New Scar on the PCNC 1100

Well, I did it again except this time it was with a 3/4" Shear Hog!!!!!!! I'm thinking that I'm going to have to invest in a large fixture plate.

Mistake was that I thought I'd programmed Z at the table height (which is where my Z/0 was set). Nope, I had F360 setup at the top of the part. So, this new scar adds to the drill hole in the middle of the table from about a year ago.

Hoping John at NYC CNC starts making a larger fixture plate. They are making a small on to fit on top of a vise but would love to see a larger one.

For your Saturday night viewing pleasure!

Attachment 345924

OUCH!!!
Your poor mill. :(

My deepest condolences.

I've been lucky to far. Work on a 1" aluminum surface plate. Only way to do any type of plate IMO.

Those aren't scars, they are honorable battle wounds...
A sign of experience and wisdom...

It can happen all too quickly when work is clamped directly to the table. I feel your pain for i too have had to fight off a hungry tool from time to time. After the job is done, and the chips are cleared away, hit the area with a nice volatile solvent (i like acetone) to clean away the oils etc. It will then be time to break out the JB quick weld. After that goodness has cured break out some oil and a large Arkansas stone and you can start to "make it better". Gotta love battle scars because they typically make your future job set-up templates and post-it notes more detailed and organized. Sorry man, I know it is like getting kicked in the guts when you first see the damage.

Ouch! :(

MDF is my goto spoil board. Saves the table.

The big bolts are bolted through to the T-nuts, the small bolts are drilled and tapped into the MDF..
Attachment 345948

Just tell someone else did it:D

Jeff

I feel your pain!!

I am a firm believer in Murphys law.......... I use a large vise for that reason.

I liked the epoxy idea, at least it would be less of a reminder.

I didn't clamp my toolmakers vise down well enough and took an ill-advised cut which dug the vise into the table before launching into my enclosure :( Left a pretty horrible ding in my table but after a bit of stoning it doesn't affect anything beyond looking bad. I bought "Smith's SK2 2-Stone Sharpening Kit" on Amazon and the fine stone in that worked well for removing any burs, though is a little small. A Norton brand fine stone in a bigger size might work better.

You may be doing this already, but one thing that reduced my "oops" rate significantly was getting really strict about always programming the stock origin the same way, with Z=0 as the top of the stock and the lower left corner as X0/Y0.

I have a passive probe and all I do is stick that in and run a routine that sets zero there. When I load the part program, it's easy to see the maximum Z travels and see where the tool tip is going below the bottom of the stock. I also have a fixture to mount a 3-jaw chuck (so the stock is perpendicular to the table) and for those I set the center of the stock as X0/Y0. Doing things consistently has helped me to speed up the rate of throughput and get the most value out of simulation.

I have been lucky for many years. Broken only a few drill bits, taps and end mills. Error in path pilot sent a 60$ end mill into a vise jaw in the middle of a program but you cant avoid those problems sometimes. The end mill needed replaced anyway. The vise jaw didn't and the what just happened moment was not fun either. I try to do the first part setup as slow as possible. "slow is fast :)" Also what has helped in the past is to start most programs / operations with some sort of drill operation. If for no other reason to just go down and spot something in the stock that gets milled away later. This allows me to verify on the fly the machine is setup right and I can hit the e-stop if something is wrong and all I break is a little 2$ drill bit. And not crash the mill and tool into the work piece and fixtures. Then I know the next operation should go where programmed. I find it easy to spot a problem by the way the machine acts on its way to the first hole :)

Conversation milling for me is a quick way to crash my mill. I avoid it as much as possible. and mostly for simple stock prep. This is just me and others with more experience conversation milling will get better and faster results.

I have ordered one of John Saunders NYCCNC new fixture plates to give me a surface that will suck to scar but beats the hell out of screwing up the main table. I also got in his smaller plate yesterday. Man, the quality of that thing is amazing!!!!

https://saundersmachineworks.com/col...late-beta-test

https://saundersmachineworks.com/col...-fixture-plate

One simple thing that has really helped to save my table has been to religiously do a G49 before I even think about setting the "Z". Also, I like MD's idea of the drill. I'm going to start doing that.

Quote:

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Originally Posted by jttoner

One simple thing that has really helped to save my table has been to religiously do a G49 before I even think about setting the "Z". Also, I like MD's idea of the drill. I'm going to start doing that.

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I dont do it as much these days. I do set up a dummy op like that when I have a program that requires a belt change! I always try to set those ops up at end of program and having a dummy op next helps me catch I did not set the belt back to correct position before starting next set of operations! This has saved me a couple times from sending a tool with wrong speed into a part that I just turned over and fixtured on a different side.
When you do multi sided parts, its no fun to ruin a part on the last side because you didnt change belt after re-fixturing part.

If you're not crashin', you're not machinin'!! (ok, maybe that's not entirely true).

It happens to all of us - I turned an Ultradex indexable drill (probably close to $200 in body and inserts) into a fancy candle in about 3 seconds on my 10HP turning center - it's the only time I have ever been able to lug the motor! Wish I had the camera rolling, the red glow brightened up the entire cabinet for a second before the inserts welded and the lathe twisted the drill shank clean off and proceeded to drill with the blunt body. Indexable Drill Melted - Help?

On a side note, that shear hog left a nice finish on that cut =)

I had a guy working for me once who was working on an odd shaped part so rather than put his part on a plate, he drilled and tapped a hole in the table of my conventional mill.

I saw that and we had a race. I wanted to see if he could get his tools loaded in his car before I could get his pay check ready. I won.

That sucks - it's starting to look like my old Bridgeport. I'm liking the fixture plates, and I love Jim's MDF solution for things that don't require closer tolerances.

Oh man! it happens. Well, 'bout a year ago I ran a 1/2 cutter right into my two week old Glacern vise...you are not alone by any means!