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dmon123
09-01-2017, 08:55 PM
Hi

I am a brand new CNCer. Just finished building a C-Beam Openbuild machine. I am using a Kress 1050 FME-1 spindle (with 5k, 7.7k, 12.5k, 16.5k, 21k and 24k rpm speed settings) and have a variety of 1/8 shank carbide endmills (1.5, 2, 3.125 mm cutting diameter) and some carbide v-bits for engraving. I was able to engrave the Openbuild logo and route it out from 1/8 plywood without breaking the machine or the bits, so that's good.

I am desperately trying to get a feel for depth of cut, rpm and feed rate. I have been using GWizard but some of the numbers seem scary. So, what I am trying to do is simple. I have a 300x300x12 mm spoiler board made out of MDF which I want to bore in an array pattern (in order to add threaded inserts for clamping purposes). Say an array of 8x8 5 mm holes evenly spaced across the piece. How do I go about choosing the right tool and DOC, RPM and FeedRate?

I created a tool path using Cut2D, and selected a 3.125 mm end mill for the job. However, I need to give it parameters. What are the best parameters for MDF. Finally, when using the GW calculator, I got the following values:

Material MDF
Tool 3.175 mm shank, 3.175 mm diameter 2 fluted spiral carbide end mill.
Depth of cut 4 mm
Rpm 21000
Feedrate 903 mm/min

Does this make sense? Seems very fast to me ( I am used to hand routing )... I would love some advice and help in advance rather than trying all kinds of variations and breaking lots of end mills :lemo: Any rules of thumb? Also, once you have parameters that work, does one use them for all operations, ie, pockets, profiles etc?

Like I said, I am a newbie's newbie!! Apologies if these are silly questions. What would be the best forum discussion to join?

Many thanks in advance to all,
D