Need help - burning bits and end grain

[robertdpittman]

I have been using the CW for a few months now. I am getting good results but have one thing I am not able to resolve. Maybe it is the way it is but wanted some help.

Attached is the project. I need to remove some wood and make a pocket in the board. I use a 3/8 straight bit. I cut away about 1/8" deep and 3/8" wide in each pass. I use a good quality 4 flute solid carbide bit.

When I cut with the 3/8" bit, the end grain burns and the bit burns. The cutting end of the bit gets all blue and becomes useless after cutting a few boards. I do not get any burining with the 1/8" straight bit.

Originally, my vector cut pattern was a spiral strating in the middle and going to the ends. This meant there was a lot of cross grain cuts and lots of burning. Now the pattern is a back and forth with the grain. It seems to help but not a lot.

Some questions I have are:
Should I cut off more/less with each pass?
Should I select a 1/4" or 1/2" bit to speed up/slow down feed rate?
Is cutting with the grain or across grain better?
Is a climb cut better?
Should I just use a smaller bit and bite the bullet on a long cut time?

Any thoughts and help are appreciated?

[Digitalwoodshop]

Do you have a QC or CT or Rock...? I am betting you have a worn QC....

AL

[robertdpittman]

I have the rock chuck. It was installed as soon as I got the CW

[bjbethke]

I have been using the CW for a few months now. I am getting good results but have one thing I am not able to resolve. Maybe it is the way it is but wanted some help.

Attached is the project. I need to remove some wood and make a pocket in the board. I use a 3/8 straight bit. I cut away about 1/8" deep and 3/8" wide in each pass. I use a good quality 4 flute solid carbide bit.

When I cut with the 3/8" bit, the end grain burns and the bit burns. The cutting end of the bit gets all blue and becomes useless after cutting a few boards. I do not get any burining with the 1/8" straight bit.

Originally, my vector cut pattern was a spiral strating in the middle and going to the ends. This meant there was a lot of cross grain cuts and lots of burning. Now the pattern is a back and forth with the grain. It seems to help but not a lot.

Some questions I have are:
Should I cut off more/less with each pass?
Should I select a 1/4" or 1/2" bit to speed up/slow down feed rate?
Is cutting with the grain or across grain better?
Is a climb cut better?
Should I just use a smaller bit and bite the bullet on a long cut time?

Any thoughts and help are appreciated?

I found my large spiral bits get hot in the CW unit. It may be the chip load. I started to use Plunge cutting straight bits, I buy the 1/2 inch shanks, and they make a better cut.

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bt_plung.html

[Digitalwoodshop]

That is the bit I use from MLCS to do my 3/8 inch outline letters. Works great...

AL

[CarverJerry]

Well ya gotta figure too that that end mill is really cranking some rpms, maybe a 2 flute end mill would work a little bit better. I use a 1/2" 2 flute and don't have any problems with burning at all. Too bad we can't control the rpms on our machine along with the feed rate.

CJ

[Digitalwoodshop]

Any chance it is a DOWN Endmill.... Pushing the chips into the hole?

AL

[robertdpittman]

Thanks for the replys.

Sounds like I need to try the plunge bit you use. The price is much better than the $35 for a solid carbide endmill. The endmill is a downcut just like the 1/8" bit that I got from CW-parts, the Rock Chuck guy. I wish there was control for RPM and feedrate. That way it could be optimized for the type of bit and material.

[AskBud]

Thanks for the replys.

Sounds like I need to try the plunge bit you use. The price is much better than the $35 for a solid carbide endmill. The endmill is a downcut just like the 1/8" bit that I got from CW-parts, the Rock Chuck guy. I wish there was control for RPM and feedrate. That way it could be optimized for the type of bit and material.

I'm going to point to this thread in the Wish list.
You are absolutely correct! We need the ability to control the "Feed rate" on each bit usage other than the carving bit. Not every piece of material has the same resistance factor, some are almost as hard as steel!
AskBud

[CarverJerry]

Like most CNC machines used in machine shops, you have a variable seletor knob for spindle speed over ride and feed rate, even if it's locked in you still have some what control because like AskBud says, not all material are exactly the same.

CJ