[conwedcncchick]

Hey all,

I use my cnc to cut fiberglass board and am wondering if anyone here has insight into having the rapid speed be the safe speed. I am working on one project in particular which takes 4hours+/- to cut one sheet because most of the cuts are drill holes. This would go significantly faster if I could program it to not slow down so much (I don't know how to do that either). My vacuum is strong so I am not worried about the board moving and since it is lighter and less dense than mdf, it doesn't need the mdf default settings (which I haven't figured out how to change).

If anyone has any ideas I would greatly appreciate.

[peteeng]

Hi ConW - 1) You need to do some air tests and determine the fastest speed your machine can move in air. That will determine your rapid speed setting. In your configuration area there will be max speed settings for each axis. Adjust these up until the machine can't follow the command ie can't go faster then back it off a bit. In conjunction with this there will be an acceleration setting again move this up until the machine cannot move at that acceleration then back it down a bit. 2) fibreglass is not less dense then MDF. MDF is 650-kg.m3 resin is about 1000kg.m3 and glass is 2700kg/m3 so most low tech laminates are around 1500kg/m3 and dense ones are 1800kg/m3. What type of drill and drilling speeds are you using? Usually the drilling speed is too fast for this sort of thing and this wears the drill really fast. 3) are you doing this dry or wet? Peter

[conwedcncchick]

Peter - our fiberglass board is 96.1kg/m3 and I am drilling with a 1/2in flat bit (spindle speed 19000rpm & feed rate 575). we are dry drilling.
thanks

[peteeng]

Hi ConW - 100kg/m3 is foam board. Better check your numbers.

You say fibreglass board so is it G10 material? Why flat end? Do you mean its a mill bit? Like a HSS 1/2" 2 flute or 3 flute bit or a carbide bit? What size hole is it? Are you drilling straight , pecking or interpolating? 19000rpm will be way too fast for that bit in composite. 575"/min is 14,605mm/min. Do you mean 575mm/min? Do you mean this is the cutting feed speed, rapid speed or the drill plunge speed?

fibreglass is 2700kg/m3 and its hard to make it at 50% fibre volume so minimum density is about 1350kg/m3... then you have to add resin so 1500kg/m3 is typical... photos of tools and spindle would help.. Peter

[conwedcncchick]

it's fiberglass board insulation (like this: https://www.amazon.com/Owens-Corning.../dp/B005V3L834) and it's 1/2" 2f ec scb and I'm drilling straight. 19000 is the standard speed we use for all cuts as it has the least amount of errors and the most edge cleanliness. 575 is the typical cut speed.
I'm trying to change the drill plunge speed, default is 150 and I have one file going at 300 as well. I'm not sure what else I can change to speed up the cuts.

[peteeng]

Oh - Insulation - interesting. I have not tried to cut that before. Your feeds they are inches/min? What machine operating software are you using? The max speeds are in the config file. You can change these. 300"/min is 7500mm/min thats quite fast for a Z. Peter