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 (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

[Digitalwoodshop]

Giving us FEED RATE CONTROL and MOTOR SPEED CONTROL would make this machine into more of a Industrial Machine. It would shed the label of HOBBY MACHINE.... Saw on another Forum the machine was the Easy Bake Oven of CNC Machines..... Remember the 100 watt bulb ovens of the 60's for girls. I disagree but everyone is entitled to a opinion...

AL

[dbfletcher]

I'd even be ok if they insist on keeping the machine "dummied down", to just give us different "material" selections when we choose the board dimension... oak, pine, acrylic, walnut, ect.. and have the machine adjust all it's rates based on that. Would still be "easy to use" but would give us at least a little control over feedrates.

[AskBud]

Giving us FEED RATE CONTROL and MOTOR SPEED CONTROL would make this machine into more of a Industrial Machine. It would shed the label of HOBBY MACHINE.... Saw on another Forum the machine was the Easy Bake Oven of CNC Machines..... Remember the 100 watt bulb ovens of the 60's for girls. I disagree but everyone is entitled to a opinion...

AL
I do not agree!
The Feed rate, is a common sense item. Most of us know that we can not plow through hardwood, with a router or saw, at the same rate we do the softer woods. It only makes sense the slow down our feed so we do not have major problems (burning, unwanted movement, jams, etc). We're not asking for faster feed. We just want to be able to reduce the feed rate on harder stock.
Respectfully,
AskBud

[Ike]

Giving us FEED RATE CONTROL and MOTOR SPEED CONTROL would make this machine into more of a Industrial Machine. It would shed the label of HOBBY MACHINE.... Saw on another Forum the machine was the Easy Bake Oven of CNC Machines..... Remember the 100 watt bulb ovens of the 60's for girls. I disagree but everyone is entitled to a opinion...

AL
No Al, I had trucks! Plus I am not that old!!( the Ike/Al bantering continues!!) Besides Al the machine has passed the hobby machine. http://store.carvewright.com/configuretemplate.htm

Hmm lets see when I cut oak the motor speed changes or gives me a cut motor error and corrects the speed of the material it is cutting. As forth to the feed rate we all know what will happen if we had control.....

Post.....

What happened my motor stopped working or the cut did not cut the depth set. Or burnt edges, feed rollers broke, better yet the PLASTIC gears in the feed table has broke teeth!

Yep Al I agree with you!

Ike

[Digitalwoodshop]

So how did AL know so much about the Easy Bake Oven?...... Didn't have one Ike..... "DADT"ell...... I know what your thinking.... My Cousin was upset at the oven not heating and ME fixing it by changing the bulb.... That is how I remember them.... I was her HERO..... Yes, I staterd fixing stuff very young....

AL

[Ike]

So how did AL know so much about the Easy Bake Oven?...... Didn't have one Ike..... "DADT"ell...... I know what your thinking.... My Cousin was upset at the oven not heating and ME fixing it by changing the bulb.... That is how I remember them.... I was her HERO..... Yes, I staterd fixing stuff very young....

AL
LOL I remember them Al!! I am a product of 1963! ( you old fart!) Yes Al like my Dad always told if he can't fix it isn't broke!

Ike

[liquidguitars]

I would say we have a little machine feed rate with "cut control" and "vector" cuts based on bias of the curve. For raster setting High vs low will slow the CW down. i will take a guess other desktop motors are running flat out at max hp.

When i start burning a bit its dull and has a little pitch/dirt replacing bits or sharpening could be the thing to try.

[Old Salt]

would like to see a choice if you select hicory over pine the speed would be set the right speed for each.
think it could be done but would take some testing, maybe in the future ?

[rjustice]

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.

For the record, all of the bits I sell are upcut. In other words, the bits auger the chips upward as they cut. I do not recommend a downcut tool in this machine.

Happy Carving,

Ron

[robertdpittman]

Ron,

My deepest apologies. I was wrong, the bit you sent and the 3/8 endmill I was using are both upcut bits.

I love getting old, I get the thrill of learning new things everyday (regardless of the fact that it is the same new thing, it's still a thrill).

Bob

[rjustice]

Bob,
No problem at all, i just wanted to make sure that there was no confusion on what is recommended for the machine. The down cut tools will pack chips in the cut if it is not going all the way through in one pass. This will cause excessive pressure on the bit, and the machine. It is likely to have problems with bit breakage in doing so.... Upcut is the way to go.

Thanks

Ron

[robertdpittman]

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

I just ran another job with the bit listed here and they don't burn the wood like the spiral fluted bits. Thanks. And they are much cheaper.

[nikole957]

would like to see a choice if you select hicory over pine the speed would be set the right speed for each.
think it could be done but would take some testing, maybe in the future ?
I would say we have a little machine feed rate with "cut control" and "vector" cuts based on bias of the curve. For raster setting High vs low will slow the CW down. i will take a guess other desktop motors are running flat out at max hp.




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