Pulling my hair out!!!

 

I cut it twice and it is still wrong. Even after changing the cutting depth to .25 from .3

The first cut is a clear out pass cut with a .25 end mill as it should have... .25 depth. Then I changed the cutter to a 1/8th end mill and ran the file for it. However, it cut the tool path slightly deeper (.3). I can figure out how this happened. The previous project worked just fine for zeroing the z axis with my new tool.

Note: VCarvePro preview indicates it will cut smooth. Not so in the picture.

 

Right now, I am at a loss, and shut down until I figure something out. Wasting wood is not what I want to do.

Edited November 17, 20178 yr by Ron Dudelston
tags added

More than likely, the big wasn't chucked tight enough and slipped out of the collet

I went back and ran the clearance file with a deeper cut and it sorta solved the problem. Good enough for my counter, but not for a Christmas present, of which I will need several. I would need to cut at least 6 and maybe a seventh. Our family has four graduates and brother and sister will want one also.

 

I need to do some further research and see what is going on. I have been doing just fine adjusting Z0 with a sheet of paper, so maybe I am not doing the right procedure with my new DIY touch off tool.

 

These turned out OK today, so WTH? Same cutters - EM .25 and EM .125.

 

 

Edited November 7, 20178 yr by MT Stringer

Apparently I didn't hit submit on this a couple of hours ago since it reappeared...duh...may be moot issue now...

 

Not a CNC tool user, but @Kenny Tarmack likely is spot on...the only other thing that comes to my mind is somehow/somewhere a chip dislodged and is resting on top of the bit in the collet?

 

Anyway to return to Home without disturbing current set-up and recheck Zero without removing the project?

 

Add: I'm sure you checked but assume no lodged chips under the T-A&M piece? Variance in the initial thickness of the work-piece from the program set-up?.

Sorta grasping at straws and probably stating the obvious things to check. Been nearly 30 years since I took any basic CNC machining classes and couldn't tell you a "G" code from an "F" code today but I still grasp X-Y-Z  coordinates especially when I try to get up.

Thanks for the suggestions. I will keep at it. I have a lot of off-cuts so I can do a test or two.

 

Just a couple of thoughts.

Lately I have been removing the collet during each bit change, blow out the dust and reinsert with new bit. I try to do the same routine each time. The reason is last week, I destroyed a bit and a collet. I loosen enough the let the bit come out of the  collet (at 12000 rpm). I had a spare and ordered a new one. So I am good to go again. So now, I check for dust between every bit change.

8 hours ago, MT Stringer said:

Lately I have been removing the collet during each bit change, blow out the dust and reinsert with new bit. I try to do the same routine each time.

Is/was it possible during the bit change on the OP project the collet did not relocate to original position for whatever reason? The .050" variance indicates something small? Was the 1/8" end mill a first use for it? Is it possible the OAL is +.050" over the OAL of the .250" cutter? I assume you used the same collet between both bits? Is the cutter always fully bottomed in the collet or do you use a small o-ring (or similar) to seat against. For dummies like me, I always use a small o-ring in the bottom of the collet bore in hand held routers (and even in the table) to seat the bit against; seems to help prevent bits from getting stuck in the collet.

I just finished cutting a different file, but got the very same result. You Vectric guys know that when you set the cutting depth at .25, then the clearance tool (.25 end mill) will cut away the waste. It also calculates the same cutting depth for the finish pass (.125 end mill). Both are spiral up cut bits.

 

I checked with the digital calipers and the difference between the two tool paths is .08 inches. So the 1/8th end mill cut a shallow groove instead of just finishing off the cut smooth at .25 in.

 

I think I will re -do the clearance file and re-cut at .33 in to see if I can save this board (third one for the trash can). This is driving me nuts but I am not giving up. The only thing I can think of is I have been using a basic file that has the outer diameter and inner diameter and basic set up as far as material thickness, and xy zero  (bottom left corner). I have the spoil board set up with x and y guides so the material fits those parameters every time, even if I remove it, which I haven't. And the work piece is clamped in place and can't move.

 

Now saying all this, that .08 difference is bugging the krap out of me. It is consistent. I think I need to create a new file and do a quick test to see if it is a corrupt file I have been using or ...

 

Stay tuned. If anyone wants to give it a shot, gimme a shout. These are cut from a 9x9 work piece, 3/4 inch thick.

Mike

Edited November 7, 20178 yr by MT Stringer

22 hours ago, Kenny Tarmack said:

More than likely, the big wasn't chucked tight enough and slipped out of the collet

what he said

 

Thanks but that's not the case. I just designed a new file using the same font (just two letters in a rectangle), and cut it out using the same two bits, and the same puck to zero the z axis. I got the exact same result. The smaller bit cut a little deeper than the clearance tool. I may start drinking a little earlier this evening! :-( NOT!

 

Maybe if I sleep on it, it will solve the problem itself over night! :-(

Thanks for all the suggestions. I think I have figured it out. Yesterday, while cutting yet another test piece, I saw the 1/8th end mill move and start cutting slightly deeper. I quickly shut the machine down and took a closer look. The collet felt sorta loose. Sorry for the non-technical term, but that was my thinking.

 

So, today I replaced the collet with the new one I purchased, and installed a new 1/8th inch upcut spiral end mill. I ran the same file and it cut smoothly with no evidence of difference in the cutting depth between the two router bits. So, 1/4 inch upcut for the clearance tool and then the 1/8th for the finish cut. Very happy  tonight. Now maybe I can get back to carving and quit all this fooling around.

 

And, I ordered a couple more collects for my 1617! :-)

2 hours ago, MT Stringer said:

The collet felt sorta loose. Sorry for the non-technical term,

I had to Google the term, but think I understand what you're talking about

Glad you got it solved and most importantly without any injuries. thanks for coming back with the root cause analysis.

Happy woodworking and full steam ahead. Only 45 days to Christmas.

OK, color me happy...very happy. I carved a pair of the Texas A&M hot pads from a single board and they turned out well. The board wasn't exactly flat and it showed in a couple of places but some light sanding took care of the small imperfections.

 

Mom is going to be a happy camper. I will let her decide whether she wants it finished with mineral oil or leave it bare wood, or paint it Maroon and White. It may never get used as a hot pad. The chicken cutting board I made for her is hanging on the wall.

Sweet! Glad the machine is performing to expectations.

Thanks for clarifying those were Texas A&M...I thought you were creating for a Texas bank ATM

Everything is back to normal. Using the DIY touch off plate, I am getting consistent bit changes with very little sanding.

Fantastic news Mike..happy it was just a relatively minor repair/parts replacement to get it up & running properly and safely.

Now, get back to work!

Yes sir. Gotta couple more Christmas presents cut out. Onward and upward. My sweetie will paint the surfboard.

 

Edited November 16, 20178 yr by MT Stringer

All are cool, well 'cept maybe that Green-Bay thingy

I like that surfboard...nice touches with the antique bottle opener and the shark bite? too.

From the looks of all, you're dialed in to a couple of microns.