LinkBack URL
About LinkBacks
Holding the cutter in a chuck?
Probably. They need to TIGHT or they can work their way out.
Been there, done that, on my SX3.
I am fairly new with my Syil X3 and have cut a few things already and haven't noticed this before.
Today I was cutting a part that was purely designed to test my ability to use my new CAM software (CAMWorks):
http://img823.imageshack.us/img823/5584/ft1pic.png
The g-code told the mill to begin by cutting away the outside in this pattern, which it did:
http://img266.imageshack.us/img266/571/millw.jpg
At point A it began slowly/consistently ramping down the z (extremely slow) all the way until point B when I noticed too late and it was deep enough to snag and almost kill the bit.
Between point A and B it probably dropped about .107" below the intended point.
Now here's the very strange part - the machine controller (Mach3) says the z wasn't moving and the g code has nothing in it that would imply a drop in z...
Any thoughts?
Thanks in advance
Holding the cutter in a chuck?
Probably. They need to TIGHT or they can work their way out.
Been there, done that, on my SX3.
Super X3. 3600rpm. Sheridan 6"x24" Lathe + more. Three ways to fix things: The right way, the other way, and maybe your way, which is possibly a faster wrong way.
Thanks for the tip - you were completely right
Here's the evidence (the sharpie mark on the bit used to be touching the collet)
http://img202.imageshack.us/img202/3075/img0528ps.jpg
http://img35.imageshack.us/img35/3145/img0530i.jpg
http://img716.imageshack.us/img716/1074/img0531o.jpg
Any tips on stopping this? We tightened it as much as we could by hand... might need a strap wrench...
Hi Graygabe
You need a milling cutter holder, most people use ER collet holders these days, a drill chuck does what it says i.e. hold drills.
Having spent a significant sum on your X3 complete the job and treat yourself to a collet holder with a set of collets you won't regret it.
The secret of using end mills is to
1) have a sharp tool,
2) use the right spindle speed / feed combination to suit the tool size also the kind of material you are cutting, most end mills these days are designed to be run at high speed 2000rpm plus
3) use right amount of coolant to suit material.
You say your are new to machineing, so experement with feed and plunge rates, go slow first I plunge at 1 in per min as if you go in to fast the mill will wobble and cut over size.
Its all part of the learning curve, once you get going you will have lots of fun cutting parts
Good Luck
Mike
On my SX3 I use 10mm carbide cutters in the chuck.
After 1000 hours, I have partially destroyed the chuck key tightening it with a 150mm long tube.
The chuck is surviving rather well. Good quality Chinese (probably out of Taiwan)
You need ER type collets that are more flexible and can be made much tighter than the 3 slit one you have.
That small cutter in a standard chuck, crudely tightened will work OK, but make sure it runs true, and is a good quality chuck, (while it lasts!) haha.
Mine has been overtightened at least 800 times.
Super X3. 3600rpm. Sheridan 6"x24" Lathe + more. Three ways to fix things: The right way, the other way, and maybe your way, which is possibly a faster wrong way.
A short update in case anyone else is having the same problem.
A ER collet is something we considered but was just too expensive for the moment. I've never used mills before that didn't have a spindle lock built into the machine so I assumed ours was just missing, but apparently this model never came with one.
Made a pin wrench (IMG_1) out of some spare aluminum, it will probably get re-milled out of steel some day, but it is actually holding up really well. It has probably been used about five times already and its not bending or deforming as I was originally worried about.
The second photo (IMG_2) is just a comparison shot. The first one is the one on the right and you can see how much it moved between the roughing and the finishing pass. The one on the left is the second attempt and is actually very good. If the mill was trammed and we stopped crashing it it would be excellent.
not being funny, but i have used collets like yours for many moons and touch wood, not had a problem.
two things spring to mind.....
1. have you done the draw bar up tight enough?
2. have you got an imperial cutter in a metric collet or vice versa.
also, (sorry 3 things) is there a bit of crap up the spindle, bit of swarf or maybe a nick on the taper that you haven't spotted that will stop the collet from closing up.
Sorry, my last post was not very clear. The problem was loose collets, that is why I made the spindle wrench. The problem is now fixed, and the end mills do not move at all.
Thanks to everyones help, we wouldn't have figured it out without you.
Posting Permissions
