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View Full Version : Thoughts on the Grizzly G3102 Benchtop Knee Mill



mayfieldtm
07-01-2008, 04:02 PM
Any of you-all own a or have any thoughts on the Grizzly G3102 (or equivalent) Bench Top Knee Mill?

I'm wondering what kind of performance I might expect with it like maximum practical drill hole in mild steel, types of finish, smoothness of the ways and typical tolerances and any mechanical issues?? (hows the tramming?)

I'm having a hard time trying to describe my expectations...
I must admit that the vast majority of the time, I'll be prototyping small 2D Forming Dies about 3" x 2" x 1/8" thick in mild steel or in O1 or D2 Tool-Steel, using a small 1/8" Dia. Mill Cutter. I had some good recommendations on some smaller and (in my opinion) better suited machines form the CAD_CAM_EDM_DRO group. My intention was to dedicate a machine to this specific task. My boss nixed that idea and would like something larger.
I would like to include in my new proposal some thoughts on the machines real capabilities. I was adamant that this is not to be a Production machine. We have plenty of full sized CNC's dedicated to Production and Tool making.

What I will be doing is immediately converting the machine to CNC (I have experience doing this in the past), installing X-Y Ball Screws driven by Servos and possibly a Step Motor on the Knee, Use commercial Drives and Isolation, build a Brute Force Power Supply and run the whole dang thing with Mach3.
I would look into either increasing the spindle speed a little or build a high speed attachment for really small bits. I would rather have a gear-head, but, then again, I would like to have a hotter wife too.

I'm thinking a total of $5000 will be my upper justifiable limit.

Thanks in advance for you ideas and advice.

Tom M.

What I'm thinking is to grab Evens new machine when he is not looking!
Sweet unit, I hope he offers plans on it sometime.

tmarks11
07-01-2008, 07:10 PM
you might try asking some of the folks over at the yahoo 6x26 group (or reading their archives), as there are quite a few owners over there:

http://groups.yahoo.com/group/6x26millingmachines/

Try this review here (which convinced me to look for a different model):

http://www.benchtest.com/w-grizzly_mill_revisited.html

Here is the build log of a gentleman who converted a warco 6x26 (look at the second page for some pictures of how he drove the quill with a ballscrew arrangement):

http://www.cnczone.com/forums/showthread.php?t=11374

My understanding is that this is a difficult mill to cnc, sometimes the solution is almost a rube goldberg approach to drive the quill (which only has 3.5" of movement).

Conventional wisdom is that it is better to convert an RF-45 clone. The Grizzly G3102 is expensive now (compared to last year); you could buy an IH manual mill for the money and convert it later.

doctor demo
07-02-2008, 01:21 AM
[QUOTE=mayfieldtm]Any of you-all own a or have any thoughts on the Grizzly G3102 (or equivalent) Bench Top Knee Mill?

.

What I will be doing is immediately converting the machine to CNC. I would rather have a gear-head, but, then again, I would like to have a hotter wife too.

.

Tom M.

+-
Tom for your sake I hope your wife NEVER sees this post. If She does I think You will get '' Hotter'' just not what you eluded to.
If You are going to convert the mill upon purchase to cnc, why not get a good-fair used full size BP or equiv. and outfit it with ballscrews etc. ?
Steve

mayfieldtm
07-02-2008, 09:37 AM
>If You are going to convert the mill upon purchase to cnc, why not get a >good-fair used full size BP or equiv. and outfit it with ballscrews etc. ?
>Steve

I would except I know it would be too attractive to the shop manager and eventually be relegated to full time production.
I want a puny looking Mill, Dedicated to my work tasks.

>Tom for your sake I hope your wife NEVER sees this post. If She does I think >You will get '' Hotter'' just not what you eluded to.

Oops! Open mouth and insert foot.

Tom M.

Bill Pace
07-02-2008, 10:26 AM
Tom, did you check out the RF-45's and the many clones? ... a dove-tail columned "mill-drill" that is gaining quite a following. Theres a yahoo site for both the 6x26 and mill-drills (of course there is!:rolleyes:--theres a yahoo site for EVERYYHING!) and I follow both pretty regularly. (I had a 6x26, and still have a R-31 mill-drill)

I dont recall ever having heard of anyone cncing a 6x26, no doubt its been done, but its certainly not a popular topic on the forum. Its glaring shortcomings are the 6" Y travel and the limited work envelope.

However, over on the mill-drill forum, cncing is a HOT topic, and the R-45s are really getting a lot of attention, you might visit over there and get some impressions, or ask a question...

http://groups.yahoo.com/group/mill_drill/