Thoughts on my X3 mill

[BillH]

For a new mill, I am quite pleased with the fit and finish for under 1000$
Now for the bad. It simply is not rigid enough, go buy a giant knee mill that weighs 3000lbs, and be done with it.
Yes, it works, yes I am happy with it. Yes, it will do what I want, sorta.
I find that a 1/2 end mill is around the max that should be used for anything other than plunge cutting.
Have yet to try a face mill or fly cutter. Only cut T6, and some mystery steel that the mill clamp set from grizzly is made from. It is a bit harder than mild steel. Or at least my X3 leads me to believe that it is harder than mild steel as anything beyond a light .010 cut causes it to vibrate like hell with a new sharp quality end mill, either 2 flute or 4 flute. Yes, applied ample amounts of wd40 for a cutting fluid.

 

[Cedge]

Bill
I have the SX3 version so I can't speak to the X3 beyond knowing the frames are quite similar. I can tell you that mine will push a 3/4 end mill with aluminum cuts of better than .150 depth at half the width of the end mill. Vibration is noticeable but not bad. Yes I can push it to chatter, but all in all it gives more than expected. Even with Steel, I'm making cuts at .050 with no real problems. I'm wondering if there is a rigidity difference?

Steve

 

[Philjoe5]

I have the X3 and routinely use DOC's of 0.025" - 0.035" on CRS, 1144 free machining, and hot rolled steels with 3/4" - 1.0" end mills of import quality. Aluminum in the 6000 series can deal with DOC's to 0.050". If I get vibration it is usually because my spindle speed is too high or gibs need adjustment. In over a year of use I've had to adjust the gibs twice.

Cheers,
Phil

 

[Jasonb]

I can also take similar cuts to what others have posted

Have you locked the quill and head when taking heavy cuts? Also make sure the spindle bearings are not slack, my spindle had 0.020" play when delivered but its fine now.

Jason

 

[Cedge]

I'm thinking the same things Jason mentioned. It almost sounds as if something is not adjusted quite as it should be. I regularly swing a 3.4 inch fly cutter on aluminum as deep as .010 and the machine doesn't complain. Are you locking the head before cutting?

I might also suggest looking a the tram. I needed to shim the column a bit to get things as they should be.

Steve

 

[SmoggyTurnip]

Mine works great just like the others have said. It was certainly worth the money I paid for it.

 

[BobWarfield]

Really bad runout can also be a problem. I had a bad ER32 collet one time and I thought the world was ending.

You might want to put a DTI on the end mill you're having a problem with and rotate by hand to check the runout. It can come from a variety of sources. I always check the cheapest to fix sources first and save the spindle bearings for last. So far I have always found the problem before I got near the spindle itself!

Best,

BW

 

[Cedge]

Bob
Good call. I had an ER40 collet that wasn't bored concentric and it cut horribly. Lots of vibration and shallow cuts. Could be.

Steve

 

[S_J_H]

Yeah, Something is wrong Bill. Your setup or adjustment or something with the machine. .010" deep with a 1/2" endmill in 7075 is absolute nothing for an X3 mill. I have had a cnc'd x3 well over 2 years now. It'll run a 3/4" 2 flute a .1" deep no trouble. A 1/2" 4 flute .1" deep in iron is no problem. A little x2 will run a 1/2" 2 flute better than .010" deep in 7075.
Something is not right.
Steve

 

[BillH]

I've been taking deeper cuts, MUCH deeper cuts and full width of the endmill cutting slots. When I do the same DOC's as you guys, with exception to that steel I was cutting, it hums along fine.

 

[BillH]

Think I found my problem. I didn't tighten the end mill holder holder setscrew tight enough. I chucked in a 1/2" roughing m42 endmill of good quality and it just PLOWS through aluminum, all is well!
I think I will need to tram the head in though by shimmimg the column, not looking forward to that!

 

[Cedge]

Bill
tramming the head won't be that bad. Loosen the 4 bolts a the base and you can rock the head a wee bit on the tapers.... at least enough to slip shims under the corners. It took me less than an hour once I got it in my head which corners to shim.

Lower the head to the table and the quill can be used to "jack" the head, lifting the front of the column. You can use a rod in the chuck to make things a bit easier to see. Let the pressure off and the head weight will give a gap at the rear of the column. Takes the sweating and grunting out of it all.

Steve

 

[lugnut]

Now that I’m getting to know my Grizzly X3 milling machine a little better, I’m finding out that you can take some pretty heavy cuts if you have every thing snubbed down. I’m also learning a lot about speed and feed, which really makes a big difference in how the machine acts.
After reading about “runout” and such I decided to check the runout on a couple of drill chucks that I bought on Ebay. They were way out. But after tightening down on the draw bar bolt some, they came right in to line. I was only holding the quill with my hand and using a little tug with the wrench on the draw bar bolt. That I soon found was not enough.
I plan on making some sort of spindle lock so I can through the two-pinned spindle wrench away. Hate that damn thing.
The more I use the machine, the more I like it.. Just have to learn, accept and operate it within it’s limits.
Mel

 

[Philjoe5]

Mel,
Right after I bought my X3 someone on this forum (apologies for forgetting who) recommended tossing the 2 pin spindle wrench and getting a 10 point 23 mm box wrench. Best accessory you can buy for this machine, it makes life so much easier.

Cheers,
Phil

 

[lugnut]

Phil, I remember that post, I think it was an answer to the same remark I made here. But I made a spring loaded locking pin for the X2 mill I had and really liked it. Never had to reach for a wrench and never forgot to remove it. I think one could be made for the X3 also. I was just trying to get someone else to do the design and then copy it ;D I guess I'll have to get off my duff and do it myself.
Mel

 

[DICKEYBIRD]

Mel,
Right after I bought my X3 someone on this forum (apologies for forgetting who) recommended tossing the 2 pin spindle wrench and getting a 10 point 23 mm box wrench. Best accessory you can buy for this machine, it makes life so much easier.

That was me. It's actually a 23 mm, 12 point wrench (spanner)

 

[Philjoe5]

Thanks Dickeybird for both the initial recommendation and the correction. Sending someone off to find a 10 point 23 mm spanner is akin to sending them off on a snipe hunt :-[ :-[ :-[

Cheers,
Phil