchy process and you will need a brass shim pack from some place like Enco as you might need the .0015 increment. I actually had to come back to this at a later date because after I bought a 2" face mill I found I was getting ridges when making multiple passes cleaning-up a AL plate. After changing the shim(s) from .0025 to .002 it went away. You can see where I shimmed in this picture (red arrow). Later on I trimmed-off the excess.



And as a bonus here's a picture of checking the tram with the old Starrett 196.



The needle barely moves on this .001 indicator when swung around and that's what was needed with the face mill. The 196 isn't the most precise indicator, but the big button on the back sure makes it handy for this job. The long rod from the collet is to to keep the table at the typical Z position. The quill, saddle and knee were locked.

 

[scwhite]

A little more about the mill.

The G0678 is cousin of the 6x26 class of mills which are a knockoff/update of the Clausing 8520/30 family. These mills have been imported from Asia for a long time now for several different retailers. The 6x26, while having a few improvements from the Clausing like an R8 spindle, shares one of the problems of it's ancestor with a short spindle-to-table distance. Riser blocks are a common upgrade for this mill.

The 8x30 mills like the G0678, along with a slightly larger table, have the riser block function achieved by a different column/base. The maximum spindle-to-table distance of this mill is 20 inches compared to 12 inches for Grizzly's 6x26 model.

All the extra cast iron pushes the weight of this mill to just a hair under 1000 pounds. This mill was made in Taiwan.

A great feature of the G0678 is the 3-phase motor and speed control with a Yaskawa VFD.

View attachment 114362

As you can see, power transfer doesn't get much simpler: 1 belt and you don't ever need to touch it.

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Here's the control panel, the red button is the spindle on/off button. At first I thought it was a little weird to use an emergency shut-off button as the off, but I guess it doesn't really matter. When your first plug-in the machine there's no visual indication on the panel of power until you twist the red button and then the pilot light on the left lights. Then when you press the green button, a relay snaps in the column where the VFD is located, the digital speed display activates and the mill starts running. Speed is selected by turning the knob and this setting sticks from one session to another. Direction control is via the knob just left of the display.

According to the manual, the speed range of the mill is 200-2250 RPM. This isn't true, as it's actually 0-2250 RPM. I almost had a heart attack when I first plugged it in and it didn't run because the knob was parked at the left stop. Initially I was worried about low-end torque with this setup. No worries. One of the first tests of the mill was drilling with a 3/4" taper bit. No issues, tons of torque and the bit went right through. I've done some other screwing around with larger end mills and I'm pretty sure there's plenty of power for what the mill can handle.

With no gears in the drive train and a 3-phase motor, this mill is really quiet and smooth. VFD's totally rock!

View attachment 114364

Here's a picture showing the one-shot oiler while I was screwing around the gibs. At first my major complaint with the mill was that some of the plastic oil lines were weeping, but after some work refastening the lines they seemed to have gotten better. Compared to my old SB lathe there's practically no maintenance on this machine.

Fit and finish on these imported machines seems to vary a great deal, but I've been pretty pleased with the G0678. I've had the mill for a month now and I've been pretty much been all over it with my Last Word indicator (.0005) and I can't find anything really wrong with it. Obviously you need to do the usual cleaning, setup and tramming and I spent awhile just working with the gibs. One thing that did need adjusted was the nod which ended-up being a simple fix with some shim stock between the column and head. There's a few cosmetic scratches on the table, but it moves smoothly in all directions. There's probably a few other things I can't think of right now but nothing that makes me feel I have to contact customer support.

Wrapping-up, I'm pretty happy to finally have a mill. Right now I'm planning on just settling-in and using the mill as-is for awhile, but future upgrade plans include a 3-axis DRO and x-axis power feed.

I think you made a good choice
That mill will do anything you want to do

 

[Ironken]

Job well done! Mine works fine. On mine I had to get some 3mm key stock for a perfect fit. I'm working on a spacer to pretty things up a bit. Busy now installing 3 axis DRO Pro. Not likely to use the dial any way

I know this is a waaaay old thread but, I ordered this graduated dial from Grizz. Power feed was a direct bolt on deal with the dial along with the dial being graduated correctly for the leadscrew pitch. The part number is in the video description. Also, I scrapped the chip pan.

 

[Jbar]

So i Just Ordered me up My dro tonight... http://www.aliexpress.com/item/High...xis-digital-readout-and-3-pcs/1556577283.html

seems like a great deal.... I was going to get the TPAC do but i figure i save the extra bucks and get the 1 um scales .... i can use that money toward my VFD conversion.

I would like a dro on the Quill so i will probably order a Igage setup and adapt it. I also wanna get one for my tailstock on the lathe....

How do you like this DRO?

 

[joedexter]

When you install / use the power feed be very careful.
When you lower the table and traverse it to the left the PF will hit the green pan/shield.
Also if you move the table to the left and lower it the power feed will come down on top of the green pan/shield possibly hitting the gear on bottom of the power feed.

I did this on my G0730, dodging the bullet both times I decided to remove that problematic shield as it just became a catch all and a nuisance. My thinking is that it will be easier to sweep up chips than replace/repair a power feed.
Tomh

Good advice regarding power feed clearances and the chip pan. I drilled and tapped 1/2. Hole and put in a 5” bolt as a stop so the bed doesn’t crash into the chip pan. Lost a bit of Z travel but it not much and I can always just unscrew the bolt if needed.

 

[animal12]

I know this is a old thread but if anyone is still listening I'm wondering how thew AlliExpress or other import DRO's are holding up ?
thanks
animal