Me again, I've run into a little issue, which seems to becoming more frequent, I believe it to be missed steps, and imagine it's because my router bit isn't clearing the wood cuttings away. Openbuilds ox with openbuilds X32 blackbox for context. I'm machining 12mm birch plywood and usually when I'm nearly through the material is when it can lose steps. (picture for clarity). I'm thinking the bit is getting bogged down in the swarf and this is the problem. The bit is a carbide spiral upcut and I'm using a DeWalt 26200 router. DOC is 3mm and speed is 1500mm/min. It's a little too slow really, the router is turned down to its slowest but still the bit is squealing. Any ideas, firstly, how I can stop the lost steps? Secondly how I can try clear the dust/ shavings off more effectively? And thirdly, has anybody tried to make the DeWalt run slower? Thanks in advance. Jim.
With the Ox, old stretchy belts that slip on pulleys, not tensioned belts, or loose setscrews on pulleys causing slip on motor shafts are the more likely reasons. The X32 has plenty of power, so more likely mechanical
I use a collet mounted fan creating a down-draft that helps a bit with clearing chips. You are correct (looking at your pic you are getting a bit of burning on that plywood) that your speeds/feeds are not optimal. Can you increase the feedrate at all (may need to decrease the doc) with your machine - but bear in mind @Peter Van Der Walt 's comment about stretchy belts. The only other thing I can suggest is making sure your bit is sharp and clean - the resin and glue from plywood can build up on the cutting edge quite quickly. Alex.
Could it be your brush vac brushes smashing down on the work surface causing too much drag? IMO best dust boot is fixed z height so you set it to just tickling the work surface and it doesn't go any lower. For an OX dual belting is the way.. search YouTube for "dual belt ox" Cheers Gary
Definitely this does cause an issue, more so when you have a tooling path that moves in one direction then reverses straight away, when all of the brush fibres have to reverse it puts a lot of upward force on the z axis, I run the brush slightly above the work surface for this reason. (At max DOC the brush may just touch the surface. A fixed z brush would be brilliant, I may have to engineer one as time goes on.
Mine does, but it isn't very powerful, I'm keen to know what Alex is using, have never heard of them but will look now.
Hmm, I shall look at the belts, they may be due an upgrade. I have found on this forum a lead screw upgrade design which has peaked my interest. **** belts
I think I'll check all the belts over and then try this, increase the feedrate and lower the DOC. What model is the fan you use please Alex?
Found the one I use on Thingiverse - there are several designs there, the one in the link below might be suitable. I've never seen a commercial one, only ones to be 3d printed. Routers and air-cooled spindles do have fans, the collet mounted fan just adds more air flow. Alex. DW 660 Collet Fan dw660 by mattr254
