Grizzly G0758 (and clones) flycutters, big milling heads use etc.

[Flynth]

I've got a Grizzly G0758 (albeit with another name on it). I got it a couple of years ago and I promptly stripped the teeth of the two speed plastic gear...

That's the item no 112 here:

I got a new one under warranty, but I had no time to swap it so I kept using the mill on the high gear only. Few years later I replaced this gear finally so now I have low range too. I was firmly decided to never use any flycutters, or any big cutters on that mill.

However, yesterday I decided to just try a very shallow pass (10 thou deep) on some mild steel with a 3 insert 1.5in milling head with triangle inserts. The finish I got was amazing... Mirror like with rainbow reflection...

So my question is, is anyone using large cutters (anything above an inch - bonus points for single edge cutters) successfully on this mill? One has to take the headstock off the column to check the condition of the two speed gear. Until it strips completely one will not know anything is wrong. So I'm starting this thread to find out if it is something people do on this mill, or am I pushing it beyond the limit?

The answer may be "stick to 10 thou or no deeper cuts", but it is easier said than done. With unsquared work there may be unevenness that means one dials in a 10 thou cut, somewhere along the way it becomes a 20 thou cut for a bit. So I would like to hear what other owners of this mill have to say.

 

[LaVern]

Hi, I just found your post. I have a GO759 that I didn't strip the low speed gear but I did some damage to a few teeth quite a while ago. It still works but makes a quite a bit of noise. I was running a 1 1/2" 6 flute mill when it just jammed and stopped. I don't remember exactly what I did but I could see that some of the teeth were deformed. I had read somewhere else that this had been a problem and someone was manufacturing metal replacement gears for them, but I couldn't find a source for them so I just run it in hi gear mostly, unless I need the low speed for tapping or larger drilling. My first experience with stalling out the machine was while using a 3/4" single insert carbide end mill. After that I found out that when using any single flute such as a fly cutter very light cuts must be taken. As for the gears I would like to find some metal gears or maybe even a belt drive.
I bought this for my home shop after I retired because I had access to a Bridgeport when I was working and I knew I would always have a need for a mill. No comparison between the two that's for sure. Any way I have managed quite awhile now with it and will continue I suppose.
LaVern

 

[dabear3428]

Hi, I just found your post. I have a GO759 that I didn't strip the low speed gear but I did some damage to a few teeth quite a while ago. It still works but makes a quite a bit of noise. I was running a 1 1/2" 6 flute mill when it just jammed and stopped. I don't remember exactly what I did but I could see that some of the teeth were deformed. I had read somewhere else that this had been a problem and someone was manufacturing metal replacement gears for them, but I couldn't find a source for them so I just run it in hi gear mostly, unless I need the low speed for tapping or larger drilling. My first experience with stalling out the machine was while using a 3/4" single insert carbide end mill. After that I found out that when using any single flute such as a fly cutter very light cuts must be taken. As for the gears I would like to find some metal gears or maybe even a belt drive.
I bought this for my home shop after I retired because I had access to a Bridgeport when I was working and I knew I would always have a need for a mill. No comparison between the two that's for sure. Any way I have managed quite awhile now with it and will continue I suppose.
LaVern

the g0759 is a lot larger than the g0758

 

[dabear3428]

have you looked into a belt drive conversion?

 

[LaVern]

Several years ago I did try finding a conversion because I had read where others had done this on their machines. I never found anything specific to my machine so I eventually quit looking. Is there a conversion kit for the GO759 available? I would like to check it out if there is one.
LaVern

 

[dabear3428]

Several years ago I did try finding a conversion because I had read where others had done this on their machines. I never found anything specific to my machine so I eventually quit looking. Is there a conversion kit for the GO759 available? I would like to check it out if there is one.
LaVern

the g0759 is the g0704 with a dro and stand so anything that works for g0704 fits.

G0704 Belt Drive Conversion Kit

This kit offers higher spindle speeds on your BF20 style mill with a quiet and smooth operation. This kit maintains the quill function for those quick "drill press" jobs. No more broken intermediate gears. No more gear noise. Everything is bolt on, and can be installed inside an hour. - Offers...

www.minipro.com

from the g0759 manual
The Model G0759 is the same machine as the Model G0704 except the Model G0759 has a 3-axis DRO. Besides the differences noted in this insert, all other content in the Model G0704 owner's manual applies to this machine

also if you look on youtube there a lot of diy belt conversions for the g0704

 

[LaVern]

Thanks for the link. I did know that the 704 and 759 are the same. I was never able to find a conversion kit. It has been quite a long time since I looked though. I see by the copyright, and installation manual release it has been around since early 2020 at least. Thanks again for the link, it looks like a fairly easy conversion.

 

[dabear3428]

added a rolling stand to my g0758, this raised the table about 7 inches, about perfect for me

 

[LaVern]

Looks good! I made a stand similar to the one you made but a little wider and not on casters. Then I built a cabinet one both sides to use as tool storage. I may have gotten that idea form some where online. I can't remember where right now. If I get a chance in the next few days and if I can remember, I'll take a couple of pictures and post them.
LaVern

 

[dabear3428]

Looks good! I made a stand similar to the one you made but a little wider and not on casters. Then I built a cabinet one both sides to use as tool storage. I may have gotten that idea form some where online. I can't remember where right now. If I get a chance in the next few days and if I can remember, I'll take a couple of pictures and post them.
LaVern

That would be great, my plan is to use a rolling tool box set up on the right and maybe the left, the stand is wide enough to keep the cart out of the table travel space.