Grizzly G0758 mill

[dabear3428]

What are some opinions on the smaller Grizzly mill, specifically how much of an issue is the brushed DC motor? are the plastic gears an issue? any one breaking them?. the short Z height? the work envelope (X Y travel)?.

inquiring minds want to know

 

[Jim F]

I have a G0463.
1HP brushed DC motor.
All other specs are close.
Know your limitations and it will do what you want.

 

[WobblyHand]

You can do a lot of work on a smaller mill. However, from experience, you will run into the limits often. When that happens, you may want a bigger machine. I could use a larger mill than I have, table size can be a problem, but usually the biggest issue is Z height. You always can use more. When I do stuff, I need to think about if the project will fit. If it doesn't fit, it forces a rethink and often a redesign. If you are ok with that, then proceed.

For myself, I already wish that I had gone up a "machine class". I have a PM25, a starter mill. I've done a bunch of stuff with it and it works well within the work envelope. Once outside the envelope, you have to resort to other things, be more clever, or use a hand drill, or all of those things. But for the moment, it's the machine I have.

 

[Aaron_W]

Agree with the above, the vertical space under the spindle or spindle to table height can be very constricting on small mills. The G0758 has less than 9", so if drilling by the time you add a chuck and a drill bit, which will take probably 4-6" of that, and then a vise, taking another 1-2" you have little room left, so any part of significant height, you will end up having to mount it to the table which is more difficult and time consuming.

Even my little Sherline mill has 12" spindle to table.

At $1900 I'd give a good hard look at something like a G0704 or the similar Precision Matthews PM25 which would only be $400-500 more. You will get a lot more mill for the extra money.

If space requires a smaller bench mill, oddly you might look at the smaller G0781 which although a smaller mill has a few more inches under the spindle (11-1/2" vs 8.75") and it is almost $700 cheaper.

Little Machine Shop also offers some mills in the same general size class

LMS milling machines

 

[markba633csi]

Brushed dc motors are great! Good torque at low speeds
Yes the brushes wear but very slowly- figure maybe one replacement every 10-12 years with moderate use

 

[dabear3428]

Agree with the above, the vertical space under the spindle or spindle to table height can be very constricting on small mills. The G0758 has less than 9", so if drilling by the time you add a chuck and a drill bit, which will take probably 4-6" of that, and then a vise, taking another 1-2" you have little room left, so any part of significant height, you will end up having to mount it to the table which is more difficult and time consuming.

Even my little Sherline mill has 12" spindle to table.

At $1900 I'd give a good hard look at something like a G0704 or the similar Precision Matthews PM25 which would only be $400-500 more. You will get a lot more mill for the extra money.

If space requires a smaller bench mill, oddly you might look at the smaller G0781 which although a smaller mill has a few more inches under the spindle (11-1/2" vs 8.75") and it is almost $700 cheaper.

Little Machine Shop also offers some mills in the same general size class

LMS milling machines

i understand, the mill came into my possession as part of a package deal and wile it is not what i would have bought if i was going to grizzly i would have gone to the g0704 pm 30MV or the RCOG-25V for cheap, i'm just playing around with this hobby and will most likely move to something like a PM940M or maybe recondition a used bridgeport mill. right now i'm just figuring out how much time and money/time i want to play/spend in this hobby.

the g0758 was part of a package deal for an AXIOM AR8 pro+ in near mint condition for an absurdly low price. the mill and the router have been sitting in storage since the owner died and have some surface rust but almost no use,so like i said hard to pass on the package.

I'm looking into reversing the Z-axis slide to gain about 3" of Z travel has anyone done that?

I'm looking at playing around with installing a replacement motor maybe a BLDC so i can get reverse on the mill (my understanding is that brushed DC motors do not like running in reverse, anyone have any input on this?

long range i'm thinking that even with the CNC router (that can cut steel) and a larger mill it would be nice to have a small mill to work on small parts and like i said the price was right.

I have built a new shop 30X60 so room for multiple overlapping machines are not an issue (right now).

as everyone can probably tell I'm long on research and short on experience, cost is an issue but not an overriding one, so any ideas from more experienced people is appreciated.

 

[dabear3428]

I went out and bought a set of metric and imp r8 collets for tool holding to ease up the z constraints and like i said before am looking at reversing the z-axis slide. the chuck eats up almost all of my z height. i have a cheap Vevor 3" milling vise on order as well as a hold down set for the small t-slots and i'm thinking of using my AR8 to machine a mini pallet from 1/2 inch aluminum. any thoughts?
I like the fact that the spindle is R8 so tooling holding will most likely be shared with my future large machines.

 

[dabear3428]

You can do a lot of work on a smaller mill. However, from experience, you will run into the limits often. When that happens, you may want a bigger machine. I could use a larger mill than I have, table size can be a problem, but usually the biggest issue is Z height. You always can use more. When I do stuff, I need to think about if the project will fit. If it doesn't fit, it forces a rethink and often a redesign. If you are ok with that, then proceed.

For myself, I already wish that I had gone up a "machine class". I have a PM25, a starter mill. I've done a bunch of stuff with it and it works well within the work envelope. Once outside the envelope, you have to resort to other things, be more clever, or use a hand drill, or all of those things. But for the moment, it's the machine I have.

yea i hear you, was looking at the PM25 mv also, i was leaning toward the cheap RCOG-25V as my starter mill but then this fell into my lap.
over all i kind of like this small mill and will probably spend more time/money upgrading it than making stuff with it. working on installing cheap glass scales on it now so i can fit a touchDRO or even just a cheap 3 axis dro, anyone have experience with putting scales on these small mills?

BTW my wife thinks i'm crazy, the sad part is i agree with her lol

 

[dabear3428]

Brushed dc motors are great! Good torque at low speeds
Yes the brushes wear but very slowly- figure maybe one replacement every 10-12 years with moderate use

ok I thought they were limited on things like running in reverse?
in your opinion is the low speed torque better than a VFD driven ac or a servo?
the BLDC is about the same as i understand it with the benefit of better performance in reverse than the brushed version and less maintenance.

 

[Mill Lee farm]

Someone help me here. Why would a brushed DC motor not like to run in reverse? Plenty do. Tons of battery powered tools for one. Also, my DC golf cart spends a lot of time in reverse.

The only thing I can think of is if the carbon brushes weren’t beveled in both directions… but are there brushes like that? (Honest question)
If so, couldn’t you simply pull the brushes and bevel the carbon yourself?