I'm going to go look at a 'gently' used Grizzly G8689 mini mill.
The only issue noted is that the y-axis hand wheel is broken. I'm not sure how broken. He says the mechanism works fine, just the wheel itself is broken.
It comes with no tooling or parts other then the machine itself. I'm not sure if that means it will not even have the collets or drill chuck that originally came with the machine or not.
Three questions:
Generally, how available and costly is MT3 tooling (drill chuck, collets, vice, etc.) for this size of mill?
Is a replacement hand wheel easily available?
And lastly, what would be a decent price range? I don't see used mini mills for sale in my area to get an idea on price and I'm not sure what the basic tooling you would get with a new machine would run as a separate purchase.
Thanks!
Question on price and ease of finding tooling for a G8689
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TheGreenMan
- Posts: 24
- Joined: Tue Feb 23, 2016 12:57 pm
Re: Question on price and ease of finding tooling for a G868
Grizzly still sells the G8689 new, you may want to have a look
on their site, user manual and parts manual are available there too.
on their site, user manual and parts manual are available there too.
Re: Question on price and ease of finding tooling for a G868
The latest issue of "Wood Workers Journal" has a Grizzly '10% off orders over $200' coupon stuck to the front cover. May not be on newsstand issues, though. Might or might not be useful in this instance.
--earlgo
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
Re: Question on price and ease of finding tooling for a G868
Grizzly has very good customer and machine support.
They probably can send you a replacement hand wheel, and all the tooling you need.
~RN
They probably can send you a replacement hand wheel, and all the tooling you need.
~RN
Last edited by NP317 on Fri Sep 09, 2016 10:25 am, edited 1 time in total.
Re: Question on price and ease of finding tooling for a G868
If the handle is broken, then unless the handle was removed, broken and re-installed, then the screw, nut and other parts would have taken some impact.
Be sure to run everything thru its complete range of motion and pay attention for any binding.
Steve
Be sure to run everything thru its complete range of motion and pay attention for any binding.
Steve
Re: Question on price and ease of finding tooling for a G868
MT 3 tooling isn't that tough to find, but if it were me? Since you don't have any tooling yet I'd seriously consider buying a replacement spindle to fit that machine from Little Machine Shop in California. I've had a MT 3 taper mini mill and my larger mill has R8. There's no compareision between the ease of tool changing. I'd never willingly go back to any mill with an MT taper unless it was something very special like a old watch maker type jig borer. Plus if you go to a larger mill in the future it's likely it would have R8 as well.Yes there's other tapers that are used and superior to the R8, but almost always in fairly large mills at a Bridgeport size or larger. If it's not made in R8 you probably don't need it, and I don't recall seeing anything in the MT taper that wasn't available in R8 as well, and almost always at a cheaper price. It also depends on your location. In the U.K. MT 3 is easier to find. In North America then R8 is.
Unless you built an ejection set up for the mills draw bar, MT tapers require much more tapping on the end of that draw bar to make every tool change. That's never good for the spindle bearings. You could add a ER collet chuck and collets and get away from most of that, but it does eat up some important Z axis room and that can quickly run out on these small mills.
And very much agree with Steve, if that handwheel got broken while it was on the machine the screw and maybe the nut took at least some impact and the end of the screw may or may not be bent. The rest of the screw and nut is also an unknown until the screw is checked for straightness.
Price, that depends on just how gently it was gently used. The broken hand wheel does lower the price a lot since he could order the parts as well as you can if he was at all serious about getting a good price for it. With the unknowns about the machine then half the new price is as high I'd go even if it looks almost unused. But then again I don't need or want another mini mill. The biggest thing to remember is that the buying price for a mill is almost incidental. The tooling costs quickly add up to as much or far more than the cost of the mill. Without any tooling at all then 1/3 of the new price.
It's not an impossible job, but improving the column rigidity on these mills is a constant thread starter on a lot of forums. It's an area that really does need improving over the original design. The heads plastic gearing used as a sort of shear pin is also a problem area and it could be changed over to belt drive with a kit that's sold for about $100. Little Machine Shop did or does sell one. Or go to metal gears but you then lose some of that protection during a serious crash. Kept within there limitations these mills are ok but they can't ever be really pushed. The head at least with an R8 taper might be the best part about them if there not pushed harder than the plastic gearing was designed for. The rear column is frustrating and tough to get properly trammed in.
Unless you built an ejection set up for the mills draw bar, MT tapers require much more tapping on the end of that draw bar to make every tool change. That's never good for the spindle bearings. You could add a ER collet chuck and collets and get away from most of that, but it does eat up some important Z axis room and that can quickly run out on these small mills.
And very much agree with Steve, if that handwheel got broken while it was on the machine the screw and maybe the nut took at least some impact and the end of the screw may or may not be bent. The rest of the screw and nut is also an unknown until the screw is checked for straightness.
Price, that depends on just how gently it was gently used. The broken hand wheel does lower the price a lot since he could order the parts as well as you can if he was at all serious about getting a good price for it. With the unknowns about the machine then half the new price is as high I'd go even if it looks almost unused. But then again I don't need or want another mini mill. The biggest thing to remember is that the buying price for a mill is almost incidental. The tooling costs quickly add up to as much or far more than the cost of the mill. Without any tooling at all then 1/3 of the new price.
It's not an impossible job, but improving the column rigidity on these mills is a constant thread starter on a lot of forums. It's an area that really does need improving over the original design. The heads plastic gearing used as a sort of shear pin is also a problem area and it could be changed over to belt drive with a kit that's sold for about $100. Little Machine Shop did or does sell one. Or go to metal gears but you then lose some of that protection during a serious crash. Kept within there limitations these mills are ok but they can't ever be really pushed. The head at least with an R8 taper might be the best part about them if there not pushed harder than the plastic gearing was designed for. The rear column is frustrating and tough to get properly trammed in.