1 - 10 of 10 Posts

#### mickelsen

·
##### Registered
Joined
·
29 Posts
Discussion Starter · ·
I'm starting to engrave a bass relief picture into some red oak using my tabletop CNC router. Could anyone suggest the best feeds and speeds to use with red oak?

Thanks,
Mark

#### LMT Onsrud (Onsrud)

·
##### Registered
Joined
·
38 Posts
Good Afternoon,

Would you be able to provide that size tool you are using or wish to use...?

Fred

#### mickelsen

·
##### Registered
Joined
·
29 Posts
Discussion Starter · ·
The engraving bit I have been using is a 15 deg, 0.125" dia. v-bit. Does this help?

#### LMT Onsrud (Onsrud)

·
##### Registered
Joined
·
38 Posts
The engraving bit I have been using is a 15 deg, 0.125" dia. v-bit. Does this help?
Good evening,

You could start around 6,000 RPM at 18 Inches Per Minute...

You could also use this formula to decipher the best speed and feed rate..we suggest a chip load of .002 - .004 typically for that size bit...

Pick a constant router speed - depending on your machine, this can vary as to the speed that the spindle can run...

Feed Rate = RPM x # of Cutting Edges x Chip Load

So for this example we will use 6,000 RPM
The tool we sell has 1 cutting edge...

Therefore:

Feed Rate = 6,000 x 1 x .003
Feed Rate = 18 Inches per minute

Increase the feed rate until the piece finish starts to deteriorate...then back the feed rate down by 10%, start to then increase the feed rate at a certain increment again until the finish again falters...

At that point, the tool is working at the best productivity level and should provide the best longevity for your tools and best finish for your part...

The above chipload was in the middle of the range...we suggest you test a piece first to see fit and finish before cutting the final part...

Let me know if this helps or if more information is needed...but this should be a good starting point...

Fred

#### mickelsen

·
##### Registered
Joined
·
29 Posts
Discussion Starter · ·
Fred,
Thanks for the information you have supplied to me.
I am using a Bosch Colt for my spindle and the slowest speed I can get is about 15000 rpm, (at least until I get my SuperPID going). Using you formula, this results in an ipm of about 30. Do you think this is too fast?
Thanks again,
Mark

#### mickelsen

·
##### Registered
Joined
·
29 Posts
Discussion Starter · ·
Hi again Fred,
While I've got your attention, could you recommend feeds and speeds for cutting acrylic and also polycarbonate using an 1/8" endmill? Again, the minimum speed I can get from my spindle is about 15000rpm.
Thanks again,
Mark

#### LMT Onsrud (Onsrud)

·
##### Registered
Joined
·
38 Posts
Good Morning,

30 inches should be ok to run at...I just verified with my tech support guy as well...if the finish isn't great at this speed, you may have to make some adjustments up or down on the rate since we know the machine rpm is constant..

Thanks!

Fred

#### LMT Onsrud (Onsrud)

·
##### Registered
Joined
·
38 Posts
Hi again Fred,
While I've got your attention, could you recommend feeds and speeds for cutting acrylic and also polycarbonate using an 1/8" endmill? Again, the minimum speed I can get from my spindle is about 15000rpm.
Thanks again,
Mark
For this application we recommend a chip load of .004 - .006 for this material...

Based off of a single flute tool -

Feed rate: 15,000 RPM x 1 Cutting Edge x .004 = 60 Inches per minute
Feed rate: 15,000 RPM x 1 Cutting Edge x .006 = 90 Inches per minute

If the tool is a double edge tool

Feed rate: 15,000 RPM x 2 Cutting Edge x .004 = 120 Inches per minute
Feed rate: 15,000 RPM x 2 Cutting Edge x .006 = 180 Inches per minute

Please let me know if this helps...

Fred

#### mickelsen

·
##### Registered
Joined
·
29 Posts
Discussion Starter · ·
Thanks again, Fred.
I have some of your single flute endmills that are supposed to be very good for cutting plastics. I'll try one of those using you guidelines and see if I can get some good cuts in poly and acrylic. I have a complicated pattern that requires some great accuracy. If I can cut it well it will yield the parts to make flexible cable chain. But the round parts must be round and smooth so that the links will rotate against each other and the whole chain will be flexible. I hope I can make it work.
Mark

#### LMT Onsrud (Onsrud)

·
##### Registered
Joined
·
38 Posts
Thanks again, Fred.
I have some of your single flute endmills that are supposed to be very good for cutting plastics. I'll try one of those using you guidelines and see if I can get some good cuts in poly and acrylic. I have a complicated pattern that requires some great accuracy. If I can cut it well it will yield the parts to make flexible cable chain. But the round parts must be round and smooth so that the links will rotate against each other and the whole chain will be flexible. I hope I can make it work.
Mark
Hello Mark,

Sounds good...thanks for the support as well and if there is anything we can do to assist, holler!

Hope it goes well!

Fred

1 - 10 of 10 Posts