[Hamzter]

Router's attached and I've cut my first part, cut using a 3mm diameter bit, 3mm cut depth at 300mm/min (12in/min). I've discovered running much faster than that causes the gantry to flex and horrible vibrations start, so I'll be stiffening that up shortly. I'm also going to look at quietnening it down to keep the neighbours happy, so I'm going to surround the motor with some kind of acoustic foam, the base board is also acting like a drum so I need to find some way of damping that out. Getting there tho

[Jack000]

can you tell what the source of the vibration is? (leadscrew whip?)

12in/minute seems a bit slow to start having racking problems, in my limited experience..

[Hamzter]

It's from the router, from it 'biting' the wood, and is more severe with bigger cutters, might disappear if I increase the rpms, there's no evidence of whipping till it's going 100in/min+.

[Hamzter]

Tried cutting out some more complicated parts and it doesn't seem to be cutting right, not sure where the problem lies however, maybe someone here can help me. I first noticed when i tried cutting out a gear, the hole was off centre, and the teeth were distorted (see first pic), but it doesn't seem to be missing steps as it zeroes perfectly. I cut a second part to see which axis was causing the problem but still non the wiser (2nd pic, x axis is vertical, cut in an anti-clockwise direction, ignore the centre hole in this one, i reached the end of travel after cutting that so it doens't match). I also cut a 17mm circle, which i measured as 17mm in the x axis, 18mm in the y axis.

Any ideas why it might be doing this?

[Jack000]

if it was missing steps, the ending point of the gear probably wouldn't match the starting point, so that's probably not it. I think it's either backlash or lack of stiffness.

What happens when you pull/push on the bit, do you notice it moving slightly? That could explain the bad teeth. Not sure about the hole though, it seems pretty far off.

[Hamzter]

Started designing a clock to build with my router, here's a test piece, an escapement wheel. About 15cm diameter, 6mm plywood, didn't realise the cut order had got messed up before cutting and so I'm missing one of the internal cutouts but it turned out pretty well. I need to recut it in some better wood though, the middle of the plywood is too weak and just crumbles when being cut very thin.

Took about 20 minutes to cut, which is a bit lengthy, mainly because I kept the cut depth and feed rates low to reduce flexing, which I measure as about +/-0.75mm on this one. I might try cranking up the spindle speed and feed rate on the next one, i'm getting bored with waiting...

[Hamzter]

Here's some shots of the clock design so far, lots to do yet, I've not yet decided where I'm going to mount the weight, might have to do some calcs to work out where's best, and I need to think about how I'm going to brace it all.

I'm not sure how I'm going to cut the text yet, I'd like to try do engraved style text with a 90 degree tip cutter (like grave stones), however I've no idea how I'd generate the G-Code for it at the moment. I was thinking I could do a swept 45 degree surface using some text as a path, the edge where the surfaces merge would effectively be my cutter path, but unfortunately I can't convince my CAD software to do it, it's not smart enough to deal with a self intersecting surface. Anyone got software/ideas on how I'd do that?

[milhead]

The clock idea looks pretty slick!

Anyone got software/ideas on how I'd do that?

Hi Hamzter;

As long as your machine accepts a standard g-code you can probably get somebody to generate you a v-carve toolpath from a .dxf file or something similar. Lots of folks in these forums own capable software.

Mil