CNC WIP - small flipper.

BossDog

BossDog

KnifeDogs.com & USAknifemaker.com Owner
Staff member
before you get too much into this thread, I am a beginner at CNC. I am slogging my way thru this after taking a few classes at the local tech school and watching lot's of videos on Youtube and a couple of the training sites.
Any suggestions and comments are welcome.
I am using a HAAS VF2, Mastercam and Solidworks.
If I was starting out from scratch today I would most likely go with Fusion360 for the CAM and CAD and it's likely I will move over to that in a year or two. The HAAS is overkill for me currently but there are plans for a few production parts and tools down the road so it will work out. I've seen guys putting out some amazing stuff with a bare bones Tormak mill.



trial fit on the first proto batch.
The blade point is a little high. It could easily be ground out during finishing but it's better to fix the design. I could shorten the arc or adjust the profile of the blade to better be in line with the top line on the liners. I'll adjust the blade profile since I like where the point is sitting.

Also the lock face on the blade needs another .050" to .075" of material. It's way past the lock bar on the liner. I intend to hand grind the lock up (and blade) since haven't figured out how to mill in the 8.5 degrees for the blade lock face.

back to mastercam to make the adjustments and run a few more.

The detent ball is a 2mm ceramic ball sitting .018" proud of the liner and the detent pocket hole is a #52 drill. I was concerned I wouldn't get much "snap" from the closed position with this small of lever but it's working fairly well. I hope I didn't jinx it for the next one by saying that.

IMG_3298.jpg
 
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"ramp" into a slot like that Tracy. You should have the ability to "follow Path" for a ramp in. Most CAM programs will allow you to set the angle of attack...5 degrees is real gentle for a slot like that...

Oh...and...see how easy CNC is...LOL!
 
OK.
After a few tweaks to speeds/feeds/cut depth we have a part.
I shortened the arc on the "closed" end to bring the tip down a bit and more in line with the top edge of the liner. It looks good.

To get there I broke another end mill. I double checked speeds and feeds, made a couple other changes and this one ran fine.

Now I'm fiddling with the arc width to eliminate some slight interference. It was fairly close to the stop pin and I added .006" additional clearance.

Once I get all the cuts tested and proofed, I'll add hard tabs with screw downs to hold all the pieces and create a jig plate to run 2 pieces at a time. Setting up a G54 and G55 isn't something I've done. Shoot, I haven't done any of this before so I guess that part doesn't matter.

After I figure that out, it will be kinda easy (hah!) to scale up to 4 to 6 pieces at a time which is about the limit of my current vice set up.
IMG_3304.jpg
 
Smallshop said:
"ramp" into a slot like that Tracy. You should have the ability to "follow Path" for a ramp in. Most CAM programs will allow you to set the angle of attack...5 degrees is real gentle for a slot like that...

Oh...and...see how easy CNC is...LOL!
Click to expand...

I had a 3 degree ramp set and lowered it to 2 degree and I also lengthened the ramp a bit to ease into it.
 
Another thing is...you know the layout of your tooling plate screw holes...pop a couple holes and add screws to hold DOWN. When you pinch a thin plate in a vise or between mitee-bites you are putting tension sideways on the plate and making it like a guitar sound board. You may not always hear or notice but it could be fluttering up and down. very hard on endmills. 4-5 screws around that profile will change how solid it cuts. You can add it to the program first, then add a programmed stop...add screws...then hit start again. Or make it two separate programs...holes then profile.
 
Found a bug in Mastercam that wasn't generating depth of cuts properly so it was just sending the end mill to the bottom of the cut. I should have noticed it when reviewing the tool paths in backpot and verify but didn't. It only took a 3 hours and 3 end mills to figure it out. Got it to generate the proper depth of cuts and should be OK now. We'll see. I will have to call the tool guy tomorrow to reload.
 
That's what the first pic you posted looked like...a straight down plunge. Glad you found the bug. Hard to see what's going on under a spray of coolant.
 
This piece ran with no issues - that I know of.
Now I have both liners and the blade profile to fit together and see if it will work.

I stopped by my local buddy Tylers shop. He has a Robodrill with 5 axis he ran a part through for me. Amazing stuff.
He gave me some ideas about tooling and depth of cuts that I'll roll into my next batch.

I'll need to program some scales and spacer bar to run in g10 or Micarta next. Those will be drilled and minimally profiled then hand cut so I don't fill the coolant pump with g10 pulp.
IMG_3305.jpg
 
Ran a couple of the blades thru the surface grinder to take off scale and make sure they are mostly flat.
I am using AEBL because it was cheap to use and I had some in the end cut bin.

IMG_3306.jpg

Setting the detent ball. I use am 2mm ceramic ball pushed into a .073" (#49) hole. The socket hole will be a #52.
I manually drilled the detent socket hole in the blade. I suppose I can/could program it into the CNC but for now I'll do it this way.
The washer is .015". When pressing the ball into the lock bar, the washer helps set the height properly. I look for around .020". The caged bearings are proud of the liners by around .018" so the detent ball needs to stick out further to clear the bearing.
IMG_3307.jpg

This is the revised blade with shortened arc. It aligns much better with the back of the liner and I now have plenty of lock face to grind into.
IMG_3308.jpg
 
Today I started working on the scales in black paper micarta.

I am still concerned about the phenolic pulp getting into the coolant and buggering things up so I ran the CNC a little and then vacuumed it up, running it all dry. It piles up quickly.
IMG_3313.jpg

I have using 4x4 sheets of metal or in this case micarta to test with. I set G54, run one part, check it, make any changes, flip the coupon and run it again. I will have to adjust the 45 degree chamfer it should have but doesn't some more.
IMG_3314.jpg

I didn't mill them completely out of the sheet. I left about a 1/4 of the thickness just because I guess. I'll add tabs in on the next test and remove most of the edge profile. Here is the front scale cleaned up a bit with the pivot head fitted. The sketchy looking spacer bar was done manually just for fitting up so far. I'll have to draw that up and get that into the CNC also but with a few changes.
IIMG_3315.jpg
 
After 4 or 5 tweaks here is a set of finished scales.
This started out as one scale as I worked through the toolpaths and ran some tests.
After I was OK with the first scale, I mirrored in the second, changed the geometry for the second scale. I ended up having to move the second scale further down the coupon to keep integrity in the center connecting tabs. I also had to modify the lead in/lead outs to the outside as it ate up the inner web and one or both came loose.

I need to find out how to match the tabs exactly from the roughing pass to the finish pass. It was trial and error getting them kind of close using verify.

IMG_6231.jpg
 
I managed to get a proto flipper done. Lots of things to tweak but I got one finished. Now I will work on several tweaks and proper hold down fixtures for the next area to practice/learn.

554FD420-CCA5-45C5-B5B5-ECF8544A4854.jpeg
 
That look real good...that blade shape appears to me to be very handy/useful for a LOT of things...perfect for a pocket knife.
 
BossDog said:
Today I started working on the scales in black paper micarta.

I am still concerned about the phenolic pulp getting into the coolant and buggering things up so I ran the CNC a little and then vacuumed it up, running it all dry. It piles up quickly.
View attachment 64606
Click to expand...

BossDog you’ve probably thought of this already but when I worked in a machine that cut lots of carbon fiber, they had it set up with a really powerful shopvac that sucked most of everything out and they just ran it dry with no coolant.
 
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