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Post by parkin79 on Dec 2, 2018 13:55:05 GMT -5
I have a quick question for you guys. Whenever I do drilling tool paths they always end up smoking and burning my bits. Is that because the RPMs or feed rate I'm kind of unsure which one I should be slowing down or speeding up and just wanted to see what you guys have done in the past.
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Post by gerry on Dec 2, 2018 14:02:18 GMT -5
Are you using downcut bits?
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Post by parkin79 on Dec 2, 2018 14:24:40 GMT -5
Yes I am .25 inch. I am also using the pecking option. I am just not sure what my settings should be. Any help would be appreciated. Ty
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Post by stevem on Dec 2, 2018 14:26:35 GMT -5
The down cut is pushing the chips back into the hole where it will burn. Use a up cut!
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Post by parkin79 on Dec 2, 2018 14:31:36 GMT -5
I feel stupid. Didn't think of that way. But now it's obvious. Thanks.
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309cnc
Junior Member
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Post by 309cnc on Dec 2, 2018 15:07:41 GMT -5
My limited success has been based on slowing the spindle waaaaaayyyyy down. However, then you have little to no torque. So the vertical feed speed also had to come way down.....
For the most part I have given up on the drilling toolpath option and am using pocket cuts with (up-)cut bits smaller than the hole diameter. Really small end mills usually limit you on how deep you can go (most 1/8in dia EMs I know of are 3/8 to 1/2in max in length) but I have not had a need to go any deeper.
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Post by gerry on Dec 2, 2018 17:59:13 GMT -5
I drill 0.25 holes all the time. I use an upcut, or at least a straight bit. With a 2 flute spiral I have no problem drilling 0.25" holes 1.0" deep for 2 sided machining without burning the holes. You can also slow the spindle speed down.
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Deleted
Deleted Member
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Post by Deleted on Dec 3, 2018 8:52:19 GMT -5
It's okay to use drill bits for loose tolerance holes and helical cut tight tolerance holes with an end mill. Or even use a drill initially followed by an end mill.
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Post by savannahdan on Dec 3, 2018 18:11:02 GMT -5
You can also control the depth the bit go by changing the Pass Depth in the Edit Tool box. If you are drilling 1" and have a Pass Depth of .25" your bit will drill in 4 cycles. You can also clean out your hole entirely by clicking on the Retract above the cutting start depth on the Drilling Toolpath screen. That would help if you just have a downcut bit. Another thought is using a high speed drill bit rather than a carbide bit.
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Post by gerry on Dec 3, 2018 18:48:43 GMT -5
Another thought is using a high speed drill bit rather than a carbide bit. Very bad advice. I would not use a drill bit in a CNC. It is entirely the wrong profile. It is not made to cut the same as a mill at 12,000+ RPM. It has a higher propensity to break or shatter at that speed. Then you have high speed fragments flying around your shop. |
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Deleted
Deleted Member
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Post by Deleted on Dec 4, 2018 10:06:33 GMT -5
Another thought is using a high speed drill bit rather than a carbide bit. Very bad advice. I would not use a drill bit in a CNC. It is entirely the wrong profile. It is not made to cut the same as a mill at 12,000+ RPM. It has a higher propensity to break or shatter at that speed. Then you have high speed fragments flying around your shop. 10K is fine for a 1/8" bit and 5-6K will be fine for 1/4". |
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