Burning Wood!

Discussion/questions about software used with your CNC Shark and programming issues

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SharkNewbieGirl
Posts: 7
Joined: Wed Sep 04, 2013 9:08 pm

Burning Wood!

Post by SharkNewbieGirl »

here's what it looks like
here's what it looks like
I am not sure if this is a programming problem or not. I've only been using my shark for a few months now. Today I encountered a new problem on something I've done many times. I was using a .25 endmill to profile my work and the wood started burning. I slowed the FRO down to 50%, tried increasing and decreasing the routing speed. Neither helped. I am cutting Pine .75thickness, the pass depth was set at .126 at 6 passes, it was set on "Climb", stepover .1 40%. I'm not sure why this occured. I have only had this happen once where the bit started to burn the wood, but I think I loaded the profiling instead of v groove at that time :( .

milo30
Posts: 553
Joined: Mon Mar 12, 2012 9:21 pm

Re: Burning Wood!

Post by milo30 »

Generally, if it is burning or the bit itself is getting hot, the speed needs to be increased and/or the router slowed. Is your bit getting dull?

tonydude
Posts: 1581
Joined: Tue Aug 17, 2010 9:23 am
Location: Buffalo,NY

Re: Burning Wood!

Post by tonydude »

I would try using about 16,500 RPM and about 85 ipm feed rate on it.

Tony
Buffalo,NY

"What will matter is not what you bought but what you built; not what you got, but what you gave”

Aspire 11.015, photo vcarve, cnc mako shark extended bed with the new upgraded HD 5 gantry with Led pendent.

SharkNewbieGirl
Posts: 7
Joined: Wed Sep 04, 2013 9:08 pm

Re: Burning Wood!

Post by SharkNewbieGirl »

OK I'll try that. Thanks. I think bit may be dull???? Because non of my other variables changed since the last time I profiled (yesterday).

drueth
Posts: 208
Joined: Sat Jul 09, 2011 7:09 am

Re: Burning Wood!

Post by drueth »

SharkNewbieGirl

It looks like there is paint or some kind of film on the top of the wood you are cutting. If you are cutting through paint or film or the wood has a lot of glue like most plywood you are going to dull your bits in a very short time, And they will start to burn.
drueth
Shark Pro Plus HD
new to CNC 12/2012

SharkNewbieGirl
Posts: 7
Joined: Wed Sep 04, 2013 9:08 pm

Re: Burning Wood!

Post by SharkNewbieGirl »

I am using solid pine, no glue and the tape is thin automotive masking paper. My husband was just cutting plywood without any tape at all with a Freud brand new bit and it started burning.

milo30
Posts: 553
Joined: Mon Mar 12, 2012 9:21 pm

Re: Burning Wood!

Post by milo30 »

What speed are you cutting at? I know you gave a percentage but it is the percentage of your setting in vcarve. What do you have there for ipm with that bit?

TDA
Posts: 44
Joined: Wed Apr 13, 2011 10:33 am

Re: Burning Wood!

Post by TDA »

The chips that are removed from the material as it cuts carry heat away from the bit. If the chips are too small it won't carry enough heat away to keep it from burning. You can solve this a number of ways. Lower your RPM, increase your feed, or use a tool with fewer flutes. All these will increase the chip load (size of the chip taken per rotation of the tool).

You are probably better off lowering the RPM in this example. The problem is that even if you increase your feedrate the machine can not accelerate fast enough through the the corners you are cutting. Basically it has to slow down before it changes direction and then speed back up. So the more twists and turns in your project the lower the feedrate could be regardless of the setting you use.

Keep in mind as the chip load increases the deflection can also increase. So you may need to take shallower passes to reduce this. In case you don't know deflection is the term used for the machine or tool bending in the cut.
John Torrez
Think & Tinker / PreciseBits

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