Finished. DIY CNC

[Husky1]

Can someone help me out. I have a working machine for some time now, very happy with my first diy project. Till recently i thought i hit the limit with feeds and speeds but when i saw how much material can cut similar or even less robust machines i am getting frustrated that i cant cut much more (Chris's machine cuts very nicely https://youtu.be/6lyh3ctUCgk ). That would mean 3h job instead of 5-6h. So for example, my parameters for 10mm carbide cutter is 12mm doc, 0.5mm stepover and 4000mm/min at ~10k rpm. I mill aluminium 6082-T6. I have tried tons of combinations (ripper too), but this is the fastest i could cut without any issues. I cut dry with help of air and also with wd40. wd40 gives better results ofc. Whenever i go more stepover (with lover doc ofcourse) i break tool or it will about to. Countless broken tools. All 3 axis have 0.01mm or less free play, machine feels solid. Is there anything i can do or is this all i can get out of it? Could be the servo motors (400W KRS servos) not tuned properly? Or the machine is just not solid enough which i doubt. I plan to fill steel frame and bed with epoxy granite too. Is maybe problem in the spindle in a way. It has a little runout, about 0,01 or 0.02...

Z axis doesn't have any counterbalance so the servo is holding the z weight. When cutting 3d contour and z axis is moving down, it is not smooth moving but i get steps on the part i mill. I fixed that with PID tuning. I didn't try that on x and y axis yet but i will asap.

Any suggestions?

@routercnc

Thanks. The base frame is just to have machine higher.

@Wal

Thanks, and as soon as i make some upgrades :)

What i cut:

[JAZZCNC]

So for example, my parameters for 10mm carbide cutter is 12mm doc, 0.5mm stepover and 4000mm/min at ~10k rpm. I mill aluminium 6082-T6. I have tried tons of combinations (ripper too), but this is the fastest i could cut without any issues. I cut dry with help of air and also with wd40. wd40 gives better results ofc. Whenever i go more stepover (with lover doc ofcourse) i break tool or it will about to.

Hi Matt,

Looking good now mate.

Are these adaptive toolpaths your using.? What Cam package.?
How many flutes.?
How long Flute lengths.?

Also does the machine actually sound like that or is the video making it sound worse than it is.? Don't remember it sounding like that when we skyped.!

[Doddy]

Handsome looking machine - and I'm interested in the design of the stand, particularly that you have horizontal members running on the floor surface. It's an area I've been pondering recently with ideas for my own router - the idea of having a ground-based solid beam on a solid floor must (says he, the non mechanically minded) provide more resistance to (making up words now) bending from forces transferred down from the bed? What I'm thinking, having played with the deflection calculators for box sections that you can find online is to mitigate the deflection on the main load carriers (the rails) into the vertical/diagonal braces then against the lower horizontal... but if that is unsupported then there will be some translation of this deflection into this lower beam. If the lower beam was on the deck (ergo with some support) is there any reduction in the deflection on the upper beam/rails? Or is this fanciful 2/3rds of cock-all?

Genuine, if somewhat rambling question before I order a couple of hundred quids worth of 50x50x5 box steel.

[Husky1]

Sorry for late reply, been busy.

I am using adaptive toolpaths with Autodesk Inventor HSM. I have used 2 flute, 3 flute, rippers. The only tool i didn't use was 1 flute. I have tested with tools diameter 10mm, 8mm, 6mm and had similar problems. Because of the nature of the workpiece i was mostly using long flute lengths (10mm x 45mm, 6mm x 35mm, 6mm x 20mm). I have tested with short flutes too ofc (10x26,8x20,6x16) and it's the same issue. The machine sound is so loud because the room is very small and echo is really loud on the camera. It's not that bad IRL but its not quite ether . Here is the last batch of broken tools



Doddy, i am not sure if i follow your questions but the frame idea was stolen from Jonathan's machine so i didn't do any calculations to be fair.

[AndyGuid]

Doddy, i am not sure if i follow your questions but the frame idea was stolen from Jonathan's machine so i didn't do any calculations to be fair.

That explains why it looked quite familiar, Cunningly disguised by a different colour paint!:-)

[Husky1]

So i am about to upgrade the machine with the combination of epoxy granite and concrete in a hope to eliminate vibrations and damping and hopefully have even better cutting performance. I got high quality epoxy granite Rampf Epument 140/8b, but i have only 100kg of it so to gain more weight of the frame, i will use concrete too. I would like to hear opinions if this would work. On the picture attached you can see how i will do this. Blue color shows where i wont use EG(have only 100kg), dark shows tubes filled with EG and gray is concrete (beton). I will also fill the gaps on gantry with EG and put the EG under the table. Will this work?

[routercnc]

Hi Matt

Your machine looks pretty stiff so for cutting aluminium faster I would have a go with mist coolant. Lots of posts on here about how to do it so you don't fog up the workshop. Do you have a compressor ?

Also it might not effect things greatly but the concrete will shrink a bit when dry so might pull away from the walls. I'd try the mist coolant first though.